What is energy? What is mass? How are they related? Does energy have mass? Is mass really ever converted to energy?
Actually, mass is a form of energy, called inertia.
What do we mean by “form” of energy? How many “forms” of energy are there?
There is this idea that inertial-mass-energy (matter) is created from empty space, or the vacuum energy. Like with gravity and a ball on a hill, the vacuum energy is the potential energy, which is converted to the kinetic energy of mass-energy (matter).
So matter is energy that has been created from the vacuum.
This means that the ultimate mystery of the universe lies in this vacuum energy (space itself).
Theorists are using quantum mechanics to extrapolate the idea of a particle called an inflaton, which decays into matter through a process called reheating.
When we think of gravity we think of massive objects exerting a force on each other, which is natural because this is what Newton taught us. But when we truly begin to digest Einstein’s advanced course on gravity we see that massive objects do not pull on each other at all; rather, we come to see that massive objects pull on space itself, deforming it, and that this deformation (or “warping”) of space in turn causes the acceleration of the matter that rests in it.
Thus the mystery becomes the nature of space itself, what it is, how it works. All of physics awaits for this answer and is incomplete without it.
I am having a hard time visualizing the distinction between energy and motion. I think kinetic energy IS motion and heat is a transfer of kinetic energy from one object to another.
But pure motion is an abstraction, like pure energy? There is only motion of some THING? Likewise, energy is not separate from some thing. Rather, energy IS a thing? There are only things? Forces are just things touching? This seems strange only because we can’t see the things that are touching? But at the very bottom of this touching, it is always the same thing touching the same other thing… electrons and photons. Their eternal dance adds up to everything there is?
Like space-time, energy-mass is the true concept (the idea of “space” as something separate and distinct from “time” is incorrect, as is the idea of energy as something separate and distinct from matter). The separation of these is a fallacy. Just as you cannot have pure motion, separate from some thing that is in motion, you cannot have time without space, or energy without mass.
That’s just facts of the universe.
So we have this energy-mass. This is what we have when we have some physical thing, like 1) a rock, or 2) a radio wave. In both cases, we have some physical thing in motion. With the rock, the atoms are in motion like planets around the sun while the rock itself seems to stand still like the solar system. But the solar system is not still, it is moving through the galaxy. And the galaxy is moving, etc.
Likewise, the rock is on the earth, which is moving… The radio wave, on the other hand, does not seem still like the rock does (even thought the rock is not really still). So what is the difference? The rock and the radio wave are both physical things and both of them are in motion, but for the rock the motion (of the electrons) is inside, caught in a loop around the nucleus of the atoms. In the radio wave, the electrons are not caught in a loop. And that is the difference. Loopy vs non-loopy motion. Matter vs energy. Rock vs light.
OK, so everything is moving. And this motion is where mass comes from, and as we pointed out above, there is no motion without mass. The faster something moves, the more massive it becomes. When it “stops moving” it’s atoms are still moving, so it still has mass.
We see this when a ball bounces on the ground, finally coming to rest. But we know from the laws of thermodynamics that motion is never lost in the universe, so where did the motion go? The ball transfered a little bit of its motion into the atoms of the floor each time they touched. And this is all physics is, really. Things touch. And when they do, motion is transferred. This is what happens when you touch your desk, look at the wall, hear a song on the radio, taste and smell. These experiences are each the result of physical touch (electrons exchanging photons) which results in the transfer of motion from one piece of matter to another.
The transfer of motion happens through a phenomena that we call heat. When the ball touches the floor, it transfers motion to the atoms of the floor and therefore heat is created.
For something to move faster, something else must move slower because the only way to make something move is through the physical touch of some other, faster moving thing pushing it. This pushing is what we call a force and this pushing creates a change in speed. This change in speed is what we call acceleration, which can only be achieved through what we call work. So we have two things. One thing is moving. The other thing is moving faster. The two things touch, creating a force. The faster thing slows down. The slower thing speeds up. The speed is called energy, the change in speed is called acceleration, (the transfer of speed from one thing to another is also described as heat – is heat and acceleration the same thing?) and as a result we say that work has occurred. The contact of the two things is called force.
Yes, you see force is not some invisible magic that goes back and forth between physical objects. Let us be clear about this: there is nothing in the universe that is not a physical object! All “forces” are nothing more than physical objects smashing into one another. For example, think of two magnets. When you push them together you can feel them repel. At first glance it seems you have two physical objects that are exerting some force over some distance between them. But we have learned that this is not what is in fact happening. The truth is that what we see as the “edge” of the magnet is not really the edge of the magnet. The physical, material parts of the magnet (its electrons) extend out into space beyond what we can see. So what seems like a force repelling the magnets, is nothing more than the magnets physically rubbing up against each other in exactly the same way that we rub up against the desk when we push our finger into it. The difference is simply in the density of the material. But when we push our finger into the desk, what we feel is nothing else but the electrons of the desk pushing back against the electrons of our finger, which is exactly what is happening when we push two magnets together. If you were to zoom in on this interaction of your finger pushing down on the desk, you would find something that looks like a sesame seed (the proton) with a grain of sand (electron) orbiting two miles around it. What you feel when you push your finger into the desk is what happens when two sesame seeds come within “4 miles” of each other. It is very difficult to get those seeds to get any closer. In fact, it takes one of the most powerful events in the universe to make those sesame seeds get any closer. And this is why it is not very easy to push your finger through the desk, despite the fact that 99.9 % of your finger, as well as the desk, is empty space.
The magic of magnets is simply that we can push one physical thing into the other. And this is simply because the arrangement of the electrons in a magnet are not 2 miles from their proton, but something more like 2 hundred thousand. The magic of magnets is that the electrons (grains of sand in our analogy) have extended their orbit much farther from their sesame seed than what we find in non-magnetic material.
This is the craziness of physics. Everything is everything. One thing is just a derivative of another thing. Energy, mass, gravity, all intertwined, not separate, but one.
You hear that heat is a form of energy, but this is wrong. Heat is a process by which energy is transferred. Heat, and the kinetic energy of molecules refer to the same thing when heat is used as a form of energy. Instead, it is more accurate to visualize the kinetic energy of molecules as their wiggle speed. Wiggle speed can go up or down. When wiggle speed goes up, we say heat increased. It got hotter. The temperature went up. What caused this? Something else that was wiggling had to come into physical contact with our original molecules and make them wiggle faster. This event we just described as “make them wiggle faster” is what we refer to when we say that we heated, or added energy to.
Thus what we call heat flow is really the average result of trillions of atoms and molecules transferring their kinetic energy, through the work process, to other atoms and molecules.
Forms of energy: light, heat, chemical, motion
There are many forms of energy, but they all fall into one of two classes: potential, and kinetic
Potential energy: chemical, mechanical, nuclear, gravitational, electrical
Kinetic energy: radiant, thermal, motion, sound
Kinetic energy is motion and potential energy is “stored” but what this seems to mean is that kinetic energy is motion released and potential energy is motion trapped. But the motion is constant. It is not created or destroyed. The atoms of still objects have a lot of motion.
First thing to realize when thinking of energy and mass is that, like time and space, these are not separate things that relate to one another or act on one another. They are the same thing. Two sides of a coin, so to speak.
Related to all of this is: motion. Would any of these exist without motion?
To say that matter can be converted to energy is just to say that the rotational kinetic energy of something that is spinning around in an atom can become the linear kinetic energy of something shooting away from an atom.
Rest mass is the quantitative value of a body of matter’s resistance to change in motion
Kinetic mass is the quantitative value of a body of matter’s increased resistance to change in motion that occurs when it is accelerated in any direction relative to its natural position of rest.
Can it be this simple? If you think of energy as motion (probably not the most accurate analogy – or is it?), then realize that the atom has a darn lot of motion in it, then it makes sense that this motion could be redirected. The redirection of all this inward, circulating motion to outward, straight-line motion is the so-called “conversion of matter to energy” described by E=MC2.
Photons don’t accelerate. They are always moving at the speed of light, whether trapped in the pieces of the atom, or redirected away from the atom.
So we have all this motion and we are redirecting it. From all this motion comes friction and heat. Heat is the transfer of motion from one thing to another.
Kinetic mass is directly proportional to the energy associated with the body’s motion relative to its position of rest according to the formula (E=MC2). Kinetic mass and kinetic energy are complimentary components of a body of matter’s motion that do not exist separately. They are the opposite sides of a coin rather than two different coins.
A photon with an energy of one has a rest mass of one. When a photon is absorbed by an atom, half of its energy stays with the photon as spin and the other half is transferred to the atom’s structure. Its kinetic energy (KE=MC2/2=1/2) remains with the photon as it becomes imbedded within matter. Its rotational kinetic energy (RE=IW2/2) leaves the photon and is transferred to the atomic structure of the absorbing matter. This energy can either remain within a single atom to be used in the emission of a photon at a later time, or in some substances it can be passed from atom to atom in a coherent wave.
When the wave reaches the surface, its energy can be used in the emission of a photon. A photon remains intact with its rest mass after it is absorbed by an atom. When it absorbs the necessary energy from the internal motions of the atom it is emitted. The spin shock waves from photons temporarily increase the kinetic mass of the atoms that they move through.
When a photon goes from rest to the speed of light, it does not accelerate. The stationary photon from which it originated was spinning with several types of circular motion at the speed of light. When the photon’s circular structure within the particle breaks, the motion of the photon’s mass changes from all circular motion to one half circular motion and one half linear motion but its velocity C remains unchanged.