Expansion vs the speed of light.

[Gozzer101]

I once read that the expansion of the universe is the only thing that is faster than light (although it's not technically a speed?). It was in a BBC focus magazine.

 

By my reckoning because of this, distance objects light will never reach Earth. Yet stories come up in the news of far fethced galaxies seen from earth and some quasars too?

 

If this is true then does anyone know what point we can see back too before light will no longer reach us, and at this point what would we see if say a galaxy was at this exact distance from earth. Would the light from it stay the same? Or would the apparent galaxy time perspective

from earth speed up?

[guenter]

If this is true then does anyone know what point we can see back too before light will no longer reach us, and at this point what would we see if say a galaxy was at this exact distance from earth. Would the light from it stay the same?

You talke about the Hubble sphere, which can be thought as a shell with radius c/Ho (Ho is the Hubble constant, c/Ho is called the Hubble lenght) around us. Galaxies on the Hubble sphere recede with c, hence the distance between the photons emitted by such a galaxy towards us and our position is constant. In that sense one can indeed say these photons stay there but should keep in mind that they travel with c locally. Note, that the Hubble constant decreases over time.

[Andeh]

perhapse because inflation was accelerating at some point.

The universe is estimated to be 150 billion light years across, but only 14 billion years old...suggesting that it was accelerating faster than the speed of light at some time in the past (?).

[Realitycheck]

It all depends on how big of a variable you assign to inflation. It's really unknowable.