Quantum Physics?

KnightoftheRose

Well-Known Member
I feel kind of retarded for posting this, but what exactly IS quantum physics? I understand it has something to do with submolecular particles, or something like that, but how exactly does it work, and what does it prove? I couldn't find any really nice websites which directly answered those two questions...at least not in a manner this pitiful brain could comprehend . Anyways, sorry for the dumb post, but we'll never learn if we don't ask

physics is out of work!!

Hello Knight, here is a dialogue that you might find useful if you really would like to go into deeps of physics in your search of the theory of everything..

My '8th friend' who is a real freak in moleculer science and his friends who are also freaky personnas dealing in quantum physics have really fun to watch debates. Let me quote this from another forum... i thought you might find this interesting... really...

--- Has anyone ever thought of describing the universe as just a large set of numbers. << all say YES WE DO

For example a universe with 1 particle and 2 positions and 2 time intervals would be described as a table:
Particle Time Position
0 1 0
0 2 1

This universe only lasts 2 time steps and has one particle. Extrapolating to a real universe with a about 1000 physical measurements and 200 decimal precision for each for 10 to the 500 particles etc.
we could get (10 to the power of 1000) numbers; Or in rearranging the numbers a universe that is a number with (10 to the power of 1000) decimal places.

By the way all possible universes would be :

10 to the power of (10 to the power of 1000) or 10^(10^1000).

Physical laws would be just extracted regularity from all these numbers by deliming areas and relating areas of numbers. The universe in this picture is just one large number chopped up in various ways to related various areas of regularity.
Strange idea but interesting ...... ?

----- This idea seems true as we use mathematics to describe physics
but ... your theory would be very non-predictive and inelegant. By describing the universe in this way we gain nothing. What we want to do is have some mathematical laws which tell us how to 'work out' what your numbers should be. In your setup, if you have all the numbers except the last one, you cannot predict what it is - you have to measure it. If you have a law, then you would be able to predict that number, and test it with experiment.

---- If quantum mechanics is correct and the universe does contain a truly fundamental 'bit' of information then yes, the universe can be desribed as a number. A very large number could describe the universe as it stands at some snapshot in time. However, such is the case with any raw binary, its relevence is limited to the mathematics you choose to interpret it with. As severian rightly points our, the mathematics we use are chosen for us by the laws of physics. So while it would be useful to know the universes overall state at any point in time without solid physical principles to meaningfully relate and interpret the data it becomes largely useless.

One of the finer points of this method is related to information/matter/energy conservation. If we know how much of each is floating around out there it would help alot with our theorising. The problem is of course, the universe is a really big place and counting all those digits may take longer than the age of the universe itself.

---- God is a number a'right?. And this number is 10^10^10^3.

A 2 hour dvd contains 10^10 numbers. There are therefore 10^10^10 possible films ever. I'm doing the same with the universe considering
every concievable measurement at 10 to the minus 100 seconds and meters for all the universe for all of time etc. (if you need more precision just put it to 10^4 etc)

Therefore a number with 10 to the 10th power to the 10th power to 3 comes out. If we line up the numbers its, still just about that big.

Try to abstract more. A person in one of these universes is a group of numbers. All laws are onlygroupings of numbers relative to others.

There is no magic anymore in mathematics like physics thinks because a given universe has some numbers organized according to a regularity like 1/r^2. It's just one of the combinations. It's quite abstract ....

---- Abstract enough to be far from the realm of physical reality. While I understand your premise I don't think the arbitrary selection of the numbers you've choosen to justify your reasoning are helping convince me of anything other than the universe being really really big. I didn't need any numbers to tell you that.

---- Oh man, I'm trying to get at 2 points here:

1) it's strange that physics thinks that math is magic; after all the 3 body problems are all really hard , high temp superconductivity is
hard, turbulence is hard etc. So maybe we perceive magic in some basic formulas because they casually end up corresponding to reality
sometimes.

2) If the "it from bit" thing is true , then this theory of mine is relevant, and a good simulation on computer is real just as matter and where is the limits at that point ? We can simulate new physics particles whatever and it is reality ...

---- Your 'model' would imply that there should be no pattern to the universe because a single number in your sequence is not derivable from the others. We know this to be wrong - we can predict physical processes and thus (some of) your numbers. In other words, my friend, all of the manifest numbers in the sequence are not independent. The job of physics to determine what these dependences are and exploit them, right?

---- Right. We extract a pattern because it is useful. The concept of pattern is an invention of the mind. Groups of numbers are just groups of numbers. In fact there are probably a huge number of partial patterns and associations that can be seen as other kinds of particles, forces, interactions (you can invent as much as you want) and world views (universes).

(silencio...)

I think I can focus the ideas better. If you let a program run that draws on a small screen and cycles through all the combinations, then sometimes something like a face will come out. It is just one of the many combinations. (like the monkey who ends up writing a novel
after typing for trillion of years etc).

Same idea is for the universe as a number. It looks as if there is cause and effect, laws and so on , but it is just one of the combinations.
We are fooled into thinking there are explanations when it is only an illusion.

The theory can be concluded like this. A given group of numbers creates the effect of consciousness. We are only those patterns of numbers that generate consiousness.

So there you go, the Grand Unified theory of physics is achieved. You only have two objects: 1) a large number 2) consciousness and one cause and effect 3) a given set of numbers creates consciousness. It is
like a scalar field where a given set creates our sensation of consciousness. If a theory then has only one explanation, then it is
just an association, a table associating numbers with an effect.

Some consequences of this is that the universe confirms extreme determinisms; in fact it would seem that there is no free will and we
are kind of like zombies executing a fixed program. Another consequence is that anything can occur and it is automatically explained by being just a combination of numbers: a big blue sphere can appear out of nowhere and it needs no explanation because we are
in a sequence of numbers where that corresponding combination is. It is also true that there could be some combination of numbers that create effects we don't know.

This theory is non falsifiable, that is no experiment can demonstrate that it is false. In this respect it is like theories that say "The world is a simulation in a computer of a higher civilization having completely different physics" or that "Everything is in our mind and there is no outside world" etc.

So I should be getting the nobel prize and theoretical physics is out of work.

FMI??

Schrodinger's Kittens and the Search for Reality: Solving the Quantum Mysteries
-John Gribbin

The New Ambidextrous Universe: Symmetry and Asymmetry, from Mirror Reflections to Superstrings
-Martin Gardner

The Elegant Universe
-Brian Greene

o r

The Great Beyond: Higher Dimensions, Parallel Universes and the Extraordinary Search for a Theory of Everything by Paul Halpern (thats quite fun to read)

GOOD luck knight ) you'll need more then that actually ;

regards,
PNGrata

KnightoftheRose said:
I feel kind of retarded for posting this, but what exactly IS quantum physics? I understand it has something to do with submolecular particles, or something like that, but how exactly does it work, and what does it prove? I couldn't find any really nice websites which directly answered those two questions...at least not in a manner this pitiful brain could comprehend . Anyways, sorry for the dumb post, but we'll never learn if we don't ask
I found this on the net. Sorry, I haven't the name of the author, as he didn't sign for it. I suspect it was done for students and explains nicely about quantum physics, the way everbody can understand.

Quantum physics tries to explain the behaviour of even smaller particles. These particles are things like electrons, protons, and neutrons. Quantum physics even describes the particles which make these particles! That's right; the model of an atom that you were taught in high-school is wrong. The electrons don't orbit like planets; they form blurred clouds of probabilities around the nucleus. Protons and neutrons? They're each made of three quarks, each with its own 'flavour' and one of three 'colors'. Lets not forget the gluons, the even smaller particles that hold this mess together when they collect and form glue balls (not a very original name). Why weren't you told about this already? Were you fluent in calculus when you took general chemistry? The quantum model of the atom is much more complex than the traditional model, so most teachers save that stuff for college. (But this doesn't mean that you can't have a basic understanding and impress your friends!) The reason that quantum physics needs complex math to explain the behaviours and properties of small particles is that the world of these subatomic particles is a very bizarre one, filled with quantum probabilities and organized chaos. For example, the exact position and velocity of an electron is very hard to find because attempts to "see" it involve bouncing other particles off of it. By doing this, you've just changed the electron's velocity, so your data is useless. What quantum physics does is give us the statistical probability of the electron's location at any one moment. By learning how these particles act, scientists can better understand the matter which makes up the universe, and the way it behaves (or misbehaves). Quantum physics even plays a part in black holes, where regular physics is thrown out the window and then some!

You may also check this site :
http://www.hpwt.de/Quantene.htm

The level of understanding is higher, but if you are interested by the topic, you'll find it useful.

I see...this reminds me why I decided not to follow in my mother's footsteps and major in something other than science Too many headaches...

Okay, so maybe I'm just blind, or dumb, or both, but how does understanding the quantum model versus the regular atomic model change anything? Scientists seem to have gotten along fine with the original model - I mean, we already have a firm understanding of the electron without benefit of the whole quantum idea, so what does the quantum model actually change? So I guess what I'm asking, is it all theoretical mathematical equations, without practical application - pointless to understand? Or can scientists put any of this to actual good use?

Damn, I'm annoying even myself with this persistant questioning

KnightoftheRose said:
So I guess what I'm asking, is it all theoretical mathematical equations, without practical application - pointless to understand? Or can scientists put any of this to actual good use?
In 1999 two Dutch physicists, Martinus Veltman and Gerardus Hooft won the Noble prize for their theories in quantum physics. It seems their research are useful for the understang of small particles behaviours and as consequence the function of the universe. And yes, they can put this on a good use, for a new generation of quantum computers. It appears such of computer can perform in days what a modern computer needs years.

Ah, I see...why thank you!

So now I'm no longer the drooling idiot sitting at the dinner table wondering what the hell everyone else is talking about when the subject of quantum physics comes up! *big breath from the run-on sentence*

Namaste knightoftheRose,

thank you for the post.

there is a question that you've posed which i've not seen addressed yet.

the "why" of QM.

here's why

so.. you are well aware of classical physics... i.e. Einstein's GR, Special Relativity, Newtons laws of motion etc? what these theories describe is phenomena of a large scale. yes, even molecules are large scale structures in the universe

what was discovered, however, is that classical physics breaks down at a singularity. i.e. the theories that describe how large structures in the universe work, isn't able to be applied to the really small things in the universe, the "quantum" as they came to be called.

these really small bits of the universe, behave very differently then how we normally expect matter to behave.

one of the implications of this goes straight to the heart of one of the major cosmological theories.

If, as the widely accepted Big Bang (Rapid Inflation), is correct, then our normal physics are not able to describe anything inside the singularity.. this has some philosophical implications which are a bit beyond me.. something to the effect of ascertaining how the classical aspects of physics were able change and move from the Quantum level.

of course, it also lends itself to a completely new cosmologial theory or two the one that i'm currently in favor of is the No Boundary Proposal coupled with the Anthropic Principle as proposed by Hawking and Hartle.

And thank you for the post, Vajradhara...

So, what you're saying is that quantum physics are the microcosmic laws of the universe which cannot be described or controlled by the more macrocosmic laws? If so, shouldn't that change all our laws as we know them? Or am I missing something here?

Anyways, I was just wondering if you'd elaborate on what the No Boundary Proposal and the Anthropic Principle are? Just curious, and all that...

KnightoftheRose said:
So, what you're saying is that quantum physics are the microcosmic laws of the universe which cannot be described or controlled by the more macrocosmic laws?
Indeed, the truly microscopic events cannot be properly described by macroscopic laws. However, the reverse is also true.

KnightoftheRose said:
If so, shouldn't that change all our laws as we know them? Or am I missing something here?
The big problem with physics today is trying to find a way to bridge the gap between the micro and macro models. For example, one key problem is that gravity cannot be properly described at the quantum level.

Hope that helps.

Namaste Knight,

Brian has the right of it... the issue is that our observations of both types of structures shows different things!

this is where the M-Theory, the Theory of Everything, is working... to unify the classical physics of large structures with the quantum physics of the micro structures in the universe.

the No Boundary Proposal, in my view, is an extraordinary theoretical model.

here's how Dr. Hawking explains it:

"We have no reason to believe the universe is asymptotically Euclidean, or anti de Sitter. Even if it were, we are not concerned about measurements at infinity, but in a finite region in the interior. For such measurements, there will be a contribution from metrics that are compact, without boundary. The action of a compact metric is given by integrating the Lagrangian. Thus its contribution to the path integral is well defined. By contrast, the action of a non-compact or singular metric involves a surface term at infinity, or at the singularity. One can add an arbitrary quantity to this surface term. It therefore seems more natural to adopt what Jim Hartle and I called the "no boundary proposal". The quantum state of the universe is defined by a Euclidean path integral over compact metrics. In other words, the boundary condition of the universe is that it has no boundary.

the rest of this lecture can be read here:

http://www.hawking.org.uk/lectures/lindex.html

this does presume a certain level of understanding of physics, there are other lectures on the site that are geared towards an audience that is not so specialised.

KnightoftheRose said:
Scientists seem to have gotten along fine with the original model - I mean, we already have a firm understanding of the electron without benefit of the whole quantum idea, so what does the quantum model actually change? So I guess what I'm asking, is it all theoretical mathematical equations, without practical application - pointless to understand? Or can scientists put any of this to actual good use?
It's been a while since I've been on the site, so I missed out on this discussion. Don't know if Knight is still around, but for anyone who was wondering about this, here goes.

The reason we need QM is precisely because we CAN'T understand the electron without it. Specifically, the electron in an atom. Get a diffraction grating spectroscope (I know that sounds hard, but you can get a little pocket one for a couple of bucks - no kidding!) and look at a flourescent light. You don't see a rainbow, you see a series of bright lines. Before QM, there was nothing in physics that could explain those bright lines. You could even say that QM was invented to explain them. By assuming that electrons jump from one energy to another (rather than moving smoothly between them as in "good old" classical physics), QM was able to explain the bright line spectrum.

To put it another way, the old rules of physics simply don't work when we try to apply them to very small objects (like electrons and atoms). The new rules (QM) have proven to be tremendously accurate. They explain the behavior of:
• lasers
• semiconductors (and therefore allow computers, playstations, etc. to be built)
• superconductors
• particle collisions
• nuclear reactions (and therefore tell us why the sun shines)
just to name a few applications off the top of my head!

There are some good books on QM for non-physicists. I'd suggest The Cosmic Code by Heinz Pagels as one place to start.

It's been a while since I've been on the site, so I missed out on this discussion. Don't know if Knight is still around, but for anyone who was wondering about this, here goes.
I'm still here, lurking...

They explain the behavior of:
• lasers
• semiconductors (and therefore allow computers, playstations, etc. to be built)
• superconductors
• particle collisions
• nuclear reactions (and therefore tell us why the sun shines)
Ah, so those are the practical applications of quantum physics? Interesting...

There are some good books on QM for non-physicists. I'd suggest The Cosmic Code by Heinz Pagels as one place to start.
I'll be ordering some books later this week...so I think I'll include that on my wishlist...but just a quick question before I do so. It was published back in '82, it looks like, so is it still accurate, or have there been major changes to the field since then? (I mean, changes serious enough to make me get a more up to date book...)

The basic theory of QM hasn't changed in about 50 years. The Cosmic Code is still a good intro. The basic ideas are all there.

There are newer developments of course. The first step was combining QM with special relativity (SR) into something called relativistic quantum field theory (RQFT). Richard Feynman wrote a wonderful little book called QED: The Strange Theory of Light and Matter, that explains it (probably in more detail than you really want!)

The next step, and the great triumph of the second half of the 20th century, was the Standard Model of Elementary Particles. This is a specific RQFT that brings together all the known particles and their interactions into one theory. A really good book on this is coming out next fall (written by yours truly - tentative title "The Theory of Almost Everything") If you can't wait that long, try James Trefil's From Atoms to Quarks or Tony Zee's Fearful Symmetry.

There are even newer theories, too. The current hot one is "String Theory" - see Brian Greene's books (The Elegant Universe and The Fabric of the Cosmos).