The Largest Known Structure In The Universe

[AB Editor]

An international team of astronomers led by the University of Central Lancashire in the UK has discovered "the largest known structure in the universe." The team says that the recently observed large quasar group — comprised of dozens of highly energetic star-like objects — has a typical size of 500 Megaparsecs, but the size of the cluster is closer to 1200 Mpc at its widest point. To put that into perspective, the distance between our own Milky Way galaxy and Andromeda is about 0.75 Mpc.

The discovery has larger implications for the study of cosmology too. Albert Einstein’s Cosmological Principle states that the universe looks the same regardless of the observation point when viewed at a large enough scale. Einstein’s principle — combined with modern cosmological theories — suggests that astronomers shouldn’t be able to find structures larger than 370 Mpc. This particular large quasar group isn’t the only structure to question Einstein’s theory either: the team is also looking at "similar cases which add further weight to [the] challenge." The group of astronomers say that they will continue their research in the meantime.

Source: http://www.theverge.com/2013/1/15/3878252/astronomers-find-the-largest-structure-in-the-universe

No question, it's just pretty cool.

[beso]

Recent telescopes have been spectacularly successful. I am eagerly anticipating what we will be able to see with the square kilometre array.

[mibn2cweus]

Oh, for heaven's sake . . . zip it up Ed!

[jake-the-peg]

Ben Kersey is playing a little fast and loose with the cosmological principal when he says

//Albert Einstein’s Cosmological Principle states that the universe looks the same regardless of the observation point when viewed at a large enough scale.//

Wikipedia puts it well:

//The second implicit qualification is that "looks the same" does not mean physical structures necessarily, but the effects of physical laws in observable phenomena.//

http://en.wikipedia.org/wiki/Cosmological_principle

That is still good - similarities over large areas of the Universe are what first had Alan Guth proposing inflation and there may be implications for this.

I guess nearly 60 years after his death Einsteins name still has more appeal

Maybe we need to formulate Jake's law of scientific Journalism:

1 - Can we work Einstein in?
2 - If not can we work Stepehen Hawking in?
3 - If not use the term "Boffins"

[Frank97]

I'd have to agree with the first comment
[I] I don’t know enough to give a valid and constructive opinion, but based on what’s written…woah! That’s big!! [I]

[Bazile]

I guess it's a bit big then ?

So i can get a better appreciation of the size ( although i guess when you are talking about the vastness of the universe , it's very difficult to do just that ) -how many light years is it across , from one side to the other ?

[jake-the-peg]

a parsec is about 3 and a quarter light years so it's about 1.5 billion light years across

[jake-the-peg]

Incidently the reason Astronomers use Parsecs and not light years is that it relates to how Astronomical distances are mesured.

The closest stars appear to move over the year as Earth goes around its orbit - this is called paralax and its the same effect you get as holding your finger out and opening and closing each eye in turn.

If a star seems to move by 1 second of arc (1/3600 of a degree) it's deemed 1 parsec (paralax second) away.

If you know the Earth Sun distance you can then work that out in miles and hence light years but any error in that gives you a corresponding error in your light years figure.

More distant objects can be worked out by their brightness or their periodicity or other factors abourt them but it is all based back on that parallax yardstick and as the distances get bigger so do the possible errors.

That is why Astronomers tend to use the parsec or megaparsec especially over very large distances

[Bazile]

So let me get this straight - travelling at approx 186k miles / second - it would take 1.5 billion years to travel across it ?

Oh my word , that's big

[jake-the-peg]

yup

Our local group of galaxies is only a few million light years across

Hundreds of times larger than that

[wildwood]

Is a cluster regarded as a structure?

[pdq1]

Bit out of my depth but if the universe is only 13bn years old how is it possible to have structure of 1200 Mpc or approx 600 bn light years?

[chris1957au]

i guess thats why it was only a theory and not a fact, because it was unproven, so may be he wasn't correct after all.

[naomi24]

That's amazing! How exciting!

//if the universe is only 13bn years old how is it possible to have structure of 1200 Mpc or approx 600 bn light years? //

Because the universe is continously expanding at an enormous rate?

[mibn2cweus]

1200 Mpc = 3.91396013 Gly

http://goo.gl/x6x1o

[society]

This is a world without end...

[mibn2cweus]

By the way, ^ that's ^ pretty much the radius of the observable universe . . . innit?

[Old_Geezer]

And as the universe expands faster than light speed (not at any edge but everywhere) it stretches the stuff in it. Thus you get stuff wider that light can travel in the time it's had available.

[wildwood]

I can't walk that far with a crook knee!

[naomi24]

By the way, ^ that's ^ pretty much the radius of the observable universe . . . innit?

Got to wonder what is there among the unobservable.