Expert: Jayendra Upadhye - 12/12/2007

Question
It seems paradoxical that images of very early galaxies (the HUDF has revealed several from the first billion years of the universe) appear so far away. If the light we see from them began travelling when the expanding universe was much smaller, then they should not appear so far away. Put another way, why do we see a galaxy at a great distance when it can't have had time to move out to that distance (when the light was transmitted)?
Thanks.

Answer
Hi Paul,
This question has been asked me more than 4 times alredy!
Each questioner phrasing it differently.

What people forget is that in the initial period (very very close to ZERO-TIME, the universe inflated, doubling and quadrupling in leaps and bounds faster than the speed of light! After this phase was over, all "inflated regions" shared the common expansion of the universe.

[The inflationary universe].
This naturally led the universe to be "bigger than expected" when people began observing its expansion billions of years later.

Next point to consider is that there was in intervening dark age after the bang, when the energy density was so high
that the CMB (COSMIC MICROWAVE BACKGROUND RADIATION light-echo of that energy density), was all in the higher energy invisible spectrum.

By the time the first stars formed and the globular clusters coalesced and congregated to form the first galaxies, and "visibility" returned due to sufficient cooling, the universe was greately expanded indeed.

It is from that time onwards that all light based "transactions" ...to see and be seen, began!

This second factor is also to be considered.
But inflation should overwhelm the contribution from the second factor.

Jayen