Gravitation
As I interpret...
When you get down to the basics of gravitation...
There is Newton's gravitation__ and Einstein's gravitation.
Newton wrote: bodies come together mutually relative to each other, due to unknown causes... and he did his calculations...
Einstein wrote: bodies come together mutually relative to each other, due to unknown alteration of space... and he did his calculations...
Einstein came up more accurate. Neither of these two gentlemen knew how gravitation worked.
We still don't know how!
But, the phenomena we call gravitation must be a reality, because, again... I can't imagine a Universe getting along without it. Gravitation may just be Space, Motion, Pressure, Light, and Matter working together in a manner to accomplish what we think of as a force; and if and when, we find out how things work to accomplish gravitation in our Universe; the actions of gravitation may not be much different than billiard balls banging together. I think gravitation has a very high probability that it will be explained by the interaction fundamentals as Matter, Motion, Pressure, Space, and Electromagnetism... which will make Gravitation just a name that man gave to something that was unexplainable at the time. The actions of, and fundamentals that cause gravitation will be the reality, and gravitation, because it is just a name, will become a fantasy.
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Gravitation may be as the western song line: "...looking for love in all the wrong places." I think, we are guilty of... looking for gravitation using the wrong road map. If you just read my page on Orbiting you probably have a hint of where we should look.
I'm going to take you on a simple tour of classical physics, and you might see why we took wrong turns along the way. I will write about simple things you may know, but are not often expressed or given much thought... There is a good quantity of phenomena out there, that if looked at differently may point the way towards understanding.
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I will start by going back to ancient times. I am quite sure it was long, long ago when man came up with the word push to indicate the forcing of something away from himself. Possibly about that period, he also came up with the word pull, for bringing something nearer his body. These words gave meaning to actions. I would wager on the notion, he did not analyze these actions that were occurring, when he pushed, or pulled. I have not read, where anyone, has analyzed these actions. But, I know that physics only calculates pull... as a pressure__ which indeed is really an action of pressure. Actually we can only measure pressure. And, our human senses can only function with pressure. A pull can never be accomplished without bringing pressure to bear, which is a push. Pressure is a push, impulse, shove, prod, repulsion, and etc. A pull is just describing actions of pressure with a variant position of leverage, pure and simple__ and easily proven by demonstrations. Try a few experiments... Can you pull a door open without bringing pressure to bear? Can you pull your pants on without holding them with pressure? Try getting food into your mouth without some kind of pressure involved. Can a horse pull a cart without pressing on the horse collar? Try putting the horse in the horse collar backwards; and imagine what is happening? The horse is now pushing the cart backwards__ yet the horse is not doing anything different at the point of contact. Can one link of a chain pull another link without curving around inside the other, to hook the inside, making contact and pressing in the direction of desired motion? This is fact, not fiction!
It is also of importance that you can never push, or pull, anything... from a distance. You can sit across a room, for an extremely long time, without ever being able to pull, or push a foot stool to where you sit! To ever have a push or a pull__ it is a requirement that there is some intimate connection, between who or what is pushing or pulling the item to be pushed or pulled! This would mean gravitation cannot occur as a push, or a pull, without some connections between bodies! To push or pull across Space is what is called: Action at a Distance.
Action at a Distance is generally associated with the word Attraction. An attraction is a word to explain bodies coming together towards themselves without any observable way of explaining why. An attraction can be singular or mutual between bodies. A magnet that attracts a piece of iron is singular. The iron is considered to be accelerated to the magnet, by whatever powers the magnet originated, but the piece of iron appears to not be doing any of the accelerating. A magnet that attracts another magnet is mutual. In the case of two bar magnets coming together mutually... it has been long known that what we call like ends, repel each other, and unlike ends attract each other. Or, it is what we say, to describe these actions. The situation is, there is quite a difference in degree of difficulty to repel or push away, verses the degree of difficulty to attract anything. But, if Space is altered to accomplish a push or a reverse push (pull)... I would wager there degree of difficulty is probably the same!
Bodies fall to earth. Galileo showed us that bodies of different weight will fall to earth at the same rate. In a vacuum size and shape does not matter. What is happening... is the force actions that cause the falling are being focused stronger, at a rate of 1 to 4, over distance doubling, the closer to earth. The rate of fall is the same, but the impact of hitting the earth is greater and lesser, depending on greater or lesser matter. One atom of matter will impact with less pressure than ten atoms of the same matter. One complex atom will hit the earth harder than a simple atom. How fast they hit the earth depends on how far away from the earth they started their acceleration. A rock dropped on your head from one inch is less painful than a rock dropped from twenty feet above.
When dropping objects, of sizes we normally deal with of a few ounces to a few pounds, they fall to earth almost equally. However, it can be a little tricky on how one describes the events of falling bodies. If we measure the time for a one pound ball to drop in a vacuum from a fixed height, and then repeat this with a ten pound ball... for all intents, the balls drop the same distance in the same duration.
However, consider if the moon was held fixed and not orbiting, then released to fall to Earth. Gravitation is a mutual phenomena. The moon would be accelerated towards the Earth, but the Earth would also be accelerated towards the moon. If they were of equal size and matter, they would both meet half way. Now, if you can imagine, dropping the moon from its height on one side of the Earth, and dropping a marble from an equal distance on the opposite side of the Earth simultaneously... what would happen? I am pretty sure, the marble would be chasing the Earth somewhat, as it moved towards the moon. If the same scenario were done with three equal planets in a row. The center one would remain fixed relative to the other two while they mimicked each other falling to the center planet.
If something is accelerated in a fall, it takes some amount of resistance pressure to stop the falling motion, or to change its state of motion. I call the measurement of resistance to this directional inertia of the falling body as the directional mass. To keep a conservation of mass, so to speak, I consider that the body has lost an equal amount of impact ability in the opposite direction of the fall.
Often people loosely will imagine that at the center of the earth, we would be squashed by gravitation. Which is not true. We would be squashed from the weight of matter pressing towards the center of the earth. If we could contrive a creature comfortable compartment to protect us, at the center of the Earth... we could float about inside quite comfortably in a gravitational null just as if we were in deep Space, in a Space craft.
Gravitation is sometimes equated with distortion of Space, and I don't rule this out... but there has to be more to the story. If a rock is inserted into the middle of a bowl of gelatin... it will displace and distort the gelatin from its former state. There will be pressure on the rock from all directions. And, I could insert another rock into the gelatin with the same effect. But, these two rocks would have no compulsion to accelerate towards each other, due to only displacement.
My, four plus inch thick, Webster's Dictionary defines gravitation as: "2. in physics, the force by which every particle of matter tends to approach every other particle in the universe. Newton's law of gravitation is that every body or portion of matter attracts and is attracted directly as its quantity of matter, and inversely as the square of its distance from the attracting body." You will find definitions written pretty much the same as this; in millions of books! What is not included, in millions of text and reference books, is the disclaimer by Newton, (that I have quoted below), relating his use of the word attraction promiscuously and indifferently... and only to describe his mathematics... and that he didn't know the causes! The other part, that really screws up peoples minds is: "...inversely as the square of the distance..." it should be something like ...inversely as the square of area at a distance, compared to the square of the area from whence measured, when the distance is doubled...
It is a natural phenomenon as recognized and set down in geometry; when any two or more straight lines radiate out from a point... the distance between them doubles, with doubling segment of distance out. If area planes are progressed parallel along these radiated lines... the areas increase at a rate of 1 to 4 with distance doubling. What this means is a beach ball that is 20 inches in diameter, has a surface area four times more than a soccer ball of 10 inch diameter centered inside the beach ball.
It not known what exactly, or if, some entity as gravity is actually radiated from bodies of mass. But, we say gravity is weaker the farther from Earth we go. This has not been shown to be true. No-one__ has ever shown__ that gravitation radiation itself, has ever weakened with distance! It spreads! Since it spreads it has less acceleration ability the farther from Earth. This rate of reduction is the same as the area scenario above, but gravitation is also not an area phenomena, but a rate of force that is measured as pressure. And, pressure is measured as weight, or push per square area.
Did you know that the astronauts floating weightless in their spacecrafts orbiting above the Earth are not weightless due to no gravitation? They are weightless because they have a centrifugal effect acting, and when they are between the moon and earth there is a second semi-null factor in play. If they were sitting on a tall tower, they would not float weightless. If they stopped still in orbit... they would fall to Earth, due to, still being in Earth's gravitation.
The Earth's radius is approximately 3964 miles. If a man weighs 200 pounds of pressure spread out on one square foot of area (200 lbs/sq. ft.) at the Earth's surface__ at a distance of 7928 miles (twice the radius distance, from Earths center)__ he would weigh 200 pounds per four square feet area (200 lbs/4sq. ft.). But, if we keep the area measurement constant as one square foot__ the man would weigh four times less__ which is fifty pounds... (50 lbs/sq. ft.), when 3964 miles in the sky.
Classical Physics has shown to have a good degree of accuracy when a small frame of reference is used, but inaccurate, if taken to extremes. An example is a bullet shot horizontally parallel to the ground, and at the same instant a bullet is dropped from the same height as the muzzle of the gun... They both hit the ground at a close approximate instant. This is because the horizontal direction, pressure forced on the bullet, as fired; has no affect on the downward gravitational forces on the projectile. But, if this scenario is taken to more extreme... a fired projectile could be shot into orbit about the Earth, or if really accelerated__ a projectile could make it into Space and never come back.
There is an experiment that is used to show how a body orbiting in a circle, at a constant speed must increase it's revolutions, if it's orbit circumference is decreased, and its speed remains constant. This is similar to uncoiling a roll of paper, with the exiting paper surface speed remaining constant__ the roll diameter shrinks, and to keep up surface exit speed, it must turn revolutions more rapidly since the roll circumference is shrinking. This experiment is done with a heavy solid steel ball (sphere) that is about 4 inches in diameter. This ball is tethered on a strong fishing line with a swivel mounting to the ball. The line goes through a hole in a table. The ball is rolled in a circle at the end of the line held in place below the table. When the line is drawn down shorter, the ball is forced into smaller orbits. Since the ball is heavy it keeps its speed fairly constant. But, it is very noticeable, as the orbits become smaller, the number of revolutions increase. If the orbit the ball is drawn in untill it is one half the diameter of the initial orbit__ the revolutions will be twice as many per a like time duration. The turning for the smaller orbit is a sharper curve, than the gradual curve of the initial larger orbit. It is probably possible, and do-able, to insert a pressure measuring device in the line to the orbiting ball. The initial orbit could be measured for how much pressure is required for one orbit, while also measuring orbit time... to give a value of work done. The smaller orbit can also be measured for one orbit, of pressure, and time. Remember the smaller orbit takes half the time of the larger, while presumably working harder to hold the tighter curving trajectory. So it should be: when revolutions go up double, while time goes down by half... the resultant work done, is equal, (elapsed ability to do work, work done = measure of energy.). The total force actions turning a ball in the larger orbit are equal to the total force actions of a smaller orbit... when maintaining the same forward speed. It is the revolutions per time that change.
To continue with some orbiting stuff... I'll need a couple of college physics student volunteers. First we will chalk out a 100 foot diameter regular dodecagon, 12 sided polygon, in the mall parking lot on Sunday. (Why Sunday? "Elementary Watson", there will be less cars!)
This first demonstration is to show the complexity of using a pull to represent gravitation holding something in orbit. One collegiate has been commissioned to start walking, following our marked out dodecagon circumference on a straight line side, and always trying to keep walking straight, unless acted upon by forces causing a turn. The task for the second collegiate is to walk alongside our first student, inside the dodecagon, and when the first student comes to any corner, he or she alongside is to... reach... grab... hold... & draw... the orbiting student until the orbiting student turns into the correct new direction of the corner. This is to be repeated for the twelve corners of the dodecagon. The degree of difficulty to keep the orbiting student in line with the orbit path is to be noted. The second phase of this demonstration is to have the orbiting student do the same thing for another orbit. But, the task now for the second collegiate is to walk alongside our first student, outside the dodecagon, and when the first student comes to any corner, he of she is to... reach... & push... the orbiting student until the orbiting student turns into the new direction of the corner. This is to be repeated for the twelve corners of the dodecagon. The degree of difficulty to keep the orbiting student in line with the orbit path is to be noted. Now, please compare notes: reach, grab, hold, and draw__ compared__ with reach and push. It seems readily apparent: pressuring a body__ to keep it in orbit, is less complex, and less work__ than: reaching out to a body, grabbing, holding using pressure , and reverse pressuring that body, with alternate leverage (if possible) towards, the alternate leverage location inwards.
My thoughts favor the concept that Space is the key to how gravitation works. I like the idea of virtual particles. I think of these as idle particles that have motion so small in our frame of reference, we have no way to measure their motion to get a value of their mass. I do think it is possible to find out more about Space... which may answer questions of gravitation. I really don't think of gravitation as an entity, but as actions of real phenomena of the Universe... I also believe it is a pressure phenomena. I have not related much on fields. I did this on purpose because, the definition for fields seems ambiguous. Fields to me are like taking a lot of measurements in different regions of space in two or three dimensions. These values can then be visualized on charts and such. The visualizations are pseudo pictures of probably real items, but they are not the real items themselves. But, field measurement are tools of man that can help us. We know radio light waves traverse space with information. In a space vacuum how is this happening? Well the thought that Space is filled with virtual and or idle particles of some sort... is probably a clue... if true.
After all the above verbiage... the gravitation phenomena or effect, whatever it might be__ is a fundamental reality required, if the Universe is to continue as normal.
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Page Relevant Quotes
DEFINITION VIII
" ...I likewise call attractions and impulses, in the same sense, accelerative, and motive; and use the words attraction, impulse, or propensity of any sort towards a center, promiscuously, and indifferently, one for another; considering those forces not physically, but mathematically; wherefore the reader is not to imagine that by those words I anywhere take upon me to define the kind, or the manner of any action, the causes or the physical reason thereof, or that I attribute forces, in a true and physical sense, to certain centres (which are only mathematical points); when at any time I happen to speak of centres as attracting, or as endued with attractive powers." From a direct Latin to English translation of Mathematical Principles of Natural Philosophy: Sir Isaac Newton
"COROLLARY III"
"SCHOLIUM"
"...I here use the word 'attraction in general for any endeavor whatever made by bodies to approach to each other, whether that endeavor arise from the action of the bodies themselves, as tending to each other or agitating each other by spirits emitted; or whether it arises from the action of the ether or of the air, or of any medium whatever, whether corporeal or incorporeal, in any manner impelling bodies placed therein toward each other. In the same general sense I use the word 'impulse', not defining in this treatise the species of physical qualities of forces, but investigation the quantities and mathematical proportions of them, as I observed before in the definitions. In mathematics we are to investigate the quantities of forces with their proportions consequent upon any conditions supposed; then, when we enter upon physics, we compare those proportions with the phenomena of Nature, that we may know what conditions of those forces answer to the several kinds of attractive bodies. And this preparation being made, we argue more safely concerning the physical species, causes, and proportions of the forces..." Newton's Philosophy of Nature: Selection from his writings; Edited & Arranged with notes by H.S. Thayer.
"GENERAL SCHOLIUM ...But hitherto I have not been able to discover the cause of those properties of gravity from phenomena, and I frame no hypothesis; for whatever is not deduced from the phenomena is to be called a hypothesis; and hypotheses, have no place in experimental philosophy. in this philosophy particular propositions are inferred from the phenomena, and afterwards rendered general by induction.
"Science cannot yet really 'explain' electricity, magnetism, and gravitation; their effects can be measured and predicted, but of their ultimate nature no more is known to the modern scientist than to Thales of Miletus, who first speculated on the electrification of amber around 585 B.C." The Universe and Dr. Einstein, Lincoln Barnett
"In fact, physics does not explain gravitation; it cannot state a cause for it, though it can tell you some useful things about it. The Theory of General Relativity offers to let you look at gravitation in a new light but still states no ultimate cause." Physics for the Inquiring Mind: Eric M. Rogers
"Newton himself regarded this 'action at a distance' as impossible." The ABC of Relativity; Bertrand Russell
"The sun does not exert any force on the planets; in Einstein's law of gravitation, the planet only pays attention to what it finds in its own neighborhood." The ABC of Relativity; Bertrand Russell
"As for attraction, it was certainly introduced by Newton, not as a true, physical quality, but only as a mathematical hypothesis." Berkeley's Philosophical Writings; George Berkeley
"The reader may have realized that nothing has been said so far about explaining what was observed. No mention has been made of theories. A law is usually not much of an explanation. We have laws for gravity in elegant mathematical form. Except for what one might read into the symbols of quantities used in the laws, they do not explain how gravity works. A full theory of gravity will include not only the mathematical law but also the description of how to use it and the background connecting it to other physical concepts." Particles in Nature; John H. Mauldin.
"As he digs deeper, the rocks above begin to neutralise the gravity of the rocks and the iron core beneath. At the center of the earth, gravity is zero." Einstein's Universe; Nigel Calder.
"A man falling off a roof does not feel any force of gravity. In modern parlance, he is weightless. Falling needs no explanation, in Einstein's theory, because cosmically speaking it is the most natural thing that can happen to anyone. Only in avoiding falling does any force come into play. The weight you feel on the soles of your feet is pushing upwards, not downwards." Einstein's Universe; Nigel Calder.
"If you take a census of what is present in a volume of high-grade space 'empty' space far away from any galaxy, and then discount all the expected things like a few atoms and plenty of particle of light passing through in all directions, something else remains. You cannot detect it in any ordinary way, but one of the strongest theories of modern physics insists that it is there__ a surreptitious hint of everything that energy is capable of creating. The existence of ghostly particles predicted by the quantum theory has been confirmed by small effects on the 'tuning' of atoms." Unknown at the moment.
"What we think of as "empty" space cannot be completely empty because that would mean that all the fields, such as the gravitational and electromagnetic fields, would have to be exactly zero. However, the value of a field and its rate of change with time are like the position and velocity of a particle: the uncertainty principle implies that more accurately one knows of these quantities, the less accurately one can know the other. So in empty space the field cannot be exactly zero, because then it would have both a precise value (zero) and a precise rate of change (zero). A Brief History of Time; Stephen W. Hawking
"Newton's explanation of gravity has been repeated so often and so authoritatively that we all believe it and indeed feel that its truth has become part of our intuition. William D. MacMillan, professor of astronomy at the University of Chicago, was moved to put it this way on the occasion of a debate on relativity at Indiana University in 1926, as he somewhat belatedly opposed Einstein's new theory: 'The mechanics of Newton, like the geometry of Euclid, was based upon our normal intuitions and it is, therefore, intelligible in the normal sense of the word, just as Euclid is intelligible.' ...But considered without prejudice, the notion of action-at-a-distance is disturbingly unsatisfactory. If it were intuitively obvious, it might have been invented sooner than two millennia after Euclid!
"The sun does not exert any force on the planets; in Einstein's law of gravitation, the planet only pays attention to what it finds in its own neighborhood." The ABC of Relativity; Bertrand Russell
"It is one of our earliest experiences that things fall to the ground if we let them go; and yet the reason for this action remains a mystery, the most familiar mystery in physical science. Newton (1687) made a great advance by finding that falling is due to a force which is of a most general sort, by means of which every body in the universe appears to attract every other body." A Survey of Physics For College Students: Frederick A. Saunders, Professor of Physics, Harvard University (© 1930)
"The law of gravitation first formulated by Newton does not explain why bodies gravitate toward one another, but only how they do so... ...The law expresses the manner of their movement, but it says nothing about the cause. Newton did not know why bodies move together, nor does anyone know now. Even the word attract has a technical sense as it occurs in the law, for it is not implied that there is any attraction in the human sense between the bodies. They may be driven together; or, as Einstein thinks, their behavior may be due, not to any force acting between the bodies or upon them, but due to the nature of space." Introduction to Philosophy: George Thomas White Patrick, Ph.D.
"The general formulation of the law of gravitation is as follows: ...Every particle of matter attracts every other particle with a force varying directly as the product of their masses and inversely as the square of the distance between them... ...This is not to be found, stated as such, in the Principia or in the System of the World." Newton's Philosophy of Nature: Selections from his writings; Edited & Arranged with notes by H.S. Thayer.
"Assuming that we know, let us say, the statistical distribution of the stars in the Milky Way, as well as their masses, then by Newton's law we can calculate the gravitational field and the mean velocities which the stars must have, so that the Milky Way should not collapse under the mutual attraction of its stars, but should maintain its actual extent. Now if the actual velocities of the stars, which can, of course, be measured, were smaller than the calculated velocities, we should have a proof that the actual attractions at great distances are smaller than by Newton's law. From such a deviation it could be proved indirectly that the universe is finite." Sidelights on Relativity; Albert Einstein.
"Newton's explanation of gravity has been repeated so often and so authoritatively that we all believe it and indeed feel that its truth has become part of our intuition. William D. MacMillan, professor of astronomy at the University of Chicago, was moved to put it this way on the occasion of a debate on relativity at Indiana University in 1926, as he somewhat belatedly opposed Einstein's new theory: 'The mechanics of Newton, like the geometry of Euclid, was based upon our normal intuitions and it is, therefore, intelligible in the normal sense of the word, just as Euclid is intelligible.' ...But considered without prejudice, the notion of action-at-a-distance is disturbingly unsatisfactory. If it were intuitively obvious, it might have been invented sooner than two millennia after Euclid!
"Recapitulating, we may say that according to the general theory of relativity space is endowed with physical qualities; in this sense, therefore, there exists an ether. According to the general theory of relativity space without ether is unthinkable; for in such space there not only would be no propagation of light, but also no possibility of existence for standards of space and time ( measuring -rods and clocks), nor therefore any space-time intervals in the physical sense." Sidelights On Relativity, by Albert Einstein.
"Hawking's early work focused on the problem of the First Event. He was able to show, using the general theory of relativity, that the origin of the universe was indeed singular... If the simple model of the big bang is pursued to its ultimate limit, then the universe was infinitely compressed at the very beginning. This state has an infinite gravitational field, which represents an infinite warping of space-time. You can no more continue space-time beyond such a singularity than to continue a cone beyond its apex." About Time; Paul Davies.
"...Gravity gets weaker the farther you are from the star, so the gravitational force on our intrepid astronaut's feet would always be greater than the force on his head. This difference in the forces would stretch our astronaut out like spaghetti or tear him apart before the star had contracted to the critical radius at which the event horizon formed! A Brief History of Time; Stephen W. Hawking
"How could we hope to detect a black hole, as by its very definition it does not emit any light? ...Fortunately, there is a way. As John Michell pointed out in his pioneering paper in 1783, a black hole still exerts gravitational force on nearby objects." A Brief History of Time; Stephen W. Hawking
"How is it possible that a black hole appears to emit particles when we know that nothing can escape from within its event horizon? The answer, quantum theory tells us, is that the particles do not come from within the black hole, but from the 'empty' space just outside the black hole's event horizon! We can understand this in the following way: What we think of as 'empty' space cannot be completely empty because that would mean that all the fields, such as the gravitational and electromagnetic fields, would have to be exactly zero. ...These particles are virtual particles..." A Brief History of Time; Stephen W. Hawking
"Hawking realised that the intense curvature of space just at the edge of a black hole could convert some of these ghostly particles into durable particles of matter and light. It was 1974 that he announced that black holes were capable of exploding." Einstein's Universe; Nigel Calder.
"The gravitation of Einstein is something entirely different from the gravitation of Newton. It is not a "force". The idea that bodies of matter can attract one another is, according to Einstein, and allusion that has grown out of erroneous mechanical concepts of nature...