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An Older, Larger Universe
Josh Fink writes "Space.com has a very interesting article as part their weekly mystery Monday series about a new calculation that shows that the Universe is actually much older than than the 14.3 billion years old that was established in 2003. From the article, "...the universe is instead about 15.8 billion years old and about 180 billion light-years wide." The calculations were based off of a recalculation of the Hubble Constant which dictates how fast the universe is expanding, and they found it is actually 15% slower than previously thought. The findings will be printed in an upcoming edition of Astrophysical Journal."
1.5 billion year between friends? She's still under 18.0 billion, so be careful! :/
The Hubble Constant is based on the idea that the redshift of spectrum of light reveals how quickly it is moving away from you. Similar to the Doppler effect with sound.
I am not a physicist but I recall another article that speculated that light may not always have traveled at the same speed. If this is true and we are measuring light that is ~90 billion years old, doesn't this drastically effect the red light shift that is so dependent on the constant of the speed of light?
They didn't go into detail in the article except that it is a new recalculation using a pair of stars instead of a single star. I do not believe this alleviates the problem of possible change in constants regarding light and its redshift, however.
My work here is dung.
As long as it's still older than 6000 years I'm happy.
Argh.
How can it be 180 billion light years wide and just 15.8 billion years old? If the Big Bang theory AND Einsteins theory that nothing can go faster than light are both correct, the universe can only be 15.8 * 2 = 31.6 billion light years wide. I am a lowly nanotechnologist, and for them everything bigger than a mm is HUGE, so the size of the universe is incomprehensible beyond imagination to me. Can anyone with more knowledge about the universe elaborate on this?
-- Cheers!
The expansion of space isn't governed by the speed of light.
Execute? [Y/N] _
> the universe is...about 180 billion light-years wide...and 15% slower
Yeah well, I'm a little wider and a bit slower each year too.
The prolific mathematician Paul Erdos, towards the end of his life, used to say that he was about four billion years old. He explained: when he was a boy, the known of the age of the universe was about five billion years, but by the time he was older, the age of the universe was had grown to nine billion. Tack on another billion and change for all of us...
What happens when you hit the border? Is there a passport checkpoint?
It is probably biometrics now but who cares when there is so much to do in this universe. Infact, anyone who wants to leave this universe is clearly unpatriotic anyway.
AP 08/07/2006, Jordan - In related news, a new scroll has been uncovered in the Dead Sea that categorically insists that God most definitely did *NOT* rest on the seventh day, and perhaps worked on the Creation at least half-way through the next week. The Universe is now believed to be 9 1/2 days old; a full 3 days older than originally thought.
-dZ.
Carol vs. Ghost
This whole article is misleading. The new research has very little to do with our knowledge of the size and age of the universe.
(And, yes, I am an astronomer).
Stanek and company have used measurements of one eclipsing binary system to determine the distance to M33. This is a good way to measure distances, as it avoids the perils of even a short "ladder" of methods. They find a distance modulus of 24.92 +/- 0.12 mag to the binary. You can read their paper on astro-ph at
http://xxx.lanl.gov/abs/astro-ph?papernum=0606279
Go to Table 7 of their paper, in which they compare their distance to previous measurements. There are 12 previous values, measured by several techniques (only 2 of the papers use Cepheids). The range of those previous values is 24.32 +/- 0.45 to 24.86 +0.07/-0.11. Their new distance is inconsistent, at the 1-sigma level, with 6 of the 12 others; thus, it is consistent with 6 of the 12 others.
Yes, it's true that the HST Key Project distance to M33, computed using Cepheids, is smaller than the new distance by an amount well outside the quoted uncertainties. But that's not a big deal, by itself. M33 is only one of a number of galaxies which serves to calibrate secondary distance indicators, which may in turn be used to find the Hubble constant. A small change in the distance to M33, even if true, would not make any major change to H-nought.
Recall that M33 is close enough to us that its radial velocity is NOT caused by the expansion of the universe, but instead by the gravitational forces of the galaxies in the Local Group. The press release's statement
is absolute nonsense. One cannot USE the Hubble constant and radial velocity of M33 to calculate its distance. The radial velocity of M33 is -179 km/sec, so "using" the Hubble costant to determine its distance would yield a negative distance. Phht.
This is a very nice, and very very worthwhile scientific project -- I have followed the DIRECT team's efforts for years, and encourage them to keep going! -- but the press release tries too hard to make it into some sort of breakthrough with profound immediate results.
Sigh.
Michael Richmond "This is the heart that broke my finger."
mwrsps@rit.edu http://stupendous.rit.edu
It depends on the shape of the universe... If you think of an Omega constant less or equal than 1, it's either flat or convex, in wich case the frontier diverges... if, on the other hand, it's more than one, you could have your spheric universe. Another missconception, AFAIK, is withe the "outside of it". The universe, by definition, is existence itself, in the form of time-space. There can't be an outside because there is no existence there, not even the absence of matter... Yeap, this is the place when phisics turn philosophers...
I don't want to get flamed by saying people are asking dumb questions, but everyone just needs to stop relying on simple arithmetic when dealing with the size of space... The concepts involved are far more complicated than that.
One thing people don't seem to be grasping is that with the Big Bang model, the size of the universe isn't measured by the distance between two particles floating on the "edge". It is actually a measure of the width of the "fabric" of the known universe, space-time. Its difficult to grasp this since it is not something easily perceived.
The real reason for the size of the universe being so much larger is that the laws governing the size of space-time are not the same as the laws of spacial relativaty, and therefore are not constrained to the upper bound of the speed of light.
The best analogy that I've heard is the ant on the balloon example. The idea is that you picture an ant sitting on a balloon with a bread crumb an inch away. If you were to blow up the balloon to twice its size, the bread crumb wouldn't necessarily move to a distance of two inches from the ant.
In this example, we are the ants and we are watching the galaxies, represented by the bread crumb, moving away from us. However, the fabric of existence is expanding at a much larger rate.
The "what's beyond the edge" question is essentially a pointless question when dealing with space-time. There is no "edge" because nothing can possibly exist outside of the realm of spacetime.
And if that concept doesn't satisfy the question, then a simple-minded answer would be that an "edge" can never be reached as space-time is always expanding faster than any particle could possibly hope to keep up with it.
--
"A man is asked if he is wise or not. He replies that he is otherwise" ~Mao Zedong
Capitalism: When it uses the carrot, it's called democracy. When it uses the stick, it's called fascism.
Exactly. It's creating it as it goes... Mindboggling, isn't it? Now that's it but just on theory... other theories that I'm not so familiar with (and at an absolute amateurish level) speculate about expansion over some other spatial coordinates that the 3D we know of. Imagine acid over a polystirene cone, eating it at a symetric rate (or perhaps not so much)... Our universe would be just this surface expanding, and it expands its borders over another spatial dimention unthinkable to the flat universe dudes (us).
Nothing can travel faster then the speed of light, universal expansion isn't the same thing as light speed.
The universe is expanding away from us in all directions. Well, it's expanding at every point.
So it is possible for a photon of light which started it's life at the opposite end of the universe when the universe was much smaller then it is now, to have not yet reached us, and indeed for it to never reach us, because of the universes expansion. No matter how far it travels, we will always be out of reach, and accelerating. Note I am ignoring the concept of the big crunch here, as it's an unproven concept.
However we are not travelling faster then the speed of light, even though we stay out of reach, what's happening is that the universe in which the speed of light is a constant is itself increasing in size. Thus the distance this imaginary photon must cover to reach us keeps getting larger.
Some time read, "The Day The Universe Changed," by James Burke. http://www.amazon.com/gp/product/0316117048/002-07 01003-8544823?v=glance&n=283155 or http://en.wikipedia.org/wiki/The_Day_the_Universe_ Changed
Just because Einstein turned Newtonian physics on its ear doesn't make Newton any less of a genius. Whenever Einstein is superceded, it won't make him less of a genious, either. It just means that someone else has stood on his shoulders, like he stood on Newton's, and has seen even further.
Newton and Einstein both "changed the Universe" because they changed how we view it and how we relate to it. Or the example Burke uses is Galileo, and how he shifted the center of the Universe from the Earth to the Sun. (I know you could argue that it was really Copernicus, and that neither was really correct.)
The living have better things to do than to continue hating the dead.
Space is stretching out between the matter. There are galaxies receding faster than light, but you'll never be able to observe them in any sort of experiment, or measure their speed, so there is no problem. The only reason we know they exist is from inferring their existence, and it's a different kind of existence, one that can never be proven by direct observation and measurement. It's like the singularity of a black hole- you can infer it's in there, but you can't observe anything inside the event horizon in an experiment anyway, so it doesn't upset theory.
When a galaxy is receding almost at the speed of light it will appear with a large redshift. Occasionally astronomers find a galaxy that sets a redshift record, and they get all excited. If the faster-than-light galaxies appeared redshifted, they would cover the sky! The astronomers wouldn't be getting so excited. But those galaxies don't appear at all- they're outside the observable universe. The distance to them is so great that more than 300,000 km of brand new space is being shoehorned in between us and them every second. So we won't even see them redshifted because the photons never even reach us.
The huge-redshift galaxies exist just inside a thin shell around us, about 15 billion light years in radius, that defines the observable universe. The observable universe and the universe sound like the same thing but are not. Most of the universe is outside the observable part- outside the shell. If a galaxy is outside the shell, we'll never see it. If a galaxy is just inside the shell they eventually find it and it might set a new z record depending on its redshift (i.e. how close it is to the inside of the shell). In theory if they found a galaxy that straddled the shell itself it would be redshifted from microwaves down through radio all the way to infinite wavelengths. In reality you'll never see that- the furthest thing you see is the cosmic microwave background, which is still coming from 400000 light years inside the shell. Even closer to the shell, you can "see" the early universe just along the inner surface, and the early universe was more opaque- light coming from there would have to have been emitted shortly after the Big Bang, when scattering was much more efficient, so that light doesn't make it here. FYI IANAA.