righthandtypist t1_is1ect9 wrote on October 12, 2022 at 4:28 PM

If near FTL speeds were ever achieved, or even some of the speeds that current satellites are going, how would they effect the human body?

I assume due to the size of the earth and how small we are the speed isn't registered by us due to relative sizes, does this mean that any vessel we create to travel those speeds needs to be proportionally scaled to say moon sized?

AtticMuse t1_is1l9d9 wrote on October 12, 2022 at 5:13 PM

Speeds don't affect the body, only acceleration. So it's not because of the size of the Earth that we don't feel our motion through space, it's because there's fundamentally no difference between being at rest and moving with constant speed relative to something. Think about being on an airplane, apart from any turbulence you feel completely at rest and can move around the cabin normally when cruising, even though you're travelling at several hundred kilometers per hour with respect to the ground.

righthandtypist t1_is3de9w wrote on October 13, 2022 at 12:24 AM

Ah, I wasn't sure if speed mattered in the case of an air plane or not, i guess not looking at the speed of the sr-71 being 2200 mph.

157,000 mph in an airplane just sounds absolutely insane. How would you survive the stop?

AtticMuse t1_is3npe6 wrote on October 13, 2022 at 1:39 AM

The same way you survived the acceleration up to that speed; spread it out over time. Astronauts on the space station are going over 17,000 mph relative to the ground, and getting up to that speed they have to pull a couple of g's in a rocket, which is tough but doable for a few minutes. On their way back to Earth the atmosphere slows them down a little more gradually and they only experience 1-1.7 g's.

And not that we would ever want to stop relative to these things, but just sitting at your desk you're moving incredibly fast through the universe. The Earth is moving ~67,000 mph around the sun. And the sun is moving ~490,000 mph around the center of the galaxy.