- #1
user9003
- 11
- 0
i have a question about the motion of galaxies and the speed limit of light.
using Hubble's law, it is theoretically found that after a certain distance(about 4200 mega parsec or something) from a observer, the galaxies are moving faster than the speed of light.
consider the following scenario:
let galaxy A be in any part of the universe. let galaxy B be at a distance greater than 4200 mega parsec from A. as per Hubble's law, B is moving away from A at speed faster than light and to B , A is moving away from A at speed faster than light . the movement of these two galaxies is observed by a observer in a absolute frame of reference F (Newtons's idea; assume such a frame exists)
here are the question:
1)for the observer in F , is the galaxy B and A moving by themselves , or are they moving due to the expanding space ?. because if galaxies were to move due to expansion of space, then aren't they violating the speed limit of light due to the following fact. let V be the velocity of the galaxy B and v be the velocity of the expanding space in which the galaxy is present . hence the total velocity of the galaxy B measured by the observer in F would be V+v ;where both V and v are comparable to the speed of light .
2) are the galaxies actually embedded in space and moving with space or are they moving in space and not embedded in the space itself?
using Hubble's law, it is theoretically found that after a certain distance(about 4200 mega parsec or something) from a observer, the galaxies are moving faster than the speed of light.
consider the following scenario:
let galaxy A be in any part of the universe. let galaxy B be at a distance greater than 4200 mega parsec from A. as per Hubble's law, B is moving away from A at speed faster than light and to B , A is moving away from A at speed faster than light . the movement of these two galaxies is observed by a observer in a absolute frame of reference F (Newtons's idea; assume such a frame exists)
here are the question:
1)for the observer in F , is the galaxy B and A moving by themselves , or are they moving due to the expanding space ?. because if galaxies were to move due to expansion of space, then aren't they violating the speed limit of light due to the following fact. let V be the velocity of the galaxy B and v be the velocity of the expanding space in which the galaxy is present . hence the total velocity of the galaxy B measured by the observer in F would be V+v ;where both V and v are comparable to the speed of light .
2) are the galaxies actually embedded in space and moving with space or are they moving in space and not embedded in the space itself?