Does a feather and a rock really fall at the same speed? Wouldn't the rock fall faster because it has more gravity?
God bless schools. So good at teaching parts of the idea, yet so poor at teaching the big picture.
This is a classic experiment. Take one feather and one rock and go up onto something high, like a junkie full of grade-A smack ... wrong kind of high ... like a tower or something. If you drop them both at exactly the same time, then they will hit the ground at exactly the same time.
Lies! All lies, I tell you!
Not really. Here on Earth, we have a little thing I like to call, "Air." You know, that stuff we breathe in order not to die. The gases that make up air (oxygen, nitrogen, menthol, and fluffernutter) don't like anything moving through them; they resist. Air resistance is more powerful on lighter objects, say a feather, than on heavier objects, say a rock.
So if you try this little experiment yourself, that rock will smash onto a car hood long before the feather. But that's with air. In space, where they ain't got air, there's no resistance. And yes, a feather and a rock hit the ground at the same time. Okay, so there's no ground to hit out there. They fall at the same rate, happy?
Yes, but don't forget that you're so wrong.
Ah! You budding-yet-annoying scientist types out there point out, "But the rock has more mass! It's gravity, although minute, would make it's rate just a bit faster than the feather!" Not bad, Einstein. You're wrong, but not bad.
The rock does have more mass, so it has more gravity than the feather. But along with mass comes that force keeping me on the couch for hours at a time: inertia. Remember that crap about "Objects at rest will stay at rest, objects in motion tend to stay in motion"? That's inertia. The more mass an object has, then the harder it is to move it.
Flock together like rocks and a feather
If the rock has five times the mass of the feather, it has five times the gravity and five times the inertia. The gravity, which would speed up the fall, is offset by the inertia, which would slow down the fall. The two cancel out, and the rock falls alongside the feather. Ta da!
By the way, don't try this experiment with the junkie on smack. You never know when that stuff is going to wear off.
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