The Archer's Paradox in SLOW MOTION - Smarter Every Day 136

Hey, it's me Destin, welcome back to Smarter Every Day. So in one of the last episodes, I introduced you to a legend with a longbow. He's from my hometown and his name is Byron Ferguson. He shot an aspirin out of the air in slow motion. But there's something that happened in the arrow I didn't understand. It was deflecting and it has something to do with what's called the "archer's paradox".

What do you think, Byron?

• "The archer's paradox is the demon for all archers, but there are ways to work around it."

Not bad! Alright, so today on Smarter Every Day, we're gonna understand how an arrow deflects and what's called the "archer's paradox". A paradox is a situation involving two things with a contradictory nature. So what is the archer's paradox? What are the two things an archer has to deconflict? My friend John explained it to me like this.

Let's pretend that this pecan tree is the bow and this is the line of our bowstring. If we take an arrow and we put it into our bow and we draw the bow back, and we're trying to hit that target over there, watch what happens. As we release the bowstring and it travels closer to the bow - look at that -, the fact that the bow is sitting here in our way between us and the target causes the arrow to point off in a different direction.

So how can we possibly hit that target when our arrow is pointed over there? This is the archer's paradox, because we know they actually do hit targets like that. Toy designers are cheaters: they don't deal with the paradox, they just get around it. For example, the guy who designed this suction cup bow, he doesn't go around the handle, straight through the middle.

Check that out! Whoever designed this crossbow, instead of being in line with the bow itself, the string is offset by this big rail. That way, the string is always pushing along the dart. So how does a longbow shooter get around this problem? Here's how: they don't have a completely rigid arrow like that, they have a bendable arrow like this.

See when it vibrates? You can see these nodal points? That's important. Check this out. As we put this real arrow into the bow here and we shoot, as we go towards the bow, the fact that we're accelerating this arrow causes it to build strain energy, causing this big curvature. That curvature then snaps back in the other direction once it bends to a certain point and look what we have. We have the arrow bending around the bow.

When we release, it does something cool. It snakes around the bow, just like this, and you're able to fly all the way to the target. So the archer's paradox is the fact that you have a bow in between you and the target and you're still able to get around the bow.

• "The first that happens is the arrow bends from the pressure of the string and the front arrow being against the riser of the bow. As it leaves the bow or has already cleared the bow, it bends in the opposite direction. When those two cross, determines where the arrow will fly. One hundred percent of the time, the arrow will fly where these two points are crossed, are pointed. Whereas if this one had been here, then the arrow's gonna fly to the left. If it was here, the arrow flies off to the right. We want those two lined up to go straight to the target."

• "Gotcha. So the fact that it bends helps it get around the arrow rest without going off in an angle, as if it were a straight line."

• "Correct."

• "You're pushing the string straight towards the handle, but somehow it makes it around the handle."

• "Right."

• "Yeah, and the bends is how it does that?"

• "That's correct."

Alright, my buddy Sander actually shoots with a compound bow. You don't do any of that longbow stuff, right?

• "I have one, but I'm not really good at it."

• "Alright, so what's the deal here?"

• "So a compound, there's a whole lot more going on on a compound. There are more things that can go wrong, too, but there are several advantages if they're working."

• "Yeah."

• "So a compound, you see that's it cut out in the middle, you get this -"

• "Oh, so the riser's not stout, is that what you're saying?"

• "Yes, so the arrow is travelling straight, it doesn't have to go around a riser."

• "Okay."

• "And many people shoot also a drop-away rest, so it's gonna drop down. Whenever you pull the bow back, a string attached to one of the bowstrings pulls the rest up -"

• "Nice!"

• "Centers your arrow, if you have it lined all up and square, your arrow is nice and level and then when you shoot, that arrow would dr- the rest would drop away -"

• "Well, shoot it, shoot it. Let's do it. Oh no, wait, let me zoom in."

"Hold on, so I'm looking at that rest, it's gonna fall away, right?

• "Real fast!"

• "Okay, I'm ready. Dude, that is super fast. So is the arrow touching the rest as it goes through?"

• "A little bit."

• "Really?"

• "'Cause it drops but it's not, I mean, immediate, it's down before the arrow passes it."

• "So the goal here is, you don't have to bend around the riser, but I bet the arrow still bends, though?"

• "It does bend and that's actually important in the straightness of the arrow flight."

Isn't that interesting? But something else is going on here. Byron Ferguson is able to predict the wobbling of that arrow so good, that he's able to hit an aspirin tablet with a vibrating arrow, just like that.

So one of two things is going on. Either a) he knows some science that we don't; or b) he's a warlock and this is all black magic.

• "Okay, the stiffness of an arrow is called the spine, right? And so the spine is what, Byron?"

• "The stiffness of the arrow."

• "Oh, right! So this is your spine tester?"

• "This is the spine tester, set up right now to test the flexion of a carbon arrow."

• "Okay."

• "So we actually have a two-pound weight and the arrow's suspended at 26 inches. That's for carbon."

• "Okay."

• "And we read the inside of the scale here to see how much it deflects."

• "So you, you test all of your arrows before you shoot, so that you can normalize the paradox?"

• "Correct, I want all the arrows to have the same stiffness."

• "And that's how you're able to hit things like an aspirin?"

• "That's part of it, yes."

• "There's a little bit of skill. If it's out of tolerance, you just don't even put it in your quiver?"

• "That's what those are."

• "Really? Really? You've just got a box of stuff that you don't shoot?"

• "Yeah, they're too far out of tolerance."

• "Really? That's amazing. So, people were asking in the last video - that arrow was deflecting so much -, they're saying 'How do you time that?' and the way you time that is you know the exact spine of the arrow."

• "Correct."

• "That's awesome. This is pretty good information. So this isn't black magic, this is science?"

• "Correct."

• "That's awesome."

Byron is using science to normalize the wobble of his arrows. But less it been, there's a little bit of wizardry here, right? Because of the certain distance from his bow, he still has to know which side of the arrow that wobble's gonna be on. And then he has to line that up with an aspirin tablet. So this is a pretty good shot.

In order to fully appreciate this trick shot, I'm gonna do a trick shot of my own, using the Phantom Miro. I hope you enjoyed this episode of Smarter Every Day; it was sponsored by Harrys.com. Harry's makes subscription razors that are really high-quality. They end up being about the same price as the old razors I used to use.

So, I have no need for my old razors, so Byron's gonna help me get rid of it. If you're interested in getting a Harry's razor - I actually shaved with one today - go to Harrys.com and use the promocode "Smarter".

• "What are you gonna try?"

• "I'm gonna try to hit it down in here, around the neck part."

• "Get it of it that way?"

• "Cut its head off."

• "Excellent. Alright, I'm gonna film this with the Phantom v711. I hope you hit it, this would be awesome! You did it! Like, I thought you would do it, but you did it! That's the first shot, Byron!"

• "Luckily!"

• "Whatever, man!"

Alright, there you go. So, if you want to support Smarter Every Day, go to Harrys.com, use the promocode "Smarter", get you a discount on some razors. Thank you for supporting Smarter Every Day, please consider subscribing and thank you as always, Byron.

• "Can I get some Harry's razors, too?"

• "You can!"

I'm Destin, you get smarter every day, have a good one - he actually did that! BEEP

• "You make your own arrowheads, right?"

• "Uh no, I designed the head, it's actually made in Austria. This is what's called a destructive test."

• "Holy cow, it didn't break, man! It didn't break! It didn't break!"

• "Did you think it would do that?"

• "I was hoping for it."