charge

[foursixand2]

a very simple, possibly stupid question. What makes an electron negative, a proton positive? Why do they oppose each other?

[Gilded]

To start with, electrical charge is a fundamental property of some particles. As to what makes electrons and protons have the charges they do, electrons are fundamental particles with charge of -e (e being the "fundamental charge"), where as protons are composite particles containing one down quark which has a charge of -1/3e, and two up quarks that have charges of +2/3e (therefore giving a proton the charge of +e). An electric field is a vector field, and two opposing fields create an attraction between the particles, like this:

 

http://en.wikipedia.org/wiki/Image:EfieldTwoOppositePointCharges.svg

 

Some of the physics expert here can explain it more thoroughly if you want to know more.

[DJBruce]

An electron has a negative charge because I was arbitrarily given a negative charge. Same for a proton. When being named I believe the just chose a name which has been kept. Also I think electrons and protons attract each other.

[Mr Skeptic]

An electron has a negative charge because I was arbitrarily given a negative charge.

 

Arbitrarily, and even accidentally. Many have wished it had arbitrarily been chosen the other way around, with electrons positive and protons negative. Electric current makes more sense that way. However, all the science books with electricity would have to be renamed.

[Mr Skeptic]

a very simple, possibly stupid question. What makes an electron negative, a proton positive? Why do they oppose each other?

 

You could say that it is because the electric field points toward an electron and away from a proton. That really doesn't say much though.

[ydoaPs]

You could say that it is because the electric field points toward an electron and away from a proton. That really doesn't say much though.

 

I think that's pretty much convention too.

[antimatter]

Doesn't spin also have something to do with it?

[Gilded]

Doesn't spin also have something to do with it?

 

Oh noes, don't pull QM into this context. But yeah it has something to do with it, IIRC it's what gives electrically charged particles a magnetic moment.

[pioneer]

Charge is based on a convention. Positive and negative reflect an age old opposition of opposites, like good and evil. It follows the traditional template in the sense the negative principle was of the world and is assigned to the electron and negative charge which fluff up matter to create reality. Pure positive charge is often compacted in terms of nuclei and not as fluffy and is more like the foundation of reality.

 

To start with, electrical charge is a fundamental property of some particles. As to what makes electrons and protons have the charges they do, electrons are fundamental particles with charge of -e (e being the "fundamental charge"), where as protons are composite particles containing one down quark which has a charge of -1/3e, and two up quarks that have charges of +2/3e (therefore giving a proton the charge of +e). An electric field is a vector field, and two opposing fields create an attraction between the particles, like this:

 

The positive charge, when broken down this far is not exactly equal and opposite to the negative charge, since positive is a trinity. If you look at Christian symbolism, God or the positive principle it is also a trinity, with one down aspect or son who came down to earth -1/3e. I am not suggesting a biblical connection, only it is an interesting coincidence. It is possible the labeling of quarks also used this basic symbolism, at an unconscious level.

Edited June 30, 2008 by pioneer

[swansont]

The positive charge, when broken down this far is not exactly equal and opposite to the negative charge, since positive is a trinity. If you look at Christian symbolism, God or the positive principle it is also a trinity, with one down aspect or son who came down to earth -1/3e. I am not suggesting a biblical connection, only it is an interesting coincidence. It is possible the labeling of quarks also used this basic symbolism, at an unconscious level.

 

 

Oh, please.

[ecoli]

I don't think I've ever read something quite that ridiculous before, but kudos for giving me something to laugh at, pioneer!

[alwynj48]

Charge is based on a convention. Positive and negative reflect an age old opposition of opposites, like good and evil. It follows the traditional template in the sense the negative principle was of the world and is assigned to the electron and negative charge which fluff up matter to create reality. Pure positive charge is often compacted in terms of nuclei and not as fluffy and is more like the foundation of reality.

 

 

 

The positive charge, when broken down this far is not exactly equal and opposite to the negative charge, since positive is a trinity. If you look at Christian symbolism, God or the positive principle it is also a trinity, with one down aspect or son who came down to earth -1/3e. I am not suggesting a biblical connection, only it is an interesting coincidence. It is possible the labeling of quarks also used this basic symbolism, at an unconscious level.

 

I guess that must make black holes hell and white holes heaven LOL

 

I always thought that the maths of QM and GR was hell does that make me a bad person LOL again

[ajb]

If you are trying to ask why is electric charge quantised look up the Dirac monopole. So far this seems to be the only explanation.

[Janus]

An electron has a negative charge because I was arbitrarily given a negative charge. Same for a proton. When being named I believe the just chose a name which has been kept. Also I think electrons and protons attract each other.

 

If you want to, you can blame Ben Franklin for giving the Electron a negative charge. During his early experiments with electricity he assumed it was a flow from and excess(+) to a deficit(-). However, he had no way of determining which was the actual direction of the flow. He took a guess and labled one terminal (+) and the other (-). His convention for labeling the terminals was carried on by others. By the time it was determined that the actual current flow ran in the opposite direction, the practice was too deeply entrenched to change easily. The particle found to be the carrier of electricity was of course called the "electron". It has sometimes been called a negatron.

 

If Franklin had guessed the other way, Electrons would have a positive charge and we would likely have negatrons in the nucleus.

[foursixand2]

Sorry i wasnt very specific originally. I wasnt meaning to ask why one or the other was called negative versus positive. I presumed it was arbitrary. What i want to know is what is the fundamental principal that makes them opposites. I think Gilded comes closest to answering that, though i need to do some reading to understand what all that means. I guess i'll look up the Dirac monopole too.

[ajb]

The best explanation as why there are two electric charges, i.e. positive and negative is due to the fact that electromagnetism has the gauge group [math]U(1)[/math].

 

The charge associated with the Noether current generated by the gauge symmetry is what we would call the electric charge. If you do this carefully, you get positive and negative charges. This will not explain why they are quantised in units of the electron charge.

 

I don't know what you know of classical and quantum field theory and if I should say much more about his.

[foursixand2]

not much. I am very interested in science, and consider myself scientifically minded, however i did not apply myself in high school, and alas i am currently employed as a convenience store clerk at a gasoline station. Which obviously does not provide me time and money for further education, beyond my internet connection. So for now wikipedia and scienceforums are closest i come to college. Not that you wanted to hear my sad story but there it is anyhow.

[steiner]

^My advice - get a good text book geared towards some sort of qualification. Read the textbook, do the questions, if you have problems ask on the internet. Then, when you're ready, take the exam.

 

Thats assuming you want some qualifications in something scientific.

 

I say this because I understand far more cosying up with a well-written text book than I ever did at school. A little boring, but worth it.

 

(Sorry for getting off topic)