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Gravity and Black Holes
Curriculum Guide |
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• Gravity is not down - it is together!
• Weightlessness is not because one is in space: it's because one is falling! Space has gravity just like everywhere else, just no fixed objects to hold against to keep from falling.
• Antigravity doesn't exist. Gravity is always attractive, always a "together" force.
• Black holes don't suck everything into them, unless the object is falling towards them in the first place. If the Sun were converted into a black hole (which it can't be because the Sun is not massive enough), the Earth would continue in its orbit unperturbed.
• Heavier objects don't fall faster!
• Astronauts on the Moon were not weightless! The Moon has gravity much like the Earth. But since the Moon is less massive, the gravitational pull is smaller. The astronauts were pulled to the Moon with about 1/6th the force of gravity back here on Earth.
• Galileo probably didn't drop cannonballs from the Leaning Tower of Pisa.
• Newton probably wasn't really hit on the head by an apple. He might have possibly gotten the idea for extending the realm of gravity to the heavens by watching an apple fall; but, if so, he was likely in the safety of his study looking out a window... (He was a fastidious man in many ways, and it's hard to imagine him lounging around in an orchard.)
• Astrology simply doesn't work! The gravitational forces between the planets and newborn infants are tiny! Far smaller than the gravitational force between the doctor and the baby! And, as discussed before, none of the other forces have long range interactions that might be important.
• Planetary alignments have absolutely no effect on the Earth.