What's missing from a true Theory of Everything

[Realitycheck]

Somebody said that theory breaks down at the singularity of black holes, but I think at least Hawking has figured his way out of that (if I didn't suggest it first). It's not exactly rocket science. Somebody said that quantum theory doesn't match up in results to classic theory. What are the exact instances of that? You're not exactly comparing apples to apples. And if I remember right, most of the differences revolve around gravity. Will this new satellite put an end to all of the discrepancies and boundless speculation? Giving us a surefire theory of everything? I guess we would have to find the elusive but oh so necessary Higgs in order for it to be everything but if not, what then? (I, frankly don't see the need for a Higgs, but my QT is pretty weak in light of the level it has evolved to, so I'm probably missing something.) I guess we'll figure out something one way or another.

[ajb]

Somebody said that theory breaks down at the singularity of black holes,

 

The curvature at the singularity is infinite. As we cannot measure something to have an infinite "value" one has to question what the curvature at the singularity means physically. The response is that the theory breaks down at the singularity, that is the theory cannot cope with the physics.

 

but I think at least Hawking has figured his way out of that (if I didn't suggest it first).

 

I don't think so, but Hawking is an expert in quantum field theory. One can study quantum field theory in the presence of black holes, but things are still going to go wrong near the singularity.

 

It's not exactly rocket science. Somebody said that quantum theory doesn't match up in results to classic theory. What are the exact instances of that? You're not exactly comparing apples to apples.

 

There are plenty of observed phenomena that just cannot be explained using classical mechanics. A good example is quantum tunnelling.

 

And if I remember right, most of the differences revolve around gravity.

 

Not really. But it is true that classical gravity as described by Einstein's general relativity cannot be quantised using standard methods of quantum field theory.

 

 

Will this new satellite put an end to all of the discrepancies and boundless speculation? Giving us a surefire theory of everything?

 

What satellite?

 

I guess we would have to find the elusive but oh so necessary Higgs in order for it to be everything but if not, what then? (I, frankly don't see the need for a Higgs, but my QT is pretty weak in light of the level it has evolved to, so I'm probably missing something.) I guess we'll figure out something one way or another.

 

The Higgs is a way of making the gauge bosons massive while keeping renormalisability. It can also be used to give masses to the leptons.

 

Other possible mechanism exists, technicolour for example.

[Realitycheck]

I think it may have been the Gravity satellite which confirmed Einstein's theory recently. It's just a bit frustrating, seeing all of these far-out hypotheses, or rather, how far out and how extensive they can be, but I guess there is a reason for everything.

[Realitycheck]

But is the curvature at the singularity really infinite, or is it just really, really, really big, entailing that science has essentially inserted a plug, leading to an infinite myriad of inaccurate misconceptions? Forgive me if my perception is vastly different from the average layperson. Don't get me wrong. I'm not chastising the evolution of knowledge. The methodology just seems odd.

[DrRocket]

But is the curvature at the singularity really infinite, or is it just really, really, really big, entailing that science has essentially inserted a plug, leading to an infinite myriad of inaccurate misconceptions? Forgive me if my perception is vastly different from the average layperson. Don't get me wrong. I'm not chastising the evolution of knowledge. The methodology just seems odd.

 

Singularities in GR are rather subtle.

 

First, by definition the curvature tensor exists and is finite at all points of spacetime. There is no singular point in the spacetime manifold.

 

A region of spacetime is said to be singular if timelike geodesics canot be extended in thev forward or backward direction. In the case of the big bang singularity it is the backward direction that fails. In te case of black holes it the forward direction that fails.

 

It is not necessarily the case that curvature becomes arbitrarily large in a singular region.

 

You can find singularities discussed in greater detail in The large scale structure of space-time by Hawking and Ellis, Spacetime and Singularities, an Introduction by Naber and The Analysis of Space-Time Singularities by Clarke.

[Realitycheck]

Yes, of course, the size of curves is largely irrelevant.

 

I've been having a bit of trouble iterating just what exactly my issue was with the history of black hole theory but I've just stumbled across something which likely factored into the mystique, an Einstein joke. Never really knowing that it was part of a joke, I would always ask myself, "Why would anyone ever divide by zero?" (seriously)

Edited August 10, 2011 by Realitycheck

[ajb]

There is no singular point in the spacetime manifold.

 

Absolutely right. You want to keep the smooth manifold structure. In essence you remove the troublesome point (or region) and then think about geodesic completeness. This gets technical and is probably not worth going into for general discussions of black holes etc to laypeople.

 

It is not necessarily the case that curvature becomes arbitrarily large in a singular region.

 

Again absolutely right, using the geodesic completeness as a definition, which I believe is the modern definition most people use.

Edited August 10, 2011 by ajb

[questionposter]

I think the problem with black holes is because they are both big and small at the same time, and we don't have a science that describes both, only one or the other. We have relativity which describes the big world and quantum physics which describes the small world, but whenever we try and use both at the same time, mathematics doesn't add up. A singularity is very small, but its effects are huge, so a black hole needs to be described by both the big and small at the same time, but whenever we try and describe gravity at the realm of the small, it doesn't work. Like with an atom, even through a proton has a gravitational pull, an electron doesn't just "fall" into the nucleus and remain there even with opposite charges pulling on the electron as well.

 

I don't know how scientists know that a singularity is "infinitely" dense though because they can't really see inside a black hole.

Edited August 13, 2011 by questionposter

[Realitycheck]

It's not infinitely dense, just take away all that space between the electrons and nucleus. Anybody have any other ideas?

 

Maybe once the mass reaches a certain critical level, the atomic structure just collapses? Maybe there is a magnetic factor? Maybe they're as big as they look and nowhere near as dense as we are concluding?

Edited August 13, 2011 by Realitycheck

[questionposter]

It's not infinitely dense, just take away all that space between the electrons and nucleus. Anybody have any other ideas?

 

Maybe once the mass reaches a certain critical level, the atomic structure just collapses? Maybe there is a magnetic factor? Maybe they're as big as they look and nowhere near as dense as we are concluding?

 

Even before matter reaches the point of a black hole, the structure of an atom collapses in a Neutron Star, composed mostly of neutrons packed tightly together with electron fluid in between some layers. Instead of electrons orbiting around a positively charged nucleus, it's just dense amounts of electrons next to dense amounts of neutrons. After that, gravity is so strong that electrons and probably some sub-particles of neutrons are forced outward and we really don't know what makes up the matter of a black hole just before a singularity. My guess is the reason a singularity is the way it is, is because of some unknown sub-particle rather than the physics of the particles we already know, like adding extra-dimensions. Maybe there's just a greater output of the gravity Gauge Boson per square inch, or there's a ton of Higgs Bosons around it, or there's a bunch of gravitons warping space at a really small point which can't escape into other dimensions like they normally would because the gravity is too high.

[Realitycheck]

I wonder what happens to all of the protons. Converted to photons and some other particle(s)? They never escape the horizon, or their volume seems trivial in comparison. Maybe they are somehow layered into a core. Too odd of a configuration. Where do they go?

[questionposter]

I wonder what happens to all of the protons. Converted to photons and some other particle(s)? They never escape the horizon, or their volume seems trivial in comparison. Maybe they are somehow layered into a core. Too odd of a configuration. Where do they go?

 

They probably get forced outward, or, I don't know exactly how it would work because the neutrinos aren't really added in the mixture, but maybe the protons could combine with some electrons to form some of the neutrons too. An electron "can" be forced into the nucleus, its just that you need energy to push an electron past the ground state for some reason.

Edited August 13, 2011 by questionposter

[UserX]

Somebody said that theory breaks down at the singularity of black holes, but I think at least Hawking has figured his way out of that (if I didn't suggest it first). It's not exactly rocket science. Somebody said that quantum theory doesn't match up in results to classic theory. What are the exact instances of that? You're not exactly comparing apples to apples. And if I remember right, most of the differences revolve around gravity. Will this new satellite put an end to all of the discrepancies and boundless speculation? Giving us a surefire theory of everything? I guess we would have to find the elusive but oh so necessary Higgs in order for it to be everything but if not, what then? (I, frankly don't see the need for a Higgs, but my QT is pretty weak in light of the level it has evolved to, so I'm probably missing something.) I guess we'll figure out something one way or another.

 

I think scientist need to go back to the drawing boards and rework earlier theories to function with all the new information we have. People discover new things all the time but fruitlessly try to jam it into models of popular theories. I’m not saying popular theories are wrong, I’m saying we need to incorporate new knowledge (things we know to be true) into older theories. Stop inventing things so you can make new discoveries fit. Look at things in a different light (so to speak). This is the reason why scientist cant mold the concrete theory of everything. I believe the answers are right in front of us we just have to ask the right questions.

 

X

[Realitycheck]

As far as I can tell, the issues are not that significant. Microperspective doesn't agree with macroperspective. So? It's not exactly comparing apples to apples. I think adjustments will be the rule rather than going back to the drawing board. An infinite amount of testing went into establishing the norm. It's not like we keep running into all of these unexplained exclusions, except maybe for detailed collider experiments. Just what is so flawed with the establishment?

[questionposter]

I think scientist need to go back to the drawing boards and rework earlier theories to function with all the new information we have. People discover new things all the time but fruitlessly try to jam it into models of popular theories. I'm not saying popular theories are wrong, I'm saying we need to incorporate new knowledge (things we know to be true) into older theories. Stop inventing things so you can make new discoveries fit. Look at things in a different light (so to speak). This is the reason why scientist cant mold the concrete theory of everything. I believe the answers are right in front of us we just have to ask the right questions.

 

X

 

Ok, scientists have been trying to find the theory of everything for almost a century, so I think the problem really is that they need to have more discoveries, not how they fit them into old models. In fact, new discoveries usually mean new models in physics, like with the older model, there was no quark, when when quarks were discovered, a new model of the atom was invented which more accurately described it.

[csmyth3025]

...I don't know how scientists know that a singularity is "infinitely" dense though because they can't really see inside a black hole.

I'm not sure that any scientists claim to know that at the center of a black hole event horizon there is an infinitely dense object. They know that the intense gravity of neutron stars is balanced by short-range repulsive neutron-neutron interactions mediated by the strong force and also by the quantum degeneracy pressure of neutrons, preventing collapse.

 

Beyond about 3 solar masses, however, the force of gravity exceeds the strength of these counteracting forces. At this point there's no force or combination of forces known to exist that are strong enough to stop the contracting force of gravity (which only becomes stronger as it further compresses the object).

 

Since scientists can conceive of no way to prevent the ever more forceful collapse of the precursor object, they speculate that the object must continue to shink in size due to the continually increasing strength of gravity until it shinks to the absolute minimum size - which they surmise must be zero. The only reason they think that this actually happens is that they can't figure out any physical laws that would stop it from happening.

 

Now anything that is zero in size must be infinite in density. If a paper clip were to be shrunk down in size to zero, it would have infinite density - even though we know it has only about one gram of mass.

 

All scientists can say about what lies within the event horizon is that there is believed to be a point-like object that our physical laws are unable to describe. To avoid having to repaetedly use that rather long and embarrasing phrase, the simply call the thing a singularity.

 

Chris

[Realitycheck]

A fifteen mile wide point. I thought Hawking was describing it. All neutrons and electrons, merged together, no space in between.

Edited August 20, 2011 by Realitycheck