String Trimmer Batteries - same weight charged and empty

[steve_bank]

Agree energy comes from the mains. Conservation of energy holds. The problem is current theory says a photon has a measurable momentum but no mass. I objected to a solution involving direct energy mass conversion in the atom. The link indicates a possible solution with mass being somehow attached to the photon. I do not have the physics to talk to it off the top of my head.

I think the problem is that you are trying to resolve it as a Newtonian process. Newton was damn good and came damned close but, after 300 years, science moved on and found a few cracks in his physics. But, even at that, Newton was close enough that, for every-day human-scale, his physics is still reliable enough to send rovers to Mars and land them safely.

A few things Newton had problems with are;
... He had no idea what gravity was even though the understood its effect well enough to give us his universal law of gravitation.
... He knew nothing of atoms, electrons, protons, binding energy, energy levels of electrons in atoms, etc.
... He assumed space was a Euclidean backdrop unaffected by matter or events.
... He assumed that time was a universal, completely independent of space and events.
... He assumed that mass and energy were completely separate and independent phenomena.

It is the last one that you are having problems with. Physics now knows and understands that there is an equivalence between mass and energy or that mass is just another form of energy. So much so that mass is expressed as an energy level in particle physics.

I don't recall reading that Newton ever tried to model where the energy released by fire came from. If he did then it must have been like his attempt to understand what gravity was... he just left it as god's mystery.

This seems to be where you are, not seeing where the energy released by fire comes from since mass is immutable and there was no source of energy. However, physics has understood since the very early 1900s that mass is not immutable but can be released as energy. Balancing mass or balancing energy is no longer sufficient... now we must balance mass/energy (which makes the answer to the question of the energy of fire obvious).

I have gone as far as I can without having to do some reading. With my eyes as it is it is difficult to parse posts. The last word is yours.

 

[barbos]

https://phys.org/news/2017-06-atomic-mass-photon-momentum-paradox.html

It looks like the question of a photon having momentum but no mass is an active problem.

If I read the link right in the theory part of the mass travels with the photon. That I can accept. The queswtion I would have for say a laser diode operating continuously the mass loss would be continuous with no restoration.

Beyond that the theory beyond my depth.

The energy in the laser beam comes from the electrical power applied not from the mass of the diode. - - electrical energy converted to light energy.

Burning paper involves a very different process though it is still energy converting to a different form. There is no electrical energy applied to the burning paper. The energy (heat and light) that radiates from burning paper comes from chemical energy which involves the energy difference (mass difference) between free atoms and those atoms when combined into a molecule.

Agree energy comes from the mains. Conservation of energy holds. The problem is current theory says a photon has a measurable momentum but no mass. I objected to a solution involving direct energy mass conversion in the atom. The link indicates a possible solution with mass being somehow attached to the photon. I do not have the physics to talk to it off the top of my head.

Your link is about "photons" in the medium, which is a solid state physics problem. Photon in the medium interacts with said medium and have to be described as such.
It's not a fundamental problem.

 

[skepticalbip]

I have gone as far as I can without having to do some reading. With my eyes as it is it is difficult to parse posts. The last word is yours.

To make the problem a bit less confusing, lets take your box with paper and make it an ideally isolated box that even light and heat can not escape or enter. No mass or energy can enter or leave the box. The box contains only paper and oxygen at some ambient temperature (m = mass of matter in the box and E = the thermal energy). Now the paper burns leaving only ashes, CO2, and oxygen that wasn’t combined, but inside the box will have a higher temperature - – the energy level has increased in the box, Where did that extra energy come from remembering that mass/energy can not be created nor destroyed?

The mass/energy problem would be:

m₁ + E₁ = m₂ + E₂

Given that, after burning, E₁ < E₂ would mean that m₁ must be > m₂ to balance the equation.

m₁ - m₂ would be the mass converted to heat and light (energy) defined as E = (m₁ - m₂)c².

 

[Loren Pechtel]

I think the problem is that you are trying to resolve it as a Newtonian process. Newton was damn good and came damned close but, after 300 years, science moved on and found a few cracks in his physics. But, even at that, Newton was close enough that, for every-day human-scale, his physics is still reliable enough to send rovers to Mars and land them safely.

Good catch. We're speaking gobbledygook in Newtonian physics.