Does an electrical charge have weight?

[winnie]

But does mass have to have wieght?

[...]

I realize it states different planets, but I can only find that electrons are not effected by the gravitational pull of the earth, thereby making them "wieghtless".

Mass and weight are different, but as far as is known, _all_ mass responds to gravity in the same way. The gravitational attraction between two masses is proportional to the product of the two masses and inversely proportional to the square of the distance between them.

If you are on a planet where a kilogram of lead has a weight of 2.2 pounds, than a kilogram of electrons would also weigh 2.2 pounds. Electrons have a known mass, which just happens to be a small fraction of the mass of the proton or neutron. The electrons in an object provide some 1/4000 of that object's weight.

-Jon

 

[winnie]

Photons, of a specific "electron volt" magnitude, have no mass.

[...]

Anything in the reaction that has mass is a particle and has a specific name, including the ones they made up and are still looking for. There is a balancing spreadsheet. In the C + O + O = CO2 + 'x' electron volts, if the reaction gained or lost any mass there would also be a balancing particle with mass in the equation. There is no gain or loss of mass, the change is heat.

I disagree with your premise.

Photons most certainly do have mass. They do not have 'rest mass', but they do have mass associated with their energy content.

A nuclear reaction can emit only photons, yet result in a change in mass.
D + D -> He + gamma

p + e -> gamma

-Jon

 

[__dan]

fusion reaction

fusion reaction

I disagree with your premise.

A nuclear reaction can emit only photons, yet result in a change in mass.
D + D -> He + gamma

p + e -> gamma

-Jon

Gamma is very high energy short wave length EM. I do not believe it has mass. Gamma is evidence of nuclear reaction and mass to energy conversion. Gamma is a nuclear binding energy and it is ionizing radiation.

In deuterium fusion all the mass is accounted for, 2(proton+neutron) >= 2proton+2neutron (helium) + emitted energy and particles.

There are intermediate steps.

http://en.wikipedia.org/wiki/File:FusionintheSun.svg

Gravitational lensing is a better argument for the photon having mass. But it also gets into the argument of the medium of propagation in the "vacuum" of space. It's a good argument, but, the photon has no mass, it is electromagnetic.

Obviously, I am not an Einstein ian

 

[Cold Fusion]

I promised I wouldn't weigh any more electons, so I won't.

But this is still fascinating - not like watching a train wreck. More like watching a mass exodus of lemmings over a cliff. I keep waiting for someone to yell, "I can FFllyyyyy Followed by, "Thump"

 

[LarryFine]

The electrons in an object provide some 1/4000 of that object's weight.

It's a LOT less than that.

 

[winnie]

It's a LOT less than that.

http://physics.nist.gov/cgi-bin/cuu/Value?mpsme

The ratio of the mass of the proton to the mass of the electron is 1836.15267247(80):1

The number of electrons in an object is roughly equal to the number of protons. (Any difference is related to charge on the object.)

The number of neutron in an object is crudely equal to the number of protons. (This is not close to rigorous, just a very rough approximation.)

-Jon

 

[steve066]

1. From the point of theoretical physics E=mc squared
so yes, a capacitor should have weight

As has been mentioned in this thread several times, that equation simply means energy can be coverted to mass and vice versa.

It in no way means that the energy stored in a capacitor has mass or weight any more than it means the energy is traveling at C squared.

Steve

 

[steve066]

FWIW: The energy stored in a capacitor is not stored with the charges on the plates. It is stored in the dielectric of the capacitor. The electric field placed across the dielectric causes the electrons orbits to be "skewed". Basically, as the electrons orbit their atoms, the center of the orbit moves closer to the positive plate, and farther from the negative plate.

 

[Rick Christopherson]

This whole topic is about things on the atomic level. The change in mass may not have anything to do with the change in particle count. What is going on at the atomic level is the real effect.

To dismiss the topic because you can't plop it down on your bathroom scale and see it is asinine.

While some posters have dismissed the topic because it is not understood; to dismiss the topic due to its lack of relevance is another matter altogether. Where the small change in potential energy results in a change in relativistic mass on the order of a handfull of electron masses, in a system where the resolution of even mathematically identifying the equivalent number of electron masses is beyond the resultant change, that is when it becomes irrelevant.

A near perfect change is when an electron and anti-electron mix to destroy each other and produce two photons of zero mass.

What's good for the goose is good for the gander. :grin: If you are going to drive down the road of relativistic mass, then you had better know that photons have a relativistic mass even though they have no rest mass. So...did you choose to dismiss the relativistic mass in this case because it "wasn't relevant"?

As has been mentioned in this thread several times, that equation simply means energy can be coverted to mass and vice versa.

It in no way means that the energy stored in a capacitor has mass or weight any more than it means the energy is traveling at C squared.

Steve

No, that is not correct. While I am disagreeing with the relevance of the application of that equation, I am not disagreeing with the existence of the concept. Special Relativity is not limited solely to the absolute conversion of mass to energy or energy to mass. What Mivey is saying is correct, I am simply contesting the relevance as used here.

 

[Rick Christopherson]

It is typically presented by those that want to show off their alleged knowledge, not for real effect.

By the Way Mivey, when I made this statement, I was not referring to you in any way, but I later got the impression that you thought I might have been. I was actually referring to a person on another forum that keeps throwing this concept into the mix at the drop of a hat, and does so simply to confuse others. Sorry if you took offense.

 

[winnie]

As has been mentioned in this thread several times, that equation simply means energy can be coverted to mass and vice versa.

That is not a correct interpretation of the equation.

The equation means that _matter_ and energy can interconvert, and comes from the principal that _both_ have mass.

-Jon

 

[ZCBee]

That is not a correct interpretation of the equation.

The equation means that _matter_ and energy can interconvert, and comes from the principal that _both_ have mass.

-Jon

I thought energy is mass accelerated to the square of the speed of light. I understand speed and acceleration, but it still does not explain what energy is. If a particle is accelerated to the square of 186K mps it becomes what we call energy and is it or is it not outside the realm of gravity/weight in the form of energy?

 

[steve066]

That is not a correct interpretation of the equation.

The equation means that _matter_ and energy can interconvert, and comes from the principal that _both_ have mass.

-Jon

I'll ask again for a reliable source. I don't think you will find one.

Here is a source (from a high school chemistry lab) that says otherwise:

"Note: A common student misconception is that energy is made of matter and therefore that it has mass. Mass can be converted to energy in nuclear reactions, but this conversion is never seen in normal life on Earth. To help students construct new knowledge, ask them to think about types of energy (heat, light, sound, energy of motion, stored energy). Then ask them: ?How could you find the mass of heat, light, or sound?? Students should realize that it is impossible to do so and that energy is not made of matter. "


Here is the link if you would like to see the entire lab:

http://www.oakland.k12.mi.us/scope/tenth_lessons/science/unit3/SC100304.doc

Steve

 

[mivey]

The charge on a capacitor is, as you know, ? CV^2.
And that charge is energy.

He has claimed to know better, even though his posts don't support his claim.

 

[mivey]

I disagree with your premise.

Photons most certainly do have mass. They do not have 'rest mass', but they do have mass associated with their energy content.

A nuclear reaction can emit only photons, yet result in a change in mass.
D + D -> He + gamma

p + e -> gamma

-Jon

That is correct. Since you can't find a rest frame for them, you can't find the rest mass. As you approach the speed of light (the rest frame for the photon) the mass would approach zero. That is why we say they have zero mass.

 

[mivey]

FWIW: The energy stored in a capacitor is not stored with the charges on the plates. It is stored in the dielectric of the capacitor. The electric field placed across the dielectric causes the electrons orbits to be "skewed". Basically, as the electrons orbit their atoms, the center of the orbit moves closer to the positive plate, and farther from the negative plate.

But that is the point. That energy becomes part of the capacitor "system" and thus part of the system weight.

 

[mivey]

While some posters have dismissed the topic because it is not understood; to dismiss the topic due to its lack of relevance is another matter altogether. Where the small change in potential energy results in a change in relativistic mass on the order of a handfull of electron masses, in a system where the resolution of even mathematically identifying the equivalent number of electron masses is beyond the resultant change, that is when it becomes irrelevant.

Fair enough. The OP was interesting to me. Considering the available resolution would have not been so catching. Dnkldorf cleverly left out a key piece of evidence :grin::

My battery died in my tractor, so I charged it up.

It felt heavier.

What's good for the goose is good for the gander. :grin: If you are going to drive down the road of relativistic mass, then you had better know that photons have a relativistic mass even though they have no rest mass. So...did you choose to dismiss the relativistic mass in this case because it "wasn't relevant"?

Massless is just the way a photon is described. But you are absolutely correct. Add a bunch of photons to a containment box and the mass of that box will increase by the relativistic mass.

 

[mivey]

By the Way Mivey, when I made this statement, I was not referring to you in any way, but I later got the impression that you thought I might have been. I was actually referring to a person on another forum that keeps throwing this concept into the mix at the drop of a hat, and does so simply to confuse others. Sorry if you took offense.

Yeah, it rubbed my fur backward. I apologize for snapping at you.

 

[mivey]

I thought energy is mass accelerated to the square of the speed of light. I understand speed and acceleration, but it still does not explain what energy is. If a particle is accelerated to the square of 186K mps it becomes what we call energy and is it or is it not outside the realm of gravity/weight in the form of energy?

That is not correct. Current physics say nothing goes faster than light.

Mass is another form of energy.

PS: Light is subject to gravity and it has no mass.

 

[mivey]

I'll ask again for a reliable source. I don't think you will find one.

Here is a source (from a high school chemistry lab) that says otherwise:

"Note: A common student misconception is that energy is made of matter and therefore that it has mass. Mass can be converted to energy in nuclear reactions, but this conversion is never seen in normal life on Earth. To help students construct new knowledge, ask them to think about types of energy (heat, light, sound, energy of motion, stored energy). Then ask them: ?How could you find the mass of heat, light, or sound?? Students should realize that it is impossible to do so and that energy is not made of matter. "


Here is the link if you would like to see the entire lab:

http://www.oakland.k12.mi.us/scope/tenth_lessons/science/unit3/SC100304.doc

Steve

Time to graduate to higher physics. The text you quoted is using mass and matter as the same thing and they are not. If I add energy to an otherwise closed system, then I have increased the system mass, plain and simple. Any reliable physics text will say the same. There have to be reliable sources on-line that you could read. Let me know if you can't find any and I'll hunt some up for you.

The specifics of the conversion between mass and energy is debated on many levels, most seem to deal with the underlying definitions. But I don't recall any debate saying that adding energy to an otherwise closed system does not produce an increase in mass of some definition. They debate things like different types of mass, whether mass and energy are the same thing, reference frames, etc.

We convert mass and energy every day. Run a marathon but keep things like hydration a constant and you will convert some fat mass into energy without even one spec of radioactive glow.

Converting matter into energy and vice versa is a whole other....matter. Particle accelerators do such things. I'm not sure if we have a natural process on earth that does that, but we do see it in nature out in space. I wonder about cosmic rays or some natural earth radiation? I guess we could research that some.