Space-Gravity Theory

This is an interpretation of the Space-Gravity Theory which was mostly conceived by Einstein.

In 1915, Albert Einstein developed the theory of general relativity in which he considered that objects accelerated with respect to each another. He developed an entirely new approach to the concept of gravity, based on the principle of equivalence, which states that gravity pulling in one direction is completely equivalent to an acceleration in the opposite direction, so that it is theoretically impossible to distinguish between gravitational and acceleration forces. He said that acceleration and gravity were actually the same phenomenon and that the gravity you feel is actually the force of acceleration acting on you as you move through space-time. Gravity could be considered an effect of space itself and not a force. Acceleration is defined as the rate of change of velocity. If a person were standing in a stationary rocket on earth, his feet would be pressing against the floor of the rocket with a force equal to his weight. If the same rocket and person is in outer space (far from object and not influenced by gravity), the astronaut is being pressed against the floor if the rocket is accelerating just like on earth. If the acceleration of the rocket becomes 9.8 m/s², the force that the rocket presses on the person is again equal to his weight. If he had no frame of reference, the astronaut could not tell whether the rocket was at rest on the earth or accelerating somewhere in space. Thus, Einstein concluded that the force of acceleration is not distinguishable from the force due to gravity.

If gravity is equivalent to acceleration, and if motion affects measurements of time and space (as shown in special relativity), then it follows that gravity does so as well. In particular, the gravity of any mass, such as our sun, has the effect of warping the space and time around it. For example, the angles of a triangle no longer add up to 180 degrees and clocks tick more slowly the closer they are to a gravitational mass like the sun. In the theory of special relativity, Einstein had stated that a person in a closed car rolling on an absolutely smooth railroad track could not determine whether he was at rest or in uniform motion. In general relativity he stated that if the car sped up or slowed down or driven around a curve, the could feel a force but could not tell whether the forces were due to gravitation or whether it was acceleration from changing speed or by turning the car sharply to the right or left. Part of his theory of general relativity states that space becomes “curved” near massive objects. The curve is not a ordinary curve that is visible or noticeable in our third dimension, but rather a bending of space in the direction of the fourth dimension. In three-dimensional space, the rocket is stationary and therefore is not accelerated; but in four-dimensional space-time, the rocket is in motion along its world line. Moving in the direction of the fourth dimension makes it harder for us to “visualize” the curve of space than in three dimensions, but it gives us an explanation of how our universe could not have boundaries but still be infinite, because our universe could actually be the surface of a hypersphere. Since a hypersphere is a curved (like a regular sphere), fourth dimensional object, we could go on in one direction and eventually reach where we began.

According to Einstein, the world line is curved, because of the curvature of the continuum around space near the earth. This meant that the rocket was in fact moving toward the earth but falling down in a dip formed by the earth itself which is what Einstein thought was the cause of gravity. These curves or dips in space-time can be described as dimples formed in space due to a large mass. Any mass creates dimples, but the larger the mass, the larger the curve in space is formed by that mass and thus a greater force of gravity comes from it. In the earth’s case, it is going around the sun, but it is pulled toward it by the funnel-like shape that the sun makes by stretching or bending space down to it. In the curved space near a massive body, the area and volume of a sphere are less than expected. Also, when a falling object moves towards the body, it is stretched lengthwise and squeezed in on the sides to reduce volume, and to make it fit into the shrunken space. One of Einstein’s predictions is that “gravity waves” are formed as a product of his gravity theory. The waves were like tidal ripples that travel through empty space far away from the massive objects that created them. If a gravity wave were to hit a football field from above, it would first make the field longer and more narrow, then shorter but more wider. The most obvious sign of curved space is the way the moon orbits the earth and the way that the planets orbit the sun. Einstein said the planets were falling freely and moving in the straightest line they could in curved space. Curved space can be described by a flat rubber sheet with a stationary mass in the center and a smaller mass rolling around it. If a mass is moving too fast to fall into orbit of a star, it may only change directions in an open orbit and leave going in a different way. This is the case with light. Light changes direction around massive objects just like other planets would. This is why we can see around the sun. The light from behind it begins away from us but the sun pulls it toward it causing it to bend. This leads scientists to believe that light has a mass.

Newton's theory of universal gravitation which states that every object attracts every other object in direct proportion to its mass is replaced with the new relativistic hypothesis that the space-time continuum is curved around massive objects. Einstein's law of gravity simply states that the world line of every object is a geodesic in the continuum. A geodesic is the shortest distance between two points, but in curved space it is not always a straight line. Similarly, geodesics on the surface of the earth are great circles, which are not at all straight lines on any ordinary map. Einstein had accounted for the previously unexplained orbital motion of the planets and predicted the bending of starlight in the curved or bent are in the vicinity of a massive body such as the sun. The confirmation of this phenomenon was made by Einstein during an eclipse of the sun in 1919 became a major media event, as well as leading to Einstein’s worldwide fame and recognition. General relativity was the first major new theory of gravity since Isaac Newton's, more than two hundred and fifty years earlier. Einstein was reported to have apologized to Newton. He also said that Newton had “discovered the one and only universe.” There is still a mystery left from general theory of relativity which is the question of how masses curve space-time.

Black holes are also explained by the theory of general relativity and by space gravity. Gravitational collapse may form black holes by a massive object bending space so much that no matter, light, or communication of any kind can escape. The greater the concentration of matter, the greater the curvature. When the radius of a star decreases below a certain limit known as event horizon which is determined by its mass, the extreme curvature of the space around the mass seals off contact with the outside universe. What was once a star is now a black hole. a black hole with a mass three times that of our sun would have a diameter of about 10 miles. Neutron stars are thought to be some of the most dense objects in the universe, which would mean that the curvature they form in space must be very large and deep. The possibility that stars could collapse to form black holes was first theoretically "discovered" in l939 by J. Robert Oppenheimer and H. Snyder, who were manipulating the equations of Einstein's general theory of relativity. According to the Big Bang theory, the universe may keep expanding forever, if its inward gravity is not sufficiently strong to counterbalance the outward motion of galaxies, or it may reach a maximum point of expansion and then start collapsing, growing denser and denser, gradually disrupting galaxies, stars, planets, people, and eventually even individual atoms. Which of these two fates awaits our universe can be determined by measuring the density of matter versus the rate of expansion.

General relativity may be the biggest leap of the scientific imagination in history. General Relativity had little foundation upon the theories or experiments of the time. No one except Einstein was thinking of gravity as being equivalent to acceleration, as a bending of time and space. Without Einstein, it could have been another few decades or more before another physicist worked out the concepts and mathematics of general relativity.

Chris Flynn's Gravity Theory