Space Itself Is Expanding: Gravity and General Relativity Explained

Time passes left to right as the graph shows the acceleration of an iPhone held upright, tossed in the air, then caught. RGB color => XYZ acceleration respectively. Yellow is the acceleration magnitude, which is 1g when supported by a user’s hand or “resting” on earth’s surface, and 0.0 when “falling” (the center section).
From the inertial reference frame of the scientist in free fall (except for wind): the cannon ball, also in free fall, is seen moving at a constant velocity in a straight line, while the earth’s surface accelerates upward. Reprinted with permission of Prof. Kip Thorne of Cal Tech.

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David Levitt

David Levitt

computer, media and political scientist, writer, physicist, pianist, satirist, MIT ScD, Yale BS, augmented reality innovator and CEO of Pantomime Corporation