No book or scientist had a clear definition of energy. the capacity to do work? what is it? word puzzle?

Electrons change energy level to emit photons? the electron has what capacity to do work? how electron carries such capacity to do work? do what work? how?

Even Einstein admitted he knows shit about what are light quanta/quantum/energy/em wave.

What is energy? potential energy, kinetic energy, chemical energy, nuclear energy, solar, wind, wave, fuel?

No, the matter is the source/container/carrier of energy.

Energy is emf, electromotive force, moving force, carried by moving matter/charge.

All matters, are connected by gravity and repulsion force between electrons on their surface atoms, at all the times.

The sun attracted earth, surface electrons on the sun repel lines of sight surface electrons in our outer atmosphere, with the force f=Ke x ee/rr. that force is the conductor of radiant energy/light/emf.

Electrons in the sun vibrate under heat energy, the emf transfer to earth electrons instantly through that force. we call it light/em wave/radiant energy.

Energy must exist with/within matter.  no matter what energy you are searching, find it from moving/vibrating matter.

Every atom inherited its own binding energy, opposite charges attract each other like a magnet attracts iron ball. they collide together to form atom and produce heat/thermal energy.

The more atoms condensed together under gravity, the more energy stored in the mass, the higher temperature. all suns' energy is from star formation.

All energy is shared by all matter, depend on their mass. energy and matter both conserved/immortal, there is no heat death.

If heat can radiate into space, the earth will be as hot as the sun, the whole universe will be at the same temperature, due to thermal equilibrium.

If heat cannot radiate into space, why all the energy we produced/used from the past didn't make the earth warmer?

Very good question.

If you have a channel between a pond and ocean, the water level will be the same.

If rained 10 foot in the pond slowly, the water level will not raise at all. both in the pond and ocean.

The repulsion force between lines of sight electrons on surface atoms of masses/matters, f=Ke x ee/rr is the water channel, thermal energy is water, mass is the water container.

Nuclear energy is atom's inner binding energy, chemical energy is atom's outer binding energy.

Atoms are not 99.99% empty space. not as present science told.