Does electricity have weight or density, and if so, who was the first to discover it?

Question

That is, who was the first to make an accurate measurement of it? This question came to me as I was watching an astronomy program today, in a long roundabout way...

Answer 1

Robert Millikan [1] conducted experiment with charged oil droplets however it is J J Thompson who actually discovered the electron and determined its mass over charge ratio[2].

Electricity does not have mass and is being carried by electrons (-) and protons(+). Electricity does exhibit density as charge per unit volume or frequently as charge per unit area.

Answer 2

The terms are not used with electricity.

Answer 3

Electricity is simply the flow and distribution of electrons. Electricity itself does not have mass or density but electrons do.

It's a bit like asking "does wind have weight or density?". No, but air does.

Answer 4

Current is not described by weight.  But moving charges is a way to describe current...and hence you can measure the weight of the charges.  I think a man by the name of Robert Milikan was to first to scientifically show the relation between charge and mass.

Answer 5

The word "electricity" doesn't have a really good definition in physics.  It's a general term that wraps up a variety of concepts.

Electric charge has nothing directly to do with weight (let's say mass), but an object with electric charge (like an electron or a proton or whatever) could have mass.

Electric current is just moving electric charges, so ditto the answer above.

Charge and current have their own densities (charge per volume and current per volume) which are similar to mass/weight density, but not directly related.

When it comes to electric fields, your question is a little more interesting.  Electric fields carry energy, which according to general relativity, implies weight.  But it takes a lot of energy in a field to create a small amount of weight, so you aren't likely to notice this unless you're looking at the early universe or black holes or something extreme like that.  And to answer who discovered that--it was Einstein.

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Answering additional questions:

First off, talking about anything prior to the big bang is speculative.  We don't know that there even was a time before the big bang.

Next, yes, gravity would have existed.  At superhigh energies, it may manifest itself a bit differently.  All the forces at those energies may well be unified because superhigh energy levels swamp whatever it is that breaks the symmetry and makes them appear different to us.  But we haven't got a good idea what this unified force is like.

Finally, there is no physical qualitative difference between mass and energy.  So the best way to look at it is that the universe is, always has been, and always will be made of energy.  Energy is the source of the gravitational field.  Energy has inertia associated with it.  So there is no real difference between the word mass (as you first learned it in physics 1) and energy.  Consequently, we've changed the way we use the word mass a bit.  It means the energy of something in its own proper frame of reference (in which it is at rest).  So light doesn't have mass.  But if you put a bunch of light in a box and close the lid, the energy of the light contributes the mass of the box.  So mass is a form of energy, and whether or not you say the early universe had mass is just a question of point of view, not a question of any real physical significance.  The individual particles in the very early universe were mostly massless, so the energy was kinetic and potential of various kinds.  But if you look at the universe as a whole (as if you could put it in a box), then it would be proper to say it had mass.  If you can understand this difference, then you understand that it really isn't much a difference at all, so I wouldn't worry too much about it.