Energy And Nuclear Fusion

There is one thing about science that I have long had questions about. It is the energy that is involved in the process of nuclear fusion.

Nuclear fusion is the process which powers the sun, and other stars. A star forms when enough matter coalesces in space to crunch smaller atoms together into larger atoms by the sheer force of gravity in the center of the mass. This does not take place in planets because there is simply not enough mass. This process, while combining lighter atoms such as hydrogen into heavier ones, releases a tremendous amount of energy so that the sun or star shines.

But not only does fusion release the energy that we see as sunlight and star light, it also forces the nuclei of the smaller atoms together so that the nuclear force can take over and hold the new and heavier nucleus together by binding energy. The nuclear force, which operates only over very short range, actually converts some of the mass of the nucleus into energy so that there is more total binding energy in the larger atom that results from smaller atoms being crunched together than there was in the smaller atoms which were crunched together. This addition to the energy in the nucleus by fusion is depicted in what is known as the Binding Energy Curve.

Binding energy is necessary for atomic nuclei to exist. The nucleus of an atom consists of protons and neutrons. The protons have a positive electric charge while the neutrons are neutral, hence their name. Under the rules of electric charges that like charges repel, while opposite charges attract, the protons in the nucleus should fly apart by mutual repulsion.

The reason that this does not happen is that the binding energy overcomes this mutual electrical repulsion to hold the nucleus together. Binding energy actually comes about by the so-called nuclear force, which can operate only over very short distances, converting some of the mass of the nucleus into the energy which holds it together. But, for this to happen, it takes energy to force the lighter nuclei together so that the nuclear force can take hold.

The Binding Energy Curve is a graph of how the binding energy per nucleon in the atomic nucleus increases as we go to heavier elements, at least up to the element iron which has a total of 56 protons and neutrons in it's nucleus. A nucleon is a member particle of the nucleus, either a proton or neutron. There is a section about the binding energy curve in the article on www.wikipedia.org , "Nuclear Binding Energy".

But where does all of the energy to force the lighter nuclei together come from during the fusion process? We can see how the binding energy in the nucleus, per nucleon, increases as small atoms are crunched into successively heavier atoms. This must be because the kinetic energy in the gravitational mass of the star, which is what crunches the atoms together, is effectively transformed into binding energy by forcing the two lighter nuclei together so that the nuclear force can take over and convert some of the mass of the nucleus into binding energy.

But if the kinetic energy which crunches the atoms together is effectively transformed into the increasing binding energy per nucleon, as illustrated in the binding energy curve, where does the vast amount of energy that is released by the nuclear fusion process come from? Clearly, a tremendous amount of energy gets released or the sun would not be shining or we could not see star light being radiated by stars hundreds of light years away.

Supposedly, this released energy is the leftover binding energy. My question is how there could be all of this leftover energy if the binding energy per nucleon actually increases as we move to heavier atoms. If the energy per nucleon decreased as we moved to heavier atoms, it would be different. We could say that this missing energy in heavier atoms is what was released as sunlight. But that is not the case, the binding energy per nucleon actually increases as we move to heavier atoms so there must be some other explanation of where the energy that is released comes from. Remember the rule of physics that energy can never be created or destroyed, but only changed in form.

At the present time, the sun is in the process of crunching four hydrogen atoms into one helium atom. This process is  known as the Proton-Proton Process and is common in stars which are not too large. The sunlight that we see, and other radiation from the sun, is the result of this process.

The binding energy per nucleon does decrease for elements heavier than iron, as can be seen in the binding energy curve. However, these elements are different from those up to iron because they are not formed by the ordinary fusion process. Elements heavier than iron are formed by the fusion of smaller atoms together only during the brief period when a large star is actually exploding as a supernova.

This is because formation of these heavier elements requires an input of energy, and this required energy is available from the explosion of the star. The reason for this is that the nuclear force, which is one of the basic forces of the universe and is the vehicle for nuclear binding energy, acts only over extremely short distances and these nuclei of the heaviest atoms are larger than this distance. This scenario explains why the atoms up to iron are exponentailly more common than those heavier than iron.

The article about nuclear fusion on Wikipedia explains that the binding energy curve is due to simple geometry. Large atoms have a lower surface area per volume so that each nucleon has more "neighbors" to help to bind it in. But this effect begins to diminish when the size of the nucleus starts to grow beyond the very short range of the nuclear force.

But the nuclear force itself contains no energy, it is only a vehicle for the binding energy which holds the nucleus together against the mutually repulsive force of the like-charged protons. This is similar to if we were to throw a ball into the air and it came back down with force. Gravity is one of the basic forces just as the nuclear force is. But there is no energy at all in gravity, we are only getting back the energy that we put into the ball in the first place.

The nuclear force is like a spring, which can hold energy. Binding energy is like the energy in the spring when it is compressed. Just as the spring acts as a vehicle for the energy which compresses it, but has no energy itself until energy compresses it, the nuclear force acts as a vehicle for energy from outside to be effectively transformed into the binding energy which holds a nucleus together against the mutually repulsive force of positively-charged protons.

( Note-Illustrations tend to depict both protons and neutrons as spherical in form. But my view of binding energy is that, since the neutron is made up of a mix of electric charges that balance out to zero, binding energy twists those charges within the neutron so that the negative portion of the neutron is more to the outside of it. The result is that the neutron acts as a "glue" to bind the positively-charged protons from mutually repelling, and holds the nucleus together).

So, if the kinetic energy of the gravitational mass of the star, which is what crunches the smaller atoms together into larger atoms, is then effectively transformed into the increased binding energy per nucleon as we move to heavier atoms, where does all of the energy that is released as solar radiation come from?

Another question concerns fission and fusion. The two both release energy, even though they are opposite processes. Fission is the splitting of heavy nuclei by the impact of a high-speed neutron, so that a large nucleus is split into two smaller ones and excess energy is released. The only two atoms which will undergo fission are plutonium, a man-made element which does not occur in nature, and the 235 nucleon isotope of uranium because it's nucleus, with fewer neutrons, is held together more weakly then the much more common 238 nucleon isotope of uranium.

But how can these opposite processes both release energy? It does not seem to make sense that energy is always released whether we have atoms combining together, or whether we have atoms splitting apart. If one releases energy, then shouldn't the other absorb energy?

Actually, fission of the heavier plutonium and uranium isotope 235 is releasing the energy that had to be absorbed to form it when the star which preceded the sun exploded as a supernova. So how then can even more energy be released by the fusion of light elements when no additional input of energy from a supernova is required to form them. Fusion actually releases far more energy than equivalent fission. Just where does this extra energy come from?

By the way, you may be wondering how fission can release energy either if the binding energy per nucleon gets less as we move to heavier elements in elements heavier than iron. The two lighter nuclei into which the nucleus of plutonium or uranium isotope 235 is split should together actually have more binding energy than the original nucleus, so that there would be no leftover energy to be released. But what actually happens is that the total number of nucleons is less in the two resulting lighter atoms. Several high-speed neutrons are released by the split nucleus during fission, an average of about 2.5 neutrons, and it is the kinetic energy of these neutrons, which in turn split other nuclei in a chain reaction, which mostly give us the energy released by fission.

The conclusion that I have come to is that there are two separate energy "avenues" when it comes to nuclear fusion. These are the internal and the external. The internal avenue is the one that we are familiar with already, the increased binding energy per nucleon as we move to heavier elements. This energy originally comes from the kinetic energy of successive crunches of smaller atoms into larger ones so that binding energy per nucleon increases as we move to heavier atoms.

I find that there is only one possible source of energy for the external avenue, the energy that we see released by the fusion process as sunlight and star light. The heavier the elements get, the more neutrons there tends to be relative to protons in the nucleus. This is why the increase in the weight of matter is not proportional as we move from lighter to heavier atoms.

Heavier elements are heavier out of proportion to atomic number relative to lighter elements. The most common isotope of uranium, for example, has 1.58 times as many neutrons as protons. The presence of neutrons is vital as a vehicle for binding energy to hold the nucleus together against the mutual repulsion of like-charged protons.

The reason that this preponderance of neutrons can occur is that neutrons can be formed, during the crunching process, by crunching an electron into a proton to give it the neutral charge of the neutron. There is an article titled "Electron Capture" on Wikipedia. This is sometimes referred to as K-capture because it is most likely that the electron will be captured from the K-shell of electron orbitals, which is nearest to the nucleus. In heavier atoms, there are many, many more neutrons in heavier atoms, relative to protons and electrons, and these could only have come from mergers of protons and electrons.

(Note-cosmology is beyond the scope of our discussion here and this article is about physics, rather than cosmology, but the fact that an electron and a proton can readily merge to form a third particle because the two have an identical electric charge, even though a proton is 1,836 times the mass of an electron, shows that a proton and electron are not completely separate entities but must have been originally "cut from the same cloth" shows that the sheet model of the Big Bang, in which both are different "cuts" of the sheet, to be correct).

But what happens to the energy that was in the electron in orbit around the nucleus when it is halted in it's motion and crunched into a proton to form an electron?

When I completed the recent posting "The Mystery Of Exploding Stars", which detailed my view of how it is the electron repulsion which keeps atoms separate and the eventual overcoming of this electron repulsion by the kinetic energy in the star's gravitational mass so that smaller atoms can be crunched together into larger ones, which is actually what drives the processes within stars, I began to think that it might also be electrons which might explain how vast amounts of energy can be both released and also incorporated into nuclear binding energy during the fusion process.

My conclusion is that the energy released by nuclear fusion, including sunlight and star light is the energy of the external energy avenue, and comes from the energy that was in electron orbitals after the electron is captured to be combined with a proton to create a neutron. This has got to be a tremendous amount of energy, which originally came from the Big Bang, and is not accounted for in explanations of nuclear fusion. When an electron is captured from the innermost orbital shell, one from a higher shell ultimately drops down to take it's place and this would also release energy since the higher shell would be a higher energy level.

The principle is similar to the energy in the orbit of the moon around the earth. The moon is actually moving further away from the earth, at the rate of about four centimeters per year, to a higher energy orbit. This is accomplished by drawing energy from the earth's rotation, and thus gradually making a day longer. This happens because the moon raises a tidal bulge in the earth's ocean, which is then moved forward by the earth's rotation which is faster than the moon orbits. The gravity of the tidal bulge being pulled ahead whips the moon into a slightly higher orbit even as the friction of the same process gradually slows the rotation of the earth.

What basically happens is that the energy in electron orbitals resists the crunching together of atoms by gravity by the electron repulsion of the electrons with the same negative charge. When this electron repulsion is finally overcome by the gravitational mass of the star, this energy in the electron orbital is radiated away so that we see it as sunlight or star light and the kinetic energy of the gravitational mass that was being resisted is transformed into binding energy in the nucleus. Before the crunching together, there was equilibrium, but afterward one goes along the external energy avenue and the other along the internal.

If the kinetic energy of the star's gravitational mass is transformed into binding energy when it finally overcomes the energy of electron repulsion which was resisting it, then that resistant energy in the electron orbitals must also be transformed into something. The electron resistance is because no two atoms can occupy the same quantum address, despite the pressure on them. This does not take place if an electron becomes positioned in an orbital of the new, larger, atom but only if it is one of the electrons crunched into a proton to create a neutron.

It must be explained what becomes of the energy in the electron orbital, just as it must be explained where the energy which is radiated from the sun and stars comes from, and this is the answer.