A Universe From Nothing

[foodchain]

In terms of cosmology, "nothing" means no space, no time, no matter, no energy. IOW, the constituents of our universe.

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The NET energy of the universe = 0. That is, the positive energy of matter/energy = the "negative" energy of gravitation. At least, this was the case before the discovery of "dark energy" -- the accelerating expansion of the universe.

 

In quantum mechanics, energy can be "borrowed" from the vacuum and particles come into existence for a very short time. The energy is then "paid back" and the particles disappear. It has been thought for at least 17 years (I read it in Paul Davies' The Matter Myth published in 1992) that the entire universe could be a quantum fluctuation and that the 13.4 billion age was just a "very short time" in this particular quantum field.

 

The problem has always been that a vacuum is in an existing spacetime. We don't see "something from nothing" or have the mathematics to get "something from nothing" in the absence of a spacetime. So, how do you get a spacetime from nothing?

 

Right and such phenomena goes into quantum tunneling and pair production right, like Hawking radiation I think with black holes. Things I don't get though are issues like proton decay. I mean from a neutron you get a proton and electron, or you can at any rate, so why does that not count for "decay", unless decay is to be viewed as something else then something becoming something else. Yet that's a quantum event right, but pair production around a black hole is something that's supposed aid in detecting them, yet a BH involves both spacetime and quantum mechanics. Would gravity around a BH be considered a scalar or vector quantity, in that does increasing the strength of the field increase rates of pair production? Plus how do you have a quantized gravitational field if you cant yet produce the field quanta of it like gravitons.

[Sorcerer]

I'll keep my above post as an example of someone being totally confused and offtopic .

 

Quotes from his speech about the anthropic principle:

 

"The answer is… There had to be. If you have “nothing” in quantum mechanics, you’ll always get something. It’s that simple. It doesn’t convince any of those people, but it’s true."

 

The key phrase being "in quantum mechanics", it just redirects the question to, "why do we have quantum mechanics?" I guess if you want to, you can just say, "we just do", alternatively you could say, "because something allowed us to have it." This doesn't necessarily have any implication of a deity, it just needs a further definition of what "something" is.

 

"Why such a universe, in which we are so irrelevant, would be made for us, is beyond me."

 

I guess thats his problem then - he can't answer the question, so he overlooks it.

 

"So the universe, is the way it is, because astronomers are here to measure it."

 

Well, I understand he's trying to be funny, but the actual deduction from his previous statements would be arranged: Astronomers are here to measure the universe, because it is the way it is. Doesn't sound so "rediculous" or "religious" now. What hes trying to do, is argue against it using a backhanded, adhomonem attack, IE hes trying to call those people who think this, stupid.

 

Again,

"why can bees tell the colour of flowers? So they can find them."

NO.... again rearranged: Bees can find flowers because they can tell their colour, (among other things). I get his point, but then he goes onto say...

 

"Now as pretty as that is, I think its wrong, its ugly.... it goes against everything I, (stutter, probably going to say beleive), think, I know about science. Now, science has told us over the last 400 years, why the must be universe is the way it is, not why it has to be something different."

 

First of all, he contradicts himself. By saying its pretty, yet ugly. Second, what's scientific about ugly? Third, the final part of the quote ( means absolutely nothing, the anthropic principle explains clearly why the universe is the way it is, not why its something different. WTF??? (check my quote, perhaps he meant to say, or I heard wrong, "....but why it has to be something different.")

 

"That I find that (the anthopic principle) repugnant, although it may be true."

He should stick to science.

 

Listen to the final question. He nearly reaches the conclusion: Therefore in one of these rooms we were created. (But skips his track, before he falls into his own trap.)

 

From your original post:

 

The universe MUST be flat????

 

He states that the accuracy the the universe is flat, according to observation, is within 1% accuracy.

 

How can he know that the part of the infinite universe we are observing is all of the universe?

 

How can he know that all of the universe is the same as the part we are observing?

 

To me it sounds like he wants to beleive that, so that he can base his beleif arround 0, so that he can do easier math,,,,,, lol.

 

I want to repeat my thought. The universe always existed, because time is dependant on the existence of something. I think the big bang was just a part of the universes evolution, it can't just be assumed it was its beginning, and it can't be known. As far as we know only this "bubble" of the universe observes a big bang happening 14 billion years ago.

 

If he wants to assume 0 as a beginning because he has problems with infinity, then he has just as much beleif as a deist. IE it is the exactly the same kind of choice between beleiving :

 

Everything has a beggining and Everything always existed

 

As between beleiving :

 

God created(/is) Everything and Everything just exists.

Edited October 29, 2009 by Sorcerer

[foodchain]

-The anthropic principal has little more then rhetoric to back it up. In all reality you could say the anthropic principle is actually based on toilets, the universe plus us needed to exist in order for toilets to exist, any change to that like the anthropic principle itself is based on really the observers desires to mold a purely philosophical concept into hard scientific stuff.

 

-I am not against the concept, I am against the fact it really has no substance to it, its something you have to take truly on faith currently like intelligent design.

 

-This is one of the reasons I want sciences to be hybrid. If you study for instance the life sciences, in particular evolutionary theory you would be hard pressed to understand how this philosophical conjecture actually stands.

 

-Most the time I really think its just people wanting something, something sacred I guess to put them back into a comfort zone, which of course destroys any reason for doing science if all of it can be destroyed to serve such desires. If you read stuff by Hawking who sort of loved if not pioneered this concept you can find actually a great deal of ignorance on subjects that did not involve his direct field of inquiry, which I think helped support the anthropic principle. Plus in physics I think its easy to see you can have dynasties really, like string theory, and all the related stuff to that such as if the anthropic principal gains lots of steam you may have difficulty getting into grad school if you don't agree with it.

 

Just because an unknown variable exists does not mean you just assume what it is and take it as scientifically valid.

[Sorcerer]

I just think that if its possible and its not proven false, then its still possible. Assuming the universe had a begging and adds up to 0, is just 1 possibility. We cannot see the big bang, we do not know what happened with complete certainty. All we can say is that at the moment the universe is expanding, we can observe X numbers of years back and we cant see past radiation, we infer/extrapolate/assume from the expansion that at one point it was a singularity and at that point it began. This is not proven, only assumed.

 

Further more, hubble volumes prevent us from seeing outside another "bubble" and we cannot know what's happening at every point in our universe at the moment. Again its assumed that the universe is uniform. We dont know whats out there, so we cannot say with certainty.

 

What would it mean if a universe popped into existence in our own and we observed it?

Edited October 29, 2009 by Sorcerer

[aeontide]

I just think that if its possible and its not proven false, then its still possible. Assuming the universe had a begging and adds up to 0, is just 1 possibility. We cannot see the big bang, we do not know what happened with complete certainty. All we can say is that at the moment the universe is expanding, we can observe X numbers of years back and we cant see past radiation, we infer/extrapolate/assume from the expansion that at one point it was a singularity and at that point it began. This is not proven, only assumed.

 

Further more, hubble volumes prevent us from seeing outside another "bubble" and we cannot know what's happening at every point in our universe at the moment. Again its assumed that the universe is uniform. We dont know whats out there, so we cannot say with certainty.

 

What would it mean if a universe popped into existence in our own and we observed it?

 

It's not just assumed, it is predicted by the fact that at high enough energies, the fundamental forces begin to break down and unify in symmetry. The electromagnetic force and weak interaction unify at relatively low energy and so it's been verified. The strong interaction takes considerably more energy to unify with the electroweak force, however, through work in the field of quantum chromodynamics, it is all but certain that these fundamental force of quantum mechanics can be unified at high enough energy. To obtain this sort of energy, providing there is no external source to fuel our universe, the only conclusion is that the universe was considerably smaller--and a size can be calculated. It's also been predicted that the gravitational force can be unified into a supersymmetry with quantum mechanics, giving rise to terms like 'the theory of everything.' Whether you believe general relativity to be unifiable with QM or that GR is more fundamental than QM, one thing is certain, the size of the universe in order to unify the strong, weak, and electromagnetic forces is knowable and we've done our best to estimate it based on our conclusions of the energies they will unify at.

 

So, it goes beyond the realm of an 'assumption,' although, true it is still highly uncertain a singularity is in fact the initial state of a universe to-be.

 

However, if indeed a universe were to suddenly pop into existence and underwent cosmic inflation--we'd never see it. The expansion would be faster than light and the bubble would in some way consume us all-- assuming we were inside the radius of the inflation caused expansion.

 

Hi, I was having a disscussion about this recently, I just began thinking about it again, and read up about vacuum energy on wiki http://en.wikipedia.org/wiki/Vacuum_energy.

 

I didnt watch the video and havent read all the posts in this thread, I was actually going to post a new one, but decided I'd jump in here instead of doubling up.

 

So to my questions:

 

I found it interesting it says in the original, gravity can have negative energy, does this mean attractive gravity, or is it talking about dark energy?

 

What is stopping universes from spontaneously appearing inside our universe then, would these appear as black holes?

 

What is stopping matter from continuously coming into existence (and staying that way) and negative energy increasing simultaneously? Are these truely balanced? (under assumption by negative energy gravity it means dark energy) Gravity has an inverse square rule (atleast simplified newtonian), does dark energy have the same rule?

 

IF dark energy isn't bound by the inverse square rule, AND matter in constantly coming into being along with dark energy, would this account for the apparent acceleration of the expansion of the universe?

 

Just fyi, I prefer the thought the universe always existed, since this also removes the need for a deity and since time is dependant on the existence of something.

 

__

sorry, I read it now, gravity is negative energy, still this doesn't explain what dark energy is.....

 

perhaps like particle/anti particle, also anti-gravity/gravity?? And particle/gravity, anti gravity/anti particle?

 

So dark energy increases as anti particles come into existence, annihilate with matter ---> more photons + more dark energy?

 

bah, just ignore me, somethings wrong here, somethings very wrong with the whole story - explain the imbalance in matter/anti matter, explain dark energy.

 

For an anti paricle to be truely anti, shouldn't it have negative mass?

 

The best answer I can give as to why no universes will spontaneously appear within our universe is linked to the cosmic censorship hypothesis, whereby, if indeed the universe began as a singularity, it is of a unique character--unifying all fundamental forces into a supersymmetry, then, no singularity that is to manifest within the universe created from this initial state can reattain this state of supersymmetry and thereby, no universes can arise within another. To do so would destroy the parent universe--plus the singularity would have to literally pull the entire universe into itself which is not terribly likely--especially since there are a large number of these entities populating the universe and we are still here. The possibility is still there though, I would assume, but unlikely.

 

As for matter or matter-like material, it does come into existence always, popping in and out of existence [virtual particles]. They 'borrow' the energy to manifest, cause some effect, and blip back out of existence. What prevents matter from being created and existing on a more long term scale is due to energetics and some quantum mechanics. You have to have free quarks, or other fundamental particles in order to be able to create new interactions between them that lead to particles like a proton and neutron. To free up quarks takes a considerable amount of energy... and to make new quarks requires even more energy--energy levels you won't often find in the universe, if at all--except during the Big Bang.

Edited October 29, 2009 by aeontide

[Sorcerer]

So, it goes beyond the realm of an 'assumption,' although, true it is still highly uncertain a singularity is in fact the initial state of a universe to-be.

 

That's right, and therefore the theory cannot answer the question, did the universe have a beginning, because it can only answer down to the initial moments after a point. To assume just before this is the beginning of EVERYTHING, because if you have nothing in quantum mechanics you have something. Doesn't follow, this is no more science than any other guess.

 

In an attempt to fill in the cause of existence, it only begs the question, why do the laws that allow that exist.

[lucaspa]

What would our view of the universe be if we had people viewing the universe from all over the place, as far away from earth as you can get, would something that simple change our current views. How do we empirically know?

 

We can look at the universe from our view and build a good 3D picture of the universe. All the empirical data we have by observation says the universe is homogenous on large scales.

 

Another thing is energy levels. Now I know in particle accelerators more juice is supposed to produce different interactions or even new physics. How can anyone really estimate what the universe would look like if it the size of a pea?

 

For this one you need to probe the physics literature. Summaries of that literature indicate that we have a very good idea of the history of the universe from 10^-38 seconds to the present.

 

So would it be a somewhat safe speculation that maybe some other form of matter could occur if we are dealing with so much mass, like the universe in total, would that be just a black hole, and why would it just be a BH and not something else, is that an effect of spacetime, or QM, or etc?

 

When matter gets very dense, it gets very hot. So hot that matter cannot exist. It is all energy. That's why you can have "infinite" density. Remember, in the case of calling the universe a "black hole", we are inside it, not looking from the outside like we do with black holes formed from stellar collapses.

 

I just don't see this as an end all by any means. I also do not think we can currently state how much and of what makes up the current universe in order to perform such a calculation. Last time I checked dark stuff was still a mystery meat,

 

It is a mystery as to the identity of dark matter, but we know the quantity of it based upon the gravitational effect on matter that we can see (stars). "Dark matter" just means that it does not shine by its own light. Therefore we cannot see it at the distances we are looking -- other galaxies. But it's existence is inferred because of the effect on the motion of stars in those galaxies.

 

Foodchain, a good place for you to start getting some answers to the questions is at the "Ask an Astronomer" website: http://www.astronomycafe.net/qadir/acosmexp.html

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I just think that if its possible and its not proven false, then its still possible.

 

Correct. Unless a hypothesis is falsified, it is possible.

 

We cannot see the big bang, we do not know what happened with complete certainty. All we can say is that at the moment the universe is expanding, we can observe X numbers of years back and we cant see past radiation, we infer/extrapolate/assume from the expansion that at one point it was a singularity and at that point it began. This is not proven, only assumed.

 

Not "assumed", but inferred. Trying to say "assumed" is a semantic way of trying to get rid of the evidence supporting the claim. Assumptions do not necessarily have evidence. There is considerable evidence to suppport the Big Bang theory. Enough that all rival theories have to have it look like the Big Bang from our perspective. The singularity comes from the definition of a singularity: a volume of space that is infinitely dense and of infinitely small volume. That is exactly what the Big Bang was.

 

Further more, hubble volumes prevent us from seeing outside another "bubble" and we cannot know what's happening at every point in our universe at the moment.

 

Here we have a real assumption: that there are "hubble volumes". Right now when we are talking about "our universe" we mean what we can observe. Bubble universe is one of many "metauniverse" theories.

 

Again its assumed that the universe is uniform. We dont know whats out there, so we cannot say with certainty.

 

That is a conclusion based upon observation. On large scales, the observation is that the universe is homogenous.

 

What would it mean if a universe popped into existence in our own and we observed it?

 

It would probably mean our universe gets destroyed! Remember, a universe is a spacetime, not just matter and energy. How can you have another spacetime pop into existence in our spacetime? Two spacetimes cannot coexist. One replaces the other.

[Syntho-sis]

I wish I'd got in on this discussion earlier, now I have to read and watch the video..

 

Could someone provide a synopsis, perhaps? I have a fairly good understanding of atomic physics...

[iNow]

From your original post:

 

The universe MUST be flat????

 

He states that the accuracy the the universe is flat, according to observation, is within 1% accuracy.

 

How can he know that the part of the infinite universe we are observing is all of the universe?

 

How can he know that all of the universe is the same as the part we are observing?

 

To me it sounds like he wants to beleive that, so that he can base his beleif arround 0, so that he can do easier math,,,,,, lol.

Sigh...

 

 

http://map.gsfc.nasa.gov/universe/uni_shape.html

The universe was known to be flat to within about 15% accuracy prior to the WMAP results. WMAP has confirmed this result with very high accuracy and precision. We now know that the universe is flat with only a 2% margin of error.

 

 

 

 

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Could someone provide a synopsis, perhaps?

Many people ask "why is there something instead of nothing?" Many people assert that "Nothing can come from nothing, therefore god did it."

 

The video explains why this is specious, and how our understanding of QM shows that something comes from nothing all of the time.

 

Much of the rest of the thread has been a debate about the semantics of the term "nothing," and people who are themselves believers trying to find ways to rationalize away the evidence which speaks against their beliefs.

Edited October 29, 2009 by iNow
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[Sorcerer]

^when observing the universe from this place in space time. remember we can only see into the past. The evidence shows the universe almost certainly WAS homogenous/flat.

[iNow]

It might behoove you to go study some of this before you continue raising such silly and uninformed objections.

 

http://www.nature.com/nature/journal/v319/n6056/abs/319751a0.html

[lucaspa]

I think you are making the common mistake of assuming spacetime to be some sort of tangible substance. It's not.

 

I'm afraid it is you making the common mistake that spacetime is not tangible. It is. See: http://www.sciencemag.org/cgi/content/summary/296/5572/1417 Science May 14, 2002

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[Many people ask "why is there something instead of nothing?" Many people assert that "Nothing can come from nothing, therefore god did it."

 

The video explains why this is specious, and how our understanding of QM shows that something comes from nothing all of the time.

 

Not exactly. Remember, virtual particles do come from "something": spacetime.

 

The reason the "Nothing can come from nothing, therefore god did it" is specious is because the First Law of Thermodynamics (matter and energy can neither be created nor destroyed) applies within the universe. It says nothing about getting a universe to begin with. Therefore you can't use the argument because it does not apply.

Edited October 29, 2009 by lucaspa
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[iNow]

I'm afraid it is you making the common mistake that spacetime is not tangible. It is. See: http://www.sciencemag.org/cgi/content/summary/296/5572/1417 Science May 14, 2002

Thanks for the link. I find it interesting that it actually reinforces my central point. It does not rebut it as you've implied.

 

From your own link:

 

Then, a mere 87 years ago, Albert Einstein introduced his Theory of General Relativity, which rolls the four dimensions together into the

concept

of a spacetime.

That's directly synonymous with what I was arguing.

 

 

Not exactly. Remember, virtual particles do come from "something": spacetime.

 

See argument above in post #21 which you have claimed to have rebutted, but didn't.

[Bob_for_short]

I need a salary from nothing. It's much less than the Universe.

[lucaspa]

Thanks for the link. I find it interesting that it actually reinforces my central point. It does not rebut it as you've implied.

 

You didn't go on to read the articles in the special edition, did you? No, you cherry-picked.

 

Here is the first paragraph of the first article:

"Traditionally, space was merely a threedimensional (3D) static stage where the cosmic drama played out over time. Einstein’s theory of general relativity (1) replaced this concept with 4D spacetime, a dynamic geometric

entity with a life of its own, capable of expanding, fluctuating, and even curving into black holes." Measuring Spacetime: From the Big Bang

to Black Holes

 

Now, iNow, would you like to tell us how you measure something that is not tangible?

 

I think you are making the common mistake of assuming spacetime to be some sort of tangible substance. It's not.

 

Einstein's equations allowed us to to describe mathematically that tangible substance that is spacetime.

 

From the second article:

 

"More than 80 years later, the strange fabric that makes up our universe is more important than ever. Scientists have been devising test after test in attempts to trip up Einstein’s description of the nature of space and time, and so far, all have confirmed the strange picture. The fabric of spacetime is

real, and scientists can see it ripple and twist." The Intelligent Noncosmologist’s Guide to Spacetime

 

Do you still want to claim that the series of articles supports your position that spacetime is intangible?

[iNow]

Yes, I read the whole link. My point remains. Let's move on. You're basically trolling now a third thread with your semantic quibbles.

 

 

Earman, John (1986), "Why Space is not a Substance (At Least Not to First Degree)," Pacific Philosophical Quarterly, 67: 225-244.

In this paper Modern Essentialism is used to solve a problem of individuation of spacetime points in General Relativity that has been raised by a New Leibnizian Argument against spacetime substantivalism, elaborated by Earman and Norton. An earlier essentialistic solution, proposed by Maudlin, is criticized as being against both the spirit of metrical essentialism and the fundamental principles of General Relativity.

 

 

Teller, Paul (1991), "Substances, Relations and Arguments About the Nature of Spacetime," The Philosophical Review, 100 (3): 363-97.

Edited October 29, 2009 by iNow

[lucaspa]

I think you are making the common mistake of assuming spacetime to be some sort of tangible substance. It's not. It's just a word we use to help aid our understanding... essentially a manifold which we can use in our calculations when we are mathematically modeling the universe, but it is not something which itself has any physical or temporal properties.

 

iNow, could a "mathematically modeling of the universe" cause photons to travel a different path? Remember Eddington's experiment with the path of light during the solar eclipse in 1919? The photons were on one path until they entered the spacetime around the sun and that curved them to a different path. Could "just a word" result in clocks keeping different time in high earth orbit from those on the ground? These data show that spacetime does indeed have physical and temporal properties. As just another example, the expansion of spacetime stretches the wavelength of light. That is a physical property.

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Yes, I read the whole link. My point remains. Let's move on. You're basically trolling now a third thread with your semantic quibbles.

 

See above. I am talking data, not semantics. What you are doing with the references is trying to use philosophy to argue against data. Not very scientific. Notice that both references are older than the one I provided. In science, data changes our ideas.

 

We are still faced with the problem that all the "something from nothing" that has been observed has occurred in an existing spacetime. Something that is real and exerts real physical and temporal effects. Can you get a spacetime from "nothing" (the absence of a spacetime)? So far, no one knows.

[iNow]

Could "just a word" result in clocks keeping different time in high earth orbit from those on the ground? These data show that spacetime does indeed have physical and temporal properties. As just another example, the expansion of spacetime stretches the wavelength of light. That is a physical property.

 

<...>

 

See above. I am talking data, not semantics. What you are doing with the references is trying to use philosophy to argue against data.

 

I really must be a masochist, as I shouldn't even both to respond to this... but, I am. There is no data which shows spacetime to be a tangible substance. All you have is philosophy and interpretation when you get down to that level of discussion, so you're wrong in asserting that I am somehow an unscientific moron for discussing the interpretation. Thanks, though.

 

 

It is a metric. It is a manifold. It is spacetime. It is not something we can touch and feel and see, but the way we model our universe with our mathematics. We can only measure the relationships of objects, the way they interact, and how those relationships change. In sum, spacetime is a shorthand we use to understand those relationships. It is not tangible like a piece of cheese or a bed linen or a pool of water, nor is it some sort of ether as you continue to suggest.

 

This thing with you has now become little more than a verbal/semantic dispute based on arbitrary (and personal) interpretations (an interpretation where your position is counter to the currently accepted definition used by most physicists and cosmologists). I will ask you yet again to please just accept that we disagree, that this is an interpretation issue and not a data issue, and move on back to the meat of the thread. I'm frankly rather tired of these continued derailments from you.

 

 

 

 

 

If two different authors use the word "red," "hard," or "disappointed," no one doubts that they mean approximately the same thing... But in the case of words such as 'place' or 'space', whose relationship with psychological experience is less direct, there exists a far-reaching uncertainty of interpretation.

 

The above was true when he wrote that, but not anymore. The debate was precisely like the one we're having here.. one of spacetime substantialism... but that debate has long since been quieted and the consensus supports my position while rebutting yours.

 

 

 

I advise you look into the Hole Argument and start a separate thread if you'd like to continue this discussion.

Until then, I ask you to please stop hijacking this thread with further semantic quibbles.

 

 

In 1915, Einstein realized that the hole argument makes an assumption about the nature of spacetime, it presumes that the gravitational field as a function of the coordinate labels is physically meaningful by itself. By dropping this assumption general covariance became compatible with determinism, but now the gravitational field is only physically meaningful to the extent that it alters the trajectories of material particles. While two fields that differ by a coordinate transformation look different mathematically, after the trajectories of all the particles are relabeled in the new coordinates, their interactions are manifestly unchanged. This was the first clear statement of the principle of gauge invariance in physical law.

 

Einstein believed that the hole argument implies that the only meaningful definition of location and time is through matter. A point in spacetime is meaningless in itself, because the label which one gives to such a point is undetermined. Spacetime points only acquire their physical significance because matter is moving through them. In his words:

"All our spacetime verifications invariably amount to a determination of spacetime coincidences. If, for example, events consisted merely in the motion of material points, then ultimately nothing would be observable but the meeting of two or more of these points." (Einstein, 1916, p.117)

He considered this the deepest insight of general relativity. When asked by reporters to summarize his theory, he said:

"People before me believed that if all the matter in the universe were removed, only space and time would exist. My theory proves that space and time would disappear along with matter."

Edited October 29, 2009 by iNow

[Airbrush]

"My theory proves that space and time would disappear along with matter."

~Einstein

 

So it is correct to say that space-time would not exist without matter.

[Sorcerer]

It might behoove you to go study some of this before you continue raising such silly and uninformed objections.

 

http://www.nature.com/nature/journal/v319/n6056/abs/319751a0.html

 

What's inflation then? (the conditions of space time changed from one state to another, ie it was expanding at a different speed, whos to say it won't happen again, whos to say, just because inflation, made space-time flat, something else won't, or hasn't already, started making it un-flat?)

 

I'm guessing your link is about Occam's razor, a useful tool, but by no means the be all and end all of truth. I'll go have a look.

 

______

Without reading the entire paper, this link doesn't change anything about my point.

Edited October 30, 2009 by Sorcerer

[moth]

airbrush

have you been reading the cern courier? i just ask because i also came accross that einstein qoute while looking for the source of the 'verse' in a mini-black hole idea stated in the video.

here's another ineresting article that seems to suggest a string theory origin for the idea,but i'm still looking.

http://cerncourier.com/cws/article/cern/31860

[Mr Skeptic]

It turns out, that in a flat universe the total energy of the universe is precisely zero...Because gravity can have negative energy. So, the negative energy of gravity balances out the positive energy of matter.[/indent]

 

Hm, how does that work out? Usually when we deal with potentials, we have them be zero at infinity, and negative closer than that. But, that is completely arbitrary as far as I know, and just done out of convenience. Since we just take the energy differences anyways, it doesn't matter. But then, how can they figure out a total energy for gravity?

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I think you are making the common mistake of assuming spacetime to be some sort of tangible substance. It's not. It's just a word we use to help aid our understanding... essentially a manifold which we can use in our calculations when we are mathematically modeling the universe, but it is not something which itself has any physical or temporal properties. For that reason, I find the argument you've just put forth to be lacking. In order for your assertion to hold, spacetime would have to be something tangible, and it's not.

 

Well, I think spacetime has some physical properties. It has electric permittivity and magnetic permeability, for example. It has a volume, which will have an effect on matter or waves contained within it. As far as I know, it also has some form of energy in the form of virtual particles. In general relativity, it has curvature. All these have real, measureable effects.

 

What exactly spacetime is I cannot say.

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It is a mystery as to the identity of dark matter, but we know the quantity of it based upon the gravitational effect on matter that we can see (stars). "Dark matter" just means that it does not shine by its own light. Therefore we cannot see it at the distances we are looking -- other galaxies. But it's existence is inferred because of the effect on the motion of stars in those galaxies.

 

No, dark matter is more restrictive than that. It does not interact electromagnetically. So it cannot absorb nor emit light, nor can you poke it with your finger (your finger would go through it).

[Sorcerer]

Lawrence Krauss argues that everything can come from nothing, so it must have done so at one point, he argues this primarily because of his dislike of deist ideas. In order for this theory to remove the possibilty of a deity, it must show that it was the beginning of Everything. Because if ours is not the first, or only universe, then there are still many possibilities. The existence of a deity can be among these.

 

If universe can come into existence from space and space is flat, then we are infintesimally likely to be the first.

 

The universe can come into existence from space.

 

The universe is flat.

 

In a flat universe there is an infinite ammount of space/time. (even if its volume only approaches infinity as time approaches infinity, because you can sum up all of space/time up to that point to be infinite.)

 

Because there is infinite space, there are an infinite number of chances for a universe to come into existence.

 

Therefore this universes chance of being the only one is infintessimal.

 

Therefore there can be an infinite ammount of universes.

 

(skipping a few hidden premises)

 

Therefore this universes chance of being the first one is infintessimal.

_____

 

Really all Krauss can say if his theory is correct, is that a universe can come into existence from a space which contains the conditions for it to do so, this is NOT the same as coming into existence from nothing.

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If the universes initial condition was a singularity, then it always existed.

 

If we could observe past the MWBGR we would be observing back towards an infinitely streched space/time that never reaches a beginning.

Edited October 30, 2009 by Sorcerer
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[iNow]

I'm guessing your link is about Occam's razor

 

You should consider reviewing peoples links before posting a response. It will make your comments much less annoying those of us who are paying attention. It had zero to do with Occam's razor.

 

 

airbrush

have you been reading the cern courier? i just ask because i also came accross that einstein qoute while looking for the source of the 'verse' in a mini-black hole idea stated in the video.

 

IINM, he was referencing my post, where I quoted Einstein in context of the Hole Argument.

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Hm, how does that work out? Usually when we deal with potentials, we have them be zero at infinity, and negative closer than that. But, that is completely arbitrary as far as I know, and just done out of convenience.

You might want to look into how the total energy of the universe is calculated. That's a pretty broad field, and in it, gravity can be considered to have negative energy. I won't pretend to know enough about it (yet) to be able to explain it to you.

 

 

 

Well, I think spacetime has some physical properties. It has electric permittivity and magnetic permeability, for example.

No, you're making the same mistake lucaspa did. It is simply the manifold... it is just how we describe the relationship of "stuff" in our math. It is not, itself, a tangible thing. See my post above if clarification is required.

 

 

It has a volume

No, it has nothing. It is a concept, not a material or an ether.

 

 

As far as I know, it also has some form of energy in the form of virtual particles.

Again, stop thinking of spacetime as a "thing." Without mass, and without the relationships of massive objects, spacetime does not exist.

 

In general relativity, it has curvature. All these have real, measureable effects.

The effects are real. I don't argue that. That spacetime is tangible is directly rebutted by the physics and cosmology communities, as well as the man who put forward the notion of spacetime... Einstein himself.

Edited October 30, 2009 by iNow
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[moth]

IINM, he was referencing my post, where I quoted Einstein in context of the Hole Argument.

you're correct i was reading your link before i was looking at cern