First Evidence of a Planet in Another Galaxy(discovermagazine.com)
discovermagazine.com
First Evidence of a Planet in Another Galaxy
https://www.discovermagazine.com/the-sciences/first-evidence-of-a-planet-in-another-galaxy
194 comments
it's incredible to me that just less than 100 years ago, we did not even know that there were other galaxies.
What will we know in 100 years from now?
Here you go:
https://en.wikipedia.org/wiki/Timeline_of_the_near_future
https://en.wikipedia.org/wiki/Timeline_of_the_far_future
https://en.wikipedia.org/wiki/Timeline_of_the_near_future
https://en.wikipedia.org/wiki/Timeline_of_the_far_future
These are things we currently know to be very likely to occur in the future, not as yet unknown knowledge.
for 500 bitcoin I will tell you all the unknown unknowns.
How much for the unknown knowns -- the stuff we think we know, but isn't true?
That's what bit us in Iraq to the tune of 5T, no thanks to DR for ignoring it.
That's what bit us in Iraq to the tune of 5T, no thanks to DR for ignoring it.
Well, in certain ages, like after the fall of Rome, most knew less than before...
probably not much as most species alive today will be extinct and there's no reason to think we wouldn't be one of the
It's unlikely that humanity as a whole will be lost. Civilization collapse is quite likely. "Natural ecosystem" collapse is even more likely (nature as we know it might stop existing). I recommend listening to Noam Chomsky. In the last few years he's been very active in pointing out how bad things are about to get (not in a fear mongering way, but to incite activism).
>It's unlikely that humanity as a whole will be lost.
Unlikely, but not that unprobable. We're one of the most easily wiped out species... Cockroaches and tardigrades will be doing fine in many circumstances where we'll be toast...
Unlikely, but not that unprobable. We're one of the most easily wiped out species... Cockroaches and tardigrades will be doing fine in many circumstances where we'll be toast...
Can you recomend something specific? What recent should i listen to? Thanks!
I'm comfortable recommending any interview or talk with him. He's been super active during the COVID crisis, so there's too many videos to keep track. From the title, this seems to be on subject: https://www.youtube.com/watch?v=RLbBF0M42DY
I actually really like Noam, I could have been a bit more general in that we very well might not advance scientifically.
A possible reason for this cynicism is the fact that we're currently in the middle of the Holocene extinction[0]:
> The current rate of extinction of species is estimated at 100 to 1,000 times higher than natural background rates.
Another thing that's interesting and worrying is the fact that wild animals take up only 4% of the biomass of mammals, 60% being livestock and 36% being humans.
[0] https://en.wikipedia.org/wiki/Holocene_extinction
> The current rate of extinction of species is estimated at 100 to 1,000 times higher than natural background rates.
Another thing that's interesting and worrying is the fact that wild animals take up only 4% of the biomass of mammals, 60% being livestock and 36% being humans.
[0] https://en.wikipedia.org/wiki/Holocene_extinction
Playing devils advocate partly just to make myself feel less depressed about that, but would it not be fair to say that humans have exploded in number, along with livestock, which makes that a somewhat misleading statistic?
Even if there was no wild animal extinctions, you would expect humans and livestock to have dominated the percentages simply from growth alone.
Even if there was no wild animal extinctions, you would expect humans and livestock to have dominated the percentages simply from growth alone.
The article itself and the referenced sources go into more detail about the species that have gone extinct and the probable causes for that, human behaviour being suspect (habitat destruction, overexploitation, agriculture, climate change; though things such as disease are also mentioned). As for the estimated numbers, at least one such study[0][1] is mentioned:
> A 2018 study published in PNAS found that since the dawn of human civilization, 83% of wild mammals, 80% of marine mammals, 50% of plants and 15% of fish have vanished.
As for the biomass distribution percentages, you might as well be right! Fig. 1. in the linked study really puts things into perspective, though, animal life being pretty miniscule in the grand scale of things, when compared to plants, bacteria and other types of biomass, which is quite interesting! Growing up, i never saw estimates such as these, which really make me conscious of just how big of an impact humans (and their lifestyle choices, such as the demand for meat) could have on other species and the ecosystems as a whole, hence me mentioning it as something interesting.
[0] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6016768/
[1] https://www.theguardian.com/environment/2018/may/21/human-ra...
> A 2018 study published in PNAS found that since the dawn of human civilization, 83% of wild mammals, 80% of marine mammals, 50% of plants and 15% of fish have vanished.
As for the biomass distribution percentages, you might as well be right! Fig. 1. in the linked study really puts things into perspective, though, animal life being pretty miniscule in the grand scale of things, when compared to plants, bacteria and other types of biomass, which is quite interesting! Growing up, i never saw estimates such as these, which really make me conscious of just how big of an impact humans (and their lifestyle choices, such as the demand for meat) could have on other species and the ecosystems as a whole, hence me mentioning it as something interesting.
[0] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6016768/
[1] https://www.theguardian.com/environment/2018/may/21/human-ra...
> would it not be fair to say that humans have exploded in number, along with livestock,
Only that part is fair to say. But that it:
> makes that a somewhat misleading statistic
Isn't "fair" at all. There the "misleading" claim, I guess, presumes that the cost of human and livestock population exploding is nothing to the rest of nature, whereas it's completely the opposite: that's one visible point, and the cause of all imbalances that follow.
The problem is, of course, that the change of the environment by humans has the consequences will impact the humans more than they are able to cope.
Only that part is fair to say. But that it:
> makes that a somewhat misleading statistic
Isn't "fair" at all. There the "misleading" claim, I guess, presumes that the cost of human and livestock population exploding is nothing to the rest of nature, whereas it's completely the opposite: that's one visible point, and the cause of all imbalances that follow.
The problem is, of course, that the change of the environment by humans has the consequences will impact the humans more than they are able to cope.
Fine, except that wild terrestrial vertebrate populations have fallen by ~99%.
This isn't "humans and livestock rising, wildlife constant". It's "humans and livestock exploding, wildlife vanishing".
This isn't "humans and livestock rising, wildlife constant". It's "humans and livestock exploding, wildlife vanishing".
congrats! just wait till your species finds out about faltrons
What's a faltron? Other than https://www.urbandictionary.com/define.php?term=Faltron
omg no
Wow wtf did I just read?
Yeah that is roughly my impression as well. Even worse that UD entry is from 2009 so either this guy just plugged some SUPER random weird shit or he was trying to be funny and picked what he thought was a nonsense word...only for it to be this. The internet might have been a bad idea?
Galaxy M51 is 23 _million_ light years away. Incredible science! And it sounds like they will be able to use this Chandra data backlog to find more.
Kind of depressing to realize we will never leave our own solar system ... more likely we are going to end ourselves as a species than taking that great leap.
There is no physical limitation that prevents us from leaving Sol system. It is actually quite easy compared to other technical problems. We have atomic power that can be source of energy for thousands of years and we have technology to build sustainable ecosystem and push it in a direction of another star (albeit very slowly). And we are also able to image other planets very precisely to something like kilometers per pixel through gravitational lensing.
It is just that humanity is not very good at consensus to even not suffocate in our own home.
It is just that humanity is not very good at consensus to even not suffocate in our own home.
> We have atomic power that can be source of energy for thousands of years and we have technology to build sustainable ecosystem and push it in a direction of another star (albeit very slowly).
We are missing the technology to build anything in space, and to create small (dozens to hundreds of km of radius) ecosystems capable of sustaining people. We really do not have the technical means for space exploration.
The good news is that people are researching both, as improvements on them lead to profits here on Earth. So I do think we'll get there reasonably quickly.
We are missing the technology to build anything in space, and to create small (dozens to hundreds of km of radius) ecosystems capable of sustaining people. We really do not have the technical means for space exploration.
The good news is that people are researching both, as improvements on them lead to profits here on Earth. So I do think we'll get there reasonably quickly.
>We are missing the technology to build anything in space
This is mainly because no one tries to do it. If the biggest countries decided that they want to build it - I am sure humanity will solve all technical problems.
This is mainly because no one tries to do it. If the biggest countries decided that they want to build it - I am sure humanity will solve all technical problems.
>This is mainly because no one tries to do it. If the biggest countries decided that they want to build it - I am sure humanity will solve all technical problems.
Isn't this "I'm sure" more wishful thinking than actual practical certainty though?
We made no contract with anyone that we can build anything we want as a species...
Isn't this "I'm sure" more wishful thinking than actual practical certainty though?
We made no contract with anyone that we can build anything we want as a species...
What technology do we have to build sustainable ecosystem? I am only aware of various failed projects of biospheres or whatever.
There is a hobby for creating sealed ecosystems in jars, with one example being sealed and stable since 1972.
The hard part is making them habitable for mammals which aren’t very hardy, need a lot of food, and reproduce slowly.
The hard part is making them habitable for mammals which aren’t very hardy, need a lot of food, and reproduce slowly.
That sounds like we do not have said technology.
It’s important to separate not having the specific design solution to a specific problem from not having solutions to closely related problems. We don’t know what the mass budget etc would look like for an interstellar colony ship.
On the other hand several known designs mostly worked for humans to the point where using them would dramatically reduce the supplies needed for a long trip. But, none of them where operating on a zero G interstellar mission.
Biosphere 2 for example depended on sunlight which would be missing, but they provided sufficient calories across several months which means it was also generated enough oxygen assuming it had been setup properly to begin with. They had a huge range of other their issues, and you would need a vastly larger population and much higher efficiency for such a trip. But, from what amounted to a publicity stunt it was surprisingly close to a working solution.
https://en.wikipedia.org/wiki/BIOS-3 on the other hand was a far less ambitious project that was much closer to a practical design even if they imported food and the longest experiment was 180 days, it was actually using artificial lights.
PS: A more significant question is how to design hardware systems that could last for such a trip and what it would take to sustain things at the other side.
On the other hand several known designs mostly worked for humans to the point where using them would dramatically reduce the supplies needed for a long trip. But, none of them where operating on a zero G interstellar mission.
Biosphere 2 for example depended on sunlight which would be missing, but they provided sufficient calories across several months which means it was also generated enough oxygen assuming it had been setup properly to begin with. They had a huge range of other their issues, and you would need a vastly larger population and much higher efficiency for such a trip. But, from what amounted to a publicity stunt it was surprisingly close to a working solution.
https://en.wikipedia.org/wiki/BIOS-3 on the other hand was a far less ambitious project that was much closer to a practical design even if they imported food and the longest experiment was 180 days, it was actually using artificial lights.
PS: A more significant question is how to design hardware systems that could last for such a trip and what it would take to sustain things at the other side.
So... If we can survive in an artificial environment for thousands of years, why we need another star at all?
To keep doing it for longer. Eventually, external resources would be required regardless.
I'm not betting on the current human race being capable of this, though-- in my opinion, we will need to more or less become a different species for anything like civilization as we know it to survive over the very long term. Otherwise we will inevitably keep wasting too much energy on emotionally driven, incredibly stupid and violent conflicts with each other.
I'm not betting on the current human race being capable of this, though-- in my opinion, we will need to more or less become a different species for anything like civilization as we know it to survive over the very long term. Otherwise we will inevitably keep wasting too much energy on emotionally driven, incredibly stupid and violent conflicts with each other.
Yes, obviously - the problem is that there is no reason whatsoever to do it at the speeds that are currently thought to be physically possible.
We can realistically each 5% the speed of light with nuclear pulse propulsion, giving a travel time of 80 years. That's not completely unreasonable, just insanely expensive with no clear payoff
We can reasonably send something to Alpha Centauri in 100 years assuming you can get the drive to work, but that’s the closest star to us, and Project Longshot was a design for an unmanned probe.
Yes, the British Interplanetary Society did do a study on what a manned mission might be like, but they always seem to underestimate the biological problems of space flight.
If you wanted to colonise a planet around a nearby star it would be a truly staggering undertaking, even getting the fuel for an unmanned probe probably require H3 mining of Jupiter.
Yes, the British Interplanetary Society did do a study on what a manned mission might be like, but they always seem to underestimate the biological problems of space flight.
If you wanted to colonise a planet around a nearby star it would be a truly staggering undertaking, even getting the fuel for an unmanned probe probably require H3 mining of Jupiter.
Try H3 mining of Uranus or Neptune rather than Jupiter! The gravity well is much smaller.
Exactly, if we send anything now, it'll probably be overtaken by superior vessels within a couple of centuries
But if we don't send anything now, there will be no superior vessels in the next centuries! Progress on technology doesn't happen on paper - you need to iteratively build, test and improve designs to get where. You can't just leapfrog a century of novel space technologies, much like you can't write a large program on paper, only ever put it on a computer when it's done, and have it compile and work correctly from the first build.
Radiation and micrometeoroids still seem to be an unsolved problem.
No, it is not. At least as long as you don't want to get there too fast (which we can't do anyway currently).
Dust is taken care by an ice shield in front of the craft.
Radiation is taken care by a water jacket. Radiation is only a real problem in the vicinity of the star. The atmosphere we have on Earth is only necessary to block radiation that comes from Sun either directly or through solar winds. The radiation from sources outside solar system might be high energy particles an photons but has very low flux.
The funny thing is, everybody focuses on technical issues where the biggest issue is most likely non technical and it is mostly about human health, physical response to lack of gravity and psychological to isolation.
Dust is taken care by an ice shield in front of the craft.
Radiation is taken care by a water jacket. Radiation is only a real problem in the vicinity of the star. The atmosphere we have on Earth is only necessary to block radiation that comes from Sun either directly or through solar winds. The radiation from sources outside solar system might be high energy particles an photons but has very low flux.
The funny thing is, everybody focuses on technical issues where the biggest issue is most likely non technical and it is mostly about human health, physical response to lack of gravity and psychological to isolation.
Indeed regarding psychological issues, my current understanding it 10% the speed of light is feasible, so 40 years to the nearest system with no guarantees there's anywhere to call home.
The water jacket is intriguing, but doesn't it require a tonnage that's never been lifted into space yet? Had me thinking about a space elevator taking water up into space and also alleviating sea levels (to the point where much more water would be exported to something other than the shield).
It surely may be possible but involves risks and costs that no one is willing to take. Perhaps that balance of risk will change in the future.
The water jacket is intriguing, but doesn't it require a tonnage that's never been lifted into space yet? Had me thinking about a space elevator taking water up into space and also alleviating sea levels (to the point where much more water would be exported to something other than the shield).
It surely may be possible but involves risks and costs that no one is willing to take. Perhaps that balance of risk will change in the future.
It is assumed that any kind of ship like that would be assembled in space and if we can't do that we are most likely not ready yet.
Water would be a good candidate for both shield and jacket for the simple reason it is readily available in space in huge amounts and doesn't have to be lifted from Earth. What is necessary is a single remotely controlled ship that will go far enough from Sun to be able to capture and steer one of the watery asteroids. The further you go the slower the orbits the less energy you need to dramatically alter course of any astronomical body.
We don't even need to bring all that water to Earth. Instead, it might be cheaper to fly half-finished craft out, finish assembly by robotic means and then turn it into center of solar system. The craft could then gain velocity, use as many gravitational assists as possible on the way in and then back and pick up the crew before it leaves solar system for its journey.
Water would be a good candidate for both shield and jacket for the simple reason it is readily available in space in huge amounts and doesn't have to be lifted from Earth. What is necessary is a single remotely controlled ship that will go far enough from Sun to be able to capture and steer one of the watery asteroids. The further you go the slower the orbits the less energy you need to dramatically alter course of any astronomical body.
We don't even need to bring all that water to Earth. Instead, it might be cheaper to fly half-finished craft out, finish assembly by robotic means and then turn it into center of solar system. The craft could then gain velocity, use as many gravitational assists as possible on the way in and then back and pick up the crew before it leaves solar system for its journey.
I don't think you can just divide distance by velocity like that, even ignoring relativity as there are the long acceleration and deceleration phases.
This calculator says it would take 80 years when I approximate a solution where max velocity is .1c: https://www.omnicalculator.com/physics/space-travel?advanced...
.1c isn't fast enough to cause significant time dilation for the travelers so they end up spending nearly the same 80 years on the ship as well.
This calculator says it would take 80 years when I approximate a solution where max velocity is .1c: https://www.omnicalculator.com/physics/space-travel?advanced...
.1c isn't fast enough to cause significant time dilation for the travelers so they end up spending nearly the same 80 years on the ship as well.
>There is no physical limitation that prevents us from leaving Sol system.
That's part wishful thinking, part hand-waving. There are tons of practical limitations that prevents us from leaving the solar system based on the nature of space and physical laws.
At best, we could get some "generational ships" out going to nowhere knows where exactly (it's not like we have some habitable planet to even aim to in mind, and the various "atmosphere-making" schemes are pie in the sky and require tens or hundreds of years, plus tons of resources in that "generational ship"), but even that is less likely than regression or extinction here...
That's part wishful thinking, part hand-waving. There are tons of practical limitations that prevents us from leaving the solar system based on the nature of space and physical laws.
At best, we could get some "generational ships" out going to nowhere knows where exactly (it's not like we have some habitable planet to even aim to in mind, and the various "atmosphere-making" schemes are pie in the sky and require tens or hundreds of years, plus tons of resources in that "generational ship"), but even that is less likely than regression or extinction here...
Kilometers per pixel? That doesn’t sound right. At that resolution Earth would be 12000 pixels wide...
But it is actually true, there are proposals to use the sun as a gravitational lens to take picture of planets hundreds of light-years away with resolutions of kilometers to tens of kilometers. Actually building such a telescope would however probably be very challenging with our current technology as it requires sending satellites far away from the sun, several times the current distance of Voyager 1. Here is the first article [1] my search found. I did not actually read this specific, so I have no idea whether it is any good but it should provide enough information to search for additional information.
[1] https://www.airspacemag.com/daily-planet/ultimate-space-tele...
[1] https://www.airspacemag.com/daily-planet/ultimate-space-tele...
Yes. So it does not require any speculative technology that we may or may not ever possess, just put together what we currently have plus some amount of research that would normally be expected of a project this size plus huge budget plus huge amount of patience.
This is just a case go get a budget and build it.
This is just a case go get a budget and build it.
We've not proven very good at ending ourselves as a species in the past. Quite the opposite. Not sure where the pessimism is coming from.
The species has barely existed for the blink of an eye in evolutionary terms so there's not much past in that regard.
On our own timescale terms we have a rare tendency to group together for intra species battles, and a unique tendency to do that with groups numbering millions.
We have an evolutionarily unprecedented and unmatched phenomenon, advanced intelligence, which we employ in scaling the destruction in those battles, to the point we now have the ability to cause catastrophic, possibly existential damage to our species, at least as a civilisation wherein this discussion makes sense; let alone the collateral damage to our environment and co-habitees.
That's just the war stuff.
The peaceful things we do are too depressing to mention.
On our own timescale terms we have a rare tendency to group together for intra species battles, and a unique tendency to do that with groups numbering millions.
We have an evolutionarily unprecedented and unmatched phenomenon, advanced intelligence, which we employ in scaling the destruction in those battles, to the point we now have the ability to cause catastrophic, possibly existential damage to our species, at least as a civilisation wherein this discussion makes sense; let alone the collateral damage to our environment and co-habitees.
That's just the war stuff.
The peaceful things we do are too depressing to mention.
Humans have had advanced intelligence across evolutionary timescales because that’s how long it took to evolve. Handmade stone tools are dated all the way back to 3.3 million years, with other examples at 2.8 million years.
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> We've not proven very good at ending ourselves as a species in the past.
We did not have the ability to end ourselves in the past.
How would dolphins or monkeys end themselves even if they wanted to, short of mass suicide?
We have had this capability only in the last 100 years or so in mainly 2 ways:
* atomic armageddon
* destroying our habitat
We managed to hold on for that first one for the last 50 years but we are busily and productively working on that second point, so I'm not quite sure where your optimism comes from.
We did not have the ability to end ourselves in the past.
How would dolphins or monkeys end themselves even if they wanted to, short of mass suicide?
We have had this capability only in the last 100 years or so in mainly 2 ways:
* atomic armageddon
* destroying our habitat
We managed to hold on for that first one for the last 50 years but we are busily and productively working on that second point, so I'm not quite sure where your optimism comes from.
Source of pessimism?
For example: https://en.wikipedia.org/wiki/List_of_nuclear_close_calls
Assign a non-zero probability that it'll actually go wrong, then extrapolate 10.000 years into the future.
The odds aren't necessarily in our favour. And that's just one of many risks out there, over the course of a blink of an eye in the history of the universe/galaxy/earth/humanity.
For example: https://en.wikipedia.org/wiki/List_of_nuclear_close_calls
Assign a non-zero probability that it'll actually go wrong, then extrapolate 10.000 years into the future.
The odds aren't necessarily in our favour. And that's just one of many risks out there, over the course of a blink of an eye in the history of the universe/galaxy/earth/humanity.
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>>Kind of depressing to realize we will never leave our own solar system
True for our generation, but then think of how far we have come just in the past 100 years (Wright Brothers to Musk). The next advances will kinda be logarithmic.
True for our generation, but then think of how far we have come just in the past 100 years (Wright Brothers to Musk). The next advances will kinda be logarithmic.
We're going to be spending the next thousand years just trying to avoid our own extinction after climate change leads to the collapse of global civilization, mass famine, world war and the erasure of most of humanity's collective knowledge from its fragile and ephemeral digital infrastructure.
The next century's advances are going to be things like "rediscover calculus" and "build a working steam engine."
The next century's advances are going to be things like "rediscover calculus" and "build a working steam engine."
Or not. We've been using the energy stored up in the Earth over eons as if it's infinite, and now realised it's not. We've gone from Ader and Weisskopf to multiple nations having space programmes off the back of a dependency on fossil fuels.
Those fuels are running out, and we have to stop using them in any case before we kill the planet.
To my view the C19-20th has been a unique period of growth. We're going to need to be much more resource and energy conservative until {and even when} we develop new technologies (fusion? some sort of zero-point energy harvesting??).
It seems renewables might be able to satisfy our current energy demands, as long as we don't do something like thinking we can continue along the curve we've been going on, particular wrt population growth, but also wrt our expectation of a bottomless pit of all elements.
Our next revolution needs to be extreme longevity of goods/tools/appliances and full reuse/recycling. IMO that's incompatible with Capitalism, we need producers who are invested in _not_ selling more products than are needed and investors who want to achieve goals beyond extracting liquifiable value from our societal systems.
Even going back to feudalism I fear we've fostered into power the sorts of people who will never choose the trajectories we need but will always go for personal wealth. It might already be too late to correct that.
Those fuels are running out, and we have to stop using them in any case before we kill the planet.
To my view the C19-20th has been a unique period of growth. We're going to need to be much more resource and energy conservative until {and even when} we develop new technologies (fusion? some sort of zero-point energy harvesting??).
It seems renewables might be able to satisfy our current energy demands, as long as we don't do something like thinking we can continue along the curve we've been going on, particular wrt population growth, but also wrt our expectation of a bottomless pit of all elements.
Our next revolution needs to be extreme longevity of goods/tools/appliances and full reuse/recycling. IMO that's incompatible with Capitalism, we need producers who are invested in _not_ selling more products than are needed and investors who want to achieve goals beyond extracting liquifiable value from our societal systems.
Even going back to feudalism I fear we've fostered into power the sorts of people who will never choose the trajectories we need but will always go for personal wealth. It might already be too late to correct that.
Layman here.
This is the first I'm hearing that - it is the first time we detect a planet outside our galaxy. Can someone remind me how it comes to pass that there are people in the scientific community who believe we are the only "intelligent" life form? (I know there are a few theories that explain why there aren't any, whose names escape me at the moment)
It boggles my mind.
This is the first I'm hearing that - it is the first time we detect a planet outside our galaxy. Can someone remind me how it comes to pass that there are people in the scientific community who believe we are the only "intelligent" life form? (I know there are a few theories that explain why there aren't any, whose names escape me at the moment)
It boggles my mind.
The idea that we are, or are not, the only intelligent life form is an opinion, not a scientific theory in the formal sense of the word -- there is no evidence either way. People's opinions on it are just that, opinions, and scientists can be wrong or biased like anyone else.
Statistical arguments, such as the Drake equation, strongly suggest that there is other life. The Anthropic Principle and the 'Great Filter' idea suggest reasons why there might not be. (https://en.wikipedia.org/wiki/Great_Filter)
Statistical arguments, such as the Drake equation, strongly suggest that there is other life. The Anthropic Principle and the 'Great Filter' idea suggest reasons why there might not be. (https://en.wikipedia.org/wiki/Great_Filter)
Does the Drake equation really strongly suggest there is other life? It seems to me there are still so many unknown variables that we can't make that determination at this point. Sure, some people have some intuition about it, but intuition is often (normally...?) wrong.
Looks like an interesting paper. In fact, it looks like it's saying basically the same thing I'm saying, we really don't know enough to make assertions about the likelihood of finding intelligent life at this point.
It’s not a question of intuition. The Drake equation tries to make a conservative calculation of the factors involved in the formation of life. As you might imagine, those odds are extremely low. It then multiplies those odds against the number of expected candidate planets. Space is so mind-blowingly big that the result becomes extremely likely.
Again, that assumes no limiting phenomena, which is what things like great filter theory posit
Again, that assumes no limiting phenomena, which is what things like great filter theory posit
There are multiple areas of the Drake equation that we have either no or only one data point on:
- Number of planets that can support life that will develop life - Number of planets that have developed life that will develop intelligent life - Fraction of intelligent life that will develop the technology to transmit signals of their existence - The length of time that those signals will be sent
We only know anything about any of these processes on one planet. That means we are guessing when we put numbers to these factors. We don't know if these numbers are 1 in 100 or 1 in a trillion. That's what I mean by having intuition but not really having evidence.
- Number of planets that can support life that will develop life - Number of planets that have developed life that will develop intelligent life - Fraction of intelligent life that will develop the technology to transmit signals of their existence - The length of time that those signals will be sent
We only know anything about any of these processes on one planet. That means we are guessing when we put numbers to these factors. We don't know if these numbers are 1 in 100 or 1 in a trillion. That's what I mean by having intuition but not really having evidence.
Sure, my counter is just that the Drake equation uses conservative probabilities on those questions. Even pessimistic answers to those questions turn into optimistic projections given the scale of the universe.
We’re obviously discussing a bunch of unknowns, but my intuition was actually more pessimistic until I saw what the Drake equation observed
We’re obviously discussing a bunch of unknowns, but my intuition was actually more pessimistic until I saw what the Drake equation observed
The problem is that we don't know if the "conservative probabilities" are actually conservative. There is only a single planet in the Goldilocks zone that we for sure contains or doesn't contain life.
Imagine if someone showed you a rock in the forest with some lichen in weird pattern and asked you for a "conservative estimate" for how many other rocks on Earth had that same pattern. Maybe pattern is common, but maybe it's something incredibly unique that no other rock has. Because you can't ever look at a different rock, there is no reasonable answer.
Imagine if someone showed you a rock in the forest with some lichen in weird pattern and asked you for a "conservative estimate" for how many other rocks on Earth had that same pattern. Maybe pattern is common, but maybe it's something incredibly unique that no other rock has. Because you can't ever look at a different rock, there is no reasonable answer.
If you ask a layperson, yes sure. Ask a geologist/biologist/whatever. There is order in the chaos. Some things can be said with certain levels of confidence without (direct) evidence. There are patterns you know.
This is actually one of those things experts are very bad at. Experts make good predictions when they have feedback about those predictions. There is no feedback about this kind of prediction, so experts would be very bad.
> Even pessimistic answers to those questions turn into optimistic projections given the scale of the universe.
I used to believe this too, but the universe is not actually that big -- taking some not-so-conservative estimates, let's say there are a trillion galaxies, each with a trillion stars.
If a couple of the terms in the Drake equation turn out to be 1-in-a-trillion, the odds of finding intelligent life no longer look so good.
I used to believe this too, but the universe is not actually that big -- taking some not-so-conservative estimates, let's say there are a trillion galaxies, each with a trillion stars.
If a couple of the terms in the Drake equation turn out to be 1-in-a-trillion, the odds of finding intelligent life no longer look so good.
> Can someone remind me how it comes to pass that there are people in the scientific community who believe we are the only "intelligent" life form?
Because the universe is 15+ bilions of years old.
Considering the speed at which we have evolved technologically, assuming life developed on earth in a perfectly average way (i.e. we are not special), and given that our solar system didn't appear particularily early, there should be a lot of much older civilizations (and thus much more advanced) around, even within our galaxy. Thus, the fact that we are unable to detect any signal from even a single other civilization is quite puzzling, we should be inundated by those signals.
P.S: I don't know if many people in the scientific community really believe that we are the only ones out there, more so that intelligent life forms could be extremely rare.
Because the universe is 15+ bilions of years old.
Considering the speed at which we have evolved technologically, assuming life developed on earth in a perfectly average way (i.e. we are not special), and given that our solar system didn't appear particularily early, there should be a lot of much older civilizations (and thus much more advanced) around, even within our galaxy. Thus, the fact that we are unable to detect any signal from even a single other civilization is quite puzzling, we should be inundated by those signals.
P.S: I don't know if many people in the scientific community really believe that we are the only ones out there, more so that intelligent life forms could be extremely rare.
> Thus, the fact that we are unable to detect any signal from even a single other civilization is quite puzzling, we should be inundated by those signals.
Or other societies realized widely broadcasting noise is bad for whatever reason. Maybe they're composed of something sensitive to certain wavelengths. Like humans don't use xrays to transmit data, maybe radio waves are harmful in some way.
Or maybe broadcasting widely resulted is a case study for getting your civilization invaded, so they avoided it it or only send signals as strong as they need to be.
Or maybe it's so consistently and universally done that we simple see it as cosmic background radiation.
Or maybe something like quantum entanglement someday makes wave transmissions for communication seem as backwards as smoke signals.
Humans have only observed a tiny slice of space over a very tiny time span--less than 100 years. It's like being born in a barren desert and never venturing out and realizing most of the world is ocean and full of activity. We don't know what to look for or where. An observer 200 light years away from earth could easily conclude that there's no life here, since all they'd have to go by is inconclusive signs of some gases in the air.
Or other societies realized widely broadcasting noise is bad for whatever reason. Maybe they're composed of something sensitive to certain wavelengths. Like humans don't use xrays to transmit data, maybe radio waves are harmful in some way.
Or maybe broadcasting widely resulted is a case study for getting your civilization invaded, so they avoided it it or only send signals as strong as they need to be.
Or maybe it's so consistently and universally done that we simple see it as cosmic background radiation.
Or maybe something like quantum entanglement someday makes wave transmissions for communication seem as backwards as smoke signals.
Humans have only observed a tiny slice of space over a very tiny time span--less than 100 years. It's like being born in a barren desert and never venturing out and realizing most of the world is ocean and full of activity. We don't know what to look for or where. An observer 200 light years away from earth could easily conclude that there's no life here, since all they'd have to go by is inconclusive signs of some gases in the air.
Star Trek posits that warp drive is the technology which merits contact from other civilizations. I would expect the technology to actually be access to interstellar communication. A planet joins the universe when it first logs in.
Wow imagine the fun reverse engineering the communication protocol, littered with millions of years of hack
Note that I personally don't have a set opinion on this subject. I am only trying to respond to OP's question of why some people would think this is a possiblity. But I like to play devil's advocate so:
> Or other societies realized widely broadcasting noise is bad for whatever reason.
> Or maybe broadcasting widely resulted is a case study for getting your civilization invaded, so they avoided it it or only send signals as strong as they need to be
Every other society realized it at the same time? Which would imply every other society is roughly born at the same time, which sounds unlikely. So some of them (like us) should not yet have discovered the danger of broadcasting signals.
> Or maybe it's so consistently and universally done that we simple see it as cosmic background radiation.
I don't think you can possibly mistake the CMB with some artifical radio signals coming from point sources.
> Or maybe something like quantum entanglement someday makes wave transmissions for communication seem as backwards as smoke signals
Definitely a possibility, but again, that would assume some kind of synchronicity between all other societies (no one is still figuring out quantum communication). But since radio signals are hard to pickup at a long range, it's possible. But we also haven't seen any other traces of civilizations: probes, dyson spheres etc.
> Or other societies realized widely broadcasting noise is bad for whatever reason.
> Or maybe broadcasting widely resulted is a case study for getting your civilization invaded, so they avoided it it or only send signals as strong as they need to be
Every other society realized it at the same time? Which would imply every other society is roughly born at the same time, which sounds unlikely. So some of them (like us) should not yet have discovered the danger of broadcasting signals.
> Or maybe it's so consistently and universally done that we simple see it as cosmic background radiation.
I don't think you can possibly mistake the CMB with some artifical radio signals coming from point sources.
> Or maybe something like quantum entanglement someday makes wave transmissions for communication seem as backwards as smoke signals
Definitely a possibility, but again, that would assume some kind of synchronicity between all other societies (no one is still figuring out quantum communication). But since radio signals are hard to pickup at a long range, it's possible. But we also haven't seen any other traces of civilizations: probes, dyson spheres etc.
>Every other society realized it at the same time? Which would imply every other society is roughly born at the same time, which sounds unlikely. So some of them (like us) should not yet have discovered the danger of broadcasting signals.
And I'll play Devil's Advocate to your Devil's Advocate. :)
It's entirely possible that there have been other technological civilizations over the past 13.7 or so billion years. That's a long time. As such, any civilization that stopped broadcasting in our direction, if they ever did so in the first place, any more than 100,000 or so years ago, would be completely undetectable to us -- ever.
What's more, as was pointed out in another comment, we haven't been looking for such signals for long (~60 years) and haven't surveyed anything close to the entire galaxy.
I guess the most accurate thing we can say would be that we haven't detected another technological civilization within 60 light years or so in the few places we've looked.
Given the lack of data, the Drake equation[0] is less a predictive device than a way to categorize our ignorance.
The Fermi Paradox[1] and its "where is everybody?" question is more in line with what I perceive to be your point.
Given that we haven't looked very hard for very long (as I mention above) in an enormous galaxy that's existed for billions of years, it seems to be in a similar position as any predictions from the Drake equation.
It's interesting to speculate, but without enough data, speculation is all it is.
[0] https://en.wikipedia.org/wiki/Drake_equation
[1] https://en.wikipedia.org/wiki/Fermi_paradox
And I'll play Devil's Advocate to your Devil's Advocate. :)
It's entirely possible that there have been other technological civilizations over the past 13.7 or so billion years. That's a long time. As such, any civilization that stopped broadcasting in our direction, if they ever did so in the first place, any more than 100,000 or so years ago, would be completely undetectable to us -- ever.
What's more, as was pointed out in another comment, we haven't been looking for such signals for long (~60 years) and haven't surveyed anything close to the entire galaxy.
I guess the most accurate thing we can say would be that we haven't detected another technological civilization within 60 light years or so in the few places we've looked.
Given the lack of data, the Drake equation[0] is less a predictive device than a way to categorize our ignorance.
The Fermi Paradox[1] and its "where is everybody?" question is more in line with what I perceive to be your point.
Given that we haven't looked very hard for very long (as I mention above) in an enormous galaxy that's existed for billions of years, it seems to be in a similar position as any predictions from the Drake equation.
It's interesting to speculate, but without enough data, speculation is all it is.
[0] https://en.wikipedia.org/wiki/Drake_equation
[1] https://en.wikipedia.org/wiki/Fermi_paradox
> It's entirely possible that there have been other technological civilizations over the past 13.7 or so billion years. That's a long time. As such, any civilization that stopped broadcasting in our direction, if they ever did so in the first place, any more than 100,000 or so years ago, would be completely undetectable to us -- ever.
But this is assuming radio signals are the only way we could detect a civilization, what about probes (von neuman or regular), dyson spheres etc. ?
> I guess the most accurate thing we can say would be that we haven't detected another technological civilization within 60 light years or so in the few places we've looked
The signals we received in the last 60 years come from the entire observable universe (it's how we define the observable universe), not just from a 60 ly radius. But the furthest the signal comes from the hardest it is to detect (or the strongest it would have to be to be detectable).
> It's interesting to speculate, but without enough data, speculation is all it is.
I certainly hope that everyone is aware that is pure speculation ;)
But this is assuming radio signals are the only way we could detect a civilization, what about probes (von neuman or regular), dyson spheres etc. ?
> I guess the most accurate thing we can say would be that we haven't detected another technological civilization within 60 light years or so in the few places we've looked
The signals we received in the last 60 years come from the entire observable universe (it's how we define the observable universe), not just from a 60 ly radius. But the furthest the signal comes from the hardest it is to detect (or the strongest it would have to be to be detectable).
> It's interesting to speculate, but without enough data, speculation is all it is.
I certainly hope that everyone is aware that is pure speculation ;)
>The signals we received in the last 60 years come from the entire observable universe (it's how we define the observable universe), not just from a 60 ly radius. But the furthest the signal comes from the hardest it is to detect (or the strongest it would have to be to be detectable).
A fair point. I should have been more specific and limited my statement: "we haven't detected another technological civilization, currently broadcasting electromagnetic signals in our direction, within 60 light years or so in the few places we've looked."
However, that doesn't mean such civilizations don't exist, nor does the fact that we haven't detected any such signals at any distance, or any other indications of such civilizations, extant or not.
A fair point. I should have been more specific and limited my statement: "we haven't detected another technological civilization, currently broadcasting electromagnetic signals in our direction, within 60 light years or so in the few places we've looked."
However, that doesn't mean such civilizations don't exist, nor does the fact that we haven't detected any such signals at any distance, or any other indications of such civilizations, extant or not.
> I should have been more specific and limited my statement: "we haven't detected another technological civilization, currently broadcasting electromagnetic signals in our direction, within 60 light years or so in the few places we've looked."
Why restrict yourself to those 60 light years? We haven't heard about any other civilizations in the entire observable even if their transmission happened a long time ago and they may be extinct by now.
It's only true in the other direction: only a civilization less that 60 ly away could possibly have detected our radio signals so far.
Why restrict yourself to those 60 light years? We haven't heard about any other civilizations in the entire observable even if their transmission happened a long time ago and they may be extinct by now.
It's only true in the other direction: only a civilization less that 60 ly away could possibly have detected our radio signals so far.
> But this is assuming radio signals are the only way we could detect a civilization, what about probes (von neuman or regular), dyson spheres etc. ?
That’s trying to find a needle in a universe sized haystack, and we’ve only just started digging. Concluding that there’s probably not a needle when we’ve only just started digging our hands in is premature.
That’s trying to find a needle in a universe sized haystack, and we’ve only just started digging. Concluding that there’s probably not a needle when we’ve only just started digging our hands in is premature.
> That’s trying to find a needle in a universe sized haystack
But that is the whole point of the fermi paradox. Given the staggering numbers of planets in our galaxy/universe, and given the staggering age of the universe (when compared to our history), it should not be like trying to find a needle in a haystack.
If it is, then that means life is extremly rare, which already answers part of the question.
But that is the whole point of the fermi paradox. Given the staggering numbers of planets in our galaxy/universe, and given the staggering age of the universe (when compared to our history), it should not be like trying to find a needle in a haystack.
If it is, then that means life is extremly rare, which already answers part of the question.
That comes with the big assumption that in basically any given corner of the universe, civilizations in galaxies billions of light years away are pumping out radio signals strong enough to be detected from earth.
How likely is it that by the time humanity would be a space faring society that we’d be pumping turbo charged radio signals that are easily distinguished from noise when doing a quick sweep? How likely is it that societies are using radio signals or something similar for a long period of time, and not simply using some better method that humans have yet to discover?
How likely is it that by the time humanity would be a space faring society that we’d be pumping turbo charged radio signals that are easily distinguished from noise when doing a quick sweep? How likely is it that societies are using radio signals or something similar for a long period of time, and not simply using some better method that humans have yet to discover?
No, the assumption is because our solar system and earth are not particularly old, if life is commonplace, then there are civilizations that should be billions of years older than us. Imagine where we would be (assuming we don't simply destroy ourselves in the next 50 years) with a billion more year of technological progress? We should be all over the galaxy, colonizing left and right, sending probes everywhere, creating dyson sphere like structures that would be easily detectable from afar etc.
And that is just one civilization on an single planet out of 100 billions planets in our galaxy.
Of course everything is just speculation, for every hypothesis on one side of the argument you can find 2 hypothesis from the other side that counter it. But the point is, to go back to the original question, that the right answer is definitely not obvious and if someone's opinion is that we are alone, or at least that life is very rare, it's not completly crazy.
Of course everything is just speculation, for every hypothesis on one side of the argument you can find 2 hypothesis from the other side that counter it. But the point is, to go back to the original question, that the right answer is definitely not obvious and if someone's opinion is that we are alone, or at least that life is very rare, it's not completly crazy.
Even if it's as rare as one in a billion we'd still have to map billions of suns, their planets and actually look for it. Other than SETI I don't know any really serious, concerted efforts to looks for other signals of life.
Even the discovery here was somewhat random and required someone to start digging through recorded data.
Even the discovery here was somewhat random and required someone to start digging through recorded data.
>Given that we haven't looked very hard for very long (as I mention above) in an enormous galaxy that's existed for billions of years, it seems to be in a similar position as any predictions from the Drake equation.
Also remember the search space isn't even just a single galaxy, it's the entire observable universe with a hundred billion galaxies, give or take.
Also remember the search space isn't even just a single galaxy, it's the entire observable universe with a hundred billion galaxies, give or take.
> Every other society realized it at the same time? Which would imply every other society is roughly born at the same time, which sounds unlikely. So some of them (like us) should not yet have discovered the danger of broadcasting signals.
Yeah, that's the Dark Forest book in effect.
If you broadcast, other civilizations could attempt to destroy you, so most civilizations find some way to dampen transmissions or limit them somehow.
Yeah, that's the Dark Forest book in effect.
If you broadcast, other civilizations could attempt to destroy you, so most civilizations find some way to dampen transmissions or limit them somehow.
> Yeah, that's the Dark Forest book in effect.
Precisely, and in the Dark Forest book we (humans) did indeed detect radio signals from other civilization very early after we built the radio telescopes capable of doing so. So the fermi paradox is not present in this alternate reality.
In our reality we haven't detected anything yet, hence the paradox.
Precisely, and in the Dark Forest book we (humans) did indeed detect radio signals from other civilization very early after we built the radio telescopes capable of doing so. So the fermi paradox is not present in this alternate reality.
In our reality we haven't detected anything yet, hence the paradox.
> Definitely a possibility, but again, that would assume some kind of synchronicity between all other societies
Does this not happen with eyes, limbs and especially blood which have evolved independently many times? Maybe whatever the reason is is actually quasi-inevitable and we're missing the few that fall outside of that evolution for some unrelated reasons.
Does this not happen with eyes, limbs and especially blood which have evolved independently many times? Maybe whatever the reason is is actually quasi-inevitable and we're missing the few that fall outside of that evolution for some unrelated reasons.
IIRC, we wouldn't be able to pick up our own broadcasts from Alpha Centauri because of the loss of radio transmission power. I doubt we would know if an alien civilization was transmitting at us, even if it was trying to get our attention.
The Breakthrough Listen initiative claims that it is sensitive to “Earth-leakage” levels of radio transmission from all 43 stars within 5 parsecs: https://breakthroughinitiatives.org/news/3
Attenuation of radio waves (long membrane) is way too high, that's true, but radio isn't the only way to transmit that we could theoretically pick up. Gravity waves for example would be a way to transmit across the whole universe.
Gravity waves would still have similar issues. The only gravity waves we can pick up right now are from extremely dense bodies colliding with each other. Not exactly a feasible means for intergalactic communication.
Unless your hobby involves collecting black holes and smashing them into each other...
Thus, the fact that we are unable to detect any signal from even a single other civilization is quite puzzling, we should be inundated by those signals.
People overestimate the detectability of our own signals. I don't have a reference, but I read an article a few years back where someone calculated how far away we would be able to detect our own signals with our current technology. The answer was about 20 light years. There are only around 100 stars in that sample. About all we can say is that there is not a civilisation similar to ours in that sample. Anything further away would have to be deliberately trying to communicate with us. If they are similar to us, they wouldn't know we are here. If they are much more advanced, we might be uninteresting to them for any number of reasons.
Technology advances, and this situation will change. The Square Kilometre Array, for example, will give us the resolving power to see whether excess radio "noise" is coming from a planet rather than a star (which might be an indication of an intelligent origin). This will increase our bubble of detectability much further out. Unfortunately, I don't have a number on that, but it is still an incredibly small volume compared to the size of the universe.
People overestimate the detectability of our own signals. I don't have a reference, but I read an article a few years back where someone calculated how far away we would be able to detect our own signals with our current technology. The answer was about 20 light years. There are only around 100 stars in that sample. About all we can say is that there is not a civilisation similar to ours in that sample. Anything further away would have to be deliberately trying to communicate with us. If they are similar to us, they wouldn't know we are here. If they are much more advanced, we might be uninteresting to them for any number of reasons.
Technology advances, and this situation will change. The Square Kilometre Array, for example, will give us the resolving power to see whether excess radio "noise" is coming from a planet rather than a star (which might be an indication of an intelligent origin). This will increase our bubble of detectability much further out. Unfortunately, I don't have a number on that, but it is still an incredibly small volume compared to the size of the universe.
> we are not special
This is a very common trap. I see this way of thinking applied to the presence of life on Earth all the time. It’s gilded in the Drake equation. It is very possible that Earth is the only planet in the galaxy or even universe with life on it. As the most powerful species on that planet, we should make responsible decisions. There is zero evidence, or even a compelling argument using existing data, that contradicts this possibility.
This is a very common trap. I see this way of thinking applied to the presence of life on Earth all the time. It’s gilded in the Drake equation. It is very possible that Earth is the only planet in the galaxy or even universe with life on it. As the most powerful species on that planet, we should make responsible decisions. There is zero evidence, or even a compelling argument using existing data, that contradicts this possibility.
Old enough to remember the times before the fist extraterrestrial planet was detected. The pessimist argument was then that circumstances leading to planetary system formation could be so extremely rare that we could possibly be the only habitable range planet in the galaxy.
It turned out since the planets are abundant. Planets being abundant increases the chances of life countlessfold, so there is a reason for cautious optimism.
It turned out since the planets are abundant. Planets being abundant increases the chances of life countlessfold, so there is a reason for cautious optimism.
But the Fermi Paradox is reason for cautious pessimism about technological life.
> As the most powerful species on that planet, we should make responsible decisions.
I think you mistake the meaning of the "we are not special" statement. From a statistic point of view, we have to assume that everything about us is roughly average (and so far our observations kind of confirm this), otherwise any probabilty you come up with is completly skewed by the bias you introduced by assuming from the get go that we are special.
But interestingly, by assuming that we are average and knowing the abundance of other planets, we should see a lot of activity out there, but we don't. So maybe that indicates that we are, in fact, not average.
I think you mistake the meaning of the "we are not special" statement. From a statistic point of view, we have to assume that everything about us is roughly average (and so far our observations kind of confirm this), otherwise any probabilty you come up with is completly skewed by the bias you introduced by assuming from the get go that we are special.
But interestingly, by assuming that we are average and knowing the abundance of other planets, we should see a lot of activity out there, but we don't. So maybe that indicates that we are, in fact, not average.
>From a statistic point of view, we have to assume that everything about us is roughly average (and so far our observations kind of confirm this).
This is the part I disagree with. It’s a hasty generalization to extrapolate from a single data point (Earth). The law of small numbers is alluring, but we must stick to our proper statistics guns and not fall into intuitive traps.
This is the part I disagree with. It’s a hasty generalization to extrapolate from a single data point (Earth). The law of small numbers is alluring, but we must stick to our proper statistics guns and not fall into intuitive traps.
> It’s a hasty generalization to extrapolate from a single data point (Earth).
But we have no choice, we have to extrapolate. And if you have a single data point, assuming that this datapoint is average makes more sense.
If there is an urn containing 100 balls some red some green, 99 of one color and 1 of the other color, and you blindly pick one ball from it that is red, you should bet that there are 99 red balls and 1 green ball, not the other way around.
But we have no choice, we have to extrapolate. And if you have a single data point, assuming that this datapoint is average makes more sense.
If there is an urn containing 100 balls some red some green, 99 of one color and 1 of the other color, and you blindly pick one ball from it that is red, you should bet that there are 99 red balls and 1 green ball, not the other way around.
We do have a choice: not to make hasty generalizations. Your example is the exact classic case of hasty generalization as a fallacy. You can say next to nothing about a bin of balls from one sample.
We can ponder the possibilities as long as we don’t start playing favorites. Saying “we aren’t special” is playing favorites. Saying “we may be special” is not.
We aren’t even confident about the state of life in the solar system. There could be life on Venus, Mars, and/or Europa. Earth may have seeded that life or those places could have seeded Earth, maybe a common ancestor seeded all three, or maybe genesis is common. Maybe life is all over the universe, or maybe Earth is the epicenter, or maybe something in between. We can say next to nothing about the state of life in the universe.
All we know for sure is that we are alive and stars have periodic dips in light intensity. We should act like we are the only life in the universe when weighing the pros and cons of self-inflicted armageddon, at least until proven otherwise.
We can ponder the possibilities as long as we don’t start playing favorites. Saying “we aren’t special” is playing favorites. Saying “we may be special” is not.
We aren’t even confident about the state of life in the solar system. There could be life on Venus, Mars, and/or Europa. Earth may have seeded that life or those places could have seeded Earth, maybe a common ancestor seeded all three, or maybe genesis is common. Maybe life is all over the universe, or maybe Earth is the epicenter, or maybe something in between. We can say next to nothing about the state of life in the universe.
All we know for sure is that we are alive and stars have periodic dips in light intensity. We should act like we are the only life in the universe when weighing the pros and cons of self-inflicted armageddon, at least until proven otherwise.
> We do have a choice: not to make hasty generalizations.
I don't think anyone is making a generalization in the sense you seem to be implying. No one is saying: given our current observation we have concluded that we are (or not) the only ones around. Things are being discussed in term of likelyhood, not in term of certainties.
> You can say next to nothing about a bin of balls from one sample.
You can definitely say something: That there are 99% likelihood that the urn was filled with 99 red balls and 1 green ball, and 1% that it was the other way around.
I don't think anyone is making a generalization in the sense you seem to be implying. No one is saying: given our current observation we have concluded that we are (or not) the only ones around. Things are being discussed in term of likelyhood, not in term of certainties.
> You can say next to nothing about a bin of balls from one sample.
You can definitely say something: That there are 99% likelihood that the urn was filled with 99 red balls and 1 green ball, and 1% that it was the other way around.
You can only say that the likelihood of a red ball is at least 1% and the likelihood of a green ball is 99% or less.
We can say the universe can support life because here we are. We can say nothing of how common it is other than it has occurred at least once in 10^24 planets over 10^9 years. It’s difficult to overstate how insignificant this amount of data is in a statistics sense.
We can say the universe can support life because here we are. We can say nothing of how common it is other than it has occurred at least once in 10^24 planets over 10^9 years. It’s difficult to overstate how insignificant this amount of data is in a statistics sense.
Note that you will always pick a red ball because it’s the only color you can pick, regardless of whether there are 99, 50 or 1 red balls in the urn. I believe that makes such a single data point meaningless, sidelining any statistical argument about its averageness—we have to rely on our understanding of physics, cosmology, astrobiology, etc. when estimating how frequent a red ball can be, at least until we have a large enough sampling of red balls.
Consider that our civilization has really only had about a 50 year window were we were rather noisy in the radio frequencies. Now, our radio transmissions (with the exception of some short pulse military ones) are much less powerful and would be much harder to detect at a distance.
From https://space.stackexchange.com/a/13013
> uoting from Tarter (2001): "At current levels of sensitivity, targeted microwave searches could detect the equivalent power of strong TV transmitters at a distance of 1 light year (within which there are no other stars)..."
We barely have the sensitivity to detect the existing strong TV transmitters of today within a 1ly sphere. The inverse square law becomes rather cruel. For a 2ly sphere, we'd need 4x the sensitivity. 3ly, 9x. To get 100 stars in the sphere, we need 21ly sphere, and that would need 400x the sensitivity that we have... and in that list of 100 nearest stars, there's only 6 G type stars.
So yes... there may be. But we're very small ( http://www.rainydaymagazine.com/RDM2011/RainyDayScience/Radi... ). Our own radio signals have barely made any significant coverage of the galaxy. Our own signals are also becoming harder to detect as our radio technology becomes better (DTV only needs 1/5th the power of analog TV).
That we're not hearing any random signals akin to what we've been broadcasting for the past century isn't surprising.
From https://space.stackexchange.com/a/13013
> uoting from Tarter (2001): "At current levels of sensitivity, targeted microwave searches could detect the equivalent power of strong TV transmitters at a distance of 1 light year (within which there are no other stars)..."
We barely have the sensitivity to detect the existing strong TV transmitters of today within a 1ly sphere. The inverse square law becomes rather cruel. For a 2ly sphere, we'd need 4x the sensitivity. 3ly, 9x. To get 100 stars in the sphere, we need 21ly sphere, and that would need 400x the sensitivity that we have... and in that list of 100 nearest stars, there's only 6 G type stars.
So yes... there may be. But we're very small ( http://www.rainydaymagazine.com/RDM2011/RainyDayScience/Radi... ). Our own radio signals have barely made any significant coverage of the galaxy. Our own signals are also becoming harder to detect as our radio technology becomes better (DTV only needs 1/5th the power of analog TV).
That we're not hearing any random signals akin to what we've been broadcasting for the past century isn't surprising.
That Stack Exchange answer from 2015 is quoting a primary source describing “current levels of sensitivity” in 2001. The Breakthrough Listen initiative, launched in 2016, claims that it is sensitive to “Earth-leakage” levels of radio transmission within 5 parsecs (16 ly): https://breakthroughinitiatives.org/news/3
Radio signal is not the only way to detect presence of other civilizations.
Von Neumann style probes, Dyson spheres etc.
Current estimates place the number of planets in our galaxy at 100 billions. And some of the stars in our galaxy are ~6 billions years older than our sun, that's a hell lot of time for a civilization to develop massively considering the technological progress we have had in a just a few thousands of years.
Von Neumann style probes, Dyson spheres etc.
Current estimates place the number of planets in our galaxy at 100 billions. And some of the stars in our galaxy are ~6 billions years older than our sun, that's a hell lot of time for a civilization to develop massively considering the technological progress we have had in a just a few thousands of years.
The issue with your argument is that earth is not a special place - there are tons of positive factors that helped life to develop and sustain. Position nearby stable sun, magnetosphere and just enough volcanic activity, our moon, big planets trapping most comets/debris that would make huge meteorite impacts much more common, oceans, tectonics. At the end, we don't know and everybody's opinion is just a gut feeling.
https://en.wikipedia.org/wiki/Rare_Earth_hypothesis
https://en.wikipedia.org/wiki/Rare_Earth_hypothesis
> The issue with your argument is that earth is not a special place
This is not my argument at all, it's actuall quite the opposite.
The argument is that, if everything about us is average (including our host planet), and given the tremendous amount of planets everywhere, we should see life basically everywhere. But we don't! So there indeed maybe something special about us, maybe our planet, maybe some extremely rare step in our evolution.
This is not my argument at all, it's actuall quite the opposite.
The argument is that, if everything about us is average (including our host planet), and given the tremendous amount of planets everywhere, we should see life basically everywhere. But we don't! So there indeed maybe something special about us, maybe our planet, maybe some extremely rare step in our evolution.
What signal are we expecting to be able to detect? AFAIK the radio signals we've been emitting are garbled beyond recognition and way too weak even a few light-years away from earth. After all, most of our communication is directed at earth and the remainder is for at most geo stationary orbit. We generally don't transmit anything high energy that would stand a chance to be recognisable from afar.
Similarly signals from other civilisations will probably become scrambled by distance and because they might overlap heavily with the radiation emitted by their sun.
Similarly signals from other civilisations will probably become scrambled by distance and because they might overlap heavily with the radiation emitted by their sun.
What if Radio waves simply don't work the same on other planets .
Or one of the first things civilizations figure out is to not broadcast your presence.
Or ... Everyone else in the universe found peace by stopping at the stone age , before all this social media made us miserable.
It's just conjecture, but I imagine aliens exist, but they might not even be in a form re recognize.
Or one of the first things civilizations figure out is to not broadcast your presence.
Or ... Everyone else in the universe found peace by stopping at the stone age , before all this social media made us miserable.
It's just conjecture, but I imagine aliens exist, but they might not even be in a form re recognize.
Well, to pick some nits, if radio waves didn't work the same way, that would be a pretty fundamental shift in physics, to the point of throwing all our assumptions out the window about our observational evidence.
We're assuming they communicate the same way we would.
I'll make up something scifi like. On planet x they use short term Seismic wave to move data around. How would we on earth ever pick that up
I'll make up something scifi like. On planet x they use short term Seismic wave to move data around. How would we on earth ever pick that up
> Can someone remind me how it comes to pass that there are people in the scientific community who believe we are the only "intelligent" life form?
Sure. I’m a strong-form rare Earther.
Interstellar pan-spermia is possible but unlikely across large distances. Independent seeding is the only way a 14bn-year-old expanding universe 93 Gly in diameter proliferates with life.
We don’t understand abiogenesis. All indications suggest it’s a difficult problem. The abundance of elements is set by the nuclear physics of stellar fusion and neutron star collision. Solvency further restricts biological chemistry. Given this, it seems likely that life in any form is quite rare.
Then we have multicellular life. On Earth, this is a product of the fusion of mitochondria and bilipid-barrier cells. Consider the number of cells in Earth’s history. The eucharyotic union occurred once. That is improbable.
I believe we will find scattered archae beyond our Solar System. (We may find single-celled life within it.) But complex multicellular life—let alone intelligence—takes so many variables perfectly aligning that it strikes me as vanishingly improbable.
We must as a species confront the moral implications of possibly being the sole light of life in this universe. That’s an uncomfortable burden. I understand why we shy from it.
Sure. I’m a strong-form rare Earther.
Interstellar pan-spermia is possible but unlikely across large distances. Independent seeding is the only way a 14bn-year-old expanding universe 93 Gly in diameter proliferates with life.
We don’t understand abiogenesis. All indications suggest it’s a difficult problem. The abundance of elements is set by the nuclear physics of stellar fusion and neutron star collision. Solvency further restricts biological chemistry. Given this, it seems likely that life in any form is quite rare.
Then we have multicellular life. On Earth, this is a product of the fusion of mitochondria and bilipid-barrier cells. Consider the number of cells in Earth’s history. The eucharyotic union occurred once. That is improbable.
I believe we will find scattered archae beyond our Solar System. (We may find single-celled life within it.) But complex multicellular life—let alone intelligence—takes so many variables perfectly aligning that it strikes me as vanishingly improbable.
We must as a species confront the moral implications of possibly being the sole light of life in this universe. That’s an uncomfortable burden. I understand why we shy from it.
It is an echo of the ‘centrist’ mindset. It was as difficult to understand that earth was not the center of the universe. Then our sun was not the center of the universe. Now that the human soul is not the center of all living things on earth.
If life is a possibility then intelligence isn’t simply a matter of time.
However, the bigger question is whether intelligence is the curse of life. Is intelligence self destructive by its very arrogance and nature.
Just published an article ‘Beyond Drake- Earth 2.0’ as the foundation for this very question. You can google and find it. It’s the start of a journey and a path to this question.
Its not about being the centre of anything... more like we had so much luck its unbelievable (stable sun, big planets cleaning asteroids, moon, magnetosphere etc.), and other life out there would quite a few more billions of years to get where we are. At least in this part of Milky way.
And its entirely possible light speed is the limiting factor that can't be crossed. Hence the civilizations of distant galaxies will remain unknown to us, same as we to them.
And its entirely possible light speed is the limiting factor that can't be crossed. Hence the civilizations of distant galaxies will remain unknown to us, same as we to them.
>> The eucharyotic union occurred once.
Once that we know of. I generally agree with the gist of your comment but we can't know what we can't know.
For me it makes more sense to admit we have insufficient data for a meaningful answer and leave it at that, until the situation changes. Science can't answer every question at any time.
Once that we know of. I generally agree with the gist of your comment but we can't know what we can't know.
For me it makes more sense to admit we have insufficient data for a meaningful answer and leave it at that, until the situation changes. Science can't answer every question at any time.
They meant, it occurred once on Earth, or at the very least it has stopped occurring for a few billion years now. That is still staggeringly low odds of a living planet seeing this event.
The same is true of abiogenesis - here we have a planet teeming with life absolutely everywhere we've looked, and yet 0 abiogenesis to be seen anywhere today. So, in general, when seeing a planet like the Earth today, we should expect to find NO life on it, as we already know teh Earth today can't sustain abiogenesis.
The same is true of abiogenesis - here we have a planet teeming with life absolutely everywhere we've looked, and yet 0 abiogenesis to be seen anywhere today. So, in general, when seeing a planet like the Earth today, we should expect to find NO life on it, as we already know teh Earth today can't sustain abiogenesis.
I'm out of my depth here (I know a few things about computers but - biology? Not so much) but I suspect that once life gets going it kind of hogs all of the resources necessary for life to begin again.
So perhaps abiogenesis hasn't happened again on Earth because it's already happened and there's no space for it to happen again until the current batch of living things has been extinguished.
If that holds any water, then life could have started any nymber of times in the past and ended soon after, without leaving any trace we can detect.
So perhaps abiogenesis hasn't happened again on Earth because it's already happened and there's no space for it to happen again until the current batch of living things has been extinguished.
If that holds any water, then life could have started any nymber of times in the past and ended soon after, without leaving any trace we can detect.
> insufficient data for a meaningful answer
Well I can't very well see that phrase and not post it
https://templatetraining.princeton.edu/sites/training/files/...
Well I can't very well see that phrase and not post it
https://templatetraining.princeton.edu/sites/training/files/...
Cheers :)
I thought your argument was well reasoned; but I would like to make a point about Life: because once life exists, things get interesting.
Life as we know it is based on genetics, which -as we know- is a kind of natural optimizer. A lot of people play with optimizers these days in AI and ML. Of course life does not optimize for click-through nor for paperclips. Instead it optimizes for "survival".
So if it is known that certain optimal points (niches) exist on the optimization landscape (fitness landscape), then one can assume they will be occupied sooner or later.
Or, in normal English: If something is at all reasonably possible, then once life exists, "Life Will Find A Way".
So once you get to the point where Life exists, the likelihood of life-related-things actually happening would actually seem to be quite high.
Of course with just life on a planet; history still moves at a slower scale than if there are planet were have actual sapients or even civilisation. Those are much faster optimizers, of course.
Life as we know it is based on genetics, which -as we know- is a kind of natural optimizer. A lot of people play with optimizers these days in AI and ML. Of course life does not optimize for click-through nor for paperclips. Instead it optimizes for "survival".
So if it is known that certain optimal points (niches) exist on the optimization landscape (fitness landscape), then one can assume they will be occupied sooner or later.
Or, in normal English: If something is at all reasonably possible, then once life exists, "Life Will Find A Way".
So once you get to the point where Life exists, the likelihood of life-related-things actually happening would actually seem to be quite high.
Of course with just life on a planet; history still moves at a slower scale than if there are planet were have actual sapients or even civilisation. Those are much faster optimizers, of course.
> The eucharyotic union occurred once.
How do we know that?
How do we know that?
That's what I thought as well. How do we know that it isn't a first-one-wins game, ie where a bunch of candidates have a reasonable chance of developing multicellular life, but whoever gets there first uses the advantage to out compete all the others?
We don’t, but we do know that there over the about 4 billion years of life, the first 1 to 1.5 billion years were purely prokaryotic. If it was a common thing to have work out, you wouldn’t expect such a massive amount of time before it occurred.
What I’m less confident on is that it’s the only path to complex multicellular life. It’s the step our history took, but it’s possible there are multiple rare pathways to the next step (or possibly different initial conditions could make the eucharyotic union or other options more probable? Just because it was unlikely here doesn’t mean that’s true on all planets).
What I’m less confident on is that it’s the only path to complex multicellular life. It’s the step our history took, but it’s possible there are multiple rare pathways to the next step (or possibly different initial conditions could make the eucharyotic union or other options more probable? Just because it was unlikely here doesn’t mean that’s true on all planets).
> We don’t, but we do know that there over the about 4 billion years of life, the first 1 to 1.5 billion years were purely prokaryotic. If it was a common thing to have work out, you wouldn’t expect such a massive amount of time before it occurred.
Based on that evidence you could also conclude that it was impossible for it to happen for 1 to 1.5 billion years (because it didn't) and then it was suddenly very likely (because it did).
Based on that evidence you could also conclude that it was impossible for it to happen for 1 to 1.5 billion years (because it didn't) and then it was suddenly very likely (because it did).
I don't think anyone in the astrophysics community thinks we're alone. But the physics also suggests that unless they are extremely common it's unlikely that we'll ever detect any (let alone meet any). So practically we are alone.
Outside the astrophysics community the majority of scientists I know also believe in life but similarly don't think we will detect/meet them. But there are some that don't believe (I don't know a single person in hard science that thinks we're alone but I do know engineers and those in soft sciences that reject the notion).
Outside the astrophysics community the majority of scientists I know also believe in life but similarly don't think we will detect/meet them. But there are some that don't believe (I don't know a single person in hard science that thinks we're alone but I do know engineers and those in soft sciences that reject the notion).
This doesn't refute what you said.
Cool Worlds is an excellent YouTube channel presented by an Astrophysics prof.
He recently gave an even-handed presentation of both sides, but on balance, he comes down slightly on the side of Life is unique to this planet.
https://youtu.be/iLbbpRYRW5Y
Cool Worlds is an excellent YouTube channel presented by an Astrophysics prof.
He recently gave an even-handed presentation of both sides, but on balance, he comes down slightly on the side of Life is unique to this planet.
https://youtu.be/iLbbpRYRW5Y
Because there are a lot of other things necessary for life. Usually we get the 'planet X may be suitable for life' PR news item first, and later in the scientific press we find out quietly 'planet X is awash in deadly gamma radiation, and the tectonics are such that there's a richter scale 13 quake every week'.
It turns out that when taking into account all known factors, us being alone is a nontrivial possibility:
https://arxiv.org/pdf/1806.02404.pdf
It turns out that when taking into account all known factors, us being alone is a nontrivial possibility:
https://arxiv.org/pdf/1806.02404.pdf
I'm still pissed about the number of people who refuse to acknowledge cetacean intelligence. Even ignoring the scientific studies performed by people like John C. Lilly, Karen Pryor and Kenneth Norris, just swimming with wild dolphins or humpback whales, it becomes clear that these creatures are at least as smart as us, probably smarter.
Think about it this way.
The Earth today is not capable of sprouting life (abiogenesis). In fact, from the fossil record and genetic studies, the Earth has almost certainly been unable to form new life (out of un living substances I mean) for billions of years.
Then, the same is true for multicellular life appearing from unicelular life. All of the living multi-cell organisms today seem to be descended from 1 common ancestor, 1 time that multicellular life has ever appeared in more than a billion years.
So right now, the very basic needs for life to even start seem to be staggeringly unlikely. Even at the huge scales of planets in the universe, it could be that the chances we'll ever meet another civilization are un conceivably low.
Of course, simple life could exist 'all over the place', and most scientists generally believe that. But life capable of interstellar communication like us may well be staggeringly rare in the universe.
We'll probably know a lot more about this in the coming decades/century, as we'll hopefully be able to send probes to look for life on Mars, Europa, Venus and other potential candidates in the Solar System. Perhaps we'll even be able to create abiogenesis in the lab and be able to learn more about the possible requirements that way.
The Earth today is not capable of sprouting life (abiogenesis). In fact, from the fossil record and genetic studies, the Earth has almost certainly been unable to form new life (out of un living substances I mean) for billions of years.
Then, the same is true for multicellular life appearing from unicelular life. All of the living multi-cell organisms today seem to be descended from 1 common ancestor, 1 time that multicellular life has ever appeared in more than a billion years.
So right now, the very basic needs for life to even start seem to be staggeringly unlikely. Even at the huge scales of planets in the universe, it could be that the chances we'll ever meet another civilization are un conceivably low.
Of course, simple life could exist 'all over the place', and most scientists generally believe that. But life capable of interstellar communication like us may well be staggeringly rare in the universe.
We'll probably know a lot more about this in the coming decades/century, as we'll hopefully be able to send probes to look for life on Mars, Europa, Venus and other potential candidates in the Solar System. Perhaps we'll even be able to create abiogenesis in the lab and be able to learn more about the possible requirements that way.
> The Earth today is not capable of sprouting life (abiogenesis). In fact, from the fossil record and genetic studies, the Earth has almost certainly been unable to form new life (out of un living substances I mean) for billions of years.
Playing devil's advocate for a bit, how do you know that existing life, honed by evolution, doesn't simply outcompete life that is continuously born abiogenetically in places like hydrothermal vents [1]?
[1] https://en.m.wikipedia.org/wiki/Hydrothermal_vent
Playing devil's advocate for a bit, how do you know that existing life, honed by evolution, doesn't simply outcompete life that is continuously born abiogenetically in places like hydrothermal vents [1]?
[1] https://en.m.wikipedia.org/wiki/Hydrothermal_vent
Of course, we can't know for sure, but the fact that in all this time no other strain seems to have made it makes that theory implausible to me.
To be fair though, there is A LOT of life on earth, so we can't discount the possibility that we'll find some forms of life that come from a different tree than us.
To be fair though, there is A LOT of life on earth, so we can't discount the possibility that we'll find some forms of life that come from a different tree than us.
We only have one data point. Earth. There is not enough information to do any kind of real statistical analysis. All we are left with is gut instinct. And that's not science.
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Something interesting I came across a few weeks back, the many possible methods of detecting exoplanets.
https://en.wikipedia.org/wiki/Methods_of_detecting_exoplanet...
https://en.wikipedia.org/wiki/Methods_of_detecting_exoplanet...
why is it named M51-ULS-1b instead of -1a? Did they pick one of the binary stars to be -1 and the other is -1a, so this planet is -1b?
That's the naming convention for exoplanets. It descends from the naming conventions for multiple star systems defined by the International Astronomical Union [0], in which the brightest (and usually gravitationally dominant) member of a multiple system receives designation "A", the second-brightest gets "B", and so on. Note the capitals. Planets, being considered a lower-mass extension of stars, get lower-case letters accordingly; so the first planet gets "b", the next planet gets "c" and so on. There is no lowercase "a" in a star-planet system. (I guess you might have that if you found binary planets without a star system; that would be very unusual).
Source: my PhD in astrophysics, and: [0] https://en.wikipedia.org/wiki/Exoplanet_naming_convention
Source: my PhD in astrophysics, and: [0] https://en.wikipedia.org/wiki/Exoplanet_naming_convention
So in this case the binary system together is 1A? Or is the brighter star 1A, the planet is 1b, and the black hole is 1C because it's darker?
I had to look at the paper itself to figure this out, but - in this paper, they designate the binary (star + stellar remnant) together as M51-ULS-1, and the planet actually orbits the two members together (a so-called circumbinary planet [0]). The logic of the nomenclature system actually breaks down in such cases - here's a quote from the Wikipedia article on naming conventions [1] stating as much:
'According to Hessman et al., the implicit system for exoplanet names "utterly failed with the discovery of circumbinary planets", and they state that it is unhelpful. '
So, yeah, take that for what you will.
[0] https://en.wikipedia.org/wiki/Circumbinary_planet
[1] https://en.wikipedia.org/wiki/Exoplanet_naming_convention#Ci...
'According to Hessman et al., the implicit system for exoplanet names "utterly failed with the discovery of circumbinary planets", and they state that it is unhelpful. '
So, yeah, take that for what you will.
[0] https://en.wikipedia.org/wiki/Circumbinary_planet
[1] https://en.wikipedia.org/wiki/Exoplanet_naming_convention#Ci...
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Not sure. I think with the Gliese bodies, the letters were assigned in chronological order of discovery. I guess that makes sense since we could later find other bodies in between and not want to rename everything.
https://en.wikipedia.org/wiki/Gliese_581_planetary_system
https://en.wikipedia.org/wiki/Gliese_581_planetary_system
What! How is it that there is yet no evidence that there is a planet in another galaxy?
You are detecting a planet (let's say bigger than Jupiter) of radius 100,000 km (1e+5 km) from (let's use Andromeda) 2.5 million light years away (2.3e+19 km).
Note that is 14 orders of magnitude.
So, let's scale that to a grain of sand (1mm or 1e-6 km) so that's 1e-11 in scale which makes the distance of 2.3e+8 km away--or roughly the distance to Mars.
So, to detect a planet in Andromeda is like detecting a single grain of sand on the Earth from Mars.
Note that is 14 orders of magnitude.
So, let's scale that to a grain of sand (1mm or 1e-6 km) so that's 1e-11 in scale which makes the distance of 2.3e+8 km away--or roughly the distance to Mars.
So, to detect a planet in Andromeda is like detecting a single grain of sand on the Earth from Mars.
More to the point, planets are next to stars. So it's more like detecting a single grain of sand on Mars that happens to be sitting next to a high-beam headlight - even if you had a telescope powerful enough to resolve it, it's tough to separate it from its host star.
While that does make it difficult, it’s also what makes it possible to see a planet from such a far distance.
In the words of Douglas Adams;
```
Space is big. Really big. You just won't believe how vastly, hugely, mind-bogglingly big it is. ...
```
```
The first possibility of a planet outside our solar system was discovered just over 300 years after the first telescope but not confirmed until 1992, almost 400 years after telescopes.
Finding the first planet outside our galaxy just 28 years later is pretty good!
Finding the first planet outside our galaxy just 28 years later is pretty good!
Planets are on average very small compared to their host stars, so you need extremely precise measurements to be able to detect a drop in luminosity caused by the transit of a very small object in front of a huge one.
It's already hard to do within our galaxy (~200k light years across), so outside of it (here 23M ly) is quite impressive.
It's already hard to do within our galaxy (~200k light years across), so outside of it (here 23M ly) is quite impressive.
Think of it this way: the best picture we have of andromeda (the galaxy closest to us) has 1.5 billion pixels. Compare that to the fact that the andromeda galaxy contains on the order of one trillion stars.
So we can't really see individual stars, except in the sense that some may be bright enough that they dominate the signal in their pixel.
So we can't really see individual stars, except in the sense that some may be bright enough that they dominate the signal in their pixel.
I guess a lot of people could not describe what a galaxy is. Solar system - our sun and the planets that go around it. Galaxy - hundreds of billions of suns clustered in space. We call ours the Milky Way after the band of stars you can see on clear nights. Other galaxies - Andromeda is well visible from Earth, but there’s probably again hundreds of billions of them.
It's been very difficult to gather the evidence until now? Given the astronomical distances involved and our technological progress?
No joke. Up until just a few years ago, we thought Pluto was a planet. Apparently, we can't even decide what a planet is. We also can't even find Planet X in our own solar system. We can find planet in other galaxies, but not our own solar system. This is what passes for science these days? Sheesh! /s
Pluto is just a matter of semantics.
Planet X is merely fantasy at this point.
Depends on what you mean by Planet X. There's a legit search for another large ice giant in the far reaches of the outer solar system.
https://solarsystem.nasa.gov/planets/hypothetical-planet-x/i...
https://solarsystem.nasa.gov/planets/hypothetical-planet-x/i...
Nibiru?
We are not even sure if there are planets beyond Pluto and that is just our own solar system.
Detecting planets is hard, even within our own galaxy.
Anyone else realize how random it is to have a (potential) planet orbit a black hole in such a specific way that it eclipses it ...> when viewed from fkn Earth.. 20 something million light years away??
lol . nuts
Same kinda 'randomness' provides for near-perfect (100%) solar-eclipses from Earth's surface .. Meaning if the Moon orbited any further or closer... it would not have the angular diameter from E's surface to perfectly block-out the angular diameter of the sun as viewed from Earth
lol . nuts
Same kinda 'randomness' provides for near-perfect (100%) solar-eclipses from Earth's surface .. Meaning if the Moon orbited any further or closer... it would not have the angular diameter from E's surface to perfectly block-out the angular diameter of the sun as viewed from Earth
I'm not sure the first is all that random. There seem to be a lot of planets and black holes likely aren't all that rare.
The second is a stupendous coincidence, and if the Earth ever becomes part of a galactic civilisation we'll have a very impressive draw for alien tourists.
Of course it might also be a business card left by the entities that engineered this reality but... probably not.
The second is a stupendous coincidence, and if the Earth ever becomes part of a galactic civilisation we'll have a very impressive draw for alien tourists.
Of course it might also be a business card left by the entities that engineered this reality but... probably not.
Sadly this particular tourist attraction will only be interesting for the next couple hundred million years, after which the moon will drift away too far to make it work anymore :(
Doesn't that suggest that lots of other moons spend some period of their lifetime in this perfect eclipse zone?
Multiple comparisons fallacy, related to the Birthday paradox.
Low probability * quadrillions of possible instances === near certainty.
There are ~100 billion solar masses (roughly; stars) in a single galaxy. There are roughly 100 billion galaxies in the observable universe. The Hubble Deep Field image has ~3,000 galaxies, looking at an empty spot of sky 1/10th the width of the full Moon. A later more intensive image within this revealed 10,000 galaxies.
100 billion * 100 billion is 10^22 stars, 10,000 billion billions. That's about a 100 billion stars for every person now living by rough order-of-magnitude maths.
The number of black holes per galaxy is likely at least in the thousands, and by models as high as 100 million (plus or minus an order of magnitude0 per galaxy (see; https://www.forbes.com/sites/startswithabang/2017/06/03/ask-...) 10^11 * 10^8 == 10^19, or 10 billion billion black holes to observe.
The likelihood that a planet might orbit one such black hole at an angle creating a transit visible from Earth is not at all low.
And having observed a rare event to have occurred, that is, with a prost hoc probability of one, declaring it improbable is a misuse of statistics.
https://en.wikipedia.org/wiki/Birthday_problem
https://theconversation.com/paradoxes-of-probability-and-oth...
https://en.wikipedia.org/wiki/Hubble_Deep_Field
https://en.wikipedia.org/wiki/Hubble_Ultra-Deep_Field
Low probability * quadrillions of possible instances === near certainty.
There are ~100 billion solar masses (roughly; stars) in a single galaxy. There are roughly 100 billion galaxies in the observable universe. The Hubble Deep Field image has ~3,000 galaxies, looking at an empty spot of sky 1/10th the width of the full Moon. A later more intensive image within this revealed 10,000 galaxies.
100 billion * 100 billion is 10^22 stars, 10,000 billion billions. That's about a 100 billion stars for every person now living by rough order-of-magnitude maths.
The number of black holes per galaxy is likely at least in the thousands, and by models as high as 100 million (plus or minus an order of magnitude0 per galaxy (see; https://www.forbes.com/sites/startswithabang/2017/06/03/ask-...) 10^11 * 10^8 == 10^19, or 10 billion billion black holes to observe.
The likelihood that a planet might orbit one such black hole at an angle creating a transit visible from Earth is not at all low.
And having observed a rare event to have occurred, that is, with a prost hoc probability of one, declaring it improbable is a misuse of statistics.
https://en.wikipedia.org/wiki/Birthday_problem
https://theconversation.com/paradoxes-of-probability-and-oth...
https://en.wikipedia.org/wiki/Hubble_Deep_Field
https://en.wikipedia.org/wiki/Hubble_Ultra-Deep_Field
(some very large number of stars) * (some rare possibility for each star) => a potentially non-too-rare number.
But it's still a huge coincidence for us. If (if!) there are millions of civilizations in the galaxy, presumably only a very few experience total eclipses.
If there were millions of civilizations in the Milky Way, we would already know it.
Not if you subscribe to the Dark Forest theory ;)
How do we "see" objects so far away from Earth? Are we somehow fetching the light? And if yes, if it's 23 million light years way from us, is it possible that the planet no longer exist at all?
They were looking for eclipses - when something blocks the signal they’re observing. In this case, they noticed the X-rays they were looking at were blocked for a few hours. There’s more to it, but the article actually does a good job of explaining it all.
There’s not really any way for us to prove if it exists or not today, that information is still quite far away. The best we can do is try to understand the system and make predictions about that.
There’s not really any way for us to prove if it exists or not today, that information is still quite far away. The best we can do is try to understand the system and make predictions about that.
> if it's 23 million light years way from us, is it possible that the planet no longer exist at all?
Yes, in the same way that if the sun were to suddenly go out, we wouldn't find out for eight minutes (the time that it takes for light from the sun to reach the earth).
Yes, in the same way that if the sun were to suddenly go out, we wouldn't find out for eight minutes (the time that it takes for light from the sun to reach the earth).
The Earth is more than 4 billion years old so 23 million years doesn't seem like much.
From the picture it looks like we're seeing M51 from the "top", does that mean that the planet is orbiting the star system at a right angle from the galaxy plane? Isn't that unusual?
I’m pretty sure our system is like this.
https://www.forbes.com/sites/startswithabang/2018/08/30/our-...
https://www.forbes.com/sites/startswithabang/2018/08/30/our-...
No, it’s not unusual. Stars form from clouds of gas and dust collapsing chaotically under their own gravity. It’s the net angular momentum of the cloud that determines the spin and ecliptic of the star system.
"pics or it didn't happen" ... they even mention awesome x-ray images of the discovery and the whole article is text -- missed opportunity
I am no astronomer, but I find this inconceivable.
that site is paywalled for me and no doubt for others...here is a non paywalled link:
https://phys.org/news/2020-09-candidate-extragalactic-planet...
Why don't you link to the original preprint [0]? phys.org and its paywalled brethren are all too often touted on HN to waste time on sci-pop.
The paper has lots of pictures.
[0] https://arxiv.org/pdf/2009.08987.pdf
The paper has lots of pictures.
[0] https://arxiv.org/pdf/2009.08987.pdf
Wow. That's hard to even imagine.