Australian Study Backs Major Assumption of Cosmology
cylonlover writes "In mankind's attempts to gain some understanding of this marvelous place in which we live, we have slowly come to accept some principles to help guide our search. One such principle is that the Universe, on a large enough scale, is homogeneous, meaning that one part looks pretty much like another. Recent studies by a group of Australian researchers have established that, on sizes greater than about 250 million light years (Mly), the Universe is indeed statistically homogeneous, thereby reinforcing this cosmological principle."
Once you've seen one suburban shopping mall, you've seen them all.
http://alternatives.rzero.com/
pots frits.
So the laws of physics still hold in Australia at least.
Give me Classic Slashdot or give me death!
So, does that mean there is atleast one Earthlike planet with life on it every 250 million light years? (and, shouldnt that be a unit of volume, not length?)
Well, except for San Bernardino.
Please do not read this sig. Thank you.
If anyone is trying to visualize that scale, it might be more convenient to consider that 250 million light years is simply 4.70279985 × 10^23 rods
there you are.
Aliens who visit us, dismember our cattle and probe us? No.
Extra-solar planets with intelligent life? Probably. Given the sheer size of the universe and the number of solar systems and planets there are quite likely some out there with intelligent life (within range of detection is a different matter). Given enough rolls of the dice you're bound to hit on any given combination more than once.
A good foundation will cover those blemishes and make the subsequent layers easier to apply.
From TFA:
"In mankind's attempts to gain some understanding of this marvelous place in which we live,..."
Hey Brian... the 1950s are deservedly over. Stick an "hu" at the beginning and you won't alienate half your readers.
(From one guy to another before you get in trouble over it.)
-- Insert witty one-liner here. --
Most comments seem to be vying for most funny, but if you do happen to care about visualizing the scale, the distance to our closest full-sized galactic neighbor, the Andromeda Galaxy is 2.5 Mly. That is 1% of the homogeneity scale cited by the article. So, they are saying that things seem smooth averaged over scales merely 100 times bigger than the distance to the nearest extra-galactic clump which is sized comparably to The Milky Way. That's actually pretty smooth, in context.
So, isn't there a concept that the Universe is closed, and we're just seeing older versions of the same stuff, but kinda repeated? (but hard to recognize because of the time lag involved)
Is this still considered a possibility, or have they figured out a way of ruling that out?
SO YOU'RE GOING TO DIE: The Comic for Dealing with Death
None. Although you might see people from time to time, they are most likely products of your imagination. Simple mathematics tells us that the population of the Universe must be zero. Why? Well given that the volume of the universe is infinite there must be an infinite number of worlds. But not all of them are populated; therefore only a finite number are. Any finite number divided by infinity is as close to zero as makes no odds, therefore we can round the average population of the Universe to zero, and so the total population must be zero.
...but is it pasteurized?
No, it just implies that you have to go 250MLY that way.
-- no sig today
Can this tell us something about the shape of space? The fabric of space could form a loop such as a sphere. Think of the arcade game Asteroids. I have wondered if the Hubble deep field images are something like a self portrait photo shot in a very large house of mirrors. The loop is so big, in fact, that we are seeing our own galaxy and all others repeated at intervals of time in the past. The minimum homogeneous volume would also place a lower limit on the size of the loop.
Obi-Wan: "I felt a great disturbance in the Force, as if millions of voices suddenly cried out in terror and were sudden
How far out around us have we really seen/studied? 250 Mly seems a large area.
Until the Billion light-year across VOID is explained, this article makes no sense! http://www.newscientist.com/article/dn12546-biggest-void-in-space-is-1-billion-light-years-across.html
the future holds NetBSD posts o_n a losing battle;
It's still an assumption. If the universe is infinite, then this observation says nothing about the non-observable universe. Any statements about the non-observable portions are purely assumptions.
I used to spend quite a lot of time worrying that I'd go 250 million light years north and it would be quite different. Now that I know this I'm much happier to go.
On y va, qui mal y pense!
Immediately moves to ban all Australians from reading about this subversive cosmology business....
who prays for Satan? Who in 18 centuries has had the humanity to pray for the 1 sinner that needed it most? ~Mark Twain