http://www.dailygalaxy.com/my_weblog/201...-universe-.html

From the article:

Thanks for the link. I hope this subject is raised again and again in order to dilute the effect of dogmatic assertions that have been made over the past few decades. Fortunately, keeping an ear to the ground and an eye on YouTube, I find that "Time began at the Big Bang" is now a widely rejected credo.

Sean Carroll spoke on this at Beyond Belief 2007, during which he said:

"...the point is that all of our firm declarations that there wasn't anything before the Big Bang are based on a theory [General Relativity] that doesn't apply at the Big Bang"

http://www.youtube.com/watch?v=dc3za2iMiv8&feature=player_detailpage

I think it's important to distinguish between saying, on the one hand, "there was no time before the BB", and, on the other, saying "there was nothing before the BB".

Time was not only inherited from another universe or from any "before".Time also plays central/primary role in inheritance code of livining as well in non living, e.g. [in DNA/RNA].

Yes, is it, and the view of cosmologists has shifted from the former to the latter, in which the pre-Big Bang universe was a spacetime containing nothing, except for a vacuum energy - we might now be hard-pressed to find astrophysicists/cosmologists who don't think this more probable. In that case, the place we live in would be a sort of bubble in an infinite and eternal universe.

And since the vacuum energy is manifestly something, this brings us back to that strange definition of nothing, in which it is actually something.

Yes, using ambiguous words is best avoided if possible; and in the currently favoured scenario, it is. 'Nothing except x y and z' will do nicely.

Is it me, or is there a spot of ambiguity here?

Do you mean that it is OK to talk of nothing containing something, as long as you are clear about what the something is?

theres no such THING as time.

saying time is like saying distance.

can you pick up a mile , or an hour?

can you stuff a hour into a quart jar?

can you stuff a mile into a quart jar?

can you travel through something that has no physical properties?

can something that has no physical properties be inherited?

animals inherit knowledge.
is knowledge a physical thing?

could our knowledge / association with time be nothing but a memory passed down through the ages?

could time be a memory?

can you stuff a memory in a quart jar?

Bill, if the word 'nothing' still concerns you, we can equally well say "the universe was x y and z" omitting "and nothing else".

Only in classic physics is time like that ... in QM it has to be far more definite we were discussing this in another thread.

QM involves the concept of "borrowing energy" the point at which it began the borrow process to when it puts it back has to be well defined.

It comes about because of the Planck constant (http://en.wikipedia.org/wiki/Planck_constant) and that leads to planck time (http://en.wikipedia.org/wiki/Planck_time).

In QM world we would say whatever measure you use for time is a certain number of planck time units and it will be non fractional.

QM is very very certain about time there is no arbitrary involved.

I should add some background between QM time and GR time.

Einstein via GR/SR bought up the famous twin paradox. Where we have two twins one jumps in a spaceship flys away very fast then returns back to his twin who hasnt moved. Einstein deduced the twins should age differently (http://triangulum.nl/Werkgroepen/documentatie%20werkgroepen/Snaartheorie/twin%20essay.pdf)

The results were put to the test with precision clocks
(http://en.wikipedia.org/wiki/Hafele%E2%80%93Keating_experiment)

It has been repeated many times in different ways since. It is one of thge hallmark tests of relativity.


Now lets alter the experiment we don't have twins we entangle a person so we have the person and an entangled copy.


Now lets repeat the test with one of the entangled twins ... want to have a guess at the result :-)


answer : http://arxiv.org/PS_cache/arxiv/pdf/1102/1102.0016v2.pdf

You guessed it the "twins" don't age differently.

And I will leave the paper conclussion to explain what that means



You can look up the later paper if you like at this point :-)


The bottom line is the science says QM has hard defined proper time GR version of time is quite abstract.

Ok, do you have an explanation why both GR and QM are right, but you get different results? After all the GR tests have all come back positive, and in QM entangled state tests have come back positive. So both theories give correct but incompatible results. Just the theoretical idea that it would happen was one of the things that really disturbed Einstein about QM.

Bill Gill

Here comes Bill S with that infinity thing again...run away!!

I'm not proposing this as a well thought out idea at this stage, there's still a lot of thinking to do. However, I mention it as something that has been lurking in the nether regions of my mind for some time.

If the cosmos is infinite, and our Universe is just the product of our 4D perception, then all the measurements we can make will confirm the 4D nature of our environment, unless we can find some way to gain access to the “true” nature of things.

Measurements made in the realm of the infinite would produce results that would be counter-intuitive and would often seem impossible to our understanding. QM certainly does that.

Could it be that QM gives us a window into the infinite? If that were the case, it would explain why GR and QM can provide different answers to the same question, and both be right.

I gave you one answer from QM you didn't like it :-)

But more seriously yes thats where my thoughts are at the moment trying to think about this.

The funny part is I am sort of musing around the area Bill S talks about.

I will give you my current study interest. Conservation of energy in GR is it implied or not. I have seen a number of people say it isn't implied in GR so I am trying to work out the reality ... would have been nice if Einstein, Hawkings etc had said something definite.

I had always followed Bill S favourite the Freidmann equations and derived conservation of energy in GR infact I thought it was implict.

I ran across an argument between Phil Gibbs and Luboš Motl (http://blog.vixra.org/category/energy-conservation/). Luboš is not someone I can just ignore his mathematics and physics is first rate so time to drill into the argument.The older back argument (http://motls.blogspot.com/2010/08/why-and-how-energy-is-not-conserved-in.html), (http://blog.vixra.org/2010/08/08/energy-is-conserved-the-maths/)

It is a clash of the titans and egos .. few more beers and nights of crunching equations yet I fear.

I will get back to you with what I think ... hmmm might be a few days or weeks yet :-)

Orac, the maths leaves me standing, but the logic in between seems quite sound. I would appreciate having a little light thrown on the following quote:

"Spacetime curvature and gravitational energy on these large scales comes purely from the expansion component of space as a function of time."

Does it mean that the ernergy (whatever that might be) that is driving expansion is the source of gravitational energy, and that, in the context of GR, that can be considered as spacetime curvature?

Okay there are a number of views on this lets go to both extremes

Lets take the Lubus Motl, Sascha Vongehr view Energy is really nothing more than account keeping the universe has nothing to do with energy no more than dollars and cents are about the economy. This is a view popular with string theory people and some QM groups.

Layman sort of backgrounds:
http://www.science20.com/alpha_meme/energy_not_golden_holy_cow_urine-72881
http://www.science20.com/alpha_meme/dont_stop_presses_energy_conservation_law_questioned
http://www.science20.com/hammock_physicist/all_zilch_much_ado_about_nothing_0

In there mind the world is about Quantum information or information of strings the physical world is just something where the story plays out like the stockmarket. This is a big simplification and we obviously have a lot of variations to draw generalizations is hard.


On the other end we have Einstein, Penrose, Hawkings the men of the physical world.

To them the world of a playpen is not something they like the idea of energy is real and tangible it therefore should be conserved it is the holy grail. In this world something is driving the expansion and it is dubbed dark energy (http://en.wikipedia.org/wiki/Dark_energy). Don't get this confused with dark matter which is like our normal matter only we can't see it or interact with it.

Different theories have one or both of these two dark entities. Dark matter can explain gravity effects, Dark energy could do the same being like say atmospheric pressure here on earth. So some theories have dark matter, some dark energy and some both.

Somewhere between those two extremes lies the truth.

So to answer your question Bill S I would need to know which theory you want to talk about.

As I suspected, the opposing argument sounds just as convincing!!!

My first thought was that I would have to get someone to talk me through the maths. Then I thought "the people who understand the maths can't agree, so where does that leave us hitch-hikers? and was it produced by the holy cows?"

Well, having scanned lightly through your info I have decided to come down hard on the side of energy conservation, unless somebody else comes up with a good reason not to. There does that get me squarely on the fence?

I do generally go with the idea of energy conservation. I certainly don't know any place close to enough math to actually make an informed decision. Of course since there are several people out there that do know enough math and they can't agree I don't suppose I will have a deciding vote.
But my intuition says energy is conserved. There is that positive enough?

Bill Gill

Seems as though we are in much the same position, Bill, but I suspect you are more proficient in maths than I am.

How’s this for a shot in the dark? The cosmos is infinite, so its energy must be infinite. What we perceive as finite energy is just part of our restricted perception.

If the energy of the cosmos is infinite it can neither be increased, nor decreased, so the question as to whether or not it is conserved is relevant only in the context of our illusion of reality.

WOW! The infinite cosmos kills off another thread. Where's Saroy 123 when you need him/her?