Slashdot Mirror
Universe 250+ Times Bigger Than What Is Observable
eldavojohn writes "The universe is only fourteen billion years old so we are unable to observe anything more than fourteen billion light years away. This makes it a bit difficult for us to measure how large the universe actually is. A number of methodologies have been devised to estimate the size of the universe including the universe's curvature, baryonic acoustic oscillations and the luminosity of distant type 1A supernovas. Now a team has combined all known methods into Bayesian model averaging to constrain the universe's size and their research is saying with confidence that the universe is at least 250 times larger than the observable universe."
I mean, what's at the outer edge? A wall?
If the universe started with a big bang, with all matter originated in an extremely compact volume, and if it's radius can't expand faster than light, then there should be no points in the universe beyond what we can see (as limited by light speed.) What am I missing?
If I can be modded down for being a troll, can I be modded up for being an orc, or a balrog?
It is, but oddly enough that does not bind the expansion. Space can be expanding faster than c and I believe the inflationary theory says just that.
The world's burning. Moped Jesus spotted on I50. Details at 11.
250 * (14.5 billion)*4/3*pi lightyears is as good as infinite as far as I'm concerned. hell, even (1Million)*4/3*pi Ly is big enough for me.
Yes, I'm left. You have a problem with that?
I recall reading a Scientific American article that indicated that the Universe had infinite size and mass, meaning that probabilistically, the exact construction and configuration of our observable universe would repeat itself (infinity tends to have nasty implications like that). Or to put it another way, another you is reading this somewhere (actually, an infinite number of you's, to be precise).
But crazy conjecture aside, does this talk of the 'full size' of the universe mean that the article even had its starting premise wrong?
(640k)*4/3*pi ought to be big enough for anyone.
From what I gather, we're stuck somewhere in the middle-ish of the universe. What if were were located near the "edge" of the expanding universe, and the "edge" was within our observable light cone. What would we see? Nothing? or is the "edge" of the universe expanding faster than the speed of light, therefore one could never see the "edge"?
Space can be expanding faster than c and I believe the inflationary theory says just that.
Damn fed printing money, now see what they've done.
But then 250 * (14.5 billion)*4/3*pi light years is also as far from infinite as zero is.
I am a free slashdotter. I will not be modded, blogged, DRM'd, patented, podcasted or RFID'd. My life is my own.
Since those areas are beyond the reach of our light cone, they almost certainly are not much better than nonexistent.
Of course still such estimates should help with cosmological models, science in general, or understanding our negligibly minuscule (heck, not even a speck of random noise...) place in the Universe (yeah, like that will happen soon...)
One that hath name thou can not otter
Didn't bill gates say 640K * (14.5 billions) * 4/3 * pi should be enough space for everybody, no matter what the activity, how much civilization expands ;)
or something like that :)
Never antropomorphize computers, they do not like that
1. You assign probabilities to the various hypotheses according to how well they agree with observed data, and form a weighted average.
2. The theories aren't inelegant. They agree quite well with observed data, down to the detailed angular power spectrum of the cosmic background radiation. There are just a few uncertain parameters that need to be nailed down.
3. The universe will probably expand forever and suffer a "heat death". Or, if not forever, it will expand for a very long time and effectively suffer one before collapsing again.
Some physicist is very welcome to fill in here, but I'm not sure it's correct to say that the universe "expands faster" than the speed of light. Locally, the expansion is slow, and objects aren't really "moving away" from each other -- rather more space is added in between them.
Think of it like blowing up a balloon with ants walking around on the surface. The distance between ants could increase faster than they can move, but none of the ants are moving relative to the space they occupy.
As a side note: One theory of the ultimate fate of the universe is that the expansion rate will increase past the point where the observable universe becomes smaller than atoms and other particles (a higher expansion rate means objects must be closer to each other for light travelling between them to overcome the expansion of the distance between them), essentially ripping all matter apart.
We *ARE* at the "epicenter".
Consider a balloon with polka dots on it. When it inflates, each dot expands away from the others. We are a polkadot on the three-dimensional surface of space-time, and every point in the universe is expanding away from us as space-time expands. If we were in M31, we would still see ourselves at the "center" of the expansion. If we were in that galaxy 14 Billion light years away, we'd still see ourselves at the "center".
General Relativity: Space-time tells matter where to go; Matter tells space-time what shape to be.
Beverly:
If there's nothing wrong with me...maybe there's something wrong with the universe!
Here's one you shouldn't be able to answer...
Computer, what is the nature of the universe?
Computer:
The universe is a spheroid region, 705 meters in diameter.
If telephones are outlawed, then only outlaws will have telephones.
Some physicist is very welcome to fill in here
Really?
Am I eval()? - http://www.monst3r.com.br
The submitter obviously did not read his own links. While the universe is only 14 billion years old, the _observable_ universe is > 90 billion light years across.
This is due to expansion, which stretched the wavelength of the light coming towards us, so redshifting those galaxies. It also makes those galaxies appear to be moving away from us at many multiples the speed of light, although they're not really moving at all, space is expanding.
An explanation
take offense to this comment. I/We/Gaia have beautifully curved boundaries that I/We/Gaia are proud of. In our assimilation of the galaxy, we will make sure to prioritize your solar system and eradicate this stupidity.
L'esperienza de questa dolce vita (The experience of this sweet life) - Dante Alighieri, The Divine Comedy
It is, but oddly enough that does not bind the expansion. Space can be expanding faster than c and I believe the inflationary theory says just that.
It did so for a VERY short while following the big bang: a period of superluminal expansion known as the Inflationary Epoch.
Physicists like to separate notable periods in time on a logarithmic scale, referring to each as the "Whatever" Epoch. As novel as the system itself is, what's most novel is how tiny of a portion of it our planet will be around for.
Recommended reading for the curious.
Boot Windows, Linux, and ESX over the network for free.
no
Yes, but c is a measure of absolute velocity, not relative velocity. You ants story is a bad analogy because their "maximum speed" is a relative velocity. It is however possible that the universe is expanding at a rate of 2 * c, as any two given objects could each be moving at c in opposite directions to another.
AccountKiller
For those of you who did not bother to read the whole article, there's a really important nugget that's lost in the 250+ times headline. The results show that the most likely curvature of the universe = 0. This means the universe, as near as our best minds can tell, is infinite. All the same dusting of galaxies in every direction, infinitely. Infinity is not a concept most people grasp easily. People ask things like "what's outside the universe?" but there is no outside, as "directionality" or "position" have no meaning outside the context of the universe. Likewise, there's no "before" the universe, as time has no meaning outside the context of the universe. My instinct says that we'll eventually come up with a nifty model of reality that includes a non-intuitive description of "position" that causes everything to make mathematical sense and has both quantum physics and relativity as predictable consequences.. but that is pure speculation. And it's a sure bet it'll be even harder to wrap our heads around than what we have now.
No. Firstly, it is at least twice that (we can see things 14 bullion years old in bot directions), and secondly space has expanded since the light set out, so it was, as it were, running up the down escalator and had to travel further to get to us. http://en.wikipedia.org/wiki/Observable_universe
Consciousness is an illusion caused by an excess of self consciousness.
But what I really want to know is...
How do fucking magnets work?
Yes, but didn't he also say that regardless of your frame of reference c is always c. (It's very likely I'm wrong, so don't flame please, educate instead)
"This calls for a very special blend of psychology and extreme violence" - Vyvyan "The Young Ones"
No, he was right, or at least closer. It's actually about 90 billion light years across (in diameter), 45 billion light years in radius, at least, measured in terms of comoving or proper distance (what you would think of as roughly the "actual" distance today).
14 billion is roughly the age of the universe, so obviously the light at the boundaries of the observable universe had to be emitted about 14 billion years ago. However, the universe was much smaller back then and has expanded a lot since. So the stuff that was a few billion light years away in the early times of the universe is now much farther away. Thus the counter-intuitive result that we are able to see things that are up to about 45 billion light-years away today (well, the oldest *thing*, i.e. galaxy, we've actually seen is around 30 billion light-years away presently, because there are limitations of present technology as well as issues related to the lack of transparency of the early universe).
Hopefully I got all that right. :)
But what I really want to know is...
How do fucking magnets work?
Like so! (alternative link.)
Beverly:
If there's nothing wrong with me...maybe there's something wrong with the universe!
Computer:
The universe is a spheroid region, 705 meters in diameter.
On no! I hope it doesn't crush 'er.
> You can't call a line infinite if you've found one end of it.
Of course you can. Consider a list of the natural numbers, for example.
Warning: this article may contain humor, sarcasm, parody, and perhaps even irony. Read at your own risk.
The cosmic background radiation we observe today has taken 13 Gigayears to get here. In all that time, the gas which emitted that radiation has not been running away from us at near lightspeed. Rather it has had random motion relative to it's neighborhood of around 0.001c., and the geometry of space has been expanding about 1000-fold since that time. That expansion of the geometry both stretches the wavelength of light from visible at 3000 Kelvin down to microwave at 3 Kelvin, and also adds to the volume of space both behind and ahead of a traveling photon. No part of space is stretching locally very fast, but the total stretching of space across the universe can exceed apparent lightspeed without violating relativity, because relativity operates locally, not globally across the universe.
Similarly, conservation of energy applies locally, but not to the universe as a whole. If dark energy is constant per volume of space (the theory of how it works), then the total energy of the universe increases as it grows. If that sounds weird, it is. Modern physics is just not intuitive to us humans that mostly deal with non-quantum, non-relativistic stuff on a daily basis.
The figure doesn't acutally show the priors (despite the labels). It shows the posteriors (inferred using the labeled priors). For example, the "Astronomer's Prior" gives uniform probability between -1 and 1. But the posterior implied by that prior, and the observed data, is highly peaked near zero, indicating that the data favor a flat universe.
The odd peak occurs because there are really separate models being considered. Some of them are flat-universe (zero Omega) models, and some aren't. If you give any weight to the flat-universe models, they'll get a "spike" in probability. There's a little bit of probability on either side of the spike, coming from the low Omegas implied by non-flat models with close-to-flat geometries.
The two panels in the figure who the posteriors you get assuming two different priors ("astronomer's" and "curvature scale").
The "250x times bigger" bound is their result for the curvature scale prior. Under the astronomer's prior, they get about 400x times bigger. They reported the first figure as a conservative lower bound (which contains the other bound).
Also from TNG, Episode 4x05 "Remember Me":
Beverly: What is the primary mission of the Starship Enterprise?
Computer: To explore the galaxy.
Beverly: Do I have the necessary skills to complete that mission alone?
Computer: Negative.
Beverly: Then why am I the only crew-member? (the computer takes a moment to process and makes a strange noise) Aha, got you there.
Computer: That information is not available.