The Game You Can't Fail - Part 2

[00:00:00]I built three mini golf courses that are so geometrically optimized, it's physically impossible to miss, no matter how badly you hit it, while also making it nearly certain [music] that your opponent will miss. Why you might ask? Well, this isn't actually the first time I've built a mini golf course like this. [music] If you haven't seen the first video, let me catch you up to speed. I built a mini golf course that uses very specific geometry to ensure that if you hit the ball from this exact spot, it would always bounce in, no matter what direction you hit it. But, if [music] you hit it from anywhere else, it becomes nearly impossible to make it in on your first try. And after countless tests of it working incredibly well, against all odds, my wife [music] defied the laws of physics and made a hole-in-one, beating me at my own game.

[00:00:51]So, what did I do? I congratulated her on a good game and moved on. Just kidding. No. I built three more even more advanced mini golf courses to ensure that there was no way my wife could beat me. And each of these mini golf courses gets progressively more complex. So, just to recap, ellipses are super cool shapes because anything starting at one focus always leads to the other. And if you squish the ellipse down until it's as tall as it is wide, it becomes a circle, where both foci are in the exact same spot, which means if you hit it in any direction, it always bounces right back across that point.

[00:01:31]And we can take pieces of these shapes and use them to choose where we want the ball to go. But, there are more shapes than just ellipses that have these cool properties. Meet the parabola. The parabola [music] is super cool because it has a focus just like the ellipse, but only one. Anything coming from that exact spot bounces out parallel to each other in one exact direction. [music] I'll explain to you why it's so important that they're all parallel to each other in a second, but for now, I decided to use half a parabola so I [music] could choose the direction the ball would go. And then I used the half circle trick from my last video to make sure that the ball would bounce toward the half [music] parabola, making sure that both the half circle and the half parabola had an overlapping focus. Now, last time I just used some string to trace out the shapes I needed and use PVC and angle brackets to build the course walls, but building a perfect parabola is actually really difficult.

[00:02:33]There's no easy string trick to draw one like there is with circles and ellipses.

[00:02:38]So, I had to come up with another way.

[00:02:40]And this is one of those instances where I'm glad we have 3D printing because you can literally design anything you want and just have it appear. So, I built the course in CAD and then split it into pieces and gave each one a unique shaped edge so I wouldn't get confused which ones went together. So, I printed them out using my Bambu Lab 3D printer, which is exciting for a couple of reasons.

[00:03:03]One, all the prints turned out great.

[00:03:06]And two, this is a small channel. So, landing a sponsor is a huge deal for me.

[00:03:10]And it has been a dream of mine to be sponsored by Bambu Lab. And somehow they said yes, which I just think is super cool because I've been using their printers long before they ever sponsored because they're such high-quality, reliable printer. For example, while printing these parts, one filament spool ran out and the printer automatically switched to another spool of the same material, continuing the print without interruption. So, if you've been on the edge about buying one, then feel free to use the link in my description. Anyway, I used the 3D printed parts to build the half parabola and half circle because I wanted them to be super precise.

[00:03:51]Then I used some 3D printed angle brackets and PVC boards for the rest [music] of the course, funneling the ball from the parabola into the hole at the other end. And yes, I also 3D printed a hole for the golf course. And with that, it was time to test our first golf course. I was a little nervous because if you've seen my videos before, you know that even if it works in theory, theory doesn't always match up with reality. But, the only way to find out was to try it.

[00:04:39]It totally worked and it was super satisfying to see it go in every time.

[00:04:44]But, while this version did make it in every time, I realized my opponent could often make it in first try, too, even without starting from that one specific spot. And this led me to my plan for the second mini golf course. Here's why it's so important that the ball always travels parallel to the walls. We know that starting at the focus of a parabola sends the ball out in one exact direction, which means we can put another parabola on the other side to intercept it, with the hole sitting right at the parabola's focus. In theory, only a ball traveling perfectly parallel would hit the parabola just right and go in. Hit it from any other angle and it should be impossible.

[00:05:25]So, I designed and 3D printed more pieces to make this second parabola, swapped out the funnel section for the new parabola, made sure the hole sat right at the focus, and tested it by hitting the ball straight at the parabola. And strangely, instead of converging at the focus, the ball kept converging just in front of it. [music] I'm still not totally sure why. My best guess is the ball loses some energy on impact, so it bounces back at a more relaxed angle, but the first parabola worked fine, so I don't know. But, I just moved the parabola forward a couple of inches and tested it again.

[00:06:17]It worked, [music] and I was surprised. Stuff like this usually never works this easily. And now, if my opponent hit the ball at an angle, it would bounce off the second parabola at an angle that would send it away from the hole. But, I ran into one issue. If I hit the ball in this direction, it would miss the parabola entirely. So, it would never get aligned, which would lead me to miss.

[00:06:41]And I'm not kidding, I actually lost sleep [music] over this. But, after 3 days, I finally got it. I had to think outside of basic geometry and include some physics, but I got it. Remember when some of the ball's energy was being absorbed by the back wall? Well, this was annoying in this instance, because I wanted it to bounce, but I figured if I built a wall that was intentionally a little bit flexible, it would just hit the wall and continue along the edge.

[00:07:09]And you might have noticed that I had used this method in my first version of this golf course. When I put in the PVC walls, I intentionally made it very loose, so that instead of bouncing, it would just follow along the wall. So, I figured I could use that again. So, I designed this shape that I could loosely screw in to have the same effect, but it was still too rigid and didn't work. So, I designed this instead, which would allow the piece to flex a little bit, which would hopefully cause it to roll all the way along this edge, all the way up until it hit the back wall, where it would bounce in because the ball would be coming in parallel to the rest of the hits. And that's what's so nice about this printer. It's so fast you can print something and then just print it again if it doesn't work. And this thing was crazy. I thought it would loop around smoothly and sometimes it kind of did but most of the time it just looked totally chaotic.

[00:07:59]But it actually worked most of the time.

[00:08:01]And when it didn't, it wasn't because it missed. I just didn't hit it hard enough. And now that I had figured that out, I realized that now that my mini golf course had every possible hit traveling in a parallel path, this unlocked a bunch of new super cool shapes that had all kinds of interesting properties. For example, this shape could completely reverse any ball coming toward it regardless of where it hit as long as the balls were moving in the same direction. And a regular straight line could do that, too. Except the line didn't have to send it straight back.

[00:08:33][music] I could angle it to send the ball wherever I wanted. And I could chain as many of these as I wanted while keeping everything parallel. So, I decided to add a line at a 45° angle to add a turn to the course and then reinstalled my 3D printed parabola at the end. I was super nervous because every time the ball bounces, it becomes less reliable. [music] And I couldn't have my wife humiliating me again. But the only way to find out if it worked was to test it.

[00:09:35]No way.

[00:09:37]No way that worked. That is crazy.

[00:09:40]>> It worked. I was thrilled. And [clears throat] to be completely honest, it didn't make it in every single time because of all the variables we've already talked about. It still gave me a massive advantage as long as I started from the focus. And from anywhere else, it really was nearly impossible to get a hole-in-one. So now there was only one thing left to do. Play my wife in a game of mini golf and get my sweet revenge.

[00:10:08]>> Okay, last time against all odds, my wife somehow won.

[00:10:14]That's not going to happen this time.

[00:10:15]>> I dominated.

[00:10:17]>> [laughter] >> Nice. Okay.

[00:10:27]>> I'm relieved.

[00:10:29]The golf course works.

[00:10:30]>> Okay, I'll try.

[00:10:31]>> go.

[00:10:32]Here's Here's the thing. I have to choose where you put the put your ball.

[00:10:35]It's not She's seen the other video. She knows the secret.

[00:10:39]That should even make it easier, right?

[00:10:40]>> Okay.

[00:10:41]I don't even know. Okay, I'll try.

[00:10:43]>> Okay.

[00:10:47]>> [clears throat] >> Okay.

[00:10:52]I had a little too much power there.

[00:10:54]>> Okay. [laughter] But here's the thing. Now we're tied. So we have to make a part three where we find out who the ultimate winner is.

[00:11:03]Yeah. Okay. So make sure to subscribe if you want to see the last of this series where we find out who actually wins between us.