From Peter Smith:
Stuf4 wrote...

You ask whether one can distinguish between gravity and acceleration.
But the question of whether one can distinguish between 'orbital
microgravity' and a 'microgravity field' is a different question.

Peter, please check "orbital microgravity" as a self-contradictory
oxymoron. Orbits require gravity in order to be orbits.

duuh - that's why I used the quote marks, Stuf4.

(A perfectly accurate term is "micro-g". No contradiction.)

I went on to explain how you could (if you were in a sealed box with no
windows and experiencing no obvious gravitational effects), how you could
differentiate between orbit and absence of (significant) gravity.

I agree with your point there. There are other ways to tell that an
astronaut is in a strong gravitational field (vice "zero gravity")
beside just the windows.

By the way, if you looked out the window, how would you detect a black
hole?

One way would be to observe the patch of blackness that defines the
black hole's event horizon circled by a haloed grouping of apparent
stars created by the gravitational lens effect.


~ CT