New Study Shows Universe Still Expanding On Schedule

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New Study Shows Universe Still Expanding On Schedule

Posted by timothy on Thursday October 4, 2012 @10:41AM from the every-time-you-jump-it-screws-things-up dept.

The Bad Astronomer writes "A century ago, astronomers (including Edwin Hubble) discovered the Universe was expanding. Using the same methods — but this time with observations from an orbiting infrared space telescope — a new study confirms this expansion, and nails the rate with higher precision than done before. If you're curious, the expansion rate found was 74.3 +/- 2.1 kilometers per second per megaparsec — almost precisely in line with previous measurements."

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Obligatory Spelling Comment by ixnaay · 2012-10-04 10:43 · Score: 5, Funny

Not to be pedantic, but that is an impressive way to misspell 'messureents'.
1. Re:Obligatory Spelling Comment by maroberts · 2012-10-04 10:47 · Score: 2
  
  Not to be pedantic, but that is an impressive way to misspell 'messureents'.
  The part of the universe covering that word hasn't fully expanded yet..
  
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2. Re:Obligatory Spelling Comment by Anonymous Coward · 2012-10-04 10:48 · Score: 3, Insightful
  
  that is an impressive way to misspell 'messureents'
  Wrong. 'messureents' is how you spell 'messureents'.
3. Re:Obligatory Spelling Comment by wonkey_monkey · 2012-10-04 11:23 · Score: 3, Insightful
  
  Not to be pedantic
  Sorry to be pedantic, but you are being pedantic.
  
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  systemd is Roko's Basilisk.
4. Re:Obligatory Spelling Comment by dudpixel · 2012-10-04 15:16 · Score: 2
  
  sory to be pedantic but it's "ditto".
  
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  This seemed like a reasonable sig at the time.
8 year old's question by RichardDeVries · 2012-10-04 10:43 · Score: 4, Insightful

It expands into what?

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1. Re:8 year old's question by hutsell · 2012-10-04 10:46 · Score: 3, Informative
  
  Hilbert Space
  
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  Yesterday's Weirdness is Tomorrow's Reason Why
2. Re:8 year old's question by UnknownSoldier · 2012-10-04 10:51 · Score: 3, Informative
  
  Nothingness. There is no space & time outside the physical universe. If that doesn't bake your noodle, I don't know what will.
  The nice thing about Religion^H^H^^H^H^ science is that it advances one funeral at a time. (With apologies to Max Planck :)
3. Re:8 year old's question by RichardDeVries · 2012-10-04 10:53 · Score: 4, Funny
  
  On behalf of all 8 year olds: thank you, that was very informative. As for myself: I'm supposed to have an IQ well above 130, but it would probably take me months to make sense of that page.
  
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4. Re:8 year old's question by MightyMartian · 2012-10-04 11:02 · Score: 3, Interesting
  
  The universe could be a compact manifold, in which case it isn't expanding into anything. That would fit with the essential notion that it is space itself that is expanding.
  
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5. Re:8 year old's question by kheldan · 2012-10-04 11:03 · Score: 5, Insightful
  
  Correction: There is no space and time that we can determine with any certainty outside our physical universe.
  
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6. Re:8 year old's question by multiben · 2012-10-04 11:10 · Score: 4, Funny
  
  Milk. The universe is surrounded by milk.
7. Re:8 year old's question by arth1 · 2012-10-04 11:40 · Score: 3, Insightful
  
  Correction: There is no space and time that we can determine with any certainty outside our physical universe.
  This is imprecise at best. There is no "outside our physical universe", because dimensions becomes meaningless at the border of the universe, so there is nowhere "outside" for other universes to be. If they exist, they don't exist "outside" our universe, at least not in a dimensional sense.
  As for time, that is a purely local phenomenon, and we can not determine it even inside our universe, except right here. Every "here" will have its own rate of time.
8. Re:8 year old's question by Anonymous Coward · 2012-10-04 11:40 · Score: 5, Informative
  
  Unless you have a generic curiosity, don't try to hard to read that, as it is not related to the universe's expansion. The grandparent was just being random or joking. A Hilbert space is just what you get when you treat the set of all continuous functions as a vector space. It has several different possible basis sets of functions you can add up to make any other function, e.g. sine waves via Fourier analysis. Instead of having unit vectors like x, y, and z, you would have unit vectors like sin(x), sin(2x), sin(3x), etc. (which makes it infinite dimensional). The concept is really important to physics, especially quantum mechanics and any where else things like Fourier analysis would be done with some mathematical rigor. But it is not what the universe is expanding into.
  The typical analogy used for what the universe is expanding into is like a balloon being inflated, with that being a 2D universe on the surface of the balloon. You could ask about the third dimension it is expanding into, but that is not really relevant (at the moment at least). The only thing that really matters is the curvature of local space (how non-flat any given spot on the balloon is). Short of discovering some new theories unlike what we've seen before or something like brane theory, the equivalent of the 3D dimension in the balloon analogy would be unreachable and meaningless, as it would not be able to affect things in anyway beyond the curvature of the surface.
9. Re:8 year old's question by MightyMartian · 2012-10-04 12:01 · Score: 3, Insightful
  
  The problem with what you're saying is the word "into". It still suggests that there is some medium into which the universe expands. It's another form of the famous Hawking problem "What's north of the north pole?" If there is nothing, then the universe is not expanding into it. It is simply expanding.
  As much as anything, it is a problem that while expressable mathematically, is, at least to most peoples' brains (mine included) something impossible to imagine. It is just another way in which our common every day perceptions of the world around us don't model every aspect of reality well.
  
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10. Re:8 year old's question by turbidostato · 2012-10-04 12:14 · Score: 4, Informative
  
  "There is no space & time outside the physical universe.
  Are you sure? How do you know?"
  He doesn't need to know: that's a per-definition fact.
  A different question would be if the physical universe is composed of four dimensions or there are more.
11. Re:8 year old's question by Sponge+Bath · 2012-10-04 12:32 · Score: 2
  
  I guess God must be a woman... with astronomical tits.
12. Re:8 year old's question by Nostromo21 · 2012-10-04 13:17 · Score: 3, Funny
  
  "In the beginning, God created the heavens and the earth. The earth was without form and void, and darkness was over the face of the deep. And the Spirit of God was hovering over the face of the waters."
  Flame away. <BFG>
13. Re:8 year old's question by __aaltlg1547 · 2012-10-04 14:08 · Score: 2
  
  Milk. The universe is surrounded by milk.
  Unlikely. Turtles don't have milk.
14. Re:8 year old's question by wonkey_monkey · 2012-10-04 21:17 · Score: 2
  
  But elephants do.
  
  --
  systemd is Roko's Basilisk.
15. Re:8 year old's question by arth1 · 2012-10-05 00:17 · Score: 2
  
  Until we can test our models experimentally (highly unlikely for this particular case), I'd say that "uncertain" is a very precise way to describe it.
  being an outside to be uncertain about.
  You can't go five feet past the edge of the universe, because there is no space to measure five feet in. There isn't a void outside the universe where other universes can be, because that presupposes that there is a void with spatial coordinates, while those are attributes that belong to our universe.
  Yes, we want to think of what's beyond, and our intuitive thinking doesn't deal well with models that doesn't represent space as we think of it.
  The background radiation of the universe is uniform in all directions, and is believed to be so everywhere in the universe. I.e. there is no "edge" that expands. Everywhere expands.
  If there isn't an "outside" anywhere or -when for a galaxy to be, degrees of uncertainty becomes a moot point. You could as well look at whether there are universes "inside" point particles like gluons and photons, or "before" time existed.
  Or inside god's navel, for that matter.
  If we are to determine other universes, it's going to be through mathematics, not physics, which are limited to this universe.
Gem Secretes as Superman by badford · 2012-10-04 10:50 · Score: 3, Funny

is an anagram of 'megaparsec messureents' thought you'd like to know.

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-badford
Re:Units by amRadioHed · 2012-10-04 11:04 · Score: 4, Informative

Due to expansion, the speed of objects accelerating away from us is proportional to the distance from us. So according to this, an object at 1 megaparsec from us will be receding at 74.3 km/s, while an object at twice the distance will be moving twice as fast.

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Not to be pedantic by ubergeek65536 · 2012-10-04 11:09 · Score: 2, Insightful

The visible part of the universe is expanding. We have no clue what's happening to the infinitely large part we can't see.
1. Re:Not to be pedantic by countach · 2012-10-04 11:18 · Score: 4, Insightful
  
  Well, to be pedantic, its a stretch to say "we have no clue". We can make some pretty damned good guesses.
2. Re:Not to be pedantic by Anonymous Coward · 2012-10-04 16:23 · Score: 2, Informative
  
  Doppler shift. Seriously.
  Light can experience doppler shift like sound can (well, really any wave can see a doppler shift). So if two objects are moving away from each other, light from one to the other will be red shifted. If two objects are moving closer together, the light will be blue shifted.
  Since chemicals have known spectral emission/absorption lines, you use that data compared with your observational data of distant objects to figure out the actual shift. Add in some math and you can even figure out how fast they are going. Hubble was one of the first to do the observations and noticed that *everything* outside the local group was red shifted. Andromeda and other members of the local group are gravitationally bound, including our galaxy, so you get other interesting values, including a blue-shifted Andromeda which gives us the idea that it will eventually collide with our galaxy as we more accurately measure that.
  But if the universe wasn't expanding, you'd expect that you wouldn't see such consistent and uniform redshifts in EVERY direction. And this concept has been backed up with data using a specific type of supernovae as a "standard candle" to figure out distances and confirm that the redshifts are telling us what we think they are telling us. Everything with bigger redshifts we've been able to also measure with a standard candle has been further away from things with smaller redshifts.
  The thing is, this red shift is also what allows us to measure the size of the observable universe, because this measured expansion is so uniform. And the constant used to describe this expansion is the Hubble constant. This particular bit of science isn't exactly new either. Hubble did the work almost a century ago now.
what's in a name? by X10 · 2012-10-04 11:10 · Score: 2

It's not called "expansion rate". It's called "the Hubble constant".

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Re:Ok. Now what is it in hogsheads per fortnight? by Nadaka · 2012-10-04 11:19 · Score: 2

hmm...
Partially right. but the universe expands in 3d, not just linearly.
What is the answer for hogsheads per fortnight per displacement of Archimedes in a bathtub.
Re:Units by sconeu · 2012-10-04 11:28 · Score: 4, Interesting

Interestingly, some back of the envelope calculations (using rough numbers ... 300000km/s for c, 75km/s/mpc for Hubble's Constant, and 3.25 ly/pc) gives a value of roughly 13 billion light years for the recession velocity to approach c. 13 billion years is also *ROUGHLY* the age of the visible universe.

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Re:Units by Relic+of+the+Future · 2012-10-04 11:30 · Score: 3, Interesting

In the vein of xkcd-what-if #11, I wonder about the physical meaning of kilometers per second per megaparsec. Kilometer and megaparsec are both lengths, so you can divide them out by the conversion factor (1 megaparsec = 3.08567758 × 10^19 kilometers) and then you are left with "per second", i.e., a frequency. A frequency of about 240 billion gigahertz. What, if anything, does that mean?

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Re:Units by sconeu · 2012-10-04 11:32 · Score: 3, Informative

No, a *parsec* is 3.26 light years. A Megaparsec is 3.26 MILLION light years.

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Re:Units by ImprovOmega · 2012-10-04 11:53 · Score: 4, Interesting

That can't be right. The universe is about 14,000 megaparsecs in radius, even if we were at the exact center that would have things traveling outward at 1.04E9 m/s or 3.46c. I'm reasonably certain they're not claiming FTL on this one so... Is it actually 74.3 m/s instead of 74.3 km/s? Or is there something else going on here?
Re:Units by j00r0m4nc3r · 2012-10-04 12:12 · Score: 4, Informative

Space itself can expand FTL, but anything inside that space is limited to c. This also means that at any given point in the universe, there is a boundary where you can never reach beyond, because the space itself is expanding away FTL, so you can never catch up to observe anything beyond that boundary...
Re:Units by Anonymous Coward · 2012-10-04 12:29 · Score: 3, Insightful

I think you got your final result messed up:
(74.3 km / s / mparsec) * (1 / 3x10^19 mparsec / km) = 74.3 ? / s * 3.3x10^-20 ~ 2.4 x 10^-18 cycles per second ~ 403768506056527590 seconds per cycle ~ 12.7 billion years per cycle.
It helps to actually include the units in your math as "unsolvable variables" that cancel each other out in your conversions. It's a fairly easy way to make sure the math comes out correct. Granted, this extremely rough number is kinda interesting because it is less than 10% off from the age of the universe. May mean absolutely nothing though.
Re:Units Space FTL, but information thru space? by shoor · 2012-10-04 12:42 · Score: 3, Interesting

Something I've been wondering about, but never knew quite where to ask. (Maybe this isn't the place either, but I'll give it a shot.)
i understand (or at least parse the semantic meaning) that the speed of light through space is fixed, and space can expand fasterthan that. Normally, it seems that the speed of information transmission is also tied to the speed of light, mainly I presume, because paradoxes would arise if it weren't. But can information travel across space at an effective speed uninfluenced by the expansion of space without causing paradoxes? Is it possible that information could still reach us even if light could not?

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The Universe has no center by seibai · 2012-10-04 13:05 · Score: 2

Just to clarify something that bothers me because so many people seem to believe it despite relativity expressly making it impossible: the universe has no center. Really, look it up. Similarly, the "big bang" does denote an explosion from a specific point.
1. Re:The Universe has no center by Anonymous Coward · 2012-10-04 17:29 · Score: 3, Insightful
  
  The center of the observable universe is exactly where I am at this moment. Beyond the observable universe, we have no idea, so we might as well assume that the center of the universe is the same as the observable universe. Me.
Re:Units by RegTooLate · 2012-10-04 14:07 · Score: 2

whatever my ship can make the Kessel Run in less than twelve parsecs.
Re:Units by thrich81 · 2012-10-04 14:38 · Score: 4, Informative

Space itself can expand such that the objects (events?) within it are moving apart at faster than c. Any two objects separating faster than c can't measure that -- they cannot pass any signal between them. Any light (or other signal) which leaves one will be redshifted away to nothing before it gets to the other. They are outside each other's observable universe. I'm pretty sure this has to handled using General Relativity, I don't think Special Relativity has any concept of expanding or contracting space-time. Space-time described by Special Relativity is flat and static.
Re:Nope. Edwin Hubble didn't believed in Big Bang by negablade · 2012-10-04 22:10 · Score: 2

That doesn't mean he was right. The prevailing opinion at the time was for a static, unchanging universe. And the discovery that it was expanding would have been difficult to reconcile with our understanding at the time. Prevailing opinions do change, albeit sometimes slowly, in the face of mounting evidence.
It's... by bunratty · 2012-10-05 01:49 · Score: 2

Monty Python's Flying Circus!

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