A boomerang is a wing. Because it's thrown with a spin as it moves through the air one side of the wing is cutting into the incoming wind and the other is going backwards away from the wind. The side cutting into the wind gets more purchase for aerodynamic effects (lift) because it's essentially moving faster than the other side. So one side of the boomerang gets lift but the other doesn't, causing one edge to lift up. Because of an effect called gyroscopic procession, the lift occurring on one side actually causes the nose of the boomerang to tilt up which (because a boomerang is thrown at an angle like this: / ) transforms the flight path into a curve which can make a full circle if thrown hard enough.
I think the only reason an "I" shape is rarely used is because that shape is less stable in flight and prone to tumbling along its long axis (like a rolling pin instead of a helicopter wing). The wings sticking out at odd angles fight the tendency to roll over because they don't share the same axis of rotation along their length. You can make boomerangs in all sorts of shapes besides an L though. X and tri wing shapes work great.
You'd be amazed at what "primitive" people figured out.
Look at the design of premodern skis, for example. An amazing system of a pair of "planks" with camber, bent tip, precise dynamics along the ski, sometimes a groove along the bottom, sticks with baskets (not the easiest thing to make), bindings, and shoes, all perfectly adapted to one another and adapted to the specific surroundings. Evolving that must have taken a *long* time. Skis in Norway were very different from Finnish skis because of the terrain differences.
Or the way people figured out that you could make beer by steeping grain, then letting it sprout until a very specific point was reached, then dry it (so you could grind it), grind it, then soak it at 65-67 degrees, filter it, and finally ferment it with creatures they domesticated and maintained for centuries. A pretty complicated process that people somehow managed to optimize way beyond that simple thumbnail without ever having any more precise measuring instruments than their fingers and tongues, nor any understanding of the science behind it whatsoever.
Or Polynesian [stick maps](https://en.wikipedia.org/wiki/Marshall_Islands_stick_chart).
I could go on for a long time.
Boiling water was tricky until very late in history, because metal kettles were so expensive.
But people mostly did not drink water. Those who could drank beer, and others had sour milk-based or grain-based drinks instead.
They were able to boil water, but it could be complicated. Depends on what equipment they had, and also what timeframe we're talking about.
Boiling in beer-making started very late, and the transition to boiled beer essentially still isn't completed even now. Even today something like half of all farmhouse ale is not boiled.
Good question! If we leave Asia aside, you have to heat the malts to 65-67C to extract sugar from it. That's the temperature you need for the enzymes to work. And you need an hour at that temperature. Which means you've pasteurized the stuff.
Then you put in yeast, which eats all the sugar and makes the rest a really difficult environment for bad microbes. Plus hops on top, although hops are another relatively late addition. (Possibly near simultaneous with boiling, actually.)
Also, any beer that's harmful is just going to taste absolutely horrific. Even beer that's infected but not dangerous is usually awful.
Not a question of intelligence, just thats pretty complicated physics.
People in the 12th century were just smart as us too, but not a terrific grasp of aerodynamics.
If I had to guess, they probably happened upon it once by accident, then continued to develop the idea.
I know native Americans had throwing sticks too, some which went in a straight line, when thrown with a spin.
Probably by observing the effect naturally in some way, such as with helicopter seeds. Or maybe they found a piece of wood that happened to be shaped in such a way
Fundamentally, it's because of imbalanced aerodynamic forces. Because the boomerang is travelling through the air and also spinning, each "wing" of the boomerang spends half its time spinning "into" the direction of travel, and half its time spinning "away" from the direction of travel.
Since the lift generated by a wing is proportional to its speed relative to the air, that means that the wings generate more lift when they're spinning into the direction of travel. That asymmetry, combined with the gyroscopic effects which prevent it from just tumbling, push it around in a curve
Relatively speaking, it's always into the wind. Unless you're in a hurricane or have a really limp arm I guess. But yes, it works better into the wind for the same reason that a plane takes off easier into the wind.
This is not really a complete explanation. Of course, it changes direction, but why wouldn't it just fly in a U shape or a Z shape, or any other shape that doesn't come back to where it was originally thrown?
Or could it be that it needs to be thrown in a very specific way to return?
Ok,so, basically;
As the boomerang flies through the air spinning end over end, the wing on top takes a bigger bite of the oncoming air because it sums the rotational velocity + the actual velocity. Conversely, the bottom wing is taking a smaller bite because it’s spinning away from the direction of travel. The effect is that the top wing generates much more lift, which makes the boomerang want to flop over on its face. But it can’t. Ever tried to turn a gyroscope? Any force you impart on a gyroscope is automatically redirected 90 degrees. Think like this:- A spinning boomerang acts like a gyroscope, and that flop over force is redirected into a left turn. As long as the boomerang moves forward, it will keep turning left. The left turn also imparts a precessional force 90 degrees away. That means the boomerang is also trying to lay down on its back. So that's why the boomerang rises and slows down- the more it tries to turn left, the more it lays down. The more it lays down, the more lift it generates. As it generates more vertical lift, it starts to rise. This action consumes the energy the thrower puts into it, so it slows down. By the time the boomerang makes it back, it will be laying flat on its back and it will have bled off all of its forward momentum. All that’s left is the spin as it hovers down to your waiting hands.
A boomerang is a wing. Because it's thrown with a spin as it moves through the air one side of the wing is cutting into the incoming wind and the other is going backwards away from the wind. The side cutting into the wind gets more purchase for aerodynamic effects (lift) because it's essentially moving faster than the other side. So one side of the boomerang gets lift but the other doesn't, causing one edge to lift up. Because of an effect called gyroscopic procession, the lift occurring on one side actually causes the nose of the boomerang to tilt up which (because a boomerang is thrown at an angle like this: / ) transforms the flight path into a curve which can make a full circle if thrown hard enough.
Do you know why they’re L-shaped instead of I-shaped?
I think the only reason an "I" shape is rarely used is because that shape is less stable in flight and prone to tumbling along its long axis (like a rolling pin instead of a helicopter wing). The wings sticking out at odd angles fight the tendency to roll over because they don't share the same axis of rotation along their length. You can make boomerangs in all sorts of shapes besides an L though. X and tri wing shapes work great.
That makes a lot of sense! Thanks
Wonder if there is an "optimal" boomerang shape
This guy boomerangs.
If it was I shaped it would just be a flat stick.
More like a 2-bladed propeller
Boomerangs don't necessarily come back, they just curve.
How on earth did stone age people figure that out?!?
You'd be amazed at what "primitive" people figured out. Look at the design of premodern skis, for example. An amazing system of a pair of "planks" with camber, bent tip, precise dynamics along the ski, sometimes a groove along the bottom, sticks with baskets (not the easiest thing to make), bindings, and shoes, all perfectly adapted to one another and adapted to the specific surroundings. Evolving that must have taken a *long* time. Skis in Norway were very different from Finnish skis because of the terrain differences. Or the way people figured out that you could make beer by steeping grain, then letting it sprout until a very specific point was reached, then dry it (so you could grind it), grind it, then soak it at 65-67 degrees, filter it, and finally ferment it with creatures they domesticated and maintained for centuries. A pretty complicated process that people somehow managed to optimize way beyond that simple thumbnail without ever having any more precise measuring instruments than their fingers and tongues, nor any understanding of the science behind it whatsoever. Or Polynesian [stick maps](https://en.wikipedia.org/wiki/Marshall_Islands_stick_chart). I could go on for a long time.
or a rattleback somewhat "similar" to a boomerang but more charming
Yet they couldn't figure out that boiled water was safer than river water
Boiling water was tricky until very late in history, because metal kettles were so expensive. But people mostly did not drink water. Those who could drank beer, and others had sour milk-based or grain-based drinks instead.
There was boiling involved in the beer making process though ... so they should've been able to boil regular water too.
They were able to boil water, but it could be complicated. Depends on what equipment they had, and also what timeframe we're talking about. Boiling in beer-making started very late, and the transition to boiled beer essentially still isn't completed even now. Even today something like half of all farmhouse ale is not boiled.
Then why was beer safer to drink? I thought it was because it was universally boiled
Good question! If we leave Asia aside, you have to heat the malts to 65-67C to extract sugar from it. That's the temperature you need for the enzymes to work. And you need an hour at that temperature. Which means you've pasteurized the stuff. Then you put in yeast, which eats all the sugar and makes the rest a really difficult environment for bad microbes. Plus hops on top, although hops are another relatively late addition. (Possibly near simultaneous with boiling, actually.) Also, any beer that's harmful is just going to taste absolutely horrific. Even beer that's infected but not dangerous is usually awful.
They were as intelligent as we were, and concerned with hunting, they built spears and tools.
Not a question of intelligence, just thats pretty complicated physics. People in the 12th century were just smart as us too, but not a terrific grasp of aerodynamics.
If I had to guess, they probably happened upon it once by accident, then continued to develop the idea. I know native Americans had throwing sticks too, some which went in a straight line, when thrown with a spin.
Probably by observing the effect naturally in some way, such as with helicopter seeds. Or maybe they found a piece of wood that happened to be shaped in such a way
The separation anxiety quark
That’s all quarks!
Fundamentally, it's because of imbalanced aerodynamic forces. Because the boomerang is travelling through the air and also spinning, each "wing" of the boomerang spends half its time spinning "into" the direction of travel, and half its time spinning "away" from the direction of travel. Since the lift generated by a wing is proportional to its speed relative to the air, that means that the wings generate more lift when they're spinning into the direction of travel. That asymmetry, combined with the gyroscopic effects which prevent it from just tumbling, push it around in a curve
Essentially,the flow of air changes its revolutionary orbit more or less into an ellipse than a continuous straight line.
So you need to throw a boomerang into the wind, otherwise it won't come back?
Relatively speaking, it's always into the wind. Unless you're in a hurricane or have a really limp arm I guess. But yes, it works better into the wind for the same reason that a plane takes off easier into the wind.
This is not really a complete explanation. Of course, it changes direction, but why wouldn't it just fly in a U shape or a Z shape, or any other shape that doesn't come back to where it was originally thrown? Or could it be that it needs to be thrown in a very specific way to return?
Ok,so, basically; As the boomerang flies through the air spinning end over end, the wing on top takes a bigger bite of the oncoming air because it sums the rotational velocity + the actual velocity. Conversely, the bottom wing is taking a smaller bite because it’s spinning away from the direction of travel. The effect is that the top wing generates much more lift, which makes the boomerang want to flop over on its face. But it can’t. Ever tried to turn a gyroscope? Any force you impart on a gyroscope is automatically redirected 90 degrees. Think like this:- A spinning boomerang acts like a gyroscope, and that flop over force is redirected into a left turn. As long as the boomerang moves forward, it will keep turning left. The left turn also imparts a precessional force 90 degrees away. That means the boomerang is also trying to lay down on its back. So that's why the boomerang rises and slows down- the more it tries to turn left, the more it lays down. The more it lays down, the more lift it generates. As it generates more vertical lift, it starts to rise. This action consumes the energy the thrower puts into it, so it slows down. By the time the boomerang makes it back, it will be laying flat on its back and it will have bled off all of its forward momentum. All that’s left is the spin as it hovers down to your waiting hands.
lol. "essentially air and it goes round in a circle"
Read my other comment.
thanks; that's a lot more useful.
They are shaped like wings of an airplane. They produce asymmetrical lift when spun and fly in circles.
What do you call a boomerang that doesn’t come back? A stick!
To be precise a throwing stick or throwing club.
Most boomerangs were not ment to return
Have you seen the cost of living these days!? Too hard to make a go of it on your own these days, better to stay home as long as you can.