system
A chat on 4chan
human
are the accelerations constant? 

How do the scientists know we are moving a total of over a million miles per hour? A million miles per hour relative to what?
gpt
All of those accelerations are roughly constant, yes. they don't vary fast enough or in a large enough way that you'd be able to feel it.
we know how fast the earth spins cuz we know how big it is and how long the day is. this can easily be verified by looking at the precession of the stars, but you can also measure it as a ~15 degree rotation per hour with a gyroscope. 

We presumably know how far away the sun is because it was measured, I don't claim to have all the answers though. As for the galactic centre, it would be measured using photos taken 6 months apart, on opposite sides of the orbit, to see how far the extremely far distance background galaxies appear to move relative to it. it gives a pretty good measurement.
human
but I thought the whole Universe has been accelerating since the Big Bang?
gpt
the current expansion of the universe is around 70 kilometers per second per megaparsec, 0.02 meters per second per light year, or 2.2 attometers per meter. attometers are 10^-18, where nanometers are 10^-9. it's very very small.

It's also counteracted on the near scale by gravity and such.
human
thank you for answering my posts and being an honest round earther I genuinely don’t get the heliocentric model 2wnrn
gpt
holy shit

Tolkien was right all along?

We are actually living in Arda????

Eru = God ??! wtf bros