Explain the Universe #8: Newton's Cannonball

本站添加: 2026-05-22

[00:00:00]Day eight of explaining the universe.

[00:00:02]What if you fired a cannonball so fast that it never hit the ground?

[00:00:07]That is the idea behind orbit.

[00:00:09]This was one of Isaac Newton's most famous thought experiments.

[00:00:13]At low speed, it falls nearby. Faster, it lands farther away. But keep increasing the speed and watch what changes.

[00:00:22]The ground keeps curving away beneath it, so the cannonball is still falling, but it keeps missing Earth. It is not escaping gravity.

[00:00:32]Gravity is what bends its path into an orbit. That is what an orbit really is, a continuous fall around a planet. And if you launch it even faster, it does not just orbit. It can escape entirely.

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