How Disc Golf Discs Are Made (MVP Manufacturing Tour) - Smarter Every Day 301

Summer of George!

I do want Destin to get back to making shorter videos like his initial, six-and-a-half-minute Prince Rupert's drops video, but I understand that he's just working to optimize for the algorithm. 

At least the Smarter Every Day videos are quality videos from tip to tail, showing brilliant views and asking questions along the way of the entire manufacturing process.

I learn so much from all of Destin's videos.

And I'm going to get myself some of those MVP discs. 

ROBOFORMING: The Future of Metalworking? (I Had NO IDEA This Was Possible) - Smarter Every Day 290

There is so much happening in manufacturing that I am blown away by.

I understand the absolute minimum basics of forging, stamping, casting, and a few other processes, but this concept of slightly deforming a metal sheet by pushing with two (by the company's founders) end effectors without any mold and just using CNC robotic arms is amazing to watch. The process is referred to as incremental forming.

The amount of computing power required to do all of this is stunning to me.

I think manufacturing might be becoming more complicated over time...just maybe.

This second video is ninety-four minutes of behind the scenes footage that Destin edited down into the thirty minute video up top.

MOLTEN GLASS VS Prince Rupert's Drop - Smarter Every Day 285

There's a whole lot to be said for YouTube videos that are five to ten minutes long. I can show an entire five to ten minutes in class without committing a full bell. The video likely has enough information to be useful but not so much as to be rambling around and further on a topic than I need to it.

But YouTube's algorithm seems to be killing those five- to ten-minute videos in favor of either long videos (between thirty and forty-five minutes from what I can tell of the posting patterns of my favorite YouTubers) and shorts that are less than a minute and a half.

I'm not happy about that.

...but I am thrilled about the video that I'm posting today and that is clearly too long to be shown in class on a whim. Today's nearly thirty-minute long video is a brilliant exploration of phase transitions of glass.

It starts with Destin recapping what Prince Rupert's drops (PRD) are, something he's covered in way more depth, then goes on to let Cal from Orbix hot glass - also from that earlier PRD video - try to capture a shattering PRD inside a class prison - rather than the epoxy prison that Destin tried to use previously.

Then at about 7:00 the stress-strain curve shows up, and we start to see that glass isn't quite as simple as we'd been lead to believe previously.

And a graph of viscosity versus temperature blows it all away around 8:00 where we hear that glass is a second order (more info here and here) transition material.

...and I was hooked. Destin continues to produce some of the best science content on YouTube. 

COLD HARD SCIENCE: SLAPSHOT Physics in Slow Motion - Smarter Every Day 112

For me, the big payoffs in this video come from the high speed videography at 2:30 and again at 5:20. Seeing the composite hockey stick flex and store up energy then spring forward even ahead of the player's hand when that stored energy is release is just gorgeous and shows the advantages of composite materials in sports as compared to older, wooden sticks.

Plus, I'm down for just about any video that Destin posts.

My YouTube subscriptions

In case you were wondering which science- or material science-themed YouTube channels I subscribed to, you could probably just skim back through and see which video sources I post from most frequently.

But I thought I could put together a list in case you wanted to subscribe to them, too. So, in no particular order...

• Smarter Every Day - Hands down, my favorite channel on YouTube. Destin Sandlin is an engineer turned YouTuber who covers a whole host of science topics both high brow - How Do We Land on the Moon - to low brow - How Do You Harvest Pecans - and covers them all with a humility, curiosity, and ease of communication that is infectious. Occasionally he gets a little too excited about things (check his collaborations with Mark Robert, for example), but most of the time his tone is spot on, and I learn something from nearly every video that he makes. Most tend to be ten to twenty minutes, but occasionally he post forty-five minute to an hour videos and takes a far deeper dive into a topic - take his nuclear sub series, for example. You could easily turn his videos into a year-long science course. I'd take it. He also has a second channel of slightly less polished videos and lots of behind the scenes footage. Destin also spoke at Skepticon about balancing his faith and his science. It's a great talk. His TED talk isn't bad, either. (equally for both blogs)
  
  
• Real Engineering - Initially this channel from Brian James McManus (yes, he's Irish) focused mostly on the rudiments and basics of engineering and used a lot of white on blueprint paper background animation. He's upped his video quality and started using a whole lot more licensed footage over the years, and he now tackles some pretty deep dives into engineering topics (solar panels, renewably powered ships, tesla's battery challenges, colonizing the moon, digital vs vinyl sound, etc). Videos tend to be in the 15-25 minute range anymore. We almost never see Brian, himself, though there have been a couple of videos where we did. I learn a TON from his videos at this point. Initially, I didn't learn nearly as much. (more for MatSci blog)
  
  
• Practical Engineering - Grady Hillhouse reports from his house in San Antonio and makes civil and mechanical engineering incredibly understandable. Some of the best parts in his videos are his small-scale, homemade demonstration aids to help him explain the video's concepts. He's built tiny rivers to show how weirs function, made rebar-reinforced concrete cylinders to show how they improve concrete's resistance to cracking, crafted complex pipe systems to show water hammer, and much more. His videos stick to the 8-12 minute range, and are great explanations of basic engineering concepts. (more for MatSci blog)
  
  
• Veritasium -  Dr Derek Muller hosts - and probably writes - the veritasium channel videos. He originally did all the work himself, but one of his more recent videos celebrating his tenth anniversary on YouTube talked a bit about his increasing team helping him make videos of higher and higher quality. Muller comes out of Canada by way of Australia and is all over the map as far as topics go. His videos are about optical illusions, origami engineering, calculating the speed of light, close packing with shade balls, and - my absolute favorite video of his - how trees get their mass. He covers chemistry, biology, engineering, physics, and general philosophy of science. (equally for both blogs)

• Steve Mould - Steve's videos are far less focused on any one area of science (or of math). He covers everything from "I calculated absolute zero with vodka" to "Tree tumors are GMOs but not made by humans" to "Self driving cars are dangerously confused by LED lights" to "Does Canadian money really smell like maple syrup?". He's a bit of all over the place, in other words, wandering pretty much anywhere that his curiosity happens to take him. The initial videos were pretty low-budget and short (1-4 minutes long), but the quality of video made a pretty big jump about five years ago. The videos have gotten longer over time, some of them wandering to the fifteen minute range, though he still makes a decent number of videos that are in four or five minutes long or shorter. (equally for both blogs)
  
  
• Mark Rober - Mark's all about building bigger, more theatrical versions of everyday things. He's build a scaled up SuperSoaker, filled a pool with jello, and set up the world's largest elephant toothpaste (or devil's toothpaste). He's also built machines to skip stones better than humanly possible, squirrel obstacle courses, and a liquid sand hot tub. Admittedly, most of his videos could be cut by about 25% of their length by eliminating the over-reaction shots. I think his best videos are the most focused. I particularly recommend the rock skipping video.

How Weed Eaters Work (at 62,000 FRAMES PER SECOND) - Smarter Every Day 236

I've spoken of my love of Destin before. One of the things that I love most about him is his scientific curiosity. He's willing to point a slow-mo camera at just about anything and set up some experiments to teach himself more about whatever that camera points at. It's kind of awesome.

In this one, Destin points his Phantom high-speed at weed eater string to see how the string cuts blades of glass (cut or rip? delaminate or clean slice?) and breaks against various wire fencing materials.

We could do a lot worse than show this when talking about destructive testing in class.

There's also a second video that tries to figure out which shape or string is best. He comes to a conclusion, but I'm not sure he does nearly enough experimenting and variable isolation to actually justify the conclusion he comes to.

HOW ROCKETS ARE MADE (Rocket Factory Tour - United Launch Alliance) - Smarter Every Day 231

So much to cover here.

The quick version is that Destin (of Smarter Every Day) shows us his tour of United Launch Alliance (ULA with their CEO, Tory Bruno. The ULA factory has some pretty highly-regulated manufacturing going on.

I'll go with a bullet point list of things I found interesting and possibly useful for a material science class. Admittedly, the full video - fifty-four minutes long - is probably more than any class could watch in total, but it's got some awesome clips.

• 5:15 - The video cuts to avoid filming "that" to Destin's left and right, items that Tory narrates but that he says flatly can't be filmed and shown.
• 7:15 - Quick discussion of the supply chain for the aluminum sheets that the rocket fuel tanks are made of
• 8:30 - We see the finished product of a machined isogrid panel as well as why that design - not the ideal design - was chosen because of the limitations of FEA analysis calculations in the 1990s.
• 9:50 - Discussion of the safety margins in space flight (1.1 - 1.25 times designed load) as compared to those of land-based transportation (7-12 times designed load)
• 12:15 - Amazingly, we get a mixture of, as Bruno says, "the pinnacle of technology...high-tech, robotic operations but mixed in [with] craftsmanship with people who are very skilled and have great attention to detail." That's amazing that something this precise is partially done by hand. This will come back in a bit.
• 13:30 - Machining, subtractive manufacturing is mentioned...as well as their recovery system for recapturing the aluminum chips for eventual recycling.
• 17:00 - 19:20 - Advertisement for Audible, skip it
• 19:30 - Replacing the isogrid with an orthogrid, saving time and weight, along with a quick discussion of strain and work hardening that happens by hand after the machining. We get a nice close-up of the orthogrid at 21:10.
• 22:00 - Destin uses the term strongback to describe the construction of the press used to curve the machined panels. That's a term I had to look up.
• 22:45 - Destin questions whether the aluminum is annealed, and Tory says they allow the aluminum to artificially age at room temperature after they are slightly work hardened from the curving process.
• 24:15 - Back to manual manufacturing to a precision level that - according to Tory - can't be achieved by automation. "You will always get better results by doing it by hand," he says.
• 27:30 - We see the anodizing facility to create a thick oxide layer for hardness and corrosion resistance. I knew that bare aluminum automatically formed an oxide layer, but I hadn't heard - as Tory says around 28:10 - that the natural layer is very thing and porous, leading to poor corrosion resistance.
• 31:30 - I wonder what the various acid concentrations are.
• 32:10 - We head toward the friction stir welding area, and Tory explains why friction stir welding is the better choice for strength of their final tank.
• 34:05 - Destin 'peaks over there' at a highly pixelated area. Cute
• 36:00 - Quick explanation of why it's better to order one large pizza than to order two medium pizzas
• 37:40 - Another pixelated section with the specialized head of the friction stir welder
• 40:15 - We switch over to stainless steel - half the thickness of a dime - instead of aluminum as we switch from boosters to upper stages. 
• 43:00 - We get a finished view of the 5m composite payload faring and a discussion of ULA having brought the manufacturing of that from Switzerland to north Alabama via business partnership.
• 44:00 - Bruno discusses ULA's record of flying both payload and actual people successfully with 135+ consecutive, successful launches. 
• 45:20 - Discussion of mass fraction (without explanation)...I had to look that up, too.
• 46:30 - Changes coming from hand arc welding to automated welding in the next version of Centaur (the upper stage) to save time (and assumedly cost).
• 47:40 - We get a quick glance of the team of people who are walking around behind the scenes with Destin and Tory. Admittedly, it looks like Tory is taking Destin around solo, but there are clearly people supervising even the CEO the whole time.

In general, I'm incredibly impressed with Bruno's knowledge of the entire process. It's amazing to see that from a CEO. Maybe that's the way that all CEOs are, but I doubt it.

And, if you want even more, there's a second video - on Destin's second channel - where the guys get into some discussion about the rocket engines themselves and ULA's position within the industry. It's less materials-focused, but it's worth watching.

How Hard Can You Hit a Golf Ball? (at 100,000 FPS) - Smarter Every Day

I'm not always down with Mark Rober's videos. He tends a bit much toward goofy, seemingly-feigned excitement for my tastes, and he tends to bring this out in Destin, too. I'm starting to see a trend in YouTube videos that could easily be made about 30% shorter if they'd just edit out the people going "Whoa!!!!!!!...Yeah Baby!...Look at that!".

But...

To hit the serious matsci/science content in bullet points here...

• 6:25 - compressed golf ball with elastic deformation
• 7:05 - "The ball is hot." - transformation of kinetic energy into thermal energy
• 7:30 - destructive testing and inelastic deformation
• 7:40 - Destin actually says, "an area of physics called material science" and demonstrates elastic and plastic deformation with a 'force-distance' curve (pretty much a stress strain curve). He also compared the curves for a generic metal and a generic plastic, then real and practice golf balls
• 9:15 - We see a plastically deformed but still intact golf ball, one that was hit somewhere above 300 mph against the anvil.
• 10:05 - 50-year old golf ball hits the anvil and is obliterated, apparent source of the apparently-color-enhanced video still above

Touching plasma - Smarter Every Day 193

Let's get this out of the way first. The video isn't remotely about 'touching plasma'. Yes, somebody touches plasma at 9:30, but it's not elaborated on or explained in the least. The title is oddly useless, something I haven't seen from Destin before.

On the other hand, the video does have three minutes of high quality material science content early. From 1:05 through 4:20, Destin goes to Dr. Kavan Hazeli's lab and shows some of the testing of '3d lattice structures printed by NASA.' They're looking at ridiculously lightweight materials, trying to see how much metal they can take away (though it's created via additive manufacturing) while still leaving the 'material strong enough to withstand a space environment.'

We get to see an impact test as the researchers explore the difference in 'quasistatic' pressure and impact pressure tests to the materials. The sample we see tested in nearly pulverized and comes out 'perfectly flat' and hot.

It's like energy is transferred or something.

The rest of the video sees Destin visit two more labs - testing ion thrusters and exploring the fluid dynamics around a butterfly's wing - but they aren't nearly as material science interesting. Watch 'em or don't. Admittedly, at 4:55, Destin announces, 'are you not entertained,' and I'll admit that I'm not. Meh...

It's probably because I don't really understand what's happening with the ion thruster.

The Physics of Slingshots 2 | Smarter Every Day 57

I keep wanting to tell Destin that he's gonna shoot his eye out.

But it looks like he still has his predator vision at the end of this video, so that's his business as to whether he wears goggles or not.

At 2:13, Destin shows a graph of the potential and kinetic energy of the ball/band system as the band stretches and releases.

At 4:39, he then uses actual data/video to show that a tapered slingshot band accelerates the bullet faster than does an un-tapered band.

Then, at 5:00, our favorite - the stress-strain curve - shows up.

Sadly, some of the links in the video description to learn more about hysteresis, for example, are dead.

Destin got two videos out of his visit with Jorg (check the slingshot channel for even more). The other video doesn't have as much material science content, but it's still fun, and it shows some momentum and energy calculation with a gigantic slingshot.

COLD HARD SCIENCE: SLAPSHOT Physics in Slow Motion - SmarterEveryDay

Yes, a hockey player with a missing tooth is frighteningly stereotypical.

The sight of the hockey stick at full flex - in motion at about 2:35 - is outstanding...as is the idea that the player likes his stick 'whippier'.

I'm not a hockey player, but I was a tennis player, and I understand the same idea in a different application. Players can choose how much tension they want in their strings when the tennis racket is strung. Stringing at a lower tension allows the ball to deflect the strings more, creating more of a trampoline effect and generating more power. The cost to that is a decrease in control - worse aim - because of that increased power.

Here's a second video going through the same physics - for the first seven minutes anyway. After the first seven, we get a look at the physics of a wrist shot and a hockey player's workout.

Personally, I prefer Destin's enthusiasm.

Shear Pins are Smart (They're Mechanical Fuses)

I'm not a car guy.

I'm even less of a tractor guy.

I pay to get my oil changed, and I'm happy to do it.

So, when it came up in our summer camp discussions that quenched metal would be useful for shear pins, I wasn't really comfortable with doing more than just nodding and smiling. "Yeah, shear pins...exactly."

Then I had to go look up what shear pins are.

Now, here's my understanding. Shear pins are hardened steel, typically quenched steel. Sometimes a rotational part of the machine - the lawnmower blade, the snow-blower - gets blocked and stopped. There's a driveshaft feeding rotational energy to that blade, however. Something in the chain  then has to break because the motor is continuing to try adding more rotational energy to the now-stuck blade.

If all the parts were equally tough, the break would take place randomly.

Instead, the engineers intentionally put in a weak spot, a quenched piece of metal called a shear pin. The intent is for that piece to be where the break happens because it's the cheapest part of the chain. It's better to break the cheap part than to maybe break one of the expensive parts.

Man, it's almost like people are smart.

I'm happy to say that I'm getting smarter every day.

Mantis Murder Shrimp (slow motion) - Smarter Every Day 121

That's pugilism at its finest.

The first punch is thrown at 1:38 and then shown again in slow motion ten seconds later - then with sound effects.

We then get an explanation of the potential energy storage mechanism at 2:45. That storage mechanism requires a strong material - an organic composite of helicular (sp?) chitin - at 4:29. The variation of the material within the saddle then, is phenomenally complex, varying throughout the surface, depth, and location within the saddle.

Go mantis shrimp!

Interestingly, this is, I think, the only time Destin's sister has been shown.

How to Escape from a Car Window (slow motion) - Smarter Every Day 144

I think I've run out of ways to say that Destin is awesome.

It's like he's put together a video to perfectly explain the differences between tempered glass (like in the side windows of a car) and annealed glass (like what's laminated on the windshield of a car).

And he does it all in super slow motion.

I wanna buy his shirt even though I'm a pudgy XL, and his website says his shirts run small. Hence the largest size available - the XL - still worries me.

Mystery of Prince Rupert's Drop at 130,000 fps - Smarter Every Day 86

Prince Rupert's drops (also known as dragon tears) are beautiful explorations of tempering glass - like the Corelle plates that we demonstrate in the first year summer course - using the opposing stresses of the outside and inside glass to create phenomenal strength.

This video does some pretty stunning things with high-speed photography, showing the shockwave travelling down the tail of the drop to the head at over a mile a second.

The video explanation - using red-, white-, and blue-shirted versions of our host - is absolutely brilliant, doing a better job of showing the stresses than any other video that I've seen. Marvelous...stunning...

And, at 4:33, there's a tiny bit of type at the bottom of the screen that tells the actual amount of pressure involved in the Prince Rupert's drops.

Great, great, great video!

Why aren't they wearing gloves, though?

Here's a similar video from Theodore Grey's Popular Science column, Grey Matter.