Wow I just came across a mind-blowing paper today..all I can say is wow. This is as exciting to me (perhaps more so) than when I came across the transactional interpretation of quantum physics.
Let me summarize it before linking to it.
It is written by Fotini Markopoulou, P.H.D. From her bio:
Born in Athens, Greece, she received her Ph.D. in theoretical physics from Imperial College, London. She held postdoctoral positions at Pennsylvania State University, Imperial College, and the Albert Einstein/Max Planck Institute for Gravitational Physics, Berlin, before moving to Canada in 2001 as a founding member and faculty at the Perimeter Institute for Theoretical Physics in Canada, a research institute devoted to foundational issues in theoretical physics.
Anyway, I am just pointing out she is not some loon on the interweb but a highly educated theoretical physicist.
Basically she addresses the problem I have been struggling with for a long time.. why is it quantum physics and einsteinian general relativity do not agree?
Her answer in a nutshell: There is no space, there is no geometry. Motion is an illusion as is anything solid, or ‘here’ and ‘there’. Geometry arises from a lower energy state of the universe.
What is real? Energy and time. In fact when we dig deep enough into “solid” matter we see it is just energy. ( And even more basic than that, all that is real is simply information. ) And to make it even creepier, energy in a state of ‘superposition’..in all places at the same time. Until it is observed. The role of the observer in this is still not understood and she does not address this..she only seeks to unify general relativity with quantum physics. Unifying quantum theory and general relativity are one of the top 5 greatest problems facing modern theoretical physics.
(if you still don’t believe me that motion is an illusion i encourage you to read the following page: http://www.mathpages.com/rr/s3-07/3-07.htm)
Anyway, here is her essay:
I’ll cut and paste some of my favorite points from her paper:
“Space does not exist, so time can” – Fotini Markopoulou PHD (Perimeter Institute for Theoretical Physics)
Quantum gravity is often seen as the problem of unifying or reconciling general relativity and quantum theory, combining the physics of the very large with that of the very small. There are certainly places where we need both, such as black hole physics, where no real progress can be made without a quantum theory of gravity. The incompatibility of general relativity and quantum theory can be stated in many ways and a classic one is the problem of time.
Quantum gravity has been facing the problem of time for half a century. Will it continue to cause trouble for the next half century? Or is the problem of time a fake problem? Could it be a paradox? We arrived at it by putting together true statements from general relativity and from quantum theory and we found a contradiction. Now, either fundamental science is stuck or we just have a paradox that will go away if we find the faulty premise. What can the faulty premise be?
I must emphasize that no geometry does not mean discrete or fuzzy geometry. It means that the most primary aspects of geometry, such as the notion of \here” and \there” will cease to make sense. In fact, we have been grappling with no geometry for a while, in the traditional quantum gravity settings. A quantization of general relativity leads to a quantum superposition of all geometries. What is not often appreciated is that the superposition of all geometries is nothing like a geometry.
Take two geometries or, equivalently, two causal structures 1 and 2. Let us say that in geometry 1 event A and event B are close while in geometry 2 they are far. If you are event A, in world 1 you see event B here, in world 2 you see event B there. Now superpose not only 1 and 2 but all possible geometries. B is all over the place. (This is the easy version, I am assuming you can identify A and B in both which, in fact, you generally cannot do since you need the notion of here and there to assign identity).
The monstrosity we just created does not even have a sensible notion of here and there, the most basic aspect of geometry. It also does not have a notion of dimension. It’s only the fact that we call it “quantum geometry”, a combination of two words we understand, that fools us into thinking we comprehend it.
Cool stuff right? This starts to make sense to me. I am convinced motion can’t be real, and by extension geometry can not be real. Here is a very solid mathematical proof (her paper has all the math, which I don’t pretend to understand, I stick to these mind exercises instead) that geometry is not real. And by extension motion can’t possibly be real. This explains some of the effects we see in quantum physics..of particles being everywhere at once, having all possibilities at once. All geometric possibilities..because the geometry is not something that is real..the energy is. The geometry (the collapse of the wave function/ decoherenece ) only becomes ‘real’ once an observer observes the particle. Again, she does not go as far as explaining why observers have any effect on reality, but I feel she hints at her opinion/theory here:
Background independence means to make no distinction between geometry and matter and to describe the dynamics of the universe as seen by observers inside it. Di eomorphisms are not about timelessness but about being inside a dynamical universe, a ffecting it and being a ffected by it, constituting it.\
Let us name geometrogenesis the process of transitioning from a fundamental quantum theory of gravity without geometry to the known geometric physics. The geometrogenesis scenario is a simple one. At high energy, or in the early universe, there is no notion of geometry or geometric locality.
Having raised the possibility that geometry does not exist at the fundamental level, we now need to find a way to do physics without geometry. This may appear hard because all our physics is done with geometry. But we can use a relational and information theoretic language.
In this essay I argued that the problem of time is really a paradox that can be traced to taking spacetime geometry too seriously, beyond its domain of applicability. Timelessness refers only to the geometric time, not the microscopic fundamental time. Fundamental time exists but space, geometry and gravity do not.
This also goes back to what I have concluded myself from my own studies. Why is it gravity and momentum are indistinguishable? The conclusion I came to is this:
What if the things affected by gravity and momentum are not real? And the “forces” we feel are a result of this? Gravity affects mass (which is not real) and momentum is the “force” we feel..the magical tugging when we move. Maybe movement is not real either..and that is why these “forces’ magically tug and push at us, and why the forces are identical. The more mass..the more gravity…the more speed…the more momentum.
This paper, and her theory, go a long way to unifying classic general relativity with quantum theory. She is one smart greek! And it is perhaps poetic that one of the original people who proposed motion was not real was Xenophanes (Zeno) over 2,500 years ago. Motion can not possibly be real..so space/geometry can not be real either.
If we come across a viable and testable quantum gravitational theory within my lifetime I will be ecstatic!
here is another paper that comes to similar conclusions: