<<< HOW DOES A BOOMERANG WORK? >>>

When you stop and think about it, the idea of throwing an object as hard as you can away from yourself and having it come right back to you (that is, without any elastic or gravity involved!) seems kind of magical, if not impossible. So how is this possible in the case of a boomerang?

There are two basic issues to deal with here…

How do boomerangs fly?
AND
How do they
come back?

The magic of the boomerang is actually due to a happy combination of two basic principles of physics coming together at the same time.

***Spoiler Alert!!!***
If you want to believe in the “magic” of boomerangs, don't read ahead!
But if you're scientifically curious, move on...


First, how do they fly?

  • Boomerangs fly due to the same physics involved in an airplane wing. That is, basically what we're talking about is “lift.” The same force that causes a fast-moving airplane wing to lift the plane up into the air is what causes the boomerang to fly through the air (and even climb) when it's thrown, rather than simply drop to the ground like a stick. Lift is a complicated principle to explain because it involves several different factors, but the key to it all is the airfoil shape of the wings. One of the most important results of that shape is that the curved top of the wing causes the air flowing over it to move faster than the air flowing under it, which results in less air pressure above than below, which therefore causes the wing to be pushed up. That being said, if you look at a boomerang's wings from the tip, you'll note that they're shaped just like an airplane’s wing—that is, thicker on the leading edge, tapering off on the trailing edge, and basically flat on the bottom. Same shape, same lift!
So that's how they fly, but…

How do they come back?
  • Now things start to get a little more complicated. Boomerangs return due to a principal of physics known as—watch out, we're about to get technical here—"gyroscopic precession.” Basically, it’s the same principle that causes a moving bicycle to gradually turn in the direction you are leaning (in fact, without even having to turn the handle bars) rather than simply falling over. The secret has to do with the fact that both the bicycle’s wheels and the boomerang are spinning. The main point of the principal of gyroscopic precession is that when an object is spinning and force is applied to it at one point, the force is manifested at a point 90° forward (in the direction of the spin) from the point at which the force is being applied. For example, a bicycle wheel turns (left or right) at the front of the wheel when the force of leaning (left or right) is applied at the top. In the case of a boomerang, the force being applied as it spins is the lift that is caused by the airfoil shape, which is stronger on the wing that is at the top of the boomerang’s spin than the wing that is at the bottom of the spin (because the wing at the top is both moving forward & spinning forward, and is therefore moving faster than the wing at the bottom, which is moving forward but spinning backward). This causes the “front” of the boomerang’s spin to turn, just like a bicycle wheel.

SO…
It's the lift pushing against the boomerang and the spin of the boomerang working in combination that causes the boomerang to fly continuously in a circle until it returns to the point from which it is thrown!

Not really "magic," but still pretty darn cool, huh?


BONUS JOKE:
“What do you call a boomerang that doesn’t come back? A
stick!”
(OK, to be perfectly accurate, many boomerangs were never intended to return—
see our “Origins of the Boomerang” page. But it’s still a pretty funny joke we think!)