Scientists say that energy isn’t created or destroyed because it takes other forms. For example, when a car slows down by road friction, its tires become hot and radiate heat, so kinetic energy is converted into heat energy, just as steam engine essentially convert heat energy into kinetic energy. Energy then is seen to take different forms, but there is one notable exception.
Lifting an object takes energy that dropping it releases, but where does it go to or come from? There is no heat flow so it is said to have potential energy based on its position in a gravitational field. This balances the energy books to conserve energy, but where is potential energy stored?
For example, if a rocket blasts off into an earth orbit, where did the liftoff energy go? If it then floats off into space, where is that energy stored when it leaves our solar system? Or if it crashes into a planet like Jupiter to release more energy than it took to leave earth, where did the extra energy come from? The current answer, that gravity gives and takes potential energy, assumes an unknown mechanism that lets energy be conserved when apparently, it isn’t.
In this model, energy is defined as the processing rate of transfer on the quantum network. Light then has radiant energy because it is a process spreading, and high frequencies spread it faster so they have more energy, while lower frequency are heat energy. Radiant energy is then conserved because photons are never destroyed but just restart, as processing can. Physical events restart photons in various forms, whether as light or matter, so photons are always conserved.
Kinetic energy can also be explained by photons. When light shines on a solar sail to make it move, radiant energy is converted into kinetic energy. If the sail moves because it acquires photons that bias its distribution, this energy is also based on photons. When objects collide in empty space, kinetic energy is conserved because the photons exchanged are constant. Nuclear energy from matter is also based on photons if matter arose from light.
What then is potential energy? Potential energy is based on gravity which as Einstein deduced isn’t a force at all, so no energy is involved. Potential energy is then just a convention that maintains the machine model of thermodynamics. In contrast when a rocket leaves earth, no photons are lost, and when it crashes on Jupiter, no photons are created, so the number of photons doesn’t change.
Current physics has many conservation laws, of matter, charge, momentum, isospin, quark flavor and color but each is partial, as nuclear reactions don’t conserve matter, nor do weak interactions conserve quark flavor. Energy is also a partial law because the expansion of space doesn’t conserve it and it needs an invented potential energy to work. The only universal law of conservation is then that of photons.
How then does the expansion of space affect this law? The answer is not at all. If our universe began with the creation of light by cosmic inflation, which was stopped by the expansion of space, the finite number of photons it created has remained constant ever since. Expanding space changed the energy of the universe but not the total number of photons in it.
Our universe then conserves light because it arose from it, but not energy because it is expanding, so the first law of thermodynamics isn’t universal. Is the second law then the same?