Two Plus Two Newer Archives  

Go Back   Two Plus Two Newer Archives > Other Topics > Science, Math, and Philosophy
FAQ Community Calendar Today's Posts Search

Reply
 
Thread Tools Display Modes
  #1  
Old 11-17-2007, 01:01 AM
vetiver vetiver is offline
Senior Member
 
Join Date: Jul 2007
Posts: 212
Default Point Particles

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?
Reply With Quote
  #2  
Old 11-17-2007, 01:34 AM
thylacine thylacine is offline
Senior Member
 
Join Date: Jul 2003
Posts: 1,175
Default Re: Point Particles

[ 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.
Reply With Quote
  #3  
Old 11-17-2007, 02:57 AM
vetiver vetiver is offline
Senior Member
 
Join Date: Jul 2007
Posts: 212
Default Re: Point Particles

I don't think the two are mutually exclusive. Can you tell me anything about the matter?
Reply With Quote
  #4  
Old 11-17-2007, 04:49 AM
madnak madnak is offline
Senior Member
 
Join Date: Aug 2005
Location: Brooklyn (Red Hook)
Posts: 5,271
Default Re: Point Particles

From wiki:

"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."
Reply With Quote
  #5  
Old 11-17-2007, 10:21 AM
Kaj Kaj is offline
Senior Member
 
Join Date: Mar 2007
Location: Bet-the-pot
Posts: 1,812
Default Re: Point Particles

[ QUOTE ]
From wiki:

"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:



<font color="white">Had to post image before my edit gets erased. </font>
Reply With Quote
  #6  
Old 11-17-2007, 12:17 PM
Borodog Borodog is offline
Senior Member
 
Join Date: Jan 2004
Location: Performing miracles.
Posts: 11,182
Default Re: Point Particles

[ QUOTE ]
Can you tell me anything about the matter?

[/ QUOTE ]

A+
Reply With Quote
  #7  
Old 11-17-2007, 01:00 PM
Max Raker Max Raker is offline
Senior Member
 
Join Date: Apr 2005
Posts: 708
Default Re: Point Particles

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.
Reply With Quote
  #8  
Old 11-17-2007, 02:04 PM
vetiver vetiver is offline
Senior Member
 
Join Date: Jul 2007
Posts: 212
Default Re: Point Particles

Crazy. Thanks for the responses. If everything is just a collection of 2-D points we must be living as cartoons.
Reply With Quote
  #9  
Old 11-17-2007, 08:14 PM
madnak madnak is offline
Senior Member
 
Join Date: Aug 2005
Location: Brooklyn (Red Hook)
Posts: 5,271
Default Re: Point Particles

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.
Reply With Quote
Reply


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 03:38 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.