BL: zero gravity, microgravity
Posted: 28 July 2014 10:51 AM   [ Ignore ]
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A weighty topic

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Posted: 28 July 2014 11:42 AM   [ Ignore ]   [ # 1 ]
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You left out “free fall”, which is also widely used and a better description of the apparent weightlessness in orbit.  The key reason that people and things appear weightless in an orbiting spaceship is that they are all falling at the same rate.  This is also the case in the “Vomit Comet” airplane dives that simulate weightlessness for brief periods.

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Posted: 28 July 2014 01:57 PM   [ Ignore ]   [ # 2 ]
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Nitpick: in the second to last sentence of the article, “Us of ‘microgravity’...” presumably should be “Use of ‘microgravity’...”.

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Posted: 29 July 2014 03:30 AM   [ Ignore ]   [ # 3 ]
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Yeah, I should probably do freefall as well.

And thanks for pointing out the typo. (I really do appreciate it when people do.)

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Posted: 29 July 2014 06:43 AM   [ Ignore ]   [ # 4 ]
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BTW, a physical scientist will use g to represent the standard acceleration (not, properly speaking, force) of gravity at Earth’s surface (about 32 ft/sec^2 or 9.8 m/sec^2), and G for the universal gravitational constant (the constant that you multiply by the product of two masses and divide by the square of the distance between them to obtain the gravitational force between them).  But non-scientists often use the capital and lower-case indiscriminately.

Interesting fact: the force of gravity at the altitude of the International Space Station is about 90% of what it is at Earth’s surface.  I.e., if you could climb a ladder to that height, you’d only weigh about 10% less that you do here.  Thus, it’s not really “microgravity” in the sense of being in an extremely weak gravitational field--the apparent absence of gravity is due to the fact that everything is in free fall together.

[ Edited: 29 July 2014 07:03 AM by Dr. Techie ]
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