Random Science Talk


(Steve) #1

So I’m just going to throw stuff I’ve heard on the internet on here and hope that my beliefs are true. Feel free to post comments on them and your knowledge that you want peer reviewed (to the best of our ability that is).

Alright, so from what I know of FTL travel in the realm of actual science is that it would revolve around time distortion over velocity. This is due to the laws of physics stating that nothing can travel faster than the speed of light and as such if you were traveling 4 times the speed of light over 4 light years that means you would only experience 1 years of time while the rest of the universe experiences 4.

Next up falls into the same type of science as FTL, wormholes. From what I know of worm holes, they are both tears in space and time. Since nothing can travel faster than the speed of light that means that going from one point to another 5 light years away then stepping through the wormhole takes you 5 years into the past or future.

Now here’s my knowledge of fusion technology. I understand how it works due to many videos and articles explaining it, however, the thing I think is true but might not be is why it is inefficient. From my knowledge, the reaction produces the amount of energy we want but a lot of it is lost through a miniature version of a solar flare making the energy burst out and be lost.


(tjwhale) #2

Interesting ideas.

I think with wormholes there isn’t a requirement that you travel forwards or backwards in time, but it is possible.

What a wormhole does is it just connects two points in space time so they are next to each other. Here’s a video on it. So the thing is once those points are next to each other you can just travel through in a few seconds as if you are stepping though a door.

Fusion power is currently reasonably well understood and a working reactor wouldn’t necessarily have flares that cause power to be lost. The main problem is getting the containment field to keep the plasma inside the reactor while it is fusing, if you can do this then you can capture a reasonable amount of energy released. If they can get fusion to work, and they are relatively close, it will be an extremely good power source, especially because Hydrogen is the most abundant element in the universe.


(He who abuses the search function) #3

Question: How? Because to my knowledge, you need deuterium and tritium, and deuterium is only 0,02% of the available hydrogen, and tritium is only available in trace amounts. This would mean that the hydrogen required is way less than what you’d think, and that you’d need some way to manufacture deuterium and tritium, which would cost a lot of energy, almost as much as the fusion generates.


(𝐓𝐡𝐞 𝐆𝐨𝐝 𝐄𝐦𝐩𝐞𝐫𝐨𝐫 𝐨𝐟 𝐒𝐞𝐚𝐟𝐨𝐨𝐝) #4

Answer: The moon!
Due to being pummelled by solar rays for billions of years, tritium is in an absolute abundance there.
More reason to set up a mining colony.


(He who abuses the search function) #5

We don’t really have a moon colony yet though. And the entire purpose of fusion being an environmentally friendly source of power doesn’t really work if you need to send rockets from and to the moon each time the fuel runs out.


(𝐓𝐡𝐞 𝐆𝐨𝐝 𝐄𝐦𝐩𝐞𝐫𝐨𝐫 𝐨𝐟 𝐒𝐞𝐚𝐟𝐨𝐨𝐝) #6

Outside of the moon, yes, all Hydrogen isotopes are rare.
Kind of a shame, but who knows where it could be hiding…


#7

I felt like that didn’t apply to stars. And I went looking and found this:
https://www.quora.com/Why-do-you-need-hydrogen-isotopes-for-fusion

Where, if the people answering that question are to be believed, then the limited pressure / force we use in our fusion reactors is the reason we need those rare isotopes. If it was possible to have similar pressure as in the center of a star we could use all hydrogen for fusion.


(tjwhale) #8

I think the current plan for the ITER reactor is to collect deuterium from sea water and make tritium from lithium. So that would work for a while I guess. Being able to fuse pure hydrogen would clearly be better.


(Steve) #9

Wait? Couldn’t we get hydrogen from the water and fuse that or is there something special about pure hydrogen that we can’t get it from water?


#10

Water contains very little of the isotopes that we need for the kind of fusion reactors that are being worked on now (as mentioned earlier).


(He who abuses the search function) #11

Nope, the fusion that people are planning on using is deuterium (1 proton, 1 neutron) + tritium (1 proton, 2 neutrons) -> 1 helium (2 protons, 2 neutrons) + 1 neutron. As said before, deuterium and tritium are both very rare isotopes (most hydrogen is 1 proton, 0 neutrons)


(𝐓𝐡𝐞 𝐆𝐨𝐝 𝐄𝐦𝐩𝐞𝐫𝐨𝐫 𝐨𝐟 𝐒𝐞𝐚𝐟𝐨𝐨𝐝) #12

Actually, on that note, is there any other form of space travel that could be considered green?


(Steve) #13

Ion engines, but they only work in low gravity environments so we would need a space elevator to get cargo up and down the atmosphere. We also have VASIMR which is still experimental, however, that would need to be powered with a nuclear reactor and that is a bit of a problem since we would need to have extreme confidence that the launches would work (unless we have smaller and more efficient fusion reactors by then).


(𝐓𝐡𝐞 𝐆𝐨𝐝 𝐄𝐦𝐩𝐞𝐫𝐨𝐫 𝐨𝐟 𝐒𝐞𝐚𝐟𝐨𝐨𝐝) #14

Alright, so for a fusion engine to work, we need a space elevator and a lunar mining base, as well as high tech rockets capable of lifting efficient quantities of hydrogen isotopes.
slaps roof of engine
“This thing is gonna pay for itself in like 3000 years”

Also a cool side note: Ion engines were first invented and tested in 1916-1917, way before the first thing ever went to space