- #36
BruceW
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It was just saying that some people think the definition of 'relativistic mass' is not very useful. They are not saying it is wrong.leothorn said:Do the conclusions of then discussion hold if the concept of mass in special relativity does not hold ? ( A contention held at the end of the article linked above ?
As Nugatory said, the molecules won't necessarily be moving around faster. Remember that the molecules have more than just kinetic energy. They also have 'chemical energy', which is energy stored in the electromagnetic field. And it is this chemical energy that changes, to provide the energy to the circuit.leothorn said:When the battery system is at higher energy that is the constituent particles are at higher state of activation, they hit the confines of the battery at a much faster rate than when the battery is at lower energy. The combined affect of higher average impulse over time should affect the weight of the battery.
Now, if you want to talk about what happens when we place the battery in a gravitational field, then put it on a scale... Well, the mass of the molecules is greater in the high-energy state. So it makes sense that the battery will then push down more on the scales when its molecules are in the high-energy state.
I guess the last 'connection' to make is that the mass of the molecules of an object effect the mass of the object. But this is classical physics. There is no relativistic argument required here.
edit: more explanation: I can see why (for fluids), it is not obvious why the mass of the molecules should affect how much the battery pushes down on the scales. But if you think of the pressure created by these molecules, the pressure will be greater when the molecules are more massive.