Quote:Original post by MooMansun
http://hypertextbook.com/facts/2000/DannyDonohue.shtml

World Book Encyclopedia. Chicago: World Book.

"The diameter of an electron is less than 1/1000 the diameter of a proton. A proton has a diameter of approximately 1/25,000,000,000,000 inch (0.000000000001 mm)."

< 10 -18 m

Ok, perhaps you missed the "less than" part then. The table simply states the experimental limits at different times. Even your own source says: "The electron is a point-like particle - that is, a particle with no measurable dimensions, at least within the limitations of present-day instrumentation."

Quote:Original post by MooMansun
Again, it depends on the model you use. The quantum model is theoretical and thus pointless to refer to, unless you want to work on a theory. For quick computations with a good resolution, the values work best.


"As a physical concept, the classical electron radius has been outdated by the advent of the quantum mechanical description of the electron; however, the value is still useful as a point of reference."
http://en.wikipedia.org/wiki/Classical_electron_radius

Aye, the Bohr model of the atom is still taught and used even at the graduate level. Why? Because it's still useful.

I suppose it's something like on a long car trip with a friend, she would spit out numbers asking "What's A divded by B?". My scientific training has taught me to be somewhat lazy and only force the result to be known within tolerance. Of course, there's quite a different tolerance when one's trying to figure out average speed (+/- a few mph is acceptable) or gas mileage (+/- a few mpg is not acceptable). Of course, she took delight in withholding this information. Of course, A and B are only known within a certain precision, so, in a way, there's no "right" answer to begin with.

Quote:Original post by MooMansun
Again, it depends on the model you use. The quantum model is theoretical and thus pointless to refer to, unless you want to work on a theory. For quick computations with a good resolution, the values work best.

Lol. missed this one. Aren't classic physics "theoretical" too? [lol]
If you simulate electron spinning around nucleus ala how Earth spins around Sun, all your hydrogen atoms will be different, depending to orbit radius, inclination, etc. Not to mention that if you simulate classic electromagnetism properly, electron simply falls onto nucleus emitting some light in process.
Said "good resolution" ends at level larger than single atoms. in this context instead of "good resolution" there should be "pretty much nowhere near obervations". I.e. the only correct thing you could get is that electron somehow hangs around nucleus.

Quote:Original post by Max_Payne
How do the electrons maintain their energy levels?

I suppose you mean energy levels as energy of electron in the atom, on certain "orbit". There are discrete orbits electron can be on, and in multi-electron atoms, these orbits have rather interesting shapes. Such things can be computed/explained only using quantum mechanics. (with classic physics you just get sorta solar system of point electrons spinning around atom, and besides "electron is somewhere around nucleus" it is almost purely fictional)

some info
some more info
(and use google)

At scale of individual atoms and electron orbitals in atom, any simulation you can do with classic physics will not resemble reality a smallest bit (let alone give "good precision"), and QM is computationally expensive to simulate.
But you can make virtual particle accelerator "simulation" that uses table of reaction areas and resulting products (and doesn't really _simulate_ things), or something like that. Or you can write near purely fictional "simulator", something like pool game but with charged balls, force fields, and other stuff. BTW, that may be really fun game to play :-)

(I'm saying that not to discourage you of course. Just think that precision issue needs to be clarified)

edit:
wikipedia entry
very cool gallery of orbitals

[Edited by - Dmytry on October 9, 2005 1:55:03 PM]

They built the atom bomb without quantum mechanics, if it worked then, it will work now.

Quote:
They built the atom bomb without quantum mechanics, if it worked then, it will work now.

They did not simulate nuclear reactions itself. To make bomb, you need to simulate hydrodynamics (of explosion) and neutron density, using experimental statistics of nuclear interactions (i.e. from experiment it was known that neutron capture probability is a, fission probability is b, and so on). For macroscopic things like airplane, or combustion engine, or atom bomb(despite the name) you do not need to simulate individual atoms. Of course classic physics are okay for combustion engine or other macroscopic stuff. But the topic of this thread is simulation of individual nucleus and individual particles. If Max would be asking about simulating nuclear reactor or other macroscopic stuff...

By the way, good analogy: even today we can't simulate chemical reactions well, yet alchemists and later chemists did a lot of empiric stuff before any physics.

I actually suggested such approach - to use tables (i.e. tables of experimental data or theoretical predictions made by somebody else, or whatever), and not simulate the nuclear interactions.

Quote:From my post
But you can make virtual particle accelerator "simulation" that uses table of reaction areas and resulting products (and doesn't really _simulate_ things), or something like that.

- that's what things you can do with classic physics.(and even there you probably would want to use SR)

[Edited by - Dmytry on October 10, 2005 4:57:49 AM]

Have fun

http://en.wikipedia.org/wiki/Wave-particle_duality
http://www.falstad.com/mathphysics.html#qm
http://www.fen.bilkent.edu.tr/~yalabik/applets/collapse.html
http://www.imaph.tu-bs.de/qi/monty/

Wow this is really cool; do not forget that attack the problem in 11 or maybe 26 dimensions (Kalusa). I hear interesting things about gravity and higher dimensions.

I cannot wait for the solution of the unified field theory that Einstein could not solved for so many years. And here the brilliant minds of the more advanced forum members will solve by the stroke of a goggle search, and in real time.

Are we on the verge of a new epoch on the field theory? Shall we say the age of the Real time Unified Field Theory Engines?

Those scientists at Fermilab, Corners, Princeton, MIT just to mention a few will be ashamed, and at the same time very grateful.

Actually, nuclear fission uses fusion to initiate the fission reaction (from what I remember). In doing, it ejects the neutron which then causes a cascade, critical mass. Rather like a quantum bullet effect.

Anonymous Poster, if a unified field theorum was found, you would never hear about it. In such a theorum, gravity would be described perfectly.

Nuclear bombs would then be upgraded to gravity based weapons. A single weapon of this magnitude would destroy the planet and most likely our solar system with it. An instant black-hole.

If somebody does have it, or is working on it, you had better pray to God that they do not misuse it, or 6 billion people will know what it is like to be flushed.

I once saw a video of the Manhattan project and it did not look to me that Oppenhimer and his team were preoccupied with such detail as simulating individual atoms, considering they were putting thing together with masking tape.

Quote:Original post by Dmytry
They did not simulate nuclear reactions itself. To make bomb, you need to simulate hydrodynamics (of explosion) and neutron density, using experimental statistics of nuclear interactions (i.e. from experiment it was known that neutron capture probability is a, fission probability is b, and so on). For macroscopic things like airplane, or combustion engine, or atom bomb(despite the name) you do not need to simulate individual atoms. Of course classic physics are okay for combustion engine or other macroscopic stuff. But the topic of this thread is simulation of individual nucleus and individual particles. If Max would be asking about simulating nuclear reactor or other macroscopic stuff...

So will this “hydrodynamics (of explosion) and neutron density” be able to simulate atoms at 60 or 30 fps? I think IBM and Intel can make a good used of this. They had tried to do molecular electrodynamics for decades without any success.
I will follow the development of this thread very closely.