Age of Universe vs Furthest Object

[pointedstarman]

The Universe is approx 13.75bn years old (last time I looked!) and I keep reading about astomomers spotting another 'furthest object from the Earth' with a distance in the region of 13bn light years.

Now's when I get confused. Even if it travelled in the opposite direction from us after the big bang the relative speed between earth and the other object must be a significant proportion of the speed of light in order for the light to be 13bn years old before we first see it (I figure something more than (13.75/13.75+0.75) times the speed of light??). Problem is we're travelling nowhere near the speed of light so how does it work???

[pointedstarman]

ewenm said:

Look up "Inflation" in connection with the early universe. The idea is that there was a period of time when space-time expanded hugely (not things moving quickly in space-time but space-time itself expanding). So things are really far away but there has still been time for light to get back to us.

See. That just confuses me. It sounds like someone couldn't to the maths so made something up to fit. Einstein et al have a lot to answer for.

[pointedstarman]

I once read that a fool can ask more questions than a wise man can answer and something tells me that there's a lot of truth in that expression.

The analogies used in the video, or that of the stretching rubber sheets with the ever more isolated ants, suggests space time is either being constantly stretched and/or created. A cynic may think this was put forward as a solution to get around the problem of the universe expanding more rapidly than 'common sense' would allow.

I think my problem stems from what seems to be absolute certainty with which solutions to such problems are put forward. Only last month I read in The Sky at Night mag that some stars are substantially further away than previously thought, something that seems fairly fundamental in the scheme of things, and it does set me thinking about how much we really know and how much we just make up to fit what we see.

[pointedstarman]

carmonk said:

I wasn't referring to your post, rather the process that results in these kind of threads.

1) I saw something on TV
2) I didn't understand it
3) Therefore these so-called scientists are just making stuff up

Wrong actually. Have some education and an interest in astronomy. Regularly in the garden with my Celestron NGT looking at stuff and using my imagination - bit of a prerequisite otherwise you're largely looking at dots and smudges.

Never figured out the age v distance thing though have heard about effects of 'stretched' space time as I'm able to use the web. I just figure there's one or two PHers who may be able to make things a bit clearer.

A little ignorance or a lack of a Phd in physics (though the OH has a BSc in physics and doesn't understand it which makes me feel better) nevertheless allows one to exercise a little scepticism.

Edited by pointedstarman on Wednesday 14th March 18:24