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Junior Member (Idle past 5261 days) Posts: 24 From: Chorley, Lancs, UK Joined: 

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Author  Topic: Missing Matter  
Agobot Member (Idle past 5663 days) Posts: 786 Joined: 
cavediver writes: QM is simply invalid as a description of reality. Do you believe in a subquantum world that could explain the weirdness of the observed phenomena? Anyway, i wonder why we should continue to close our eyes to uncomfortable questions. QM says the floor you are sitting on is made 99.999% of empty space. Einstein proved that matter is a form of condensed energy. De Broglie claimed that all matter has related to it a wave length and a frequency of that wave, a certain number of wave cycles per second. Not only had humanity learned that matter was not matter, we now had to believe that everything is a wave. Everything ” you and I included. Seventy years of experiments have sustained both Einstein's and de Broglie's preposterous, counterintuitive(to avoid my favourite "fucked up") claims. What we perceive as solid matter is actually de Broglie's waves separated by open space, made impermeable by invisible, immaterial fields of force that somehow pervade the space. The world simply is not as it seems and De Broglie tells us light and stones is one and the same.The substructure of all existence is just an idea. As Einstein has found out, the substructure of energy is even more elusive. So why do we keep saying there is nothing wrong with the findings of QM? How does that not change the way we look at reality and our existence? Here is a short list of the most prominent physicists of our time that believed in a creator(not always the same as God): 1. Steven HawkingPacific News 2. Albert Einstein 3. Machio Kaku 4. Max PlankHomepage  adherents 5. Werner Heisenberghttp://www.edinformatics.com/great_thinkers/heisenberg.htm 6. Niels Bohr 7. Enrico Fermi(the father of the atomic bomb) 8. Nikola Tesla Etc. If all these greatest physicists of our time, that have dedicated their whole lives to physics, reality and QM have found the existence of a higher intelligence mandatory to their discoveries, why should we doubt them? How is human Free will not an incoherent notion when it requires one to be the author of oneself, a logical impossibility and paradox, wheter you think of it in terms of Evolution or God(Biblical or not)? Edited by Agobot, : No reason given. Edited by Agobot, : No reason given. Edited by Agobot, : No reason given.


cavediver Member (Idle past 3776 days) Posts: 4129 From: UK Joined: 
No, no, no, no, no... perhaps SG was right and we should have kept this to ourselves. I'm not talking about Quantum Theory being invalid, I simply mean one particular prescription of quantum theory  namely the original nonrelativistic quantum mechanics.
Quantum Theory is not only valid, it is an essential description of reality...


Agobot Member (Idle past 5663 days) Posts: 786 Joined: 
cavediver writes: No, no, no, no, no... perhaps SG was right and we should have kept this to ourselves. I'm not talking about Quantum Theory being invalid, I simply mean one particular prescription of quantum theory  namely the original nonrelativistic quantum mechanics.Quantum Theory is not only valid, it is an essential description of reality... Ok i thought you meant that the relativity theory is an essentially deterministic theory and the quantum theory is essentially indeterministic and hence the rift between them.


cavediver Member (Idle past 3776 days) Posts: 4129 From: UK Joined: 
Ok i thought you meant that the relativity theory is an essentially deterministic theory and the quantum theory is essentially indeterministic and hence the rift between them. No, this is merely how some have portrayed the rift, and they are simply confused. And Quantum Theory is deterministic. Some *interpretations* of the quantum/classical transition introduce indeterminism  but it's not in the quantum theory itself. The real barrier to quantising gravity is much more mathematical in nature and is rather mundane to the layreader. Edited by cavediver, : No reason given.


Agobot Member (Idle past 5663 days) Posts: 786 Joined: 
cavediver writes: No, this is merely how some have portrayed the rift, and they are simply confused. And Quantum Theory is deterministic. It seems you are saying that Einstein was right in his famous remark: "God does not play dice" "Science without religion is lame. Religion without science is blind" "I am a deeply religious nonbeliever  This is a somewhat new kind of religion" Albert Einstein


ramoss Member (Idle past 745 days) Posts: 3228 Joined: 
Not only does God play dice, but... he sometimes throws them where they cannot be seen.  Stephen Hawking


Agobot Member (Idle past 5663 days) Posts: 786 Joined: 
Why do scientists try to use General Relativity at the Singularity? The way i see it is this  prior to the BB there was nothing physical, just energy. After the BB there is still nothing physical, just energy and thus nothing arose of nothing and something did not arise of nothing. There was just an enormously dense enegy prior to the BB that has since then spread out considerably. Why would we try to apply physical laws from our classical world to an energy point with no physical dimensions?
Edited by Agobot, : No reason given. "Science without religion is lame. Religion without science is blind" "I am a deeply religious nonbeliever  This is a somewhat new kind of religion" Albert Einstein


onifre Member (Idle past 3084 days) Posts: 4854 From: Dark Side of the Moon Joined: 
Agobot writes: Why do scientists try to use General Relativity at the Singularity? It's not that they are trying to apply it to the singularity, it's that using GR the equations break down into a singularity.
The way i see it is this  prior to the BB there was nothing physical, just energy. After the BB there is still nothing physical, just energy and thus nothing arose of nothing and something did not arise of nothing. And there will always be energy. However, our reality is one of a physical matter, and thus can be explained by physics.
There was just an enormously dense enegy prior to the BB that has since then spread out considerably. That is what GR tells us about T=O, the equations breaks down into infinite density, temperature, and curvature. But, thats not the only theory. Like we were talking about on Bertot's thread, the NoBoundary proposal introduces a noboundary unviverse that does not require a BB singularity; since the universe has no boundaries there is no starting point. It would be like trying to explain to me at what point on the Earths surface does the Earth begin. But, there are other theories as well, Loop QM also has no singularity in it's equation nor will any unifying theory. So it's a bit premature, IMO, to say for certain what conditions were like before the BB, because for all we know there was no beginning point.
Why would we try to apply physical laws from our classical world to an energy point with no physical dimensions? The universe works within a frame of physical laws Abogot, I think you are well aware of that. We humans have been able to understand most of it. Our reality is of a physical nature and if we are the one's trying to explain the origin of the universe we must use a system that we can work with...like physical laws. We are just doing our best to explain. Don't get so cynical. "All great truths begin as blasphemies" "I smoke pot. If this bothers anyone, I suggest you look around at the world in which we live and shut your mouth."Bill Hicks "I never knew there was another option other than to question everything"Noam Chomsky


Agobot Member (Idle past 5663 days) Posts: 786 Joined: 
However, our reality is one of a physical matter, and thus can be explained by physics. Hi onifre, How is a singularity part of our reality? In what way? In my classical reality, infinite energy dots with zero physical dimensions don't make sense at all. They simply don't belong in my realm of existence. I've seen quotes stating the singularity to be 2 cm in diameter as well as zero. Is there a concensus in the scientific community on this topic? Edited by Agobot, : No reason given. "Science without religion is lame. Religion without science is blind" "I am a deeply religious nonbeliever  This is a somewhat new kind of religion" Albert Einstein


onifre Member (Idle past 3084 days) Posts: 4854 From: Dark Side of the Moon Joined: 
Bogot writes: How is a singularity part of our reality? They are not, thats the need for the unifying theory. We should be able to explain everything with physical laws. A singularity is unsatisfactory and as such needs to be removed.
They simply don't belong in my realm of existence. Neither in mine. A unifying theory will remove the singularity, but I should say also that in your realm of reality, which is to say today at T=Now, there is no singularity, so your realm of reality is unaffected by what happened 14 Bya. It would just be in a physics equation where reality breaks down, not in reality. "All great truths begin as blasphemies" "I smoke pot. If this bothers anyone, I suggest you look around at the world in which we live and shut your mouth."Bill Hicks "I never knew there was another option other than to question everything"Noam Chomsky


Son Goku Inactive Member 
I've a few posts lined up for the weekend.
Weekends have been known to move forward several days..... Hilbert SpaceAnyway, in my last post I discussed how we can understand quantum field theory. We use (,t), the probability amplitude for a field to be in a given configuration at time t. First of all probability amplitudes are square roots of probabilities. So when I discuss them below the numbers should be squared to get the probability. However quantum field theory is meant to describe particles. How are particles to be described with (,t)? The answer lies in a construction called a Hilbert Space. Bypassing several decades of functional analysis, I will define a Hilbert space very simply. Obviously you can have several different (,t). To explain this let me go back to the picture from the last post:Here I'm looking at four different field configurations. A sample (,t) is where I have an equal probability amplitude. (,t) = (0.5, 0.5, 0.5, 0.5) This says that there is an equal chance of the field being in any one of the configurations. However it could be that there is a much greater probability amplitude to find the field in the fourth configuration. For this case I could use: (,t) = (0.25, 0.25, 0.25, 0.9013) (The last figure is rounded, so the squares will not add to 1 exactly). Hopefully the point is clear. (,t) is a big long list of probability amplitudes to be in different field configurations. In reality there are an infinity of field configurations so (,t) is infinitely long. A Hilbert space is then the set of all these lists or the set of all (,t). (Basically Hilbert Space is a space where each "point" in the space is a specific (,t))It is this space that the mathematics of quantum theory centers around. ParticlesNow the genius of using such a space is that it allows one to work on things in a concrete way. Using mathematical devices known as operators, I can find not only the probability amplitudes to be in a field configuration from the list (,t), but also I can extract the probability amplitudes to possess certain quantities such as energy, momentum, angular momentum and spin. Then one notices that certain (,t) have specific classical properties. Some (,t) have a definite (enough) momenta, are localised (enough) in space and have a specific spin so that certain lists have particle like properties. Using the Hilbert space structure I can use this to rewrite everything. Instead of having a list (,t) to be in a specific field configuration at time t, I can rewrite things in terms of new lists (n,p,s,t). The probability amplitude to have n particles with momentum p and spin s. Basically this is just the old lists (,t) rewritten to be probability amplitudes for possessing particle quantities rather than field configurations. Since we're working with quantum theory and probability amplitudes the particles are automatically quantum mechanical. Also since the original field configuration probability amplitudes obeyed relativity and causality, the new particle ones will as well. Voila!, a theory of relativistic quantum particles. Depending on the field we used at the beginning we get a different kind of particle when we rewrite the lists. If we use the electromagnetic field, we get photons and if we used something called the Dirac field we'd get fermions or matter particles. (If anybody is familiar with linear algebra, a Hilbert space is just a type of vector space and rewriting things in terms of particle quantities is just choosing another basis for the vector space.) Next time Feynman diagrams and renormalization.


Son Goku Inactive Member 
Yep, and my personal view is exactly as you suggest  I view this as backwards, even though it is the obvious chronological approach. I think we get tricked into reading too much into quantum mechanics by taking it before QFT.* I used to debate this for hours with a colleague who thought much as you did  he was very much into the preeminence of Hilbert space  or Pontryagin space in his case, as he loved his indefinite norms
To make this interesting I present a counterexample to both our positions. (Although the counter example to my position is a bigger problem than the counter example to yours.) First the counterexample to my position. Which is the "double well" quartic interaction scalar field theory or the Higgs field with one component. Here I can build a Hilbert space and define the Hamiltonian of the theory on it. I later discover that scattering processes with initial states in this Hilbert space have no final states in the space. However, if I take the fields and use their algebra, I find that the fields have three other representations, besides the one I'm using. If I direct sum the Hilbert spaces of the three other representation and my original one, then indeed all initial states have final states in this larger Hilbert space. Hence there is certainly no way a Hilbert space first approach is going to achieve this. I must look at the representation theory of the fields. Second the counterexample to your position. This is the fact that even though the fields have different representations (infinitely many) in most interacting field theories only a few or even only one are actually correct. In all others the Hamiltonian will not be defined. This means that many interacting theories are associated with just one representation and hence a specific Hilbert space. The theory is tied to a certain Hilbert space. (Warn me if you feel this has strayed too far away from standard physics and into axiomatic field theory. Unless you enjoy axiomatic field theory.) Edited by Son Goku, : Less generic title


Son Goku Inactive Member 
For anybody interested....
The discussion between myself and cavediver can be understood in the language of my message #56. I mentioned mathematical devices called operators which you can use to extract information from lists in the Hilbert space. It turns out (to cut things short) that all the information in a Hilbert space can be gotten at by the operators and that, in a certain sense, all the information is already in the operators to begin with. In fact one could start with the operators and use their information to build the space. I In the language of message #56, instead of using operators to extract information from the lists, one can extract information from the operators and rebuild the lists. This causes a question to arise, which comes first the operators or the Hilbert space? It's a big discussion in mathematical physics and investigation of it has lead to the discovery of new physical phenomena. My view is the older conservative one, which may be considered unusual as I am younger than cavediver.


Straggler Member (Idle past 198 days) Posts: 10333 From: London England Joined: 
A Hilbert space is then the set of all these lists or the set of all (,t). (Basically Hilbert Space is a space where each "point" in the space is a specific (,t)) So a Hilbert space is a space of points where each point is a probability amplitude of all the possible field configurations. Each probability amplitude is itself infinite because the number of possible field configurations is, in practise, infinite. So what decides how many points there are in a particular Hilbert space? Is the number of points also infinite in practise? Or not? How many would there be to represent your 4 possible field states? How many dimensions does a given Hilbert space have, what decides this, what do these dimensions physically reperesent? Apologies if the questions are dum but if they are I doubt I am alone in my lack of comprehension............


cavediver Member (Idle past 3776 days) Posts: 4129 From: UK Joined: 
Warn me if you feel this has strayed too far away from standard physics and into axiomatic field theory. Unless you enjoy axiomatic field theory. No, this is great. I just wish I wasn't so damn busy at the moment  I'll get back to this as soon as I can. ABE
In all others the Hamiltonian will not be defined. This means that many interacting theories are associated with just one representation and hence a specific Hilbert space. The theory is tied to a certain Hilbert space. Could this simply be a sign that we are dealing with effective fields in 4d rather than the original fields in ddimensions? Whichever "GUT" (i.e. Sugra, strings, M, etc) we are considering, we are breaking many symmetries to arrive at our target space. Once we lift back up to the unbroken theory, we should regain rep "invariance"  it would be great to make a toymodel of this. Can you provide an example for us to work with? Edited by cavediver, : No reason given.



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