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  • 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 a 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 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 considering 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 that!

  • BEEP

  • - "You make your own arrowheads, right?"

  • - "Uh no, I designed the head, it's actually made in Austria.

  • This is what 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."

Hey it's me Destin, welcome back to Smarter Every Day.

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慢動作中的射手悖論--每天更聰明 136 (The Archer's Paradox in SLOW MOTION - Smarter Every Day 136)

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    林宜悉 發佈於 2021 年 01 月 14 日
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