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."
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.
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 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...
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...
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.