In addition to being an absolutely fantastic (if often scientifically inaccurate) film starring Sandra Bollocks and the Cloondog, gravity is what gives everything on Earth weight. In the inescapable force of nature’s namesake film, you may have noticed that astronauts Bullock and Clooney are (mostly) unaffected by gravity. This is because, being in outer space, they’re beyond the earth’s gravitational pull.
It stands to reason, then, that, somewhere between the surface of our planet and the airless reaches of space, gravity cuts loose. But just how far off the ground does one need be before gravity starts to lighten up a bit? There’s only one way to find out…
Bust out your permission slips, because you’ll be going into the wild for this one. You’ll need to take your class to a tall building—the taller the better—but we’ll leave the planning and the logistics to you. They’re your students, after all, so you can deal with that schwa.
In addition to said tall building, agreeable parents, a school bus and driver, and perhaps an additional chaperone or two, you’ll need a bathroom scale—or multiple scales if you can round ‘em up. If you can, use a fancy digital scale that gives decimal readings; the more precise the readings, the better. And be sure your students all have notebooks and writing utensils with them, so they can record their findings.
Starting on the bottom floor, have your students weigh themselves and record their results. Be sure no one sees anyone else weight who doesn’t want them to, because blah blah body shaming blah blah blah whatever. Just avoid the trouble of some chubby little kid’s parents berating you because Kevin saw how much their kid weighs and made a typically Kevin-esque joke and keep the students’ hefts secreted.
Then, load up the elevator and take everybody up to a floor about halfway up the building. Have your students weigh themselves again and write down what they find. Then, elevator up again and hit the top floor. Repeat the weighing and recording steps.
From there, you can wait until you get back to the classroom to discuss your findings, but little kids being who/what they are, you might want to start the discussion right away so they don’t forget everything with their smelly, attention-deficient minds. Comparing their weights from the three different heights at which they measured, what trend do your students see?
Is That Why Really Tall People Are Skinny?
As they ascended, the students’ weights should have decreased. Not significantly, but enough to register on your advanced, high tech, state-of-the-art scale. This literal lightening up occurs because weight is the measurement of the net amount of downward force placed upon an object by good ol’ gravity. As we move away from Earth’s surface (even just a few dozen feet), the gravitational pull decreases. The further up one goes, the less affected by gravity one will be. Once you reach space, you’ve totally left gravity behind and are, therefore, weightless.