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vetiver
11-17-2007, 01:01 AM
So I have this eccentric philosophy professor that started talking about matter, why quantum mechanics is wacky, and how electrons and quarks have been found to not actually exist three-dimensionally, but only as point particles. Is this accurate? How the hell do you wrap your head around this possibility, and can these things have mass?

thylacine
11-17-2007, 01:34 AM
[ QUOTE ]
So I have this eccentric philosophy professor that started talking about matter, why quantum mechanics is wacky, and how electrons and quarks have been found to not actually exist three-dimensionally, but only as point particles. Is this accurate? How the hell do you wrap your head around this possibility, and can these things have mass?

[/ QUOTE ]

Your philosophy professor isn't eccentric. He's just a bullsh!t artist.

vetiver
11-17-2007, 02:57 AM
I don't think the two are mutually exclusive. Can you tell me anything about the matter?

madnak
11-17-2007, 04:49 AM
From wiki (http://en.wikipedia.org/wiki/Electron):

"The electron is currently described as a fundamental particle or an elementary particle. It has no substructure. Hence, for convenience, it is usually defined or assumed to be a point-like mathematical point charge, with no spatial extension."

Kaj
11-17-2007, 10:21 AM
[ QUOTE ]
From wiki (http://en.wikipedia.org/wiki/Electron):

"The electron is currently described as a fundamental particle or an elementary particle. It has no substructure. Hence, for convenience, it is usually defined or assumed to be a point-like mathematical point charge, with no spatial extension."

[/ QUOTE ]

You missed the first line in Wiki:

http://i84.photobucket.com/albums/k27/tyrus_donovan/Untitled-1.jpg

<font color="white">Had to post image before my edit gets erased. </font>

Borodog
11-17-2007, 12:17 PM
[ QUOTE ]
Can you tell me anything about the matter?

[/ QUOTE ]

A+

Max Raker
11-17-2007, 01:00 PM
People determine the structure of particles by analyzing scattering patterns. Basically you shoot a bunch of high energy particles at an electron and see where they go after they interact with the electron. Scattering from a point particle has a certain pattern and deviations from this are evidence of structure.

When the nucleus was first discovered people treated it as a point particle, but then they found that if they shot particles with high enough energy at it internal structure was present. For a long time people considered the nucleus to be made of a collection of point particles, the proton and neutron. Later they found out that the proton and neutron have structure as well and are made up of quarks. This concept was first developed theoretically but there was some experimental verification later.

So basically we can say that if the electron has any structure it has to be smaller then a certain distance, not sure what this is off the top of my head, but much much smaller then protons. Basically there has been no reason, theoretical or experimental, to treat the electron as anything other than a point particle.

vetiver
11-17-2007, 02:04 PM
Crazy. Thanks for the responses. If everything is just a collection of 2-D points we must be living as cartoons.

madnak
11-17-2007, 08:14 PM
Well, it's just simple to model it that way. We can never know what a fundamental particle actually "is," only how it behaves. So our models are really just descriptions of how particles behave.