Nuclear blast sends star hurtling across galaxy(bbc.com)
bbc.com
Nuclear blast sends star hurtling across galaxy
https://www.bbc.com/news/science-environment-53415294
7 comments
900000 km/h = 250 km/s. This is fast but comparable to 224 km/s that the sun moves. Our galaxy itself moves at ~600 km/s relative to local cluster center of mass.
The Sun is way slower in regards to neighboring stars. 250 km/s is an order of magnitude faster than Sun/Alpha Centauri relative speed.
Edit: checked the actual paper, 250 is relative to galactic center, just like my sun number [0]
[0] https://watermark.silverchair.com/staa1761.pdf?token=AQECAHi...
We are in a milky way, it is reasonable to look at the speed relative to the galactic nucleus, which is what I did. Kind of how we talk about speed of earth/comets/etc around the sun.
[0] https://watermark.silverchair.com/staa1761.pdf?token=AQECAHi...
We are in a milky way, it is reasonable to look at the speed relative to the galactic nucleus, which is what I did. Kind of how we talk about speed of earth/comets/etc around the sun.
Yep, there's no true reference frame in the universe - Einstein realized that more than 100 years ago and put it down as the theory of relativity.
Microwave background provides a kind of reference frame for the universe. We are moving ~370km/s relative to it [0]. We are fairly certain CMB is homogenous so this reference frame is same everywhere.
[0] https://en.m.wikipedia.org/wiki/Cosmic_microwave_background
[0] https://en.m.wikipedia.org/wiki/Cosmic_microwave_background
Those speeds are not comparable.
If you search for high speed differences, you just look for far enough target.
It is much more impressive for any body to generate its own delta V than to follow an orbit.
This is the reason why you discuss cars moving at tens of meters per second forgetting that they are already moving at over 200km/s around our Galaxy. Because some reference frames just aren't interesting.
If you search for high speed differences, you just look for far enough target.
It is much more impressive for any body to generate its own delta V than to follow an orbit.
This is the reason why you discuss cars moving at tens of meters per second forgetting that they are already moving at over 200km/s around our Galaxy. Because some reference frames just aren't interesting.
The velocity of the star in the paper, and our star, are both with respect to galactic nucleus. The star is still following orbit, just presumably a very eccentric one. I never said it is not impressive, just that it is similar to typical orbital velocities in our galaxy. The eccentricity of the orbit is the atypical thing here.
Imagine being on some planet far away, just living your life, and a literal star comes through and ends all life in the system.
If the star is a direct hit on your planet, it would look as if a second sun was getting brighter and larger, and the heat so unbearable you’ll be dead before there’s any impact.
Finis, by Frank Pollack: http://gutenberg.net.au/ebooks06/0605041.txt
Books from fifty years ago are difficult to read now, mostly due to a blatant sexism. An example from the first page of this text: “Probably she had brains...” That’s right! Men are smart, women are beautiful and wear nice clothes.
Your post comes across as needlessly biased, pejoratively modernist, and ignorant.
> Books from fifty years ago are difficult to read now, mostly due to a blatant sexism.
Fifty years ago was 1970. I don't think anyone has a problem reading Are you there, God? It's me, Margaret, Johnathan Livingston Seagull, or Ringworld due to blatant sexism.
"Finis" is a short story and was first published over 100 years ago.
> An example from the first page of this text: “Probably she had brains...”
"Probably she had brains..." is not evidence of sexism. It's not even evidence of a bias that people generally don't have brains, much less women. It's literally a character's (Eastwood's) conclusion based on observation of another character's (Mrs. Davis') behaviors and habits. Eastwood doesn't show surprise that a woman could be smart. He doesn't deny that she is smart in spite of the evidence. And even if he had done so, a character being sexist wouldn't ipso facto make the work as a whole sexist.
> Books from fifty years ago are difficult to read now, mostly due to a blatant sexism.
Fifty years ago was 1970. I don't think anyone has a problem reading Are you there, God? It's me, Margaret, Johnathan Livingston Seagull, or Ringworld due to blatant sexism.
"Finis" is a short story and was first published over 100 years ago.
> An example from the first page of this text: “Probably she had brains...”
"Probably she had brains..." is not evidence of sexism. It's not even evidence of a bias that people generally don't have brains, much less women. It's literally a character's (Eastwood's) conclusion based on observation of another character's (Mrs. Davis') behaviors and habits. Eastwood doesn't show surprise that a woman could be smart. He doesn't deny that she is smart in spite of the evidence. And even if he had done so, a character being sexist wouldn't ipso facto make the work as a whole sexist.
What a fantastic short story. Thanks for sharing!
Somewhat related, although it's not a central part of the plot: Polaris by Jack McDevitt.
It wouldn't just show up some day, ambush style.
It would be slowly getting closer and closer over centuries.
The warning doesn't really change how the story ends though...
It would be slowly getting closer and closer over centuries.
The warning doesn't really change how the story ends though...
It could, if you're where we are now developmentally you could conceivably determine a safe place in the solar system to colonize in the thousands or more likely millions of years it would take to arrive, right? Or maybe more realistically leave or build large scale space habitats (since there might be no safe planet due to rotation of them).
Generally a star plowing through your solar system is going to throw most orbits into wack, so you may not want to be in the solar system at all.
Assuming you lack the capacity to leave for good, you probably want to be in the system, but in a well-stocked tin can rather than a planet. You won’t be able to maneuver a planet but your tin can might be able to stick around. Afterwards you’ll need a star and whatever planets didn’t get eaten or flung out of the system.
You definitely don’t want to be on a planet that gets flung out of both systems. Even if you somehow had millions of years of fuel, your civilization would probably never be close to any other body in space again.
You definitely don’t want to be on a planet that gets flung out of both systems. Even if you somehow had millions of years of fuel, your civilization would probably never be close to any other body in space again.
Hah, amusingly I failed to consider that. I wonder how fast a sun would have to move through to have a negligible (or at least not catastrophic) effect on orbits?
The Oort cloud around the Solar system ranges halfway to the next star. That far out the Sun is probably not the only relevant influence anymore. Even though stars would have to get really close to be able to mess up orbits of the inner Solar system, a large comet can absolutely wreck the biosphere if it hits us.
Or maybe just move Earth out of the way: https://en.wikipedia.org/wiki/The_Wandering_Earth
It would be a rare case where doomsayers would actually be right.
Everyone’s views in this discussion are really enlightening for someone like myself who has been consumed with nothing but programming the last few months! Miss being a kid and dreaming about space travel.
Is that picture real? Drives me crazy seeing articles with stock art that might as well be completely fabricated
That looks like an illustration, not a photo
Question is, in what direction.
Something hot and bright far away emits photons. What are those? Heat transfer through the medium of time, right? A fast clock is bright and speeds up a slow clock that's dark.
What's the difference between a tiny spot on the Hubble, or any material for that matter, turning colder and darker always when pointed into that direction? Voltage spikes up at that sensor and it sees a hot spot because it caves in on itself instead of being hit with a beam of energy in motion for billions of years.
Weak force parity violation?
Is that just some higher abstraction on top of pair production and spontaneous particle creation?
Electromagnetism is the emission of photons and the absorption through the photovoltaic effect. Matter decay is mass decreasing and releasing energy without EM. Or EM plus negating the effect by messing with that EM counterbalance. Or gravity, the heat transfer through the medium of time, interaction so fine it looks like you are broadcasting to everything at once if something else tries to trace it.
That's what I'm thinking. Eventually spontaneous particle creation is the basis of all interaction. Not EM or photons. I think humans get to it, that we do it already. Massive celestial objects pop into existence because highly accurate sensors here on Earth say they must. Particles here pop into existence and they give the data of everything out there for no other reason than they must. Instead of being loss in a vast sea of stuff, the universe is a very complex filter to a massive energy source.
When they talk of causality violation, backwards time travel, I think of hitting the big bang itself, or original energy source. Throwing dynamite into the wave you're surfing on.
Forget worrying about a star crashing through Earth. Earth is the source of all destructive acts in the universe for the most trivial of reasons, and we have soverign access to all that out there to make our lives the slightest bit better for any reason.
Just some thoughts I get when I read these things. Thanks for that article.
What's the difference between a tiny spot on the Hubble, or any material for that matter, turning colder and darker always when pointed into that direction? Voltage spikes up at that sensor and it sees a hot spot because it caves in on itself instead of being hit with a beam of energy in motion for billions of years.
Weak force parity violation?
Is that just some higher abstraction on top of pair production and spontaneous particle creation?
Electromagnetism is the emission of photons and the absorption through the photovoltaic effect. Matter decay is mass decreasing and releasing energy without EM. Or EM plus negating the effect by messing with that EM counterbalance. Or gravity, the heat transfer through the medium of time, interaction so fine it looks like you are broadcasting to everything at once if something else tries to trace it.
That's what I'm thinking. Eventually spontaneous particle creation is the basis of all interaction. Not EM or photons. I think humans get to it, that we do it already. Massive celestial objects pop into existence because highly accurate sensors here on Earth say they must. Particles here pop into existence and they give the data of everything out there for no other reason than they must. Instead of being loss in a vast sea of stuff, the universe is a very complex filter to a massive energy source.
When they talk of causality violation, backwards time travel, I think of hitting the big bang itself, or original energy source. Throwing dynamite into the wave you're surfing on.
Forget worrying about a star crashing through Earth. Earth is the source of all destructive acts in the universe for the most trivial of reasons, and we have soverign access to all that out there to make our lives the slightest bit better for any reason.
Just some thoughts I get when I read these things. Thanks for that article.