The Ridiculous Engineering of Jet Engines

Jet engines are miracles.

The more I learn about them, the more amazed I continue to be by them. 

I've heard a number of times that the hot gasses passing by the turbine blades is hotter than the melting temperature of those blades.

It simple enough to say that the blades have ceramic coatings (thermal barrier coatings) on those blades and internal cooling channels that together keep the blades cool enough not to melt (or to creep too much outward toward the turbine's housing) at that phenomenal high temperatures.

...and then we get the bubble raft demonstration - which is just my absolute favorite.

And I just found out that the older video I had posted explaining the pigtail's function in creating single crystal turbine blades has disappeared from YouTube. I'm suddenly very sad about that.

The $1 Trillion Problem Diamonds Can Solve

Polycrystalline diamonds aren't nearly as pretty as monocrystalline ones are, but they seem to be much easier to produce - especially if you're trying to grow them onto a computer chip.

...which I would never have thought to do but which seems to be really desirable because diamond is a phenomenal conductor of heat, seemingly an improvement on aluminum as a heat sink for electronics on a massive scale.

image from YouTube video above

All that's left is to grow those diamonds via chemical vapor deposition - which is also incredibly cool.

The pastry and marble counter myth

I demonstrate something like this in my classroom using Flinn's ice melting blocks and a knock-off MiracleThaw from a second-hand store.

As one of the comments for the above video notes, "Thermodynamics is often very counter-intuitive." 

See, it's funny because Adam's talking about counter materials in the kitchen.

I'll wait while you laugh.

Remember, vinegar leg on the right.

Can We Throw Satellites to Space? - SpinLaunch

This is another overly long video that is filled with a massive amount of science in all sorts of disciplines: physics, material science, chemistry, engineering, mechanics.

The video sees the Real Engineering host, Brian McManus, visit SpinLaunch's centrifuge being built to launch satellites into space primarily via kinetic energy rather than through rocket fuel combustion...which sounds totally bonkers but might work out.

One of the main technologies here involves a carbon fiber-reinforced polymer tether. At 3:00 that concept is explored with a laminated carbon fiber reinforcement mock-up of the thickness that they need the tether to be to hold the millions of pounds of force that would be necessary.

Then - 8:00 - they look at the need to spin up that tether in a vacuum chamber so that it doesn't melt the carbon fiber from the friction due to air resistance. They also describe how truly low pressure vacuum chamber pumps work and why the SpinLaunch people don't need a vacuum chamber with quite that low a pressure. The idea of outgassing from the metallic parts - 10:25 - was amazing to me. It makes sense to me that there would be small amounts of oxygen gas 'dissolved' in any steel parts, but I had certainly never thought about it before. It's an equilibrium problem, I guess, as oxygen is removed from the atmosphere around the part.

At 16:20 they take a look at the challenges of opening a low pressure chamber at near vacuum to the atmospheric pressure outside without destroying the chamber inside when the air rushes in. They've used a pairing of mylar layers that are broken through and two incredibly quick closing doors.

From 21:30 they explain how they address and minimize vibrations - especially once the payload is let go, leaving a highly unbalanced weight on the arm.

The next section - from 26:45 - they look into the ballistic coefficient of the projectile and why a heavier vehicle might be better for their launch process - something that is very well against the traditional method of launch's goals. With rockets, lighter is better. With the SpinLaunch, heavier and denser is somewhat better because it allows the projectile to gain more momentum without corresponding drag and heating due to friction with the lower atmosphere.

The whole process is fascinating, and I'm hopeful that it turns out to be feasible because I would love to see a full scale SpinLaunch facility built and functioning - for the science and novelty if for nothing else.

Flamethrower vs Aerogel

They killed that poor kid's flamethrower.

That sucks.

Dr Derek got himself some big sheets of aerogel and stood behind them while a makeshift flamethrower went full bore at the sheet from barely a feet or two away.

I think aerogel might be a pretty good insulating material.

I may need to get myself some of that stuff...and not to let Rebecca get ahold of it.

To me, the demonstration after the blow torch - around 6:20 or so - is more impressive. Dr Derek touches a piece of metal that is mostly coated with a 1mm thick layer of aerogel. The coating is at 125 C, hot enough to boil water. Dr Derek then rests his hand on the aerogel coating without harming himself - because the aerogel does such a spectacular job of not allowing the thermal energy to be transferred to his fingers.

He also shows a few other commercial uses of aerogel to keep really cold things really cold - like pipes carrying liquid natural gas in industrial settings...and deep undersea insulating oil pipelines.

My closing take-away is that this stuff is miraculous.

Searching for Starlite

Extraordinary claims require extraordinary evidence.

I stumbled upon - thanks to YouTube's recommendation algorithms - the video below...




...which references a material named starlite and claims to have reproduced something akin to starlite.

But I didn't know what starlite was...and didn't know why the egg test was a big deal.

So I went looking, and it turns out lots of people are looking for starlite.

And they've been looking for a few years...(from wikipedia)

Starlite is a material claimed to be able to withstand and insulate from extreme heat. It was invented by British amateur chemist and hairdresser Maurice Ward during the 1970s and 1980s, and received significant publicity after coverage of the material aired in 1990 on the BBC science and technology show Tomorrow's World. The name Starlite was coined by Ward's granddaughter Kimberly. 

Despite interest from NASA and other major technological companies, Ward, who died in 2011, never revealed the composition of Starlite, which is still unknown. He once mentioned that his close family knows the fabrication process, but after his death neither his wife nor any of his four daughters have produced any sample to demonstrate that they know the process.

From historic mysteries

According to the New Scientist, Ward negotiated with several leading organizations. Boeing, NASA, and the British Department of Defence all held talks with Ward. It seemed Ward was more concerned that he might not be able to protect himself in a litigation battle. He did maintain the utmost faith in Starlite. However, trying to broker the right deal for himself gave him the unwanted reputation as an unreliable negotiator. Supposedly, he asked for a £1 million one day but upped that price tenfold the following day.