To begin with, let's briefly review the nature of energy, kinetic energy in particular. It is well-established that energy can never be created or destroyed but only changed in form. Kinetic energy is the energy stored in a body, such as a ball or a stone, due to it's position or velocity. A brick on the roof of a building would cause an impact on the ground below if it fell, thus it has kinetic energy. This kinetic energy is not an innate property gravity or of the brick itself, it is the result of the work done, the energy expended, to get the brick to the roof in the first place.
Now, let me ask you a question. You are familiar with the tides in the oceans. Where does the energy come from to move the endless thousands of millions of tons of water every day to make high and low tides?
Every astronomy book that I have ever read claims that it is "gravitational energy" that causes the tides. Sure enough, the tides are caused by the gravity of the moon and to a lesser extent, the sun. The problem is that any physics class can prove that there is no energy at all in gravity, not even a bit. If you throw a ball in the air, the ball will come back down with force. But it is only the force that you put into it in the first place being redirected by gravity. It is impossible for the ball to come down with more kinetic energy than you imparted to it with your throw.
If there was any energy in gravity itself, the ball could gain kinetic energy by being thrown into the air. But gravity is nothing more than a force of nature containing no energy at all. So, that still leaves us with our unanswered question of where the energy comes from to create the tides every day.
The energy may be transmitted by the gravity of the moon, as the books say. But since there is absolutely no energy in gravity itself, it must come from somewhere and I have never seen this question answered.
I have decided that there is a great gap in the field of astronomy. We have tended to take orbits and rotations in space for a given without delving into the great story behind these phenomena. If we see a man-made satellite in orbit, we would logically conclude that it must have required a considerable expenditure of energy to put it there. Yet, astronomy books tend to simply state that the moon orbits the earth while it rotates and the earth orbits the sun without explaining where the energy came from to make it so.
If a satellite requires energy to get into orbit around the earth, then where did the earth get the energy to orbit around the sun? We can easily prove that there is energy in orbits, that must have gotten put there somehow, by the fact that the earth's rotation and the moon's orbit creates tides. We cannot say that the energy came directly from the Big Bang that began the universe because the earth and moon are made of heavy elements that were not created in the Big Bang.
My answer to this mystery is the supernova, the exploding star that must have preceded the formation of the Solar System. Large stars go on creating energy by the process of nuclear fusion. This is done by fusing two or more lighter atoms, such as hydrogen, into a heavier atom. When this is done, the binding energy in the nuclei of the light atoms is released and some of it goes to bind the nucleus of the new atom of a heavier element. But a little bit is left over and released.
This is why the sun shines, at this stage of it's life it is creating energy by fusing four hydrogen atoms into one helium atom. What this means is that the star gradually creates heavy elements from light elements. A supernova, a massive explosion of the star, occurs when it gets to the point where it runs out of fuel because there is not enough lighter atoms left. When the supernova occurs, the component heavy matter in the star; iron , copper, oxygen, aluminum, etc. is thrown out into space.
Of course, when this happens the remaining hydrogen in the giant star (only very large stars explode in supernovas) may come back together again to form what we could call a "second-generation star". We know that the sun is a second-generation star because it contains a significant amount of heavy elements, even though it is only at the stage of fusing hydrogen into helium, the two lightest elements.
There are other theories around about how the solar system formed. Some claim that the matter that formed the planets was pulled from the sun by a passing star but there is no evidence at all for this and the planets contain too much angular momentum to have formed out of matter from the sun or from a cloud of gas and dust at the same time as the sun. We can be fairly sure that it was an exploding star that threw it's component matter across space and some of it condensed into the solar system that we have today. This is fairly well-established.
My claim is that the tremendous energy released by this exploding star more than five thousand million years ago, which is the approximate age of the Solar System, is where energy such as tidal and nuclear comes from. (Note-I try to avoid using the word "billion" because it has different meanings in different countries) It is the left-over kinetic energy of this titanic explosion of long ago that explains so much about the way the Solar System is today.
The supernova had an escape velocity, just as a planet does. Some of the matter strewn across space by the explosion was no doubt moving fast enough to be gone forever. But much of the rest of the matter began to be affected by the gravity of the other expelled matter so that it formed a vast cloud of debris from the inside of the star. This debris cloud is what formed our Solar System.
We know that the orbits of the planets around the sun form a plane. The orbit of Pluto is about 30 degrees out of alignment but the rest of the planetaryorbits are remarkably close to being in the same plane. There is not an eclipse every time the moon orbits the earth because the moon's orbit around the earth because there is a difference of about five degrees between it and the orbit of the earth around the sun.
But we can easily see that this geometric orbital plane is a relatively recent development. The moon and the planet Mercury are covered with craters from thousands of meteorite impacts. Yet the craters are all over the surface. There seems to be no concentration whatsoever along the equators or ecliptics (the plane of it's orbit) of either body. In fact, the largest known impact crater in the solar system is the Aiken Crater at the moon's south pole.
This gives us a view into the earlier days of our Solar System where chunks of matter was strewn in all directions. As the matter came back together by gravity, it was only then that the orbital plane we have today began to form. The same happened on the other planets, but the moon and Mercury are the only ones that preserve craters for millions of years because there is little or no erosion. On earth, we can see on a resource map that deposits of metals like iron, copper, gold and, aluminum tend to be found in limited areas, unlike coal and oil, and are haphazardly strewn all over the planet. These deposits were clearly formed by impacts from space from the metallic elements cooked up in the star that exploded. (Which, by the way, means that there must be gold and other resources on the moon.)
In a cloud of matter like the debris from the exploded star, random collisions and gravitational attraction occurs until one geometric plane dominates and matter becomes concentrated there. The kinetic energy of the moving chunks of matter from the explosion are pulled sideways by gravity from other such pieces of matter until the direction of movement forms a vector between the outward thrust and sideways pull to cause the cloud to rotate. As with the geometric plane, collisions and gravitational attractions occur until, by random chance, one direction of motion dominates.
As with the impact craters on the moon and Mercury, today we can see evidence of this stage in the rotation of the planet Uranus, which is opposite that of the other planets. More evidence of the time before the present geometric orbital plane became established is seen in the orbits of comets, many of which are nowhere near the same plane as the planets.
Remember that energy cannot just disappear. The fantastic amount of energy released by the supernova of so long ago had to go somewhere. This is one fact that astronomers seem to have neglected and I see it as explaining how the Solar System is today.
As we can see by man-made satellites in orbit around earth, an orbit is evidence of energy. Whenever we see one body orbiting another, it shows that energy must have been expended to put it there. The orbit is the continuation of the kinetic energy that it took to get the body into the orbital position.
In the case of the planets, formed from agglomerations of the matter thrown out by the supernova, their orbits around the sun can only be explained as vectors between the outward force of the explosion and the lateral gravitational attraction with other such chunks of matter. Rotation of a planet is a form of orbit. The energy that started a planet such as the earth rotating is also leftover kinetic energy from the supernova explosion that began the Solar System.
The magnetic fields that earth and other planets have is caused by the churning of the molten iron core of the planet and this requires an input of energy. This energy had to come from somewhere. When a spaceship is sent on an interplanetary mission, it's trajectory is often planned to pick up momentum by using the gravity of a planet is passes. This is known as the "slingshot effect". But it clearly consists of transferring energy from the orbit of the planet to the spacecraft.
So obviously there is a lot of energy in the orbit of a planet around the sun. Since it is established that there is absolutely no energy in gravity, this energy had to come from somewhere. It is the kinetic energy of position consisting of leftover energy from the supernova explosion.
The orbits of the planets around the sun and the rotations of these planets should no more be taken for a given requiring no further explanation. The tremendous energy to place these bodies in such positions of high kinetic energy had to come from somewhere and it came from this exploding star more than five thousand million years ago. The tides, the magnetic fields of planets and, the slingshot effect used to propel space craft also use this tremendous reservoir of leftover kinetic energy.
This scenario also throws a light on other cosmic processes. This explosion and then reforming into a somewhat smaller star, our sun, and it's family of planets can be considered as a form of stellar reproduction. When a star large enough to explode into a supernova runs out of light element fuel for it's fusion process, it does so and throws out it's heavier elements into space so that it regroups into a smaller star which goes on with the fusion process with the remaining nuclear fuel. Whenever we see planets orbiting stars in the universe, we can be sure that this is the process which took place.
I would like to offer a related idea concerning the development of life on earth. We can see how the earth and other planets were continuously bombarded by large meteorites earlier in their history. As most of the loose matter within the gravitational domain of the solar system became incorporated into one or another of the large bodies, the moons and planets, this bombardment diminished until today when large meteors are rare.
In the development of life on earth, living things were at first quite simple in form. This changed in what is known as the "Cambrian Explosion". The Cambrian Period in the earth's history was from roughly six hundred million years ago until five hundred million years ago. In this period, the life forms on earth greatly increased both in number and complexity. Most of the basic life forms that we have today originated in this period.
My hypothesis is that the Cambrian Explosion of life on earth was made possible by the reduction in large meteorite impacts on earth as most of the loose matter in nearby space was absorbed by the planets and moons. How could complex, higher forms of life exist with the earth under such a bombardment? It makes sense to me that the great diminishing of this bombardment resulted in the great increase in life on earth known as the Cambrian Explosion.
We are always trying to find out more about what goes on inside of stars. The two lightest elements, hydrogen and helium, were formed following the beginning of the universe. The elements that are heavier than those two were cooked up inside stars by nuclear fusion, crunching smaller atoms together into larger ones, and scattered across space when the star eventually exploded. (You can read "The Mystery Of Exploding Stars" if you wish).
It may seem that the sun is the most accessible star to us for study. The next closest star, the Alpha Centauri system, is about four light-years away. Today, I would like to give my opinion on which is the most accessible star to piece together the internal processes that took place, and it is not the sun.
The sun is actually what is known as a second-generation star. This is because it already contains heavy elements that it could not yet have fused itself. There was a large star that exploded long ago, more than five billion (5,000 million) years ago. Virtually every atom in the Solar System, including every atom in your body, was once a part of this star. As far as I know, the star does not have a name.
To see what happened inside this star of long ago, prior to it's destruction, we only have to look all around us. We can tell by the composition of the Solar System that a lot of iron, silicon and, oxygen were scattered by the explosion of that star. Silicon and oxygen compose most non-biological rocks, such as chalks and limestone, which is calcium carbonate. The earth has a heavy iron core, and Mercury contains so much iron that it is known as the "Iron Planet".
Deposits of minerals on earth, such as iron, lead, copper, silver, gold, etc. come from meteorites which are fragments of the original star that have been floating around in space since the star exploded in a supernova. As the remnants of the star were thrown across space, there was enough mutual gravity to hold much of the matter together, which is today the sun and the rest of the Solar System.
Such minerals are usually found separately one earth. This means that the meteors, chunks of the former star, tend to be composed mostly of a single element or at least they were originally. However, stony meteorites are made of silicon and oxygen atoms, which got together to form molecules following the explosion of the star, long before crashing into the earth. We could say that, in nature, atoms form inside stars and molecules outside. (See "The Mystery Of Salt", sodium and chlorine must have combined to form salt before landing on earth).
Elements which tend to be found together in molecules, like silicon and oxygen or sodium and chlorine, are because of their relative positions in the factor tree of nuclear fusion, as well as their affinity for one another due to the number of electrons in their outer electron shells.
Recent news articles concern the global market for the so-called "rare earth" elements. These elements are basically the rare elements that are the highest elements in atomic number (the number of protons in the nucleus), from 90 on up, on the periodic table of the elements. This does not include plutonium, which is man-made and does not occur in nature. What is different about the rare earth elements is that, much unlike the lighter and more abundant elements, they tend to be found together under the ground.
This caught my attention as I believe it to be an issue of astronomy, rather than of geology, as it gives us a clue as to what went on inside the previous star before it exploded in a supernova.
In the center (centre) of a star, atoms are crunched together by the tremendous heat and pressure, fusing lighter elements into heavier ones. The excess binding energy from the nuclei is released as heat and light, which is why stars shine. The process is far from neat and orderly. When the newest and heaviest elements begin to form, they tend to be close to one another inside the star. When a large amount of an element has formed, it will have a layer or large section of the star to itself.
As a general rule, the lighter elements are fused first even when heavier elements are present simply because it requires less energy to do so. When the star exploded, there was not yet enough of the rare earth elements for them to have settled into their separate zones inside the star, unlike the more common elements. If the star had lasted longer, there would today be less hydrogen and more of the rare earth elements, and those elements would be found separately in mines instead of together.
The heaviest elements are all radioactive. This means that their atoms give off either alpha particles, basically helium nuclei, beta particles, basically electrons, or gamma radiation. The reason for radioactivity is that the structures of the nuclei are less than stable and these emissions are an attempt to gain stability. The process of fusion that formed these elements inside the star before it exploded could not seal their nuclei tightly enough to prevent the nuclei from eventually decaying.
As unlikely as it may seem, one of the best ways to study what happens inside stars is to look in the opposite direction, under the ground.
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