fundamentals: gravity in astronomy
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Moving with the Tides
Have you ever been to the beach? If you’re from California like me, then I’m betting you have. If you’re from a place that’s not near an ocean and you’ve never been near the water all your life, then I’ll…
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How Orbits Work
Since Aristotle’s time over 2000 years ago, we have accepted that the moon orbits the Earth. We didn’t always know why, and we didn’t always accept this for the right reasons. We used to assume that it happened just because…
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Newton and Gravity
So, the moon stays in orbit around the Earth, right? Yeah, I thought so. But why? The moon’s orbit is not a straight line, which means it’s accelerated motion (using the physics definition, which is absolutely any change in speed or…
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Newton’s Laws of Motion
It’s said that Sir Isaac Newton was sitting under an apple tree when an apple fell on his head, and that’s when all his discoveries began. Personally, I doubt that story — just as I doubt that Galileo Galilei ever dropped…
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Galileo and Motion
Before Galileo’s time, Aristotle was the god of gravity. Seriously. Before Galileo came along, the question of how gravity worked was answered with another question: “What would Aristotle say?” Obviously, this method was faulty, since Aristotle was actually wrong about…
