Notion of matter, space and time

[wuliheron]

Originally posted by Eh
Spin has to do with energy, and the properties of fields such as EM do as well. So the uncertainty applies there. Really, it's not really debatable. The uncertainty principle by definition, only deals with the energy and position. It does not make the metaphysical claims you say it does.

Exactly, they are all inter-related and which position you choose to view the subject from is entirely subjective. Is it really merely energy and position, shape and spin, or whatever? To assert that it is merely the position and energy levels is to assert the reductionist position which remains unproven and, in fact, is contradicted by the theory itself and the observational evidence.

 

[Eh]

They are all fundementally the same thing. So the uncertainty of position and momentum of a particle can be related to the equivalent for fields. Remember that quantum theory is a theory about energy. It is not a theory of space and time, and it certainly is not a theory about the laws of physics. In fact, quantum field theory itself is built on these physical laws, (the postulates of special relativity are included) and requires a backdrop of spacetime.

So QM in its current state does not say there is no metaphysical basis for nature. A quantum theory of spacetime simply does not yet exist.

 

[wuliheron]

Originally posted by Eh
They are all fundementally the same thing. So the uncertainty of position and momentum of a particle can be related to the equivalent for fields. Remember that quantum theory is a theory about energy. It is not a theory of space and time, and it certainly is not a theory about the laws of physics. In fact, quantum field theory itself is built on these physical laws, (the postulates of special relativity are included) and requires a backdrop of spacetime.

So QM in its current state does not say there is no metaphysical basis for nature. A quantum theory of spacetime simply does not yet exist.

Again, exactly! Quantum theory is an ad hoc theory arrived at by default precisely because no other theory at the time could describe what was being observed. Whether or not such a theory can be said to possesses a metaphysics or not is extremely debatable and the subject of controversy. Exactly what QM describes and does not describe is the entire focus of the theory!

 

[Eh]

There is no debate though, that current quantum theory does not describe spacetime itself. In fact, quantum theory assumes a fixed background of some absolute spacetime metric in which events of the quantum world take place. Since spacetime seems to be fundamental in nature, it will take a TOE to see what metaphysical claims about the ultimate reality of the world quantum theory can make.

In it's current form, QM is not contradicted by Einstein's famous equation, and simply does not deal with the issue of space and time.

 

[r637h]

Thank you for your answer concerning spin.I suppose spin is considered a quantum unit. The same way with quarks: since they have mass, they must obey quantum principles.

My statement concerning concerning Physics vs. Philosophy (more properly, Metaphysics) was intended as analogy, not a logical proposition.

Back to Planck: I believe the hypothesis is that, before Planck time,
there was no dichotomy between matter and energy. Some believe it was singularity (particle, if you will) and some believe there was only energy; I believe the concepts are moot. The laws of Physics did not exist before Planck time. We can't ever know (a bold statement) what existed before Planck time, because it cannot be measured.

 

[ando]

Question for the gurus:

Have a running debate with a friend of mine that says if I run 1 mile then I will have burned the same energy when I walk a mile. I say that since E=MC2, then the amount of energy I burn increases exponentially as I increase my rate of travel. Does anyone have a difinitive answer to this question? Could you possibly quote sources or provide a URL to an essay or article that explains this?

 

[FZ+]

You are both wrong.

Your friend is wrong because the way your body does work is not an ideal system. You are not working up some potential or something, but rather the running or walking movement, and the use of your muscles is extremely inefficient. There is an optimum rate of motion for your muscles that would save more energy and give the most effective technique, minimising waste heat.

You are wrong because you misuse E=mc^2. E= mc^2 is a conversion formula from mass to energy for resting objects. The human body sadly does not run on nuclear power...

 

[heusdens]

Originally posted by FZ+
The human body sadly does not run on nuclear power...

Sadly? Let us be happy we have all the nuclear power we need, but in safe distance for the next couple of biliion years.