Does an electrical charge have weight?

[chris kennedy]

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

It felt heavier.

Are you kidding me???:grin::grin::grin:

This is the best thread ever!

0912125-1421 EST



The flow rate of the St Clair River is 182,000 cu-ft/second, at Niagara the rate is 212,000 cu-ft/second. Over the falls it is 100,000 during the day and 50,000 at night.

I'm not following the highlighted statement. I read that as the volume that flows over the falls slows at night. I know thats not true.

 

[charlie b]

But adding charge (or energy) to a system does change the weight. Shame on you if you were inferring otherwise as you should know better.

That is because the only available way to add charge is to add electrons, or add protons, and that process is what adds weight. The charge itself has no weight, nor does it have mass. And while I am on a roll, I will add that charge itself has no energy either. It takes energy to move something that is charged, and a charged item in motion is a form of energy. But the charge itself, not the electron upon which it resides, is not a form of energy.

So you see, I do know better. And it is the listener (or reader) who infers; the speaker (or writer) implies.

 

[Dnkldorf]

Are you kidding me???:grin::grin::grin:

You not around for the whole "Does a electron oscillate" discussion?

You should here how I thought of that question.

 

[skeshesh]

This is out of my realm but when you charge a capacitor you are adding energy (stored) right? So it seems like the mass could change.

There seems to be a lot of information on this on the net as in this article:

http://www.intalek.com/Index/Projects/Research/TRANSIENT%20MASS%20FLUCTUATIONS.htm

Search for "capacitor". There are other references to a person named "Woodward" in terms of a capacitor changing mass with a charge change.

Curse you ELA... (*shakes fist)

I just spent a good part of lunch reading the article you posted. What I hate about reads like this is that some of the claims seem very outlandish yet I don't quite recall all the equations/effects well enough to refute it to my satisfaction. One thing I'll say is present in the article and the two referrences: the author makes claims of specificity in many places while he's using huge approximations to get rid of effects/variables. But anyway I'm gonno try to get home and read the rest of this absurdity.

 

[mivey]

I'm not buying it. I would also like to see a reference. Like the example Charlie gave, a brick on a table has more potential energy than a brick laying on the floor, but the mass of the brick is the same.

I don't see why you think more energy means more mass.

Steve

Mass is just a form of energy. The battery is not full of photons (it is not a perfect light box) so what do you think happened to the energy that was pumped into it?

 

[mivey]

I don't know if we have any measurement tools that could detect the mass difference between fuel + oxidizer and combustion products. I've not looked recently, so it entirely possible that such measurements have been made.

But we can look at a somewhat higher energy system, and we can clearly measure mass differences between two different arrangements of the same particles. For example: two Deuterium atoms can be combined in a nuclear reaction to make one Helium atom. The mass of both Deuterium and Helium is known well enough to see a difference, and that difference is accounted for by the energy released in the reaction.

-Jon

Yes. A nuclear reaction is a case where we can actually measure the change in mass to energy. Even then it is only about 1% of the mass that changes.

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

 

[mivey]

Now it's a party.

The point charge model of the electron is a non physical, non deterministic algorithm. Using the point charge electron model in a classical physical sense, physically having position + momentum + acceleration, leads to contradictions and obviously defective conclusions. A moving point charge would radiate which is not observed. The electron would be drawing energy from an infinite source to maintain its orbit. The electron would change its parameters in its distribution, position, momentum, by not moving (if it moved it would radiate). The electron changes by being observed.

The mathematical descriptions at the subatomic level are statistical. To take a nonphysical model and then try to say it has a mass increase or decrease, you do not have a mass change, you have a collective neurosis.

As already stated above E=M*C^2 is associated with a method of nuclear energy conversion, fission, fusion, pair production. Without a reaction there is a mass equivalence in energy but no change from one form to another. If there were we would drop another orange peel into the Mr. Fusion engine.

It does not require a nuclear reaction. It happens all over the earth every day.

 

[mivey]

OK but that's a nuclear reaction (either fussion or fission or something similar.) I don't think anyone is going to argue that mass and energy are converted back and forth in those types of reactions.

And Mivey gave an example of a standard chemical reaction. Again, I agree that some mass may be converted to heat in a chemical reaction.

But for a capacitor storing an electric charge, no nuclear or chemical reactions take place. Its just a matter of moving electrons from one plate to the other.

Anyhow, I think the original post was probably asking about a significant change in mass due to the storage of extra electrons. And I think we all agree that doesn't happen. If there were any changes in the weight of a capacitor due to E=mc^2 conversions (and I still don't think there are), they would be extremely minute.

Steve

Steve

I agree there is no change that we would be able to measure by a scale or picking up the battery (i.e. significant on a practical scale) but there is a change.

 

[gar]

091125-1701 EST

skeshesh:

The point is to provide some background for those that may not be close to the the concepts of conservation of energy, kinetic energy, and potential energy.

A chemical reaction may require energy or give up energy, but it does not change the total mass. Density may change, but mass does not.

chris:

The difference between the St Claire river and Niagara is additional water that is flowing into Lake Erie.

At Niagara Falls a great deal of the water is always diverted from the falls and into the power plants. Note the difference between Niagara River flow and the Falls flow. 212,000 cu-ft/sec minus 100,000 during the day leaves 112,000 for power, then at night when not many tourists are around the flow is reduced over the falls and fed to the turbines or to very large reservoirs.

The great potential in the great lakes area for renewable energy is there is a vast amount of water for use in pumped storage that provides a very large battery to average day and night or windless vs windy or sunlight vs no sunlight. There are problems with the technique, but it has potential. In Denmark they are experimenting with conversion of electrical energy to dissociated H and O and then back to electrical energy with a fuel-cell. Efficiency is quite low.

.

 

[mivey]

That is because the only available way to add charge is to add electrons, or add protons, and that process is what adds weight. The charge itself has no weight, nor does it have mass. And while I am on a roll, I will add that charge itself has no energy either. It takes energy to move something that is charged, and a charged item in motion is a form of energy. But the charge itself, not the electron upon which it resides, is not a form of energy.

So you see, I do know better. And it is the listener (or reader) who infers; the speaker (or writer) implies.

I'm glad you do know better. Thanks for the english lesson.

 

[Dnkldorf]

I am surprised no one has mentioned gravitational force, and whether electrons are effected by the earths gravitational pull. After all, isn't this where weight comes from any way?

 

[chris kennedy]

At Niagara Falls a great deal of the water is always diverted from the falls and into the power plants. Note the difference between Niagara River flow and the Falls flow. 212,000 cu-ft/sec minus 100,000 during the day leaves 112,000 for power, then at night when not many tourists are around the flow is reduced over the falls and fed to the turbines or to very large reservoirs.

Very interesting indeed, thank you.

 

[mivey]

I am surprised no one has mentioned gravitational force, and whether electrons are effected by the earths gravitational pull. After all, isn't this where weight comes from any way?

True. Weight and mass are not the same thing.

 

[TOOL_5150]

An electrical charge does not have weight. Charge is a property that is possessed by an electron, and the electron itself has weight. The question is the same as asking if age has weight. OK, I am a person, and one property, or characteristic, that I possess is that I have weight. As I age, my weight may change. But that is not because age itself has weight, and the change in age has caused the change in weight. In the same sense, charge does not have weight.

Very good description. Now I understand [basically] the answer.

~Matt

 

[BAHTAH]

Heavier or lighter

Heavier or lighter

Does a fully charged cap, weigh more than an uncharged cap?

Does a charged battery weigh more?

On the lighter side....
The charged capacitor has the same weight as the uncharged.
The battery does not have more weight when fully charged unless you replace the water that was lost during charging.
I know that my car always weighs more when either the capacitor is not charging and or the battery has lost its charge. It gets so heavy I need a tow truck.

Have a happy Thanks Giving and a Merry Christmas everyone!

 

[Besoeker]

But the charge itself, not the electron upon which it resides, is not a form of energy

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

 

[Snowjob]

E=mc squared and Gasoline

E=mc squared and Gasoline

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

 

[winnie]

Okay, I should be peeling beets right now Happy Thanksgiving!

I am solidly of the opinion that if you charge an ideal capacitor you will increase its mass.

I am specifically talking about the mass of the electric field, created when electrons are moved from one plate to the other, with no net change in the number of particles that make up the capacitor. The total number of protons, neutrons, and electrons remains exactly the same, but the electrons are moved into a different _higher energy_ arrangement, and the total mass of the capacitor (including its electric field) increases.

However I do not believe that the above statement is experimentally verifiable given the current state of technology.

As I mentioned in my previous post, we have direct measurement of change in mass for nuclear reactions. IMHO this is applicable evidence, because a nuclear reaction is simply a re-arrangement of nucleons in the potential fields that they create; in other words the difference in mass of Deuterium versus Helium is caused by a change in potential energy of the protons and neutrons relative to each other. A change in electron potential energy should also create a change in mass.

We know that electromagnetic waves are attracted by gravity. (This was one of the earliest experimental tests of Einstein's work, measuring how the path of light bends around the sun.) As far as we know, gravity always works in both directions: if a mass attracts a light beam, then the light beam has to attract that mass. But I doubt that the experiment could be run in the reverse direction. Additionally, I doubt that we could measure the change in gravitational attraction created by a charged capacitor.

I think that the most practicable experiment that might be made is to use an extremely high resolution mass spectrometer to measure the mass of different chemicals. For example, if you could measure the mass of Carbon, Oxygen, and Carbon Dioxide with sufficient resolution, then you would be able to directly detect any change in mass associated with the 'heat of formation' of the CO2. I did a quick calculation; such an experiment would need to be able to resolve mass differences of about 1 in 10^14. I don't believe that any hardware even comes close to this resolution.

I did find a relevant discussion among professionals in the field, directed toward educators:
http://www.newton.dep.anl.gov/askasci/phy00/phy00950.htm
http://www.newton.dep.anl.gov/askasci/chem03/chem03641.htm

Note the difference in answers in the first archive, and the way things converge in the second archive. I especially like the last answer of the second archive, which boils down to: "All the things that we can measure suggest that when you put energy into a system, that system becomes more massive...but for the low energies of chemical reactions this mass change is too small to measure. The only reason that we believe that such low energy changes are associated with mass change is because it is simpler to believe that low energy changes will be consistent with high energy changes, but until we actually make the measurement this is just a good guess. Also the idea that simply re-arranging the atoms should change the mass bugs me."

-Jon

P.S.
Calculation notes:

The 'atomic mass unit' is currently believed to be 1.660538782(83) ? 10^27 kg. ('Believed to be' because it is _defined_ as 1/12 the mass of a Carbon-12 atom, and that is open to measurement uncertainty.)
The speed of light is defined to be 299792458 m/s
The energy associated with a single AMU is thus 1.49241783 * 10^-10 J

The 'standard enthalpy of formation' of Carbon Dioxide is -393.52 kJ/mol.
The number of molecules in a mole is 6.02214179(30) ? 10^23
The energy released when 1 atom of carbon reacts with 2 atoms of oxygen is thus approximately 6.53*10^-22 J ( I say approximately because 'standard enthalpy' is defined in terms of standard conditions and I don't know if that really applies when talking of a single molecule.)

So the energy change of this chemical reaction (making CO2 from C and O) is something like 4*10^-12 AMU

 

[Dnkldorf]

I am solidly of the opinion that if you charge an ideal capacitor you will increase its mass.

But does mass have to have wieght?


Here is what I found:

The relationship between mass and weight is that mass is constant in any environment, whereas weight changes from planet to planet because the gravitational pull is different, from which the weight depends on.

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".

 

[__dan]

Conservation of energy

Conservation of energy

Any type of reaction, chemical or nuclear, both sides of the "=" sign balance algebraically. Energy gains or losses are photons and the per unit standard is the "electron volt". The change is usually a gain or loss of heat. Heat has no mass.

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

"This is a unit of energy. It is defined as the energy an electron receives when it falls through a potential difference of 1 volt. As a comparison, the breaking of chemical bonds yields from 5 to 10 electron volts, whereas the splitting of an atomic nucleus releases about 200 million electron volts. The symbol for electron volt is "eV"."

In chemical reactions that gain or lose energy, the balancing unit has no mass. It is heat, a unit of energy in joules which are also electron volts, btu's, kWH.

The chemical reaction can also store energy by rearranging ions into higher energy molecules, ie the lead acid battery.

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.

There are tons of everyday low level nuclear reactions that have a mass change, they emit particles. Alpha radiation is the emission of the Helium nucleus, beta radiation is the emission of an electron, neutron radiation - it's pretty easy to bounce neutrons out of a nucleus with tabletop equipment.

These reactions have a change in mass. Losing protons is transmutation to a different element of lower atomic number. Losing neutrons changes the isotope of the element. Losing electrons changes the "charge" and mass.

http://en.wikipedia.org/wiki/Alpha_particle

http://en.wikipedia.org/wiki/Beta_particle