How does quantum gravity explain cosmology events prior to “10[-43]” seconds after the start of the universe?

Question

Before answering remember - Biological information is not encoded in the laws of physics and chemistry … (and it) cannot come into existence spontaneously. … There is no known law of physics able to create information from nothing.’

To Anki Rocks -Thanks for the background on quantum physics..However your statement does nothing to answer my above question, because only an intelligence/Creator can provide the information needed prior to "10[-43]".. The biggest mystery of all is the one cited by Stephen Hawking in A Brief History of Time: Why is there something rather than nothing? More specifically, what triggered the Big Bang, and why did the universe take this particular form rather than some other form that might not have allowed our existence? Attempts to solve these mysteries often take the form of what I call ironic science—unconfirmable speculation more akin to philosophy or literature than genuine science. Another example of ironic science is string theory,but the theory comes in so many versions that it predicts virtually everything—and hence nothing at all. Critics call this the "Alice's restaurant problem," a reference to a folk song with the refrain,"You can get anything you want at Alice's restaurant!

To PhysicsD..This is the correct format for my question which is asked from a science-point-of-view however because as you correctly stated "Nothing" existed prior to "10^-43". So the correct answer to ny question is "Quantum cosmology cannot explain the event prior to "10^-43" because the probability of something's coming out of nothing is incoherent.

To Gengi M. Wrong! - Scientists have never observed abiogenesis (i.e. the creation of life from non-life) happening in nature, nor have they been able to create any lifeforms through controlled (i.e. manmade) experiments. Abiogenesis seems out of the realm of empirical science. Furthermore, the extreme complexity of all lifeforms seems to point in the direction of an outside Intelligence..Now your question Where did God come from - 1-Everything WHICH HAS A BEGINNING has a "cause" 2 - The Law of Thermodynamics prove beyond any doubt that the universe has a beginning 3- Therefore the universe has a "Cause". Einstein's general relativity showed that TIME is linked to matter & space. So TIME itself begun along with matter & space at the start of the universe. Since God by definition created the universe he also "Created" TIME! and is NOT limited by the time dimension HE CREATED so he has NO BEGINNING in time. Therefore he does not have or need to have a "cause"...

Answer 1

Well, first of all, I really don't think this question belongs in the physics section. It should be place under religion or theology.

But here is some food for thought related to your question:

1. Space and time are also quantized, and the smallest unit of time happens to be...you guessed it...10^-43 seconds. So it may not make any sense to ask: what happened before 10^-43 seconds? because there was NO time before that, and NO space, and NO existence of any kind.

You say that there cannot be spontaneous existence. Why not? You say that there is no known laws of physics able to create information from nothing. But the problem is that:

2. Laws of physics may NOT be absolute: (a) there may NOT just one set of THE laws of physics, and (b) these laws may change over time.

So to argue for the existence of God, I think it is best NOT to invoke logic or reason, or laws of physics. Faith alone should be enough.

Answer 2

If we ever come up with a comprehensive theory of quantum gravity, and if it turns out to be correct, it probably still won't answer that question. If some future superstring or M-brane theory meets those same criteria, it might. Some say it could have been an intersection of two branes. But as you already know, that just pushes the ultimate cause question farther back, to where did the branes come from? Or where did the laws of physics come from? Where did spacetime come from? The Bible says God created it. Any other hypotheses?

Answer 3

biological information is in coded in molecules such as DNA and yes it can come into existence spontaneously, ever heard of Boltzmann brains.

i see that you have now moved from quantum tunnelling to gravity. they both have nothing to do with god.

because you are arguing there is a god with your "logic". can you answer me this one question? who created god?


EDIT.
any proof of that at all, if not according to your logic it can be what ever i want. ergo it is me i am god i created time and everything, all this talk of ID is rubbish it was an accident and dont worry about be creating the unerverse before i was born, ill make up some bullshit explanation and throw a couple of scientific words in there and presto i just proved that i created the unerverse.

Answer 4

Quantum gravity is the field of theoretical physics attempting to unify quantum mechanics, which describes three of the fundamental forces of nature, with general relativity, the theory of the fourth fundamental force: gravity. One ultimate goal hoped to emerge as a result of this is a unified framework for all fundamental forces— called a "Theory of Everything" (TOE).

Much of the difficulty in merging these theories at all energy scales comes from the different assumptions that these theories make on how the universe works. Quantum field theory depends on particle fields embedded in the flat space-time of special relativity. General relativity models gravity as a curvature within space-time that changes as a gravitational mass moves. Historically, the most obvious way of combining the two (such as treating gravity as simply another particle field) ran quickly into what is known as the renormalization problem. In the old-fashioned understanding of renormalization, gravity particles would attract each other and adding together all of the interactions results in many infinite values which cannot easily be cancelled out mathematically to yield sensible, finite results. This is in contrast with quantum electrodynamics where, while the series still do not converge, the interactions sometimes evaluate to infinite results, but those are few enough in number to be removable via renormalization.

In recent decades, however, this antiquated understanding of renormalization has given way to the modern idea of effective field theory. All quantum field theories come with some high-energy cutoff, beyond which we do not expect that the theory provides a good description of nature. The "infinities" then become large but finite quantities proportional to this finite cutoff scale, and correspond to processes that involve very high energies near the fundamental cutoff. These quantities can then be absorbed into an infinite collection of coupling constants, and at energies well below the fundamental cutoff of the theory, to any desired precision only a finite number of these coupling constants need to be measured in order to make legitimate quantum-mechanical predictions. This same logic works just as well for the highly successful theory of low-energy pions as for quantum gravity. Indeed, the first quantum-mechanical corrections to graviton-graviton scattering and Newton's law of gravitation have been explicitly computed (although they are so astronomically small that we may never be able to measure them), and any more fundamental theory of nature would need to replicate these results in order to be taken seriously. In fact, gravity is in many ways a much better quantum field theory than the Standard Model, since it appears to be valid all the way up to its cutoff at the Planck scale. (By comparison, the Standard Model is expected to break down above its cutoff at the much smaller TeV scale.)

While confirming that quantum mechanics and gravity are indeed consistent at reasonable energies (in fact, the complete structure of gravity can be shown to arise automatically from the quantum mechanics of spin-2 massless particles), this way of thinking makes clear that near or above the fundamental cutoff of our effective quantum theory of gravity (the cutoff is generally assumed to be of order the Planck scale), a new model of nature will be needed. That is, in the modern way of thinking, the problem of combining quantum mechanics and gravity becomes an issue only at very high energies, and may well require a totally new kind of model.

The general approach taken in deriving a theory of quantum gravity that is valid at even the highest energy scales is to assume that the underlying theory will be simple and elegant and then to look at current theories for symmetries and hints for how to combine them elegantly into an overarching theory. One problem with this approach is that it is not known if quantum gravity will be a simple and elegant theory (that resolves the conundrum of special and general relativity with regard to the uniformity of acceleration and gravity, in the former case and spacetime curvature in the latter case).

Such a theory is required in order to understand those problems involving the combination of very large mass or energy and very small dimensions of space, such as the behavior of black holes, and the origin of the universe.

At present, one of the deepest problems in theoretical physics is harmonizing the theory of general relativity, which describes gravitation, and applies to large-scale structures (stars, planets, galaxies), with quantum mechanics, which describes the other three fundamental forces acting on the atomic scale. This problem must be put in the proper context, however. In particular, contrary to the popular but erroneous claim that quantum mechanics and general relativity are fundamentally incompatible, one can in fact demonstrate that the structure of general relativity essentially follows inevitably from the quantum mechanics of interacting theoretical spin-2 massless particles (called gravitons). While there is no concrete proof of the existence of gravitons, all quantized theories of matter necessitate their existence. Supporting this theory is the observation that all other fundamental forces have one or more messenger particles, except gravity, leading researchers to believe that at least one most likely does exist; they have dubbed these hypothetical particles gravitons.

If the graviton turns out not to exist, it will render all work based on quantized macroscopic physics flawed, and destroy virtually all the accepted notions of a unified theory of physics since the 1970s, including string theory, superstring theory, M-theory, loop quantum gravity, and quantum gravity, among others. In an attempt to prove that modern physics is on the right track, CERN has promised to dedicate a large timeshare to search for the graviton using the Large Hadron Collider, the world's largest particle accelerator and collider, which is scheduled to complete construction in May 2008.

Recent work[1] has shown that by treating general relativity as an effective field theory, one can actually make legitimate predictions for quantum gravity, at least for low-energy phenomena. An example is the well-known calculation of the tiny first-order quantum-mechanical correction to the classical Newtonian gravitational potential between two masses. Such predictions would need to be replicated by any candidate theory of high-energy quantum gravity.

Historically, many believed that general relativity was in fact fundamentally inconsistent with quantum mechanics. General relativity, like electromagnetism, is a classical field theory. One might expect that, as with electromagnetism, there should be a corresponding quantum field theory. However, gravity is nonrenormalizable. For a quantum field theory to be well-defined according to this now-outdated understanding of the subject, it must be asymptotically free or asymptotically safe. The theory must be characterized by a choice of finitely many parameters, which could, in principle, be set by experiment. For example, in quantum electrodynamics, these parameters are the charge and mass of the electron, as measured at a particular energy scale. On the other hand, in quantizing gravity, there are infinitely many independent parameters needed to define the theory. For a given choice of those parameters, one could make sense of the theory, but since we can never do infinitely many experiments to fix the values of every parameter, we do not have a meaningful physical theory. At low energies, the logic of the renormalization group tells us that, despite the unknown choices of these infinitely many parameters, quantum gravity will reduce to the usual Einstein theory of general relativity. On the other hand, if we could probe very high energies where quantum effects take over, then every one of the infinitely many unknown parameters would begin to matter, and we could make no predictions at all.

However, from the perspective of effective field theory, one sees that all but the first few such parameters are suppressed by huge energy scales and hence can be neglected when computing low-energy effects. Thus, at least in the low-energy regime, the model is indeed a predictive quantum field theory[2]. (A very similar situation occurs for the very similar effective field theory of low-energy pions.) Furthermore, most theorists agree that even the Standard Model should really be regarded as an effective field theory as well, with "nonrenormalizable" interactions suppressed by large energy scales and whose effects have consequently not been observed experimentally.

However, any meaningful theory of quantum gravity that makes sense and is predictive at all energy scales must have some deep principle that reduces the infinitely many unknown parameters to a finite number that can then be measured. One possibility is that normal perturbation theory is not a reliable guide to the renormalizability of the theory, and that there really is a UV fixed point for gravity. Since this is a question of non-perturbative quantum field theory, it is difficult to find a reliable answer, but some people still pursue this option. Another possibility is that there are new symmetry principles that constrain the parameters and reduce them to a finite set. This is the route taken by string theory, where all of the excitations of the string essentially manifest themselves as new symmetries.

A fundamental lesson of general relativity is that there is no fixed spacetime background, as found in Newtonian mechanics and special relativity; the spacetime geometry is dynamic. While easy to grasp in principle, this is the hardest idea to understand about general relativity, and its consequences are profound and not fully explored, even at the classical level. To a certain extent, general relativity can be seen to be a relational theory, in which the only physically relevant information is the relationship between different events in space-time.

On the other hand, quantum mechanics has depended since its inception on a fixed background (non-dynamical) structure. In the case of quantum mechanics, it is time that is given and not dynamic, just as in Newtonian classical mechanics. In relativistic quantum field theory, just as in classical field theory, Minkowski spacetime is the fixed background of the theory. Finally, string theory started out as a generalization of quantum field theory where instead of point particles, string-like objects propagate in a fixed spacetime background. Although string theory had its origins in the study of quark confinement and not of quantum gravity, it was soon discovered that the string spectrum contains the graviton, and that "condensation" of certain vibration modes of strings is equivalent to a modification of the original background. In this sense, string perturbation theory exhibits exactly the features one would expect of a perturbation theory that may exhibit a strong dependence on asymptotics (as seen, for example, in the AdS/CFT correspondence) which is a weak form of background dependence.

Quantum field theory on curved (non-Minkowskian) backgrounds, while not a quantum theory of gravity, has shown that some of the assumptions of quantum field theory cannot be carried over to curved spacetime, let alone to full-blown quantum gravity. In particular, the vacuum, when it exists, is shown to depend on the path of the observer through space-time (see Unruh effect). Also, some argue that in curved spacetime, the field concept is seen to be fundamental over the particle concept (which arises as a convenient way to describe localized interactions). However, since it appears possible to regard curved spacetime as consisting of a condensate of gravitons, there is still some debate over which concept is truly the more fundamental.

Loop quantum gravity is the fruit of an effort to formulate a background-independent quantum theory. Topological quantum field theory provided an example of background-independent quantum theory, but with no local degrees of freedom, and only finitely many degrees of freedom globally. This is inadequate to describe gravity in 3+1 dimensions which has local degrees of freedom according to general relativity. In 2+1 dimensions, however, gravity is a topological field theory, and it has been successfully quantized in several different ways, including spin networks.

There are two other points of tension between quantum mechanics and general relativity. First, general relativity predicts its own breakdown at singularities, and quantum mechanics becomes inconsistent with general relativity in a neighborhood of singularities (however, no one is certain that classical general relativity should necessarily be trusted near singularities in the first place). Second, it is not clear how to determine the gravitational field of a particle, if under the Heisenberg uncertainty principle of quantum mechanics its location and velocity cannot be known with certainty. The resolution of these points may come from a better understanding of general relativity

well thats all i know about quantum gravity...

Answer 5

Can you point me to any scientifically valid information about quantum gravity -- it's still under development last I heard.

Answer 6

it cant