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208 The Bible According to Einstein The sixth book of Physics, called
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The New Testament 209
And in 1916, this new insight enlightened Einstein and mankind about the force of gravity the insight into gravity was suddenly turned on, like someone turning on a light. Chapter II: Curved Spacetime Now how shall the strong equivalence principle be incorporated into general relativity? The answer shall be by making spacetime curved. Gravity shall be the result of the curvature of space and time. The First Law of Newton shall be generalized. A body, whether or not it be under the influence of gravity, shall follow a path of minimum length in the geometry of spacetime. And such a path shall be a geodesic. Now on a flat surface a geodesic shall be a line. Thus the shortest path between two points on a tabletop shall be a line. And when there is no gravitational field, spacetime shall be flat. And the straight lines in flat spacetime shall correspond to constant motions. Thus in the absence of a gravitational field, a body at rest shall remain at rest, or a body moving at a constant speed in a line shall continue to move at a constant speed in that same line. Thus in the absence of gravity, Newton’s First Law of motion shall follow from general relativity. But when a gravitational field is present, spacetime shall be curved, and geodesics shall not be straight. Spacetime shall be distorted as is like a sphere the shortest path between two points on the surface of a sphere is a great-circle arc.194 And when a body moves along a geodesic in curved spacetime, it shall accelerate because it shall follow a curved path. And because it accelerates, a force shall be said to act upon it. And this force shall be Einsteinian gravity.
____________________ 194 Great-circle arcs are the arcs of the largest circles that can be draw on a sphere. For example, a segment of a line of longitude of Earth is a great-circle arc. |
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210 The Bible According to Einstein
Now how shall Earth be attracted to the Sun? The Sun shall be like unto an iron cannon ball, the Earth shall be like unto a marble, and the surface of a bed shall be like unto spacetime. And if an iron cannon ball is placed upon a bed, shall not the surface of the bed depress? And if a marble is tossed, lands on the bed and rolls, shall it not roll toward the iron cannon ball? And why does the marble so behave? It does so due to the surface of the bed the surface is not flat. Chapter III: Consequences of Einsteinian Gravity And as for planetary motion, Einstein’s theory of gravity shall produce small differences from Newton’s theory of gravity. And for example, the orbit of Mercury, which is an ellipse, shall through Einsteinian effects rotate forty-three seconds of arc per century. |
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The New Testament 211
Now gravity shall affect light in other ways. Light shall take longer to traverse a region of space where there is gravity. And it will seem as if the speed of light be less than in a vacuum. And for example, when light neareth the Sun, the light shall enter a region of curved space. And while passing by the Sun, the light shall travel a longer distance than if the Sun were not there. And it is like unto a marble which rolls down a bowl and out such a path is longer than if the marble moved from brim to brim. Now a second Einsteinian gravity effect is this: Photons shall lose energy as they climb out a gravity. And so if one stands on Earth and "throws photons upward," then the photons, like rockets, balls or birds, shall lose kinetic energy. Now when photons lose energy, their wavelengths shall increase. And this shall render blue light a little yellow, and yellow light a little red, and red light even redder. Thus the spectrum shall shift a bit toward the red. This shall be called the gravitational energy red-shift. Thus light, originating on the surface of the Earth, shall be slightly red-shifted high above the Earth. And the same shall be true of light emitted from the surface of any massive body. |
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To Chapter I of Quantum Mechanics ![]() |