Theoretical Physics

[Karim]

I was listening to a theoretical physicist from Cornell. He covered several topics but two that stood out for me were:

1) He had no way of explaining free will. The smallest component of our being (the vibrating strings of string theory) are all governed by the laws of physics as we understand them. Free will, personalities, consciousness are unexplainable with modern day physics. He accepted free will on 'faith' (in a non-religious sense) just as a way of living day-to-day.

2) There is the possibility that our known universe exists inside a black hole and we are approaching the singularity. Obviously there is no way to stop such a reality. If stellar phenomena all start growing/stretching/expanding, well... I don't know why but this possibility (of all the possible possibilities) depressed me even though it has no actual bearing on our lifetimes. The inevitable extinction of the human race is more difficult to bear than the inevitability of individual death.

[st.cronin]

I still think it's a better than even chance we're all living inside a simulation designed by somebody named Solecismic.

[TLK]

but how does this relate to the Indy 500? :D

[Greyroofoo]

It means the race is fixed!

[MrBigglesworth]

1) He had no way of explaining free will. The smallest component of our being (the vibrating strings of string theory) are all governed by the laws of physics as we understand them. Free will, personalities, consciousness are unexplainable with modern day physics. He accepted free will on 'faith' (in a non-religious sense) just as a way of living day-to-day.
What about the Heisenberg Uncertainty Principle? It will always create some randomness in the world that keeps us from having an ultimate destiny and gives us 'free will', even if it is just the illusion of free will.

[RPI-Fan]

What about the Heisenberg Uncertainty Principle? It will always create some randomness in the world that keeps us from having an ultimate destiny and gives us 'free will', even if it is just the illusion of free will.

The Heisenberg Uncertainy Principle, AFAIK, doesn't apply to modern physics -- it's application is limited to quantum physics.

[MrBigglesworth]

The Heisenberg Uncertainy Principle, AFAIK, doesn't apply to modern physics -- it's application is limited to quantum physics.
No doubt it is possible that I just can't wrap my head around it, but I don't see how randomness can be introduced for electrons and then discarded for strings. Do you know of any places I can read about this, because I have never heard about it?

[Surtt]

The Heisenberg Uncertainy Principle, AFAIK, doesn't apply to modern physics -- it's application is limited to quantum physics.


Could you explane? When did quantam physics go into the dust bin?

[Karim]

but how does this relate to the Indy 500? :D
http://dynamic.gamespy.com/%7Efof/forums/images/smilies/tongue.gif So I fell asleep at the wheel...

[TLK]

http://dynamic.gamespy.com/%7Efof/forums/images/smilies/tongue.gif So I fell asleep at the wheel...
DANICA
DANICA
DANICA

Don't worry.... most folks were in the same boat as you......

[Karim]

More on the guy. I must admit to finding cosmology interesting but inevitably beyond my comprehension.
http://www.randomhouse.com/knopf/catalog/results2.pperl?authorid=11013

[RPI-Fan]

More on the guy. I must admit to finding cosmology interesting but inevitably beyond my comprehension.
http://www.randomhouse.com/knopf/catalog/results2.pperl?authorid=11013

I don't think expressing an interest in make-up is a good move on a football board.

:D

[TLK]

DANICA
DANICA
DANICA
DANICA
DANICA

[RPI-Fan]

Could you explane? When did quantam physics go into the dust bin?

The Heisenberg Uncertainty Principle has to do the with the measurement of the elements of quantum physics (namely electrons). Since there are no way you can ever measure the strings in string theory, there can obviously be no error in measurement.

[amdaily]

Here's is a pretty good site about Brian Greene's Nova episode a while back: http://www.pbs.org/wgbh/nova/elegant/

Looks like you can watch it online too: http://www.pbs.org/wgbh/nova/elegant/program.html

[Tara]

Free will, personalities, consciousness are unexplainable with modern day physics. He accepted free will on 'faith' (in a non-religious sense) just as a way of living day-to-day.

*****
As a Physic, I don't deal with Hi-Theoretical research, that's because I've never had a real interest in such abstract topics. I've always considered more important to solve, with the help of well known theories, problems that could really develope our knowledge on 'real' daily-life related matters.

On my personal opinion, Physic can't be used in order to explain personalities, free will an so on. That's not the tasks of natural science, because of 'being' and Physic are on two different level. With this I'm not referring to a religious difference between soul and matter.
What I want to say is that the way a complex system, as a human being, works is out of Physic possibilities.
A human being on the other hand is made also of his personal experience and interaction with other people. Also this things rule on his personality. Talking of physic here would be too fucking complex.

You must have clear that in Physic all the problems scientists deal with, are just an idealization of the real thing. They work using models and most of the problems, even the classical mechanics ones, have only approximated solutions.
So, even if It could be theoretically possible reduce feelings, will and personalities to an amount of elementary physical process, the number of interaction that plays a role in this 'phenomena' should be too hight to solve.

We can't even completely solve, without any approximation a sistem of three interacting bodies, do you think is really possible to deal with the bilions of phenomena taking place when a human is thinking?

Moreover, Quantum Mechanics on a molecular-atomic-subatomic range, and General Relativity on a macroscopic level are the only two big theoretical sistem that actually works. String theory was born to unify this two level but is too far from a real succes in this direction. (Anyway I don't really know enough on this topic, as I've already said no deep knowledge on theoretical physic.)



There is the possibility that our known universe exists inside a black hole and we are approaching the singularity. The inevitable extinction of the human race is more difficult to bear than the inevitability of individual death.

Sun death will lead anyway to the extinction of the human race before before any approach to a black hole singularity...
even if we will destroy ourself before.

[Yossarian]

If you agree that all 'bits' of matter and energy follow the rules of physics (even if you disagree with the current laws!)

And if you agree that everthing that moves in the universe does so because something imparted energy on it and THAT did so because something imparted energy on THAT etc... then there isn't any room for free will.

Free will is a mental construct but underneath it all, we are just complicated mathematical patterns govened by the laws of physic[sic].

[Mac Howard]

I find it difficult to visualise any mechanism that ties the uncertainty of sub-atomic particles to what we like to think of as "free will" in human behaviour. If this free will exists I suspect that, like consciousness, it's something that comes out of complexity not from the physics of fundamental particles.

[Surtt]

The Heisenberg Uncertainty Principle has to do the with the measurement of the elements of quantum physics (namely electrons). Since there are no way you can ever measure the strings in string theory, there can obviously be no error in measurement.

The Heisenberg Uncertainty Principle states there is a limit to the amount of information about a particle. If you measure a particles momentum, it's location becomes spread out and dos not have an exact location. It has nothing to do with measurements. You can not measure what doesn't exist.

[RPI-Fan]

The Heisenberg Uncertainty Principle states there is a limit to the amount of information about a particle. If you measure a particles momentum, it's location becomes spread out and dos not have an exact location. It has nothing to do with measurements. You can not measure what doesn't exist.

You just completely contradicted yourself.

Anywho, string theory can't be proved or disproved with experimental science, so there's no point arguing.

[Surtt]

You just completely contradicted yourself.

In what way?

[Tara]

The Heisemberg principle, as is known, in his simpler form states that:
For two coniugates variables, (position-momentum, time-energy...) the uncertainties are related by the relation (i write this for position and momentum):

dx*dp>=h

where h is the Planck constant. Whitout enter too much in the specific, this simply says that if you know with sufficient precision the position of a particle, you lost info on his momentum---> velocity.

The same can be said on the other coniugated variables.

This principle is the basis of quantum mechanics. In classical mechanics on the contrary you can completely know with absolute precision (limit arise only on stumentation used) all the variables involved with the problems.

[dixieflatline]

Anywho, string theory can't be proved or disproved with experimental science, so there's no point arguing.

Wow that's news to me. I thought that since string theory required an 11 dimensions space(see <a href=http://arxiv.org/pdf/hep-th/9503124>Witten</a>) that you could disprove it by ruling out extra dimensional space. You learn something new everyday. Actually, you might want to tell the people who currently are seaching for extra dimensional space at <a href=http://www.if.ufrgs.br/~jgallas/BIBLIO/PR_focus.html>Washington</a>, who are using torsion pendulum, and <a href=http://www.fnal.gov/pub/today/archive_2004/today04-06-17.html>Fermilab</a>, who are using a huge particle collider. They haven't found any evidence yet but there is a lot of "space" still yet to look.

BTW, I for one, would really like it if string theory isn't the answer.

[Tara]

BTW, I for one, would really like it if string theory isn't the answer.

I totally agree.

[RPI-Fan]

Wow that's news to me. I thought that since string theory required an 11 dimensions space(see <a href=http://arxiv.org/pdf/hep-th/9503124>Witten</a>) that you could disprove it by ruling out extra dimensional space. You learn something new everyday. Actually, you might want to tell the people who currently are seaching for extra dimensional space at <a href=http://www.if.ufrgs.br/~jgallas/BIBLIO/PR_focus.html>Washington</a>, who are using torsion pendulum, and <a href=http://www.fnal.gov/pub/today/archive_2004/today04-06-17.html>Fermilab</a>, who are using a huge particle collider. They haven't found any evidence yet but there is a lot of "space" still yet to look.

BTW, I for one, would really like it if string theory isn't the answer.

You can never say extra-dimensional space doesn't exist, you can only say it has never been found.

[Mr. Wednesday]

While that's true, if you look in enough places, I think you may be able to say with some degree of confidence that it is highly unlikely to exist and researchers' time and money would be better spent on other avenues.

[dixieflatline]

You can never say extra-dimensional space doesn't exist, you can only say it has never been found.

Actually, that isn't quite true either. In fact exactly one extra dimension that solved the theoretical equations has already been ruled out. Here is a <a href=http://moriond.in2p3.fr/EW/2000/transparencies/3_Tuesday/pm/Han/Han.pdf>link</a> to a pretty good talk on the subject. But you are absolutely correct the limits that are set for more than one extra dimension are pretty weak. And indeed if string theory is correct there are 11 dimensions and we don't really have any good bounds on that space yet. Still, there are other predictions that string theory needs that are going to be within our reaches relatively quickly. And just to reiterate:

Down with string theory!

[RPI-Fan]

Actually, that isn't quite true either. In fact exactly one extra dimension that solved the theoretical equations has already been ruled out. Here is a <a href=http://moriond.in2p3.fr/EW/2000/transparencies/3_Tuesday/pm/Han/Han.pdf>link</a> to a pretty good talk on the subject. But you are absolutely correct the limits that are set for more than one extra dimension are pretty weak. And indeed if string theory is correct there are 11 dimensions and we don't really have any good bounds on that space yet. Still, there are other predictions that string theory needs that are going to be within our reaches relatively quickly. And just to reiterate:

Down with string theory!

My biggest issue was with the application of Heisenberg's Uncertainy Principle. It really hardly related to string theory.

[MrBigglesworth]

My biggest issue was with the application of Heisenberg's Uncertainy Principle. It really hardly related to string theory.
It relates to M-theory, but you are thinking of it as a position-momentum thing only when, as Tara pointed out, any conjugate variables obey the uncertainty principle. In string theory, it is the vibrations of the string that are quantized. The momentum and wave number of those vibrations obey the uncertainty principle.

[dixieflatline]

My biggest issue was with the application of Heisenberg's Uncertainy Principle. It really hardly related to string theory.
Yes your absolutely right about that. I just didn't want people to think that we won't ever be able to test string theory.

[Tara]

This thread make me think little more about this Hi-Theoretical stuff. For my work just a deep knowledge of quantum theory is needed...so I've always 'forgotten' to get interested in matters as string theory....
So yesterday I've read a related book....no bad. This stuff is directed much more far than I supposed. And even if a TOE (theory of everything) based on a vibrating sting concept could sound a little strange of science-fictional, that's the biggest thing around at the moment.
...in the end also Quantum theory sounded, in the past, really strange and out of any classical logic ...

Finallt I just want to point out something i wrote yesterday that at a second reading could be misunderstood.

What I want to say is that the way a complex system, as a human being, works is out of Physic possibilities.
A human being on the other hand is made also of his personal experience and interaction with other people. Also this things rule on his personality. Talking of physic here would be too fucking complex.

when I says it would be complex, I'm talking about the mathematical model that support the physics.
No new phenomena in brain, just to much interaction---->too much equations and variables---->computational problem.