At seven years old I learned the Earth spins along on its axis at 1,040 miles per hour.
So of course I wondered: if I jump high enough, will I come down in a different spot? Obviously I should, because the Earth is moving under my feet, and if I step off of it, the two of us would separate. Just like a merry-go-round, right? You step off and look back and see it still spinning without you. You don’t go spinning along with it all around the park. Right?
A thousand miles per hour was hard for me to imagine because I didn’t have any reference point for that. My bicycle was in the 5-10mph range. But it equals 1,525 feet per second, and I could work with that. That’s about five football fields. In a second. If I jumped up for one whole second (it’s harder than you think—try it) I should come down somewhere in the next neighborhood.
But of course I didn’t. I had jumped plenty of times before, without even thinking, and didn’t go crashing through the hedges of my front yard. So the effect must be more subtle. If it’s moving and I’m moving, then we’d both move together a bit before separating, like jumping off the roof of a moving car.
So to begin my experiment, I started small. Why take chances?
I drew a chalk line on the sidewalk. I aligned the toes of my red Keds up to it. I gave a little hop.
A bigger hop. Then a full jump. Then a give-it-all-you-got heave-ho.
I actually came down behind the line. Maybe I was facing the wrong way? After a few more trials, I could see the results were random. While I hardly ever came down exactly on the line, my in-fronts and behinds were about even. I was crushed. Why didn’t this work?
I’ve learned since by both observation and inference that it’s just as well. In sixth grade I would see how high I could throw a baseball, and it’s good I didn’t break a window in the next town. It took until high school for me to grasp the why of it all—the relative motion, the physics. But I’m still a little disappointed and I still have a lot of questions.
In 2012, Felix Baumgartner rose in a balloon to 128,097 feet—that’s over 24 miles high—and then he let go. He was in a free-fall for four and a half minutes. You can’t even imagine four and a half minutes, because if you try, you’ll get bored and go do something else before you get to four and a half minutes. That’s how high he went. That’s how far he fell. He fell for four and a half minutes. He rose 24 miles up from Roswell, New Mexico, and do you know where he came down?
I think of that when I feel I’m not getting anywhere. While things in my little sphere of awareness may not be changing much, I’m moving right along nonetheless. Just think:
- Because it’s spinning and we’re on it, we’re riding along on the face of the Earth at 1,040 miles per hour.
- But! The Earth is moving too: it zips around the Sun at 67,000 miles per hour.
- Meanwhile the Sun, dragging Earth along with it, is ripping through the Milky Way at a cop-taunting 515,000 miles per hour.
- Thanks to a push from the Big Bang, the Milky Way disk itself is skipping across waves of space space at 1.3 million miles per hour.*
So behold we humans, tagging along all the while like a bug on a windshield wiper, at nearly 2 million miles per hour.
It’s impressive progress, without even lifting a foot. Lucky for me, I stayed with it even when I jumped up off the Earth’s surface. If it didn’t work like that, and I jumped off the ground from my house in Omaha for about one second, I’d come down near Denver, leaving one hell of a skid mark.
We’re moving right along. We’re definitely getting somewhere. And we’re all gonna be fine.
* Yikes! I forgot continental drift! It’s an additional inch per year — about as fast as fingernails grow. Not much, maybe, but it adds up.