universe is 1 trillion years old

[gib65]

I read an interesting article that suggests the universe is actually 1 trillion years old... or older:

 

http://www.guardian.co.uk/science/story/0,,1768191,00.html

 

There's a paragraph near the middle that says:

 

"Today most cosmologists believe the universe will carry on expanding until all the stars burn out, leaving nothing but their cold dead remains. But there is an inherent problem with this picture. The Cosmological Constant - a mysterious force first postulated by Albert Einstein that appears to be driving the galaxies apart - is much too small to fit the theory. Einstein later renounced it as his 'biggest blunder'."

 

I can't say that I know much about this stuff, but it sound to me like they're refuting the law of entropy. Is this indeed what they're saying? Is the law of entropy refutable?

[Dr. Dalek]

I don't know much about physics myself.

From reading the article it sounds like they are saying that the Univers is a self-recycling mass.

If you were to reflect on the nature of more well understood phenomenon . . .

Stars born, stars die, matter recycled, more stars born. Tree sprouts, tree dies, matter recycled, more trees born.

It would only make sense in my opinion that these smaller systems would reflect the larger one.

[SkepticLance]

The universe is 14 billion years old, give or take a few million.

 

Trying to base anything on purported values for the 'cosmological constant' is a sure fire way of making serious errors.

[Dr. Dalek]

Pardon a simple Microbiology major for asking but why?

[Dark Photon]

interesting

[gib65]

The universe is 14 billion years old' date=' give or take a few million.

 

Trying to base anything on purported values for the 'cosmological constant' is a sure fire way of making serious errors.[/quote']

 

I don't know how credible the cosmological constant is (don't even know what it is), but the conclusion this article reaches makes a lot more sense to me. Time just seems to be something that should be eternal. If the Big Bang were just a huge explosion like any other explosion, there wouldn't be nearly as much mystery surrounding it as there would be if it counted as the beginning of all matter, energy, space and time and that there was nothing, not even space or time, before it.

[[Tycho?]]

I wouldn't be suprised if this was correct; ie that the universe is in fact a lot older than we think.

 

But I also wouldn't be suprised if everything in the article is wrong. As has been mentioned, the cosmological constant isn't exactly a good base for a theory, there is serious debate as to whether or not it even makes sense to have such a thing, and nobody has any idea what actually causes it.

[MattC]

The idea that the universe might have a beginning has aways seemed to me somehow problematic. But then, there are problems with the idea that the universe has simply always been, in some form.

Calculations of the age of the universe should, I suspect, be taken with a few kilos of salt. We don't even know if there is more put there than what we currently call the "universe" (which is basically the area that we can see, all of which is expanding from one point). For all scientists know, the "big bang" and the "universe" that came from it is merely one grain of sand in an endless beach. It may be more accurate to say that the known universe started expanding 14 billion years ago. Not that I know much at all about this field.

[SkepticLance]

MattC.

It is tricky trying to come to definitive conclusions about the origin of the universe, since there are enormous gaps in our knowledge. Some things appear sound. The date for the age of the universe at 14 billion years appears to be sound. It may be out by a few hundred million plus or minus. But it is basically correct. The universe is NOT a trillion years old.

 

Was there anything before the Big Bang??

Maybe. We now enter the realm of intense speculation. Scientific conjecture that maybe, just maybe, might be a littlemore reliable than fantasy. The brane hypothesis suggests that a four dimensional 'brane' (short for membrane) in a multi-dimensional multiverse, intersected with another. The energies involved led to the Big Bang. Our current universe is where the two branes intersect.

 

Of course, there are lots of other speculations. A lot of quite respectable physicists believe it is very possible that there may be an enormous number of universes, with basic laws of nature varying from one to another.

 

On the other hand, some people believe in the Easter Bunny.

 

When we start getting into these areas of speculation, it may be a fascinating mental exercise. But it ain't gonna give us any answers. At least not in the near future.

[MattC]

Don't get me wrong - I most certainly agree that the best estimate to date of the age of the known universe is ~14 billion years old. Actually, the most current figure is 13.7 with a 2% margin of error and it is based on studies of the ambient temperature of the universe. Analysis of the age of stars (by Hubble, I believe) yields a similar age, between 13 and 14. Bear in mind, I only agree that these estimates are the age of the known universe insofar as the age is based upon a scale with 0 being the point in time of the big bang. That was my point - not that the science behind these estimates is not robust.

[Dr. Dalek]

This reminds me of the beginning of the 20th century. Originally the Earth was thought to be several million years old, and now we know it is 4 billion or so.

[holly_2009]

ok .... one question if all of what you say is true then the big bang theroy is flawed if it stared the expansion of the univese where did the 2 intersectiong masses come from? what were they? and where were they because if this theroy is correct space did not exist and therefore the theroy could not possibly be complete because the masses would not have existed..... another thing if they (the masses) were from a previouse universe where did it come from??? this seems to be an ongoing dilema what happened to trigger such a giant chain reacton in the fist place....... those are just some of my thoughts while reading this....

[SkepticLance]

holly.

Your comments about two interesecting masses.

I guess this came from my posting about 'branes'. I do not, myself, know what branes are. I am not sure if anyone really does. The nearest thing is to describe them as 4 dimensional 'membranes' in multidimensional space. When two collide, they cause the Big Bang, and everything else originates from that.

 

The branes are not masses, though their collision leads to the 'creation' of mass.

 

Having said that, remember that all this is simply high powered speculation, currently unproven.

[Severian]

The article is not to be trusted. It doesn't really make wrong statements, but it puts emphasis in strange places and misrepresents ideas. For example, in the part you quoted the author uses the cosmological constant to make statements about the heat death of the universe, but these two things are not related at all.

[Prime-Evil]

So when is it's Birthday?

[GrandMasterK]

What would be the remaining elements of the universe once all the stars have burned out?

[[Tycho?]]

The article is not to be trusted. It doesn't really make wrong statements, but it puts emphasis in strange places and misrepresents ideas. For example, in the part you quoted the author uses the cosmological constant to make statements about the heat death of the universe, but these two things are not related at all.

 

I was wondering about that oddity actually, I just figured it was something I had yet to learn.

[silkworm]

Is this indeed what they're saying? Is the law of entropy refutable?

 

Don't worry, put your trust in entropy. Very few people unterstand it though, generally for 2 reasons 1) oversimplification of "disorder" by putting it in a dramatic context 2) misunderstanding of a closed system. "Heat death" is actually from the first law, even when everything is the same temperature there still is gravity.

 

I think that that universe is "forever" old and goes through cycles. It has evidently been 14 billion years since the Big Bang, as it effects us. Whether or not there was something before that, there may be no way to tell, but I'm also sure it certainly is a possibility. I've also always thought of the Big Bang as possibly just being a localized event or just the newest beginning of many.

 

Maybe I should have proposed this. I always talk about this and the edge of the universe with every astronomer I can stalk.

[SmallIsPower]

I don't understand why people think that there is no possibility that under certain conditions the Second Law can't possibly become irrevevant. Newton's laws were around for 200 years before Einstein. While Newton's laws hold in everyday situations, it can scarcely be said to hold at 99.999% of light speed.

[Ragib]

14 billion...I have read in multiple sites that its 13 billion give or take 0.1%. I know its sounds like a small difference, but its a billion years.

[Locrian]

I don't know how credible the cosmological constant is (don't even know what it is)

 

In the late 90's some astrophysicists (Reiss, anotherbignamei'veforgottenbutwilllookuplater, et al) did some work to determine how fast the universe was expanding. They were using supernovae to do distance/redshift measurements, and hoped to measure how much the expansion of the universe was decelerating. The first big paper was actually included the word "deceleration" in its title. For the past 60-70 years a deceleration was assumed because there was no known force to cause an accerleration, and there was a known force to cause a deceleration - gravity.

 

There was a problem with their paper though. If you read to the very end, they come up with a negative value for this deceleration. Over the course of the next couple of papers they published it became clear that the universe is accelerating its expansion. Many groups have repeated this study. There is little or no argument that it is valid.

 

Since there is an acceleration, there must be a force. This is typically called the "cosmological constant," thanks to our most famed and overrated scientist, Einstein. You may also see it called "quintessence." That this force exists there is little doubt. Of its exact value and whether this value is constant over time and space, there is much more doubt.

 

The fact that there is this potential energy threw a huge monkey wrench in quite a few theories, especially string theory*, but actually did a great deal to validate the inflationary big bang theory.

 

 

*I remember reading a paper at the time saying something like "you can get anything you want out of string theory except a small, positive cosmological constant"... but of course, that was five years ago, so its ancient history. Now people working in string theory will tell you that a small, positive cosmological constant is a natural outcropping from their... well, whatever you want to call what they've got.

[Locrian]

I don't understand why people think that there is no possibility that under certain conditions the Second Law can't possibly become irrevevant.

 

I can think of lots of cases where it's irrelevant. If you ignore time and consider a static system the second law is irrelevant. Given near infinite time the universe could become so devoid of potential that nothing will happen and the second law could become irrelevant.

 

What it can't be is wrong. To see why you actually have to consider philosophy as opposed to physics, and ask yourself what that law says.

[alt_f13]

If humans, the age of our sun and our exponentially growing advances in technology are anything to go by, I'd say a trillion years is a bit long to go without an almost all-powerful species that has its fingers in every corner of the universe, including Earth.

 

Then again, maybe the believers are right...

 

Either that, or the aliens adopted the Prime Directive.

[Martin]

I'll echo Tycho

']I wouldn't be suprised if this was correct; ie that the universe is in fact a lot older than we think.

 

But I also wouldn't be suprised if everything in the article is wrong. As has been mentioned' date=' the cosmological constant isn't exactly a good base for a theory, there is serious debate as to whether or not it even makes sense to have such a thing, and nobody has any idea what actually causes it.[/quote']

 

and partially also what Severian said in post #14

 

The article is not to be trusted. It doesn't really make wrong statements, but it puts emphasis in strange places and misrepresents ideas. For example, in the part you quoted the author uses the cosmological constant to make statements about the heat death of the universe, but these two things are not related at all.

 

I think maybe it even makes wrong statements, but if it doesnt then at least it shows confusion and poor judgement on the journalists part and makes unreliable or MISLEADING statements, as Severian rightly indicated.

 

The journalist is James Randerson. IMHO it might be well to avoid anything written by him in the future.

 

----------------------------

Anybody who wants to get the story direct can look at the original scientific article by Steinhardt and Turok that this journalist is hyping and embellishing or otherwise messing around with.

 

You may think the Steinhardt Turok scientific article is ALREADY pretty speculative , but at least it is the firsthand story. Just go here and click on PDF.

 

http://arxiv.org/abs/astro-ph/0605173

Why the cosmological constant is small and positive

Paul J. Steinhardt, Neil Turok

15 pages, 1 figure

 

"Within conventional big bang cosmology, it has proven to be very difficult to understand why today's cosmological constant is so small. In this paper, we show that a cyclic model of the universe can naturally incorporate a dynamical mechanism that automatically relaxes the value of the cosmological constant, taking account of contributions to the vacuum density at all energy scales. Because the relaxation time grows exponentially as the vacuum density decreases, nearly every volume of space spends an overwhelming majority of the time at the stage when the cosmological constant is small and positive, as observed today."

 

the two guys are respectable reputable scientists. One at Princeton and the other at Cambridge.

[Martin]

Locrian this is a really nice brief account of cosmological constant history. Loved it.

 

In the late 90's some astrophysicists (Reiss' date=' anotherbignamei'veforgottenbutwilllookuplater, et al) did some work to determine how fast the universe was expanding. They were using supernovae to do distance/redshift measurements, and hoped to measure how much the expansion of the universe was decelerating. The first big paper was actually included the word "deceleration" in its title. For the past 60-70 years a deceleration was assumed because there was no known force to cause an accerleration, and there was a known force to cause a deceleration - gravity.

 

There was a problem with their paper though. If you read to the very end, they come up with a negative value for this deceleration. Over the course of the next couple of papers they published it became clear that the universe is accelerating its expansion. Many groups have repeated this study. There is little or no argument that it is valid.

 

Since there is an acceleration, there must be a force. This is typically called the "cosmological constant," thanks to our most famed and overrated scientist, Einstein. You may also see it called "quintessence." That this force exists there is little doubt. Of its exact value and whether this value is constant over time and space, there is much more doubt.

 

The fact that there is this potential energy threw a huge monkey wrench in quite a few theories, especially string theory*, but actually did a great deal to validate the inflationary big bang theory.

 

 

*I remember reading a paper at the time saying something like "you can get anything you want out of string theory except a small, positive cosmological constant"... but of course, that was five years ago, so its ancient history. Now people working in string theory will tell you that a small, positive cosmological constant is a natural outcropping from their... well, whatever you want to call what they've got.[/quote']

 

I think Tegmark was in on it. Perlmutter. One of my old teachers Alex Filippenko a wonderful guy.

Maybe those i mentioned came in later groups and your Reiss was the first. I don't remember the names. Would be easy to find the articles though. Circa 1998.

 

I am fascinated that you think that even just on PHILOSOPHICAL GROUNDS one can see that the 2nd Law precludes a bounce.

 

Penrose makes this argument frequently and with conviction. I am willing to suppose that both you and Penrose are quickerwitted and betterinformed than I and I STILL cannot follow this.

 

the argument is that the collapse is a HIGH ENTROPY phase-----a black hole or a big crunch, some sort of gravitational collapse producing a bounce----and the bang is a super LOW ENTROPY circumstance because right at the start of a universe. So in between some where-----right at the rebound---it went from high to low WARNING **VIOLATION**WARNING!!!

 

But philosophically, IMHO, that does not hold water because defining entropy requires an observer and NO OBSERVER EXISTS at the rebound.

One can imagine an observer in the former spacetime who sees the collapse. One can imagine an observer in the subsequent expanding region who sees the first stars and galaxies forming. Both of them see nondecreasing entropy. But I cant picture an observer who goes through the fiery furnace of the bounce---through the "planck regime" of planck temperature, pressure, density where some QG says gravity becomes repulsive.

 

If no one ever SEES the second law violated and therefore it is not violated. Datt veroff von kann nott obszerff deroff mussst mann nicht kvatchen!!! Right? Or something nice and positivist like that.

 

Actually I think it takes an observer to have an idea of what is a microstate and what is a macrostate and what the average number of micros per macro is and take the log.

Or with a quantum definition of entropy there is a hilberspace, a micro statespace, and you take the LOG OF THE DIMENSION of the hilbertspace.

But to my way of thinking----which may be a philosophical bias---no tickee no shirtee: if there is no observer then THERE IS NO HILBERT SPACE. because the hilberts space represents the past experience of available to the observer and what he has learned and what is his STATE OF KNOWLEDGE AND UNCERTAINTY. The hilbert space is not something in Nature, but an honorable mental construct representing one things information about another thing.

if there is is no observer (at a point around the rebound say when things are at planck density and so forth) then there is no hilbertspace and no ratio of dimensions and no logarithm and therefore no entropy is defined.

 

how about that Locrian? you sound like someone who might have an interesting response to that.