Most distant galaxy found.....

[Stu]

Interesting.... Apparently 30 billion LY away, accounting for the expansion if the universe since it's light left it.

How big is the universe now then, including the bits we can't see???

http://www.bbc.co.uk/news/science-environment-24637890

Stu

[sharkmelley]

What a bizarre artist's impression! 

What on earth are all those spidery things? 

An artist's impression of diffraction spikes I guess!

Mark

[Naemeth]

30 Billion light years away, wow.

Stu, I would guess it's a bit more than 30 billion light years across, expanding at an ever increasing rate.

[Stu]

Yes, sure that's right. I've heard 47 billion mentioned somewhere but not sure if that's right.

Re the image, I'll confess I overlooked that somewhat, it's not real so didn't mean anything to me. It was the distance that I thought was amazing

Stu

[Naemeth]

Yes, sure that's right. I've heard 47 billion mentioned somewhere but not sure if that's right.

Re the image, I'll confess I overlooked that somewhat, it's not real so didn't mean anything to me. It was the distance that I thought was amazing

Stu

At this size and distance it only looks like a very small smudge, even with long exposures. You'd need a lot more resolution and focal length to get that close.

[Stargazer_00]

I dont understand 30 billion light years away.

If you assume that the speed of light is the physical speed limit for everything and then assume that our position is at one 'edge' of an exapansion bubble (which it isnt) and that another object is at the opposite side of the expansion bubble in relation to us and the central expansion point and that the universe is 13.798 billion years then surely the maximum distance between point A and B can only be 27.596 billion light years?  2.4 billion light years is a bit of a remainder to ignore isn't it?

[Stu]

I dont understand 30 billion light years away.

If you assume that the speed of light is the physical speed limit for everything and then assume that our position is at one 'edge' of an exapansion bubble (which it isnt) and that another object is at the opposite side of the expansion bubble in relation to us and the central expansion point and that the universe is 13.798 billion years then surely the maximum distance between point A and B can only be 27.596 billion light years? 2.4 billion light years is a bit of a remainder to ignore isn't it?

They mean the size that the universe is now, rather than the observable universe which as you say is around 13 billion light years. Since that light left the galaxy, it has carried on expanding away from us and their estimate is that it is now 30 billion LY away. Does that make sense?

Cheers

Stu

[ronin]

You need to consider both the movement of the object and the expansion of space/time between us and the object.

Over simplified:

You stand still.

I stand still, but I am on one of the moving walkway at an airport.

Neither of us is moving but the distance between us increases.

Now say I cannot run any faster the 10mph (doubtful to do that) if I am on the belt I will recede from you at say 15mph, a speed I actually cannot attain. As far as aware there is no limit of c that governs how fast space/time can expand.

So now 2 galaxies which are "physically" moving apart at close to the speed of light, owing to the space/time expansion the "apparent" speed of movement is greater the c.

Every galaxy (except the local group) is moving away, that is because even if they were actually moving towards us the expansion of space/time is much greater so they are moving away on the big expanding carpet of space/time.

c is the limit of anything moving in space/time but not the limit of the expansion rate of space/time.

What is often stated as the size of the universe is realyy to observable size of the universe, not necessarily the actual size.

[spurius]

Interesting.... Apparently 30 billion LY away, accounting for the expansion if the universe since it's light left it.

How big is the universe now then, including the bits we can't see???

http://www.bbc.co.uk/news/science-environment-24637890

Stu

Whos to say that this galaxy isnt moving towards us at a speed far less than the speed of light? It will obviously look redshifted due to the fact that its light is travelling at the speed of light for such a long time. It would appear further away because it formed further away and the light we see from it now is of when it was further away. Just supposing.

About this big bang thing. If the universe came from a single point which blew up, chances are we are no longer at the centre of the universe (the location of whereever everything was at the time of the big bang). So is it possible to see 13 or 14 billion light years in 1 direction but only 2 or 3 billion light years in the complete opposite direction depending on how close we are the the edge of the universe? I dont buy it.

[Stu]

Whos to say that this galaxy isnt moving towards us at a speed far less than the speed of light? It will obviously look redshifted due to the fact that its light is travelling at the speed of light for such a long time. It would appear further away because it formed further away and the light we see from it now is of when it was further away. Just supposing.

About this big bang thing. If the universe came from a single point which blew up, chances are we are no longer at the centre of the universe (the location of whereever everything was at the time of the big bang). So is it possible to see 13 or 14 billion light years in 1 direction but only 2 or 3 billion light years in the complete opposite direction depending on how close we are the the edge of the universe? I dont buy it.

Somebody far more knowledgeable than me will have to answer that one properly. My simplistic understanding is that you have to imagine a 3D equivalent of the surface of a balloon. When the balloon expands, the surface grows but you are never any closer or further from the edge because there isn't one!!

As said, someone else will explain better, but I think it's along those lines

Stu