Ten Scientists Commit Suicide!

[ponderingturtle]

Yes they're discrete, but it seems to me they could still be volume charges.



Unless there was an amazing experiment I missed, cathode ray experiments only showed the electrons had a charge to mass ratio of some value. Milikan's oil drop experiment then determined the charge, and that allowed calculation of the mass, which they found to be a small part of an atoms mass. But I'm not aware of any experiment that measured a spatial size of electrons. There are semiclassical electron sizes, and I don't think any of them are based on experiment, and I'm not too sure anyone really believed they were true.

It is not about if they are a true point partical or not, it is that regardless if they have some volume or not, it is so small compared to atoms and nucleons that its size can be be safely ignored for these interactions. If it has a radius or not doesn't matter if it is on a totaly different scale than everything else you care about.

So they knew that compared to everything else it did not have a size that was relevent and could be treated as a point particle and get accurate results. That is all physics ever does, it is all about aproximations like this.

Do electrons have a volume? I don't know and I don't have not seen it matter

 

[Dilb]

It is not about if they are a true point partical or not, it is that regardless if they have some volume or not, it is so small compared to atoms and nucleons that its size can be be safely ignored for these interactions. If it has a radius or not doesn't matter if it is on a totaly different scale than everything else you care about.

So they knew that compared to everything else it did not have a size that was relevent and could be treated as a point particle and get accurate results. That is all physics ever does, it is all about aproximations like this.

Do electrons have a volume? I don't know and I don't have not seen it matter

I still have to disagree. A spherical charge distribution is pretty much indistinguishable from a point charge, so even when something is obviously not a point charge it can have the same field. I still think it wasn't obvious that it's volume was small compared to atoms, in general. Just because electron might have a larger volume doesn't mean things are going to 'hit' it and scatter. The 'solidness' of matter is caused by the outer electrons applying an electric force against each other, so it seems reasonable to think that other particles can pass through the electron and are only affected by the electric field. With the small field of individual electrons this makes the size irrelevant for most experiments, but it doesn't mean the electron is small.

 

[ponderingturtle]

I still have to disagree. A spherical charge distribution is pretty much indistinguishable from a point charge, so even when something is obviously not a point charge it can have the same field. I still think it wasn't obvious that it's volume was small compared to atoms, in general. Just because electron might have a larger volume doesn't mean things are going to 'hit' it and scatter. The 'solidness' of matter is caused by the outer electrons applying an electric force against each other, so it seems reasonable to think that other particles can pass through the electron and are only affected by the electric field. With the small field of individual electrons this makes the size irrelevant for most experiments, but it doesn't mean the electron is small.

A sphereical charge distrobution is indistingushable from a point charge, unless you hit the sphere. So if it was not obvious why did the plum pudding model(the standard before rutherford's experiment) have the electrons as small items with in the larger positive charge of the atom?

That model shows that electrons where concidered to be much smaller than an atom, it is built on that principal. So why are you saying that this idea was not understood at the time of discussion? The accepted model of the atom had electrons being very small compaired to the rest of the atom. What rutherford showed was the the real pieces of the rest of the atom where small as well.

You don't seem to have a good grasp what was known at the time being discussed. If no one new that electrons where very small compaired to atoms, why was the commonly accepted model using such a definition of electrons.

As for the solidity of matter, that understanding was a result of learning that most of matter is empty space, and that was discovered by rutherford when he discovered the nucleous.

 

[Dilb]

A sphereical charge distrobution is indistingushable from a point charge, unless you hit the sphere. So if it was not obvious why did the plum pudding model(the standard before rutherford's experiment) have the electrons as small items with in the larger positive charge of the atom?

I've never seen the plum pudding model use tiny electrons. Having just browsed through the two historical articles from wikipedia neither say anything about size, expect as an assumption in order to try and model what would happen in a plum pudding atom. If it was commonly accepted that electrons were points I really would have expected to have heard about it at somepoint.