I've tried to search for news articles that were even a month old and have had trouble locating links to stories I know happened. I don't know any tricks to working around this. And if I don't recall specifically when the article came out (say, somewhere around 6 months ago), I'll usually give up.
Having been looking for a way to add comments to a static site for a while now, this is very cool and should get more love. Thanks for the service and the post!
I don't think the author was concerned with performance. I was providing the list.* type suggestion to make it easier to delete elements syntactically.
However, you're likely right for slices with len < 500 or so due to garbage collector churn on linked lists.
I agree with the author that Go is not as easy as Python or Ruby. However, the first example given is bad.
Running delete on a slice is the same as trying to delete an element of an array. It's the wrong data structure if you need that type of access pattern. That's why it's hard. You can cut a tree down with a hammer, but it's going to take a while and you're going to have some blisters.
Go has built-in linked lists. https://golang.org/pkg/container/list/
and I will agree, they're not as easy to use as other languages due to the lack of generics in go, at present. Using the list.* package requires type conversion to evaluate and pull values out of the structure.
I think it's fair to say that Go needs to do a better job explaining the list package or possibly including it in the "Tour of Go" guide. That might help avoid these misconceptions in the future.
This article didn't explain it at all, so you're right to ask.
tl;dr: Gaseous propellant (I'm guessing hydrogen) is heated with fission then pointed in the opposite direction of intended travel.
The uranium in this design is not a propellant, but a heat source. Aside: you can use photons/heat as a propellant, but it's thrust is very low https://en.wikipedia.org/wiki/Pioneer_anomaly. Ideal propellants typically have a high exit velocity and low mass. That gives you the longest amount of "burn" time, and the greatest amount of control for the weight. https://en.wikipedia.org/wiki/Specific_impulse
Back in the day when the US was building more of these nuclear rockets, the propellant of choice was typically hydrogen https://en.wikipedia.org/wiki/NERVA. Old timey video explaining it https://youtu.be/eDNX65d-FBY?t=238. I'm assuming this proposed design would also use hydrogen, but I couldn't find any sources on the propellant for their design.
Liquid hydrogen served to keep the reactor cool as it transitioned from liquid to gas as that phase change absorbs energy. The gas is the directed through the reactor core where the gas heats up. As gases heat up, they absorb energy, their average particle velocities increase.
Eventually, the hydrogen molecules (mostly H2 or H-H gaseous hydrogen), makes it to the nozzle and is ejected. The high-velocity hydrogen is what actually provides the bulk of the thrust to the spacecraft.
Compare this to Project Orion (https://en.wikipedia.org/wiki/Project_Orion_(nuclear_propuls...) which intended to detonate nuclear warheads and the craft essentially rode the shock wave into the stars. I would classify this method of propulsion, not safe.
Natural gas conversion mostly reduces particulates. The EIA data says natural gas produces more CO2/MkWh than coal:
Electricity generation CO2 emissions
million kWh million metric tons million short tons pounds per kWh
Coal 1,124,638 1,127 1,240 2.21
Natural gas 1,246,847 523 575 0.92
Petroleum 21,860 21 23 2.11
Ironically, particulates decrease insolation and actually slightly reduce warming (CO2's half life is a lot longer than particulates, so the "cooling" is short-lived and will go away when you stop burning coal, net warming, overall). Natural gas doesn't produce as many particulates, so I would expect that converting to natural gas would increase global warming in the short and long term compared to continue to burn coal.
It's far better to switch to solar/wind/geo/nuclear than natural gas in the long run, but there are health benefits to removing the coal particulates:
"Coal impacts: air pollution
When coal is burned it releases a number of airborne toxins and pollutants. They include mercury, lead, sulfur dioxide, nitrogen oxides, particulates, and various other heavy metals. Health impacts can range from asthma and breathing difficulties, to brain damage, heart problems, cancer, neurological disorders, and premature death." https://www.ucsusa.org/resources/coal-power-impacts#:~:text=....
I presume that the primary driver of this conversion isn't the environment, but economics. The price of coal/kWh is more expensive than the volume of gas required to generate the same kWh. The Total system LCOE is usually the number people want to minimize.
https://www.eia.gov/outlooks/aeo/pdf/electricity_generation....
tl;dr: No. Burning gas is worse from a climate perspective.