Origin of universe

[jobyts]

[Please move this question to appropriate form, if it does not fit here]

Many of my theist friends ask me, "if science tells you matter can neither be created or destroyed, how did the universe originate from nothing". I'm unable to answer them clearly . Can someone explain this in currently accepted scientific (not philosophical) theories? If it is too complex, please point me some urls.

Thanks,

 

[mgb_phys]

The glib answer is that there was no universe around to notice any laws being broken!
A slightly less glib answer is that if the universe was created at a singularity (an infinitely small point) and time was created at the same time (as it were) then the laws of physics didn't apply.

Another way of looking at it is, physics doesn't say that mass cannot be created or destroyed - it says that mass+energy cannot be created ... but they can be converted into each other (e=mc2).
So if the total energy of the universe (in the form of mass of all the stars etc) is balanced by the negative gravitational energy of the expansion - then the total energy of the universe is zero and no laws have been broken.

http://www.astrosociety.org/pubs/mercury/31_02/nothing.html

 

[DavidSnider]

Nobody knows. That is in the realm of philosophy still.

Let's just say that a God is necessary to create something out of nothing. That says nothing about the validity of angels\demons, the trinity, sin\salvation, his 'plan' and all sorts of other weird theistic concepts.

 

[Dale]

Also, a singularity is not "nothing". It is a lot of stuff all at the same point. So the big-bang is most definitely not creatio ex nihilo.

 

[Chalnoth]

There are three possible ways I know of approaching this issue:

1. We don't actually know that the universe had a start, so it's a bit premature to assume there was one. Regions like our own might well have been born from some other region, and that one from some other, and on back ad infinitum.
2. We actually do know of things that come from "nothing", as it were: quantum vacuum fluctuations. What this means is that if it is possible for a particular type of matter to exist in a region of space-time, then it will necessarily pop in and out of the vacuum in that region. Perhaps it is similarly possible for space-times to just pop in and out of nothing in the exact same way?
3. In a very real way, our universe is still nothing: its total energy is identically zero. This is clear if we look at the Hamiltonian formalism, which considers not only the energy stored in matter, but also the energy stored in gravitational potential energy. It turns out that the energy stored in gravitational potential energy is negative, and exactly cancels that stored in matter.

Point 3 is a very important point to make, as points 1 and 2 only deal with a singular event that started it all off. But point 3 shows that the whole "matter cannot be created or destroyed" idea is total bunk. Of course matter can be created and destroyed! The matter we see all around us was created when inflation ended. The energy that produced that matter was created as inflation progressed. And all of it will go away when the universe dies a heat death and becomes nothing but empty space.

 

[marcus]

3. ... It turns out that the energy stored in gravitational potential energy is negative, and exactly cancels that stored in matter.
.

I'm curious, have you actually done the calculation? I know people used to say that, e.g. back in the 1980s.
Alan Guth famously conjectured that the universe might be 'the ultimate free lunch' because negative gravitational energy might conceivably exactly cancel positive (matter etc.) energy.
But I haven't seen anybody maintaining that lately, at a scholarly level.

I see that MGB just gave a 2002 source derived from a 2001 textbook. It was aimed at a general audience and was not a rigorous statement. I know one of the authors. I kind of doubt he would say the same thing now in 2009.

So at the moment I don't have a source. Maybe you can provide one. I'm hoping for some recent scholarly article that maintains total energy = 0 and gives some solid reasoning. Something on arxiv dated > 2005 maybe? A page reference to Steven Weinberg's 2008 Cosmology text?

Hopefully whatever calculation will not depend on inflation, because inflation has not been proven. I'm guessing you would agree that inflation scenarios are just that, scenarios---based on any number of assumptions about exotic inflaton fields. All that supports them is that they explain a few puzzles, for which there may be alternative explanations, so nothing clinches the deal. But even an argument that depends on some inflation scenario would be a help.

====================
BTW Chalnoth, I certainly agree with your point #1!
I think most cosmologists would be quite surprised if it turned out that the universe began around the time of the big bang. The mainstream research community seems to have moved away from that supposition. I don't know of any scientific reason to imagine that the universe had a beginning and I like your characterizing the idea as "premature".

I'm leery of your point #2 because I don't think a prior universe in which such a quantum fluctuation might happen could properly be characterized as "nothing". I don't know any professional cosmologist who currently says our universe came from nothing. A lot of prominent people are working on what the pre-big-bang state could have been---detail, mathematics---and I don't know of any who describe it as "nothing".
Just like someone who knows what they're talking is not apt to say "it came from a point of infinite density".

 

[hellfire]

I agree with marcus that the claim of a zero energy universe is not rigorous. Specially because we do not have a definition of gravitational energy in a FRW universe.

As far as I know, this idea is suggested by an argument similar to this one:

Assume that the zero energy balance between energy stored in a mass and its gravitational energy can be written as:

$$m c^2 - \Sigma G \frac{m \, m_i}{r_i} = 0$$

This means

$$\frac{G}{c^2} \Sigma \frac{m_i}{r_i} = 1$$

Considering $$M_U$$ and $$R_U$$ as mass and radius of a homogeneous universe, this can be written as

$$\frac{G}{c^2} \frac{M_U}{R_U} \approx 1$$

$$M_U \approx \frac{c^2}{G} R_U$$

On the other hand, we know that

$$M_U = \frac{4}{3} \pi R^3_U \rho_U$$

with a density equal to the critical density

$$\rho_U = \frac{3 H^2}{8 \pi G}$$

thus

$$M_U = R^3_U \frac{H^2}{2G}$$

equating both expressions for $$M_U$$

$$R^3_U \frac{H^2}{2G} \approx \frac{c^2}{G} R_U$$

$$R_U \approx \sqrt 2 \frac{c}{H}$$

The total null energy arises for a radius of order of the Hubble radius.

 

[granpa]

I don't know what all that means but I do know that most of the energy in a field is within a few radii of the object that creates it.

 

[Chalnoth]

I'm curious, have you actually done the calculation? I know people used to say that, e.g. back in the 1980s.
Alan Guth famously conjectured that the universe might be 'the ultimate free lunch' because negative gravitational energy might conceivably exactly cancel positive (matter etc.) energy.
But I haven't seen anybody maintaining that lately, at a scholarly level.

Not personally, no. But it's a well-known result. However, there is a caveat that I did not mention: the result only applies for a closed FRW universe:
http://www.springerlink.com/content/jg1350836415r215/

That aside, it's largely irrelevant, because it's only a heuristic tool anyway at this level of discussion. The fact of the matter is that gravity, when acting on the right kind of matter, will cause a very small region with a large energy density to become an incredibly large region with nearly the same energy density. And it doesn't matter what the overall curvature is for this fact to be true: as long as the right kind of matter is around, it works.

Bear in mind that energy just isn't a conserved quantity in the typical formalism of General Relativity. The conserved quantity is the stress-energy tensor, which, under a variety of conditions, forces energy to not be conserved.

Hopefully whatever calculation will not depend on inflation, because inflation has not been proven. I'm guessing you would agree that inflation scenarios are just that, scenarios---based on any number of assumptions about exotic inflaton fields. All that supports them is that they explain a few puzzles, for which there may be alternative explanations, so nothing clinches the deal. But even an argument that depends on some inflation scenario would be a help.

While I will agree that the specific scenarios of inflation that we have devised so far may well not be accurate, and in fact may well be highly unlikely to be accurate, the general idea of inflation is essentially guaranteed to be accurate.

Basically, there needs to be an accelerated expansion of space in the distant past for there to be any large-scale correlations on the CMB whatsoever. If there isn't such an accelerated expansion, then the fact that the CMB is nearly uniform is a fundamental impossibility, as different regions of the CMB will not have had enough time to ever be in contact with one another. So we can be quite certain of an accelerated expansion in the distant past. Secondly, when the COBE and later WMAP data was released, we got confirmation that the distribution of correlations indicates a nearly constant scaling rate for the fluctuations, which is the scaling rate for an accelerated expansion driven by something like a large vacuum energy, precisely as inflation predicts.

Therefore we can be confident at least in these general properties. We don't yet know the mechanism that caused it, but we're working on that.

I'm leery of your point #2 because I don't think a prior universe in which such a quantum fluctuation might happen could properly be characterized as "nothing". I don't know any professional cosmologist who currently says our universe came from nothing. A lot of prominent people are working on what the pre-big-bang state could have been---detail, mathematics---and I don't know of any who describe it as "nothing".
Just like someone who knows what they're talking is not apt to say "it came from a point of infinite density".

Well, the worry is that we just don't know how to describe "nothing" to begin with. Note that if it happened to be true that our universe came from "nothing", then it is trivially true that whatever this "nothing" is, it can contain, in a sense, a universe like our own. Given this fact, if we were ever learn how to describe this "nothing" properly, we might well discover that it demands that a universe be generated. But since we don't know how to describe "nothing", we can't say whether or not this is the case just yet.

 

[marcus]

Not personally, no. But it's a well-known result. However, there is a caveat that I did not mention: the result only applies for a closed FRW universe:
http://www.springerlink.com/content/jg1350836415r215/

That aside, it's largely irrelevant, because it's only a heuristic tool anyway at this level of discussion...
...
... forces energy to not be conserved.

Your reference is to a 1992 paper which is available for a price of $12.50.
==exerpt==
THE ENERGY OF A CLOSED UNIVERSE IN A REFERENCE FRAME
FORMED BY A SET OF FREELY MOVING CLOCKS
N. N. Gorobei and A. S. Luk'yanenko UDC 530.12:517.988.38
The Hamiltonian of a closed universe is found in a reference frame formed by a
set of freely moving clocks. In this physically defined gauge the energy of the
universe is positively defined.

In gravitational theory in the absence of a planar asymptote the Hamiltonian of a closed
universe reduces to a linear combination of couples of the first sort and vanishes on the surface of the couples. This serves as the basis for the assertion found in the literature that
the energy of a closed universe is equal to zero [1]...
==endquote==

This is the sort of thing that bothers me when people talk about the total energy being zero. In 1992 one typically did not consider a constant dark energy density. After 1998 we think of dark energy as over 70 percent. And the amount increases as the volume increases.

As you point out there is no Energy Conservation law for the universe.

It is far from certain that the total energy of our universe is even well-defined. If the spatial volume is infinite the energy might be infinite or simply not defined.

I fail to see how it could be considered as heuristic to study a spatial finite case with zero cosmological constant. It is too unreal. Too unrelated to the actual universe to serve as a reliable guide, I would think. But that is what these two 1992 authors seem to be doing with their closed FRW case.

Of course I can't be sure without seeing the article that they are assuming the cosmological constant is zero, but that was normal back then. It would help if you could find a paper that proves this result in the case of positive Lambda.

I remain unconvinced for the time being, but thanks for looking. It was interesting to see what you did come up with!

================================
You give a nice summary of the usual justifications for assuming one of the various inflation scenarios. You mention the horizon problem, you mention the scale-independence of the CMB power spectrum (which I think is one of the strongest supports), you didn't mention flatness though you might have. I agree that these are strong arguments, and one hears them recited over and over.

However there are other ways of addressing the horizon problem, for example. The various types of inflation are not the only answers to these puzzles. I believe I have the option to remain unconvinced at this point. It may be a matter of taste, and level of skepticism.

the general idea of inflation is essentially guaranteed to be accurate.

I don't believe that. I like the idea of inflation very much! I don't however consider it guaranteed to be accurate.

Basically, there needs to be an accelerated expansion of space in the distant past for there to be any large-scale correlations on the CMB whatsoever. If there isn't such an accelerated expansion, then the fact that the CMB is nearly uniform is a fundamental impossibility, as different regions of the CMB will not have had enough time to ever be in contact with one another.

No, that is not true. What you say is model dependent. In some models there would not have been enough time, in others there would have been enough time.

So we can be quite certain of an accelerated expansion in the distant past.

Not on that grounds. Inflation is not the only way of addressing the horizon problem---the near temperature-uniformity of the CMB. Therefore we cannot be certain inflation occurred merely because the CMB is nearly the same temperature all over.

Secondly... a nearly constant scaling rate for the fluctuations...

That is what I was referring to earlier when I mentioned the scale-independence of the CMB power spectrum! From my point of view that is pretty impressive. It is much stronger evidence for inflation than the horizon business--the temp uniformity. Temp uniformity too easy to explain by newer mainstream models.

Therefore we can be confident... We don't yet know the mechanism that caused [inflation], but we're working on that.

I'm not sure who "we" is. Are you personally working on "inflaton" mechanisms? Or any other exotic physics that might be responsible for the fine-tuned behavior, the graceful exit, the decay, the re-heating...? I haven't seen much research about possible inflation mechanisms lately. If you know of anything recent, say in the past 2 or 3 years, please let me know---hopefully available at arxiv online.

 

[Chalnoth]

This is the sort of thing that bothers me when people talk about the total energy being zero. In 1992 one typically did not consider a constant dark energy density. After 1998 we think of dark energy as over 70 percent. And the amount increases as the volume increases.

Perhaps, but it doesn't actually matter for the result. After all, if it works for an FRW universe with a radiation energy component, which has an energy density that scales as 1/a⁴, then I see no reason why it won't work for an energy component with arbitrary scaling. As near as I can tell, the paper makes no assumptions at all as to the contents of the universe, so it should work just fine with any form of matter/energy.

I fail to see how it could be considered as heuristic to study a spatial finite case with zero cosmological constant.

I consider it as being heuristic because it's not necessary to show. There's no reason to bother about the Hamiltonian formalism when things work just fine in the Lagrangian formalism. It's just kind of superficially appealing because we're used to energy being conserved.

 

[marcus]

As near as I can tell, the paper makes no assumptions at all as to the contents of the universe, so it should work just fine with any form of matter/energy.
...

So you think their argument would go through even with dark energy, a positive cosmological constant?
Did you pay the $12.50 and read the article?
I just looked at the first page they give as a sample.

Chalnoth, you mention that radiation energy density decreases as 1/a⁴. That is true, and matter energy density decreases as 1/a³.
But what does that have to do with dark energy density? Dark energy density does not decrease as space expands. It is constant. So it behaves quite differently. It scales as 1.

I don't see how a 1992 argument, in that rather unrealistic case, could carry over to contemporary (positive Lambda) cases. Maybe we will get some help on this from someone more knowledgeable than myself who can explain, or cite a more up-to-date paper available online.

 

[Chalnoth]

So you think their argument would go through even with dark energy, a positive cosmological constant?
Did you pay the $12.50 and read the article?
I just looked at the first page they give as a sample.

Haha, no, I grabbed it from the university. They'd actually charge me $34 for it here in Italy...

 

[marcus]

Haha, no, I grabbed it from the university. They'd actually charge me $34 for it here in Italy...

You are fortunate to be able to use the university connection. It is a scandal how much they charge for downloading just one paper. I am retired and it is more complicated for me---I have to go on campus and make a request with the librarian.

 

[Chalnoth]

You are fortunate to be able to use the university connection. It is a scandal how much they charge for downloading just one paper. I am retired and it is more complicated for me---I have to go on campus and make a request with the librarian.

Yeah, I know. This is why I absolutely love the new move to free resources such as arxiv.org. It helps the science because it gets new information out there faster, and there remains little problem with the signal-to-noise ratio, despite the lack of general oversight.

Journals do, however, still serve a purpose as they provide a measure of prestige and also provide much-needed independent verification.

 

[marcus]

...Journals do, however, still serve a purpose as they provide a measure of prestige and also provide much-needed independent verification.

It's a dilemma. Peer-review is essential. Maybe the PLoS model will work out. The question is how to share the cost of that independent verification you refer to.

I agree..that the claim of a zero energy universe is not rigorous. Specially because we do not have a definition of gravitational energy in a FRW universe.

As far as I know, this idea is suggested by an argument similar to this one:
...
...
...

Hellfire thanks! I didn't see your derivation at first. Your post kind of settles the question for me, at least for the time being.

 

[Chalnoth]

It's a dilemma. Peer-review is essential.

Well, the official peer review that goes into publishing is just the first step of peer review. It's only really effective in catching egregious errors. Quite a lot of crap still makes it through. Publication isn't really the end of peer review, it's just the beginning.

Maybe the PLoS model will work out. The question is how to share the cost of that independent verification you refer to.

We shall see. I definitely hope that all of science moves towards free distribution.

 

[marcus]

Let's consider the question that Jobyts asked in the original post.

Many of my theist friends ask me, "if science tells you matter can neither be created or destroyed, how did the universe originate from nothing". I'm unable to answer them clearly . Can someone explain this in currently accepted scientific (not philosophical) theories? If it is too complex, please point me some urls.
...

Jobyts, your friends ask you "how did the universe originate from nothing?"

Conventional standard cosmology does not suggest that the universe originated from nothing.
Cosmology is changing with the recent appearance of some new models that do not experience a "singularity" and work back further into the past. But to keep things simple, let's just talk about the classic cosmology model. The one that has been standard for many decades.

This classic conventional model does not say anything about the universe "originating". The model is admittedly incomplete. It's domain of applicability does not reach back to the beginning of expansion---it breaks down at "t=0" and stops computing meaningful numbers.

The domain of validity of the traditional model only goes back to within a few Planck time-units of the "t=0" mark. From there on it is either not reliable or does not function at all.

So as a scientist one cannot say that the traditional model tells us that the universe had an origin. There is no scientific evidence of an origin---so according to the model traditionally used in cosmology, we must admit ignorance. The universe might have always existed. It might have been doing something else before "t=0".
We just don't know.

You might find it helpful to read the page of information called A Tale of Two Big Bangs at the Einstein Online website
http://www.einstein-online.info/en/spotlights/cosmology/index.html
The term "big bang" is used in two very different senses, which causes newcomers a lot of confusion. E-O is clear and up-to-date--straightens several things out. It is the public outreach website of a major research institution in Germany. The language is English.

=========================
Now suppose your friends ask you "how did the universe originate from nothing?"
What can you say to them? If you tell them the truth---that science does not say that the universe originated from nothing, and it would make no sense for a scientist to try to explain what he has no reason to believe---would your friends be able to accept that as an answer?

The trouble is that the public has been lied to by popularizers who say things like "the Big Bang theory is that the universe began from a singularity, a point of infinite density!" This is hogwash. Or they say "Big Bang theory says that Time did not exist before the Big Bang." This is baloney. We do not know these things and cannot rationally assert them. Standard cosmology (also known as the Big Bang theory) does not make those claims. On the other hand, authors who wanted to sell popular books and magazine articles have said things like this so much that the general public tends to be programmed to expect something like this. Many half-informed people are certain of it!

So what can you say? I want to leave the question open. What response will work with your friends? Can you yourself suggest something? It would be great to get suggestions from others as well! Perhaps you could respond to your friends by asking them a question back, like "How do you know that the universe originated from nothing? For that matter why do you think that it originated at all?"

What there is no good reason to suppose does therefore not require an explanation.

 

[wolram]

According to this page in Wiki, point particles have no structure.

http://thisquantumworld.com/ht/content/view/43/41/ [Broken]

According to all i have read space is not (thing), it is just geometry.

So all of our universe, because nothing in has any volume ,can be reduced to an arbitary small size, i think the only limit to how compacted it can get may be the size of all the(vibrations) of the point particles added together , but what the heck would that even be?

 

[Chalnoth]

According to this page in Wiki, point particles have no structure.

http://thisquantumworld.com/ht/content/view/43/41/ [Broken]

According to all i have read space is not (thing), it is just geometry.

So all of our universe, because nothing in has any volume ,can be reduced to an arbitary small size, i think the only limit to how compacted it can get may be the size of all the(vibrations) of the point particles added together , but what the heck would that even be?

Well, the thing is, nobody actually knows that particles are genuinely point-like. This fact is in our equations not because it's true, but because it's easy to perform calculations from. As we progress to investigating higher and higher energy reactions, we may well find that particles are not actually point-like, just very small.

In fact, most physicists consider this to be extraordinarily likely, as one of the effects of genuinely point-like particles is that they lead to infinities in the theory, infinities that are certainly non-physical, and have to be renormalized away.

 

[Charlie_V]

You know, all I typically notice from these types of discussions is that atheists have replaced conventional religion with science (science IS their religion). If they could only prove that a scientific model without a God was completely valid they could say "HA told you God didn't exist you superstitious fools!" And then what? Would the world convert to "Science"? Does it all really matter in the end?

I think trying to explore the origins of the universe should be more about simply expanding our knowledge, maybe discovering some new effects that could aid man kind (new power sources etc), not trying to replace one ideology with another. Don't you?

Now on the subject of the universe, I find it hard to believe that any expansion or singularity or anything really (which was in a present state of equilibrium - assuming) could move from that state without any energy input, or be likewise ordered to that state without energy input. Personally, I feel the simplest solution to a problem is the one that stares you right in the face - perhaps energy + matter CAN be created. Perhaps the entropy we observe is the balancing mechanism to an anti-entropy effect (an ordering mechanism). In this way the universe is in equilibrium.

Yea I know, an idea like this cannot be shown valid until the ordering mechanism is first observed. Well, it seems to me like looking for an ordering mechanism would be just as fruitful as deriving a bunch of math - and not nearly as boring haha (sorry I'm an experimentalist).

The first place I would look for such an ordering effect would be the back emf interactions between a coil and permanent magnet. All you have to do is be able to energize a coil without the back emf of the coil interacting with the magnet - a one way street of flux. To do something like that would show a special case where the law of conservation of energy did not apply and introduce an ordering mechanism that perhaps the universe would use. HAHAHA of course such a feat ain't easy now is it - some might say its impossible?

 

[Chalnoth]

You know, all I typically notice from these types of discussions is that atheists have replaced conventional religion with science (science IS their religion).

Right, so, where are the holy men? The holy books? The rituals? The supernatural beliefs? The codes of conduct?

Science is as much religion as engineering is religion.

 

[heldervelez]

Well, the official peer review that goes into publishing is just the first step of peer review. It's only really effective in catching egregious errors. Quite a lot of crap still makes it through. Publication isn't really the end of peer review, it's just the beginning.


We shall see. I definitely hope that all of science moves towards free distribution.

Can Einstein publish today ? He was from the outside (an administrative clerk in the patents office), remember ?

We need the next Einstein to put an end to the present era of cosmology (The Dark Era of Cosmology, eheh).

The next Einstein will come from the outside. A kind of a prediction...
and all the Darkness will survive just in our memories.

We will see, or not, in the future.

 

[Chalnoth]

Can Einstein publish today ? He was from the outside (an administrative clerk in the patents office), remember ?

Certainly! There is no requirement that anybody have a specific degree to be published. However, there is a requirement that the person has a decent understanding of the current status of the field, and be able to write coherently and specifically. These things are obviously easiest to do through the more traditional route of getting a formal education, but it's certainly plausible that some could do it without a formal education.

Though, by the way, Einstein did get a formal education in the modern physics of the era. He had a degree in physics.

We need the next Einstein to put an end to the present era of cosmology (The Dark Era of Cosmology, eheh).

What we actually need are better observations and experiments. There is no shortage of ideas in cosmology. It's determining which ideas are correct or not that is the tough part.

 

[Nereid]

Can Einstein publish today ? He was from the outside (an administrative clerk in the patents office), remember ?

Genuine question for you heldervelez: do you know how easy it is to get a preprint up onto http://arxiv.org/" [Broken]?

Would you care to estimate how many times each (astro-ph, gr-qc) preprint is read?

Oh, and as I'm sure you already know, Einstein had a degree in physics ...

We need the next Einstein to put an end to the present era of cosmology (The Dark Era of Cosmology, eheh).

Why?

Specifically, what's wrong with modern cosmology, as a science (in your opinion)?

The next Einstein will come from the outside. A kind of a prediction...
and all the Darkness will survive just in our memories.

The next Einstein will be an invisible pink fairy. A kind of prediction...
and all the Nonsense will survive in the memories of just a few crackpots.

Doesn't exactly contribute much to an intelligent discussion, based on science and critical thinking, does it?

We will see, or not, in the future.

I guess it's impossible to disagree with this ...

 

[Nereid]

You know, all I typically notice from these types of discussions is that atheists have replaced conventional religion with science (science IS their religion).

Hmm ... I wasn't aware that in "conventional religion" the formulation of testable hypotheses was regarded as critical.

Nor the recognition that models (etc) that cannot be tested, even in principle, are of only secondary relevance (as a spur to new ways of thinking about old puzzles, perhaps).

Further, I didn't realize that "science" has a body of sacred texts, the contents of which is considered Truth ... can you give me a link - to somewhere in Amazon say - where I can go buy such books?

Oh, and aren't these thoughts of yours out of place, here in this Cosmology section of PF?

[...]
I think trying to explore the origins of the universe should be more about simply expanding our knowledge, maybe discovering some new effects that could aid man kind (new power sources etc), not trying to replace one ideology with another. Don't you?

What I really, truly think about this cannot be written here, without violating PF's rules.

Let me simply say that I think the ignorance I see in these words is both profoundly depressing and astonishing.

Now on the subject of the universe, I find it hard to believe that any expansion or singularity or anything really (which was in a present state of equilibrium - assuming) could move from that state without any energy input, or be likewise ordered to that state without energy input.

Ah the ever faithful 'argument from incredulity'! :tongue:

May I ask if you find it 'hard to believe' any major aspect of quantum mechanics? HUP, perhaps? Or the resolution of the EPR paradox?

Personally, I feel the simplest solution to a problem is the one that stares you right in the face - perhaps energy + matter CAN be created. Perhaps the entropy we observe is the balancing mechanism to an anti-entropy effect (an ordering mechanism). In this way the universe is in equilibrium.

OK, so when may we expect to see your preprint, based on these ideas, in astro-ph? or gr-qc?

Until such time, would you agree that this kind of speculation has no place in this part of PF, per https://www.physicsforums.com/showthread.php?t=5374"?

Yea I know, an idea like this cannot be shown valid until the ordering mechanism is first observed. Well, it seems to me like looking for an ordering mechanism would be just as fruitful as deriving a bunch of math - and not nearly as boring haha (sorry I'm an experimentalist).

The first place I would look for such an ordering effect would be the back emf interactions between a coil and permanent magnet. All you have to do is be able to energize a coil without the back emf of the coil interacting with the magnet - a one way street of flux. To do something like that would show a special case where the law of conservation of energy did not apply and introduce an ordering mechanism that perhaps the universe would use. HAHAHA of course such a feat ain't easy now is it - some might say its impossible?

I, for one, look forward to reading your specific, concrete, testable ideas ...

 

[heldervelez]

...
because inflation has not been proven. I'm guessing you would agree that inflation scenarios are just that, scenarios ---based on any number of assumptions about exotic inflaton fields.
...
. I don't know of any scientific reason to imagine that the universe had a beginning ...

The Inflation means " Physical laws, as we know them in our local world, do not hold at all times", and it made its appearence in scene because there is no other way out within this Dark Cosmology. Like it or not when I say Dark Cosmology I am saying just the same as everybody does in all papers and news.

But physical laws have to be generalized to all times.

I agree with the above statements. I do not believe in Big Bang, not even in space expansion, although we measure it. Before Galileu everybody knew , and precise measures are done, that the sun, and all the Universe, rotates around the Earth in 24 hours, without any question.

 

[heldervelez]

Genuine question for you heldervelez: do you know how easy it is to get a preprint up onto http://arxiv.org/" [Broken]?

Would you care to estimate how many times each (astro-ph, gr-qc) preprint is read?

Oh, and as I'm sure you already know, Einstein had a degree in physics ...
...

Specifically, what's wrong with modern cosmology, as a science (in your opinion)?

do you know how easy it is to get a preprint up onto http://arxiv.org/" [Broken]?
-- Easy if you belong to some university. The rules have changed a bit with arXiv in recent years; someone already in will have to say : Oh, he is a good fellow.
But even back in 2002 a particular fellow had to became associated to someone else (*) already in to get his ideas published.
(*) In the particular case that I know the other guy as nothing to do with the genesis and development of the paper.

Marcus in the initial post quote one arxiv paper that forces physics to become even out of physics (to just the world of math).

Geometry is not physics as it is a mental construction (as math in general), and quoting from http://en.wikipedia.org/wiki/Space
"...Henri Poincaré, a French mathematician and physicist of the late 19th century introduced an important insight which attempted to demonstrate the futility of any attempt to discover by experiment which geometry applies to space.[15] He considered the predicament which would face scientists if they were confined to the surface of an imaginary large sphere with particular properties, known as a http://en.wikipedia.org/wiki/Sphere-world" [Broken]. In this world, the temperature is taken to vary in such a way that all objects expand and contract in similar proportions in different places on the sphere. With a suitable falloff in temperature, if the scientists try to use measuring rods to determine the sum of the angles in a triangle, they can be deceived into thinking that they inhabit a plane, rather than a spherical surface.[16] In fact, the scientists cannot in principle determine whether they inhabit a plane or sphere and, Poincaré argued, the same is true for the debate over whether real space is Euclidean or not. For him, it was a matter of convention which geometry was used to describe space.[17] Since Euclidean geometry is simpler than non-Euclidean geometry, he assumed the former would always be used to describe the 'true' geometry of the world.[18]..."

Of course that I know that physics needs to be described by math.
But now we have the physics poluted with mathematicians that are trying to solve the first 'cagagésimo´ (*) of a second. Dreaming with parallel universes, finite or infinite. Some say that in each point of space-time an infinite quantity of universes could be emerging (at expense of what energy ?). Is this physics, or magic ?

By the early time of Einstein the physics of FIELDS are well established, and the particle story are just in the beginning. Einstein does not understand the graviton, the inflaton, (there is a new one, born very recently, for the time of pre-BB, that I do not remember the name)

When Einstein formulated the GR the Standard Model were unborn, as space expansion, as BB, as Inflation.

What I think is that theoretical physics has the need to get back to those times, and restart. GR is coherent, not augmented, nor amended, and it is not a collection of N theories, patched together and giving us unsurmountable questions, each one deserving us a comment 'we are just, just 'presque à résoudre' (about to solve).

To me is about to say 'The King is naked'
(*) not in the dict, just a way of say an infinitesimal quantity.

 

[heldervelez]

back to the OP

... "if science tells you matter can neither be created or destroyed, how did the universe originate from nothing". I'm unable to answer them clearly . Can ...
Thanks,

matter/energy i.e. matter/fields are in balance..
the problem gets worst with 'space expansion'. Space is the 'continent', the 'arena' or stage where the material world is expressed thru matter/fields. We use rules made of local matter to measure the so called 'space expansion'. But expansion at expense of what ? Space expand itself is equal to say 'space is the almighty god'. Of course we measure the expansion! It is inquestionable.

In Physics we must honour the before/after, cause/consequence, to allow a predictable universe (just physical laws, not a magical one)

I do not intend to deviate from the OP, but in the threads bellow I have put forward two provoking conceptual experiments that ilustrate the appearances that surround us.
world ‘o’ and world ‘O’ at https://www.physicsforums.com/showthread.php?t=279200
and particle creation and annihilation and the remaining fields problem
at https://www.physicsforums.com/showthread.php?t=271606

 

[heldervelez]

...

Assume that the zero energy balance between energy stored in a mass and its gravitational energy can be written as:

$$m c^2 - \Sigma G \frac{m \, m_i}{r_i} = 0$$
...

What are the extent of space that you consider in that equation ?
-- all of the space of the entire universe? beeing finite the existence of the universe, beeing finite the speed of the expansion of gravity (= c)
-- How do you equate the summation ?
-- You have to consider that m.c^2 is evolving thru time, because the summation do so.
-- Think about that.

 

[Nereid]

do you know how easy it is to get a preprint up onto http://arxiv.org/" [Broken]?
-- Easy if you belong to some university. The rules have changed a bit with arXiv in recent years; someone already in will have to say : Oh, he is a good fellow.
But even back in 2002 a particular fellow had to became associated to someone else (*) already in to get his ideas published.
(*) In the particular case that I know the other guy as nothing to do with the genesis and development of the paper.

[...]

These ideas are interesting, but don't fit this Cosmology section of PF.

I've started a new thread, in GD, with a title taken from your earlier post: https://www.physicsforums.com/showthread.php?t=285898"

I'm interested to learn why you think such revolutionary ideas in physics as GR would be difficult to get published in relevant peer-reviewed journals, so I hope you'll join the discussion in that thread.

 

[Nereid]

[...]

Marcus in the initial post quote one arxiv paper that forces physics to become even out of physics (to just the world of math).

Geometry is not physics as it is a mental construction (as math in general), and quoting from http://en.wikipedia.org/wiki/Space
"...Henri Poincaré, a French mathematician and physicist of the late 19th century introduced an important insight which attempted to demonstrate the futility of any attempt to discover by experiment which geometry applies to space.[15] He considered the predicament which would face scientists if they were confined to the surface of an imaginary large sphere with particular properties, known as a http://en.wikipedia.org/wiki/Sphere-world" [Broken]. In this world, the temperature is taken to vary in such a way that all objects expand and contract in similar proportions in different places on the sphere. With a suitable falloff in temperature, if the scientists try to use measuring rods to determine the sum of the angles in a triangle, they can be deceived into thinking that they inhabit a plane, rather than a spherical surface.[16] In fact, the scientists cannot in principle determine whether they inhabit a plane or sphere and, Poincaré argued, the same is true for the debate over whether real space is Euclidean or not. For him, it was a matter of convention which geometry was used to describe space.[17] Since Euclidean geometry is simpler than non-Euclidean geometry, he assumed the former would always be used to describe the 'true' geometry of the world.[18]..."

Of course that I know that physics needs to be described by math.
But now we have the physics poluted with mathematicians that are trying to solve the first 'cagagésimo´ (*) of a second. Dreaming with parallel universes, finite or infinite. Some say that in each point of space-time an infinite quantity of universes could be emerging (at expense of what energy ?). Is this physics, or magic ?

By the early time of Einstein the physics of FIELDS are well established, and the particle story are just in the beginning. Einstein does not understand the graviton, the inflaton, (there is a new one, born very recently, for the time of pre-BB, that I do not remember the name)

When Einstein formulated the GR the Standard Model were unborn, as space expansion, as BB, as Inflation.

What I think is that theoretical physics has the need to get back to those times, and restart. GR is coherent, not augmented, nor amended, and it is not a collection of N theories, patched together and giving us unsurmountable questions, each one deserving us a comment 'we are just, just 'presque à résoudre' (about to solve).

To me is about to say 'The King is naked'
(*) not in the dict, just a way of say an infinitesimal quantity.

This sentiment, paraphrased sufficiently broadly, is not uncommon.

There are two strands that I'm interested in: the disquiet and discomfort that string theory has engendered (see http://www.math.columbia.edu/~woit/wordpress/" [Broken] for example), and "what's the alternative?"

There's already a great deal of discussion on the first, here in PF, on the internet, and throughout the physics community; less discussed is the second, at least when it comes to cosmology.

Let's agree, for the sake of discussion, that all your points are valid ... what next?

What does a programme of 'restarting' look like? How does one go about developing such a thing? What criteria should we use to assess any alternatives that get put forward?

Suppose, for a moment, that you, heldervelez, are a professional cosmologist (drawing a good salary, from a leading university say), and that you've bitten the bullet ... what is it that you actually do on Monday when you sit down in your office chair?

 

[heldervelez]

...
There are two strands that I'm interested in: the disquiet and discomfort that string theory has engendered (see http://www.math.columbia.edu/~woit/wordpress/" [Broken] for example), and "what's the alternative?"
...

quoting from the link above "Second, the string theorists think of themselves as physicists rather than mathematicians. They believe that their theory describes something real in the physical world. And third, there is not yet any proof that the theory is relevant to physics. The theory is not yet testable by experiment. The theory remains in a world of its own, detached from the rest of physics. String theorists make strenuous efforts to deduce consequences of the theory that might be testable in the real world, so far without success."

To be testable is fundamental to Physics, and this subject can not be avoided.
We can have a bad model, or a not so bad one, or a good one, and thay must be conform to observations to some degree. The good model is more accurate than the others, and possibly some predictions are derived from first principles. The good one as a strong possibility of beeing the simpler.

The String Theory(s) are out of the domain of testability, by its nature, and so are out of the reaml of Physics.

Until now we describe the events in this Universe (the one that is testable) only with simple 3D+time. At least I don't know of any single example that does not fit.

I'm not a specialist in String Theory, and cannot contend about its contents. To remain out of ST is enough that not even its sponsors and specialists can think of a test or prediction.

"what's the alternative" ? you ask.
In my opinion the effort must be done in the wave description of matter, the fields they originate and the properties of the space. The actual availability to large particle colliders has leading us to the particle nature of matter, and inhibited the pursue on the wave nature of matter.

As an example of the consequences you can see the post #7 by hellfire and #30 of this thread:
In the 1st equation the assumed gravitacional energy say nothing about fields. Is this ok? I think not. Each particle sets field(s) that evolve in the space. Any work to be done on other particles is to be done by the field.
A mathematician may say that the equations are ok. But physically the reasoning had a bad start.

I do not agree with the formula as of #30 but I agree with the contents that is expressed in bold, and the equation can be reformulated in a more sustainable way.

Another example: in the Particle Physics Forum I put a conceptual problem about https://www.physicsforums.com/showthread.php?t=271606" and, because I mention Fields (without mention to any intervenient particle), I noticed a difficulty by others on the perception of the problem.

 

[heldervelez]

...
Suppose, for a moment, that you, heldervelez, are a professional cosmologist (drawing a good salary, from a leading university say), and that you've bitten the bullet ... what is it that you actually do on Monday when you sit down in your office chair?

Well, suppose I am as you say. I have lots of phone calls to make and receive, lot of coordination on my collaborators, prepare the next conference, the anual meeting on special subject XPTO, control if the quantity of papers that my nucleus is producing are enough to guarantee the next annual budget to the department. A colaborator had some idea that I'am afraid of pursue or estimulate because it is non mainstream and I'm an inconfessable fear of become out, to be in is more confortable and pays my check.
Some students are waiting for guidance. And I have a full agenda. I am a specialist of XPTO.
Also I have XXX pappers published, (peer reviewed of course), written Y books about the 'N cagagésimo' of the untestable theory that nobody understands. Everyone applauds and I am a sucess. And I have free access to papers.



-- Now the way I like. My monthly pay check comes regularly and it is ok.
I love physics but I'm unconfortable with the panorama.
I am an amateur in the proper sense of the word (amateur = lover) and I read everything that I can. I am not an specialist, but a generalist and even the non-mainstream theories I' read about (The net as a lot of crackpot). I've not an agenda, and have time to talk to many intelligent guys that I know. I have the net, and access to all papers (that I could not reach because they are paid). May be that way I could find something interesting.
Study Einstein again (not Minkovsky - this is the mathematician), rethink and doubt systematically.

The best time to human thinking was in the classic antiquity (greek time). Lazy times.
To be uncommited to the production is fundamental to reach anything new. Do it for fun, not as an obligation.

 

[Chalnoth]

quoting from the link above "Second, the string theorists think of themselves as physicists rather than mathematicians. They believe that their theory describes something real in the physical world. And third, there is not yet any proof that the theory is relevant to physics. The theory is not yet testable by experiment. The theory remains in a world of its own, detached from the rest of physics. String theorists make strenuous efforts to deduce consequences of the theory that might be testable in the real world, so far without success."

To be testable is fundamental to Physics, and this subject can not be avoided.
We can have a bad model, or a not so bad one, or a good one, and thay must be conform to observations to some degree. The good model is more accurate than the others, and possibly some predictions are derived from first principles. The good one as a strong possibility of beeing the simpler.

The String Theory(s) are out of the domain of testability, by its nature, and so are out of the reaml of Physics.

There is no evidence in support of this. What you have just shown is that string theory is difficult, not that it is untestable by nature. But why on Earth should we expect a theory of everything to be easy?

"what's the alternative" ? you ask.
In my opinion the effort must be done in the wave description of matter, the fields they originate and the properties of the space. The actual availability to large particle colliders has leading us to the particle nature of matter, and inhibited the pursue on the wave nature of matter.

The wave nature of matter is basic quantum mechanics and is used every day.

In the 1st equation the assumed gravitacional energy say nothing about fields. Is this ok? I think not. Each particle sets field(s) that evolve in the space. Any work to be done on other particles is to be done by the field.
A mathematician may say that the equations are ok. But physically the reasoning had a bad start.

There's a good reason for this, however: we don't know how to unify gravity and quantum mechanics. If you try to quantize General Relativity like we did with electricity and magnetism, you end up with a theory that produces infinities that can't be dealt with. If you try to not quantize General Relativity, you end up with unreconcilable contradictions.

String theory is one attempt to reconcile quantum mechanics and gravity. Loop quantum gravity is another. We don't yet know which, if either, is accurate.