Sidebar Sidebar
Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.

Universe is 13.7 billion years old

P

peter2002

macrumors 6502
Original poster
Aug 1, 2002
253
1
Dallas, TX
http://www.space.com/scienceastronomy/map_discovery_030211.html

http://www.space.com/php/multimedia...ed as an oval. Credit: NASA/WMAP Science Team

In a nutshell, the universe according to WMAP is 13.7 billion years old, plus or minus one percent. It is geometrically "flat," in accordance with the simplest solutions of Einstein's equations, which equate gravity with the bending of space time. By weight it is 4 percent atoms, 23 percent dark matter — presumably as-yet-undiscovered elementary particles left over from the Big Bang — and 73 percent "dark energy."
 
Yeah, nice. All subject to change until the next 'fact' comes out. If you follow the quote a little more you get: "and about 73 percent dark energy, a totally unknown and exotic force that causes the universe to accelerate at an ever-faster pace."

What I love about this is that almost 3/4 of the matter in the universe is in some unknown form, yet we can figure everything else out. I think that there is a long way to go before we really know what happened at the birth of our universe. And where is all that dark matter? My guess is hidden away in dimensions we just can't see right now cause we don't know where to look. Einstein's theories assume 11 or so dimensions - which is pretty mind blowing itself.

D
 
Originally posted by dukestreet
Yeah, nice. All subject to change until the next 'fact' comes out. If you follow the quote a little more you get: "and about 73 percent dark energy, a totally unknown and exotic force that causes the universe to accelerate at an ever-faster pace."

What I love about this is that almost 3/4 of the matter in the universe is in some unknown form, yet we can figure everything else out. I think that there is a long way to go before we really know what happened at the birth of our universe. And where is all that dark matter? My guess is hidden away in dimensions we just can't see right now cause we don't know where to look. Einstein's theories assume 11 or so dimensions - which is pretty mind blowing itself.

D
Click to expand...

I agree.

I mean basically the universe is alot of NOTHING.

eh, and now I feel lonely. :(
 
Originally posted by dukestreet
What I love about this is that almost 3/4 of the matter in the universe is in some unknown form, yet we can figure everything else out. I think that there is a long way to go before we really know what happened at the birth of our universe. And where is all that dark matter? My guess is hidden away in dimensions we just can't see right now cause we don't know where to look. Einstein's theories assume 11 or so dimensions - which is pretty mind blowing itself.

D
Click to expand...

Well, astronomical evidence for Dark Energy has only been around for a few years, and it is still in dispute since it relys on the use of a type Ia supernova as always producing the same amount of energy.

I read some recent writings about it possibly being related to the vacuum energy (i.e. a vacuum isn't empty) but measurements of the vacuum energy aren't precise enough to really be compared with the Dark Energy evidence. Still, if you're into this kind of stuff, it's an exciting time.

BTW, although relativity uses Riemannian geometry which is generalizable to higher dimensions, I thought relativity assumed 4-dimensions. If I'm not mistaken, I think you're thinking of string theory. Quantum field theorists operate in those higher dimensions (4 flat dimensions and the rest are curled up on themselves) to remove certain mathematical difficulties which show up.

crackpip
 
These aren't facts, they're just theories. If the theory is wrong (and it likely is, seeing as how 3/4ths of the universe is still unknown), then the math is wrong. Simple. (Personally, I love the name of the article "Findings pin bown age of universe")

However, thats not meaning that there isn't any chance at all that this isn't accurate. It agrees with the previous theories on the origins of the universe.

Pardon me for being stupid, but what exactly is dark energy?

And I guess that this means that the big bang theory is generally being postulated?
 
This is most interesting, I have a theory that blackholes are taking all this energy/matter and returning it to where it all originated. The Big Bang is still a mystery and this dark matter may be just stuff that leaked into our universe during the big bang but really isnt here at all due to it lying in another dimension.?
 
Originally posted by syco
These aren't facts, they're just theories... If the theory is wrong (and it likely is, seeing as how 3/4ths of the universe is still unknown), then the math is wrong. Simple. (Personally, I love the name of the article "Findings pin bown age of universe")
Click to expand...

careful comparing these two ideas: dark matter/energy with the age of the universe. I'm also wary of saying "If the theory is wrong then the math is wrong" - I'd propose to change that to "if the theory is wrong than the assumptions could be wrong" (and vice versa); math is math and (unless through human/computational error) is never wrong (I know that sounds cocky, but I say it nonetheless).

The age of the universe has been approximated for some time by studying the rate of expansion (a quantifiable number known to a high degree of accuracy) and background radiation. The numbers produced by these findings show that there must be more matter in the universe than we can see visibly, hence the theories of dark matter and energy were created. Dark Matter followed the approx. of the age of the universe (which is almost as reliable as the theories of relativity and quantum mechanics) so it is a breach of logic to say "if there is no dark matter than the theory [about the age of the universe] is wrong." it just means that the matter is somewhere else, unless it turns out that the rate of the universe is changing or other than what we have measured it hundreds of times to be, in which case we'd have reason to 'go back to the drawing board.'

I couldn't tell from reading these articles what "new" information has come to light. We've "known" when the birthday of the universe was for decades; Stephen Hawking goes into great detail about the implications of the CMB in his book.

and about black holes "taking in energy and returning it to where it all originated" - this is absolutely correct, but the matter is transformed into high-speed virtual gamme rays, which means that a black hole would give off an intense amount of energy in the x-ray - gamma spectrum of light. Stephen Hawking and Brain Green (The Elegant Universe) have more to say on this I think.

lastly, it goes with out saying that these are all theories; my grandpa used to say that the only emotions are fact, and I think that pretty much hits the mark.
 
I've also read that the speed of light has not remained a constant over life of the universe thus far. So that also throws a wrench into the equation because the speed of light is what is effectively used to determine the dates.

D
 
Good point Duke, I'm pretty sure I've read that the speed of light may be slowing down.

I was surprised by the 13.7 billion years (american billion) (and so precise, too! Not 13.8 or 13.6) because I thought I'd read it was more like 30. Next we'll be hearing that a scientist has determined that the big bang occurred in 1983.:rolleyes:
 
Originally posted by syco
These aren't facts, they're just theories. If the theory is wrong (and it likely is, seeing as how 3/4ths of the universe is still unknown), then the math is wrong. Simple. (Personally, I love the name of the article "Findings pin bown age of universe")

Pardon me for being stupid, but what exactly is dark energy?
Click to expand...

First off, remember that in the scientific process, theories don't get promoted to fact. They remain theories because by definition they cannot be proven. They can only be disproved, which leads to either a correction or an abandonment of the theory.


When Einstein formulated general relativity, he added in a constant (the cosmological constant) which represented a repulsive force. Einstein believed that the Universe was static and therefore needed a force to balance the mutual gravitation of all the matter in it. He later retracted his constant when learning of the work of Hubble.

When looking at the doppler data for very distant type Ia supernovae, scientists have recently found that over the course of time, the universe is accelerating in its expansion. If gravity was the only force acting on the Universe, then the expansion should be slowing down. There is another force that is repulsive, and they named it dark energy. The cosmological constant is now included in the general relativity field equations again.

crackpip
 
Originally posted by cubist
I was surprised by the 13.7 billion years (american billion) (and so precise, too! Not 13.8 or 13.6) because I thought I'd read it was more like 30. Next we'll be hearing that a scientist has determined that the big bang occurred in 1983.:rolleyes:
Click to expand...

I don't think I've ever heard the age of the Universe being 30 billion years, but there was a lot of uncertainty in initial calculations of the age of the universe because it relys on finding the distance to very far objects, which is notoriously difficult.

crackpip
 
I realize that in science nothing is ever true (always theories), but they shouldn't use words like "pinned down". It's only "true" until someone else proves it wrong...which is the definition of a theory. So, saying that _they_ got it just, in my mind, makes it that much less believeable.
 
13.7 billion years, 30 billion years...after a certain age it becomes unflattering and you keep it to yourself.

nevertheless, Happy Birthday !:D
(ok, I am going to put that crackpipe down)
 
regardless of how long the universe has been around, we still won't ever know for sure unless we figure out the time travel problem. Until then all of it is going to be theory.

I do know/understand/believe that the universe is really old, that's a given. ;)

D
 
Wasn't there some sort of supernova, which credited a couple of deep, underground scientists with the discovery of some other matter? I forget what it's called, it starts with "n", something like neolites, neurites, I know it's not neutrons.

I've heard the universe be as young as 9 billion years old, 12, 13, 15, 20 billion years old, etc. I'd say 30 is a bit of stretch.

I would also expect that there is some form of energy we haven't discovered as a concentrated source outside of our current electromagnetic spectrum. But how accurate are those numbers? The age of the universe to three significant digits? I would have just used one and say 1 x 10^10 years. :rolleyes:
 
You must log in or register to reply here.
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.
Top Bottom
Back