The bullet isn't freed from Earth's gravity; if it was, it would go into orbit about the Earth, or even more so, escape from the Earth altogether.
The bullet isn't freed from earth's
gravity, but it is freed from the confines of the gun barrel, or indirect contact with the earth's surface. Therefore, it is set free to act in response to the wind currents it encounters, and according to its own
inertia --which can be thought of as a sum of its muzzle velocity plus the mysterious interaction between it and the universe beyond our atmosphere.
The same phenomenon applies to Foucault's pendulum. If you go to any of the public displays at museums and observatories in the world where docents speak to tourists about the theory behind the apparatus' operation, they tell you that the cyclical rotation of the pendulum's swing is due to the rotation of the earth. They don't wait for you to ask how the stars in the sky have an effect on the pendulum. They pronounce that the pendulum is showing us that the rotation of the earth WITH RESPECT to the depths of outer space (with all its galaxies and stars, including our own sun) causes the pendulum to move in this way, and therefore, this proves the earth rotates on its axis! :tinfoil:
But every tourist who asks one question never gets an intelligible answer. What question is this? The question goes as follows:
Question they can't answer: "But how does the pendulum 'know' that there is relative motion between the stars and the earth?" It's actually a lot of fun to see how different docents cope with this querry from the audience. You get quite a show of hedging and humming and hawing. Sometimes they suddenly remember they have a pressing appointment and run away.
They can't answer this because, A) they don't want to mention the word "ether," and B) if they try to answer this, it is easy to then ask what is the difference between the earth rotating while the stars remain relatively still, and alternatively, the earth being relatively still while the stars do the rotating? Not even Einstein has any solution to this quagmire, and there has been exactly no progress in astrophysics since his time in this matter.
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