Can someone please clear this up?
If the space is expanding between galaxies, are the random wisps of gas and molecules also expanding? If one were to fly into such space, would you see giant hydrogen atoms flying around (at some point)?
And why is recession the same thing as expansion? Why...
Just thinking of Hubble's simple expansion of the universe or galactic recession (ignoring inflation).
How is it possible or practical to say that the universe is expanding? For something to expand, it has to expand relative to something else (if not, then inertial frames would not be...
I read that the speed of light is constant, that everyone measures the same speed of light from their own reference frame.
Yet I have also read that light can't escape from a black hole, because of the gravitational effects. How can you measure it's speed at 'c' and yet at the same time not...