Slashdot Mirror
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."
Correct me if I'm wrong, but I think at the end of 180 billion light years you've just wrapped around to the other side, in a similar manner to travelling around the world. If there was a "border," whatever is outside that border is also part of the known universe.
Bill Clinton: Pimp we can believe in. - The Shirt!!!
Cosmologists have to be the weathermen of astronomy. Every five to ten years they come up with their definitive measurements of the (age,shape,nature, ending,begining pick one or more) universe. Once they have settled into an attractive basin they defend the viewpoint religously and then in five to ten years it happens all over again. If you catch a cosmologist between shifts they act as if the current viewpoint is the be all and end all.
Just like "What came before there was time". Without a frame of reference, words like "beyond" or "before" become meaningless. You might as well ask what lies "beyond" the point you see on a cartesian plane.
I never spellcheck and I freely admit it. Save your karma for more worthwhile "lol erorrs" replies
Stating that the age of the universe is 15.8 billion years old gives the impression that this is accurate to around 1 percent or better. The error bars on this sort of figure are probably closer to +/- 2 billion years or more, implying that the 99% percentile answer is something in the range 12 - 20 billion years.
No, the startling thing about recent cosmological work is that we do know this number to ~percent. The flagship for this new "precision cosmology" are the WMAP results. The number is weighing in at 13.7+/-0.2 billion years. Take a look at the tables of cosmological parameters in this paper and the carefully calculated error bars.
This particular press release's sweeping claims do overreach, as nicely summarized by Michael Richmond in a post above. M33 isn't at a cosmological distance, the observations being done by this project help to understand the lower rungs of the distance ladder, from which you can figure out distances to far-off galaxies and try to calculate numbers to independently compare to the microwave background fits. These results are one of many such distance calibrations, and have to be factored in statistically with the others. On the whole, several other means of figuring out cosmological parameters (such as the Age of the Universe) agree with the WMAP results within errors. You only get TFA's 15% increase if that is the only measurement you use to calibrate distances, throwing out all the rest.
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.
Chewing through that paper (interesting one by the way) shows that those error bars are based on analysis of the data after processing. Therefore, those error bars on the age of the universe are assuming that the removal of foreground sources and fluctuations due to the Sunyaev Zel'dovich effect have been done absolutely correctly. No attempt (that I can see) has been made to model the errors arising from that procedure. That alone suggests that there are systematic effects which are not accounted for in those results.
I'm extremely sceptical of a lot of error bars on a lot of data. Confusion is a huge topic in radio astronomy (and I don't mean the chaotic, running-around, headless-chicken type of confusion) and I see paper after paper that really doesn't understand it, deal with it or present any full explanation of how errors in confusion analysis would propagate into the answers.
Cheers,
Toby Haynes
Anything I post is strictly my own thoughts and doesn't necessarily have anything to do with the opinions of IBM.
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.