Is energy equivalent to motion?

Question

Energy can be described in many contexts, such as the energy required to move something - be it translational or rotational - being kinetic energy, temperature/heat, electricity, light, etc. However, many energies learned of at a young age are simply multiple forms of a single energy. That is, heat and movement are the same thing, the former being movement on a micro scale, the latter being on a macro scale. Similarly, electricity is, to my understanding, due to the movement of electrons, and light is the movement of photons.

As an aside, primarily to add details I've yet to properly organize, there are a number of thoughts I've considered. For one, we consider energy as measured in Joules. The formula for kinetic energy ($K = 1/2mv^2$) is mathematically the integral of momentum with respect to velocity ($p = mv$). This implies to me that energy is directly related to momentum, which relates mass to motion. However, light is considered to be massless, yet has energy. Specifically, I read somewhere in my searches on the topic that light, though massless, will add to the effective mass of a container. But my considerations would be that either 1) light does have mass, but simply the smallest possible mass, or 2) light is not adding to effective mass, but rather "applying force". My searches have indicated that light does transfer momentum, but to my basic knowledge momentum measures mass and speed, which would imply that the former (light having mass) would need to be true. Perhaps the energy of light is proportional to its frequency, given gamma rays are, to my knowledge, more energetic than radio waves, and the electrons of a chemical give off different colored photons based on the degree of energy state changed. On a separate note, I've found mention that the curvature of spacetime due to matter will cause objects to accrue motion, as even if the object technically isn't moving, the spacetime is.

All this to say, it would seem reasonable to me to say that all energy is simply some form of motion, be it the motion of an elementary particle, or motion of atoms on a micro scale, or motion of objects on a macro scale. However, it seems possible that there are nuances I'm not considering or otherwise am unaware of that would indicate that energy is its own factor separate from mass and spacetime rather than a combination of the two.

Simply, is energy equivalent to the motion of matter and subsequent transference of that motion, or is that not the case, and if so why?

Have you learned about potential energy? It is not due to motion. — G. Smith, Dec 25 '20 at 21:50
@G. Smith, potential energy, to my knowledge, is based upon an object's location in a field, such as a magnetic field or gravitational field. Regarding the latter, spacetime curvature (gravity) would be space trying to move, and the only reason the object doesn't is because of a resisting force. For the former, I believe a magnetic field is caused by photons (the messengers of electrons), so motion is still involved. In a way, potential energy is really just the measure of the motion that could occur if a resistant force wasn't present. (To my understanding, anyway) — Iter, Dec 25 '20 at 21:58
These views are your personal theory and not mainstream physics. — G. Smith, Dec 25 '20 at 22:00
Whether mainstream physics is correct or incorrect is irrelevant. Questions on this site must be about mainstream physics. If you want to understand what energy is according to mainstream physics, you should edit your question to ask that and not state your non-mainstream current understanding. Otherwise it is possible that your question may get closed. — G. Smith, Dec 25 '20 at 22:14
@G.Smith the question branches from mainstream physics (at the very least my understanding of it), specifically regarding understanding energy as it exists in reality. Given mainstream physics, in theory, regards reality, the question should be on-topic. I'm not asking about fantastical laws that don't coincide with reality. It is fully possible, however, that I misunderstand you or the site, so if it would seem that the question somehow does not follow the concepts of mainstream physics, I would be more than happy to reformat it for the sake of achieving meaningful discourse regarding it. — Iter, Dec 25 '20 at 22:22
Closing this question would be inappropriate. He isn't asking about theory of his own so much as asking "Here are my thoughts. Is this right?" His thoughts are reasonable even where incorrect. We can straighten him out rather than shut him down. — mmesser314, Dec 25 '20 at 22:48
Here are a couple links that may help. Energy and momentum are deeply connected, but still different things. This talks about some differences. Difference between momentum and kinetic energy. This talks about energy and momentum of a photon. How can a red light photon be different from a blue light photon?. — mmesser314, Dec 25 '20 at 22:59
Also see Why does kinetic energy increase quadratically, not linearly, with speed? — mmesser314, Dec 25 '20 at 23:57
@mmesser314 Thank you for the links! They definitely provide a great place to start looking! — Iter, Dec 26 '20 at 14:21
@mmesser314 Closing this question would be inappropriate. It got closed because five members disagreed, but you can vote to reopen it. — G. Smith, Dec 27 '20 at 18:49

score 3 · Answer 1 · answered Dec 25 '20 at 23:37

Simply, is energy equivalent to the motion of matter and subsequent transference of that motion?

Not quite - anything that has motion (massless or not) has energy inherent in that motion, but not anything that has energy has motion.

Quite simply, there's tons of energy you encounter every day that is not stored in motion: Batteries, fat cells, gasoline, oil, nuclear reactors, etc.

But my considerations would be that either 1) light does have mass, but simply the smallest possible mass, or 2) light is not adding to effective mass, but rather "applying force".

Light doesn't have mass. It does have momentum. The relativistic formula for momentum is $p=\gamma mv$; $\gamma = \infty, m = 0 $ so you can't use it for light as its undefined.

One interesting facet to consider, however - The rest mass of the quarks that make up a proton is only 3% of the total mass of the proton - the rest comes from the QCD binding energy of the quarks. The same concept governs how light adds to the mass of the container it's in.

Very interesting. I'd never seen momentum with the 'y' term before. I'll have to look into that to learn what that is and how it applies (or doesn't) to light. Thanks for the insight! — Iter, Dec 26 '20 at 01:41
The 'y' term (actually called gamma $\gamma$) is basically just 1 for all speeds until you get to >10% the speed of light, so for that reason you normally see $p = mv$. Look up "relativisitic momentum" for more info — Señor O, Dec 26 '20 at 02:38

score 0 · Answer 2 · answered Dec 26 '20 at 03:31

My point of view is primarily from the classical application of kinematics and dynamics to the design of machines. This may be unsatisfying but three topics I can think of that need to be sorted out: [1] relativity (general and special), [2] the principle of inertia, [3] 1st & 2nd laws of thermodynamics. Each of these topics puts limitations on particles or systems of particles whether open or closed. Studying these limitations may provide more insight into the question of whether energy is ultimately related to motion. Perpetual motion machines have not been discovered for good reason. Achieving velocities greater than the speed of light remains elusive for good reason. You ask a good question.

Is energy equivalent to motion?

2 Answers2