I'd heard that at one point the average electric car (or hybrid) is worse for the environment to produce than even a Hummer because of the energy that goes into the production of the battery. The moment the two vehicles start driving, the electric vehicle starts catching up with its Hummer competitor.
The video today doesn't necessarily get into that. It looks at the efficiency of electricity produced by power plants and compares that to how efficient a gas-powered car would need to be in order to be more efficient than an average EV in various states of the US.
I did not know that - as of this video being produced in 2018 - Colorado was the dirtiest power-generating state and that Alaska was the cleanest.
I assume the gloves are there so nobody gets cut by accident.
I would have thought that glass would be the absolute easiest material to recycle. It's effectively sand, after all. It could go into coastline; it could be remelted into new glass; it could go anywhere that sand can go.
I wouldn't have thought about the problems of weight and shipping of the recycled glass to its final, useful location.
Here's to hoping we can get all of this stuff worked out, because I'm trying to use more glass and less man-made polymers at any opportunity I get.
I have to hunt down some of those metal oxides to add to my glass in matsci class.
Just look at the possibilities...
source - from YouTube video above
Oh, and the video talks about how some metal oxides (erbium and holmium, in particular) change color in different light sources, but that doesn't diminish how pretty they all are.
source - from YouTube video above
I may make a project out of producing that rainbow up there for myself.
Anybody want to pitch in to share in the purchase of the various oxides? I know I won't be able to buy less than like a quarter pound each, and I'll only need like twenty grams
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 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.
I understand that the quality of the final product is important and noticeable by really discerning artists and art lovers, but I'm amazed that anybody still uses this method to produce ultramarine blue from lapis lazuli. I'm kind of glad to know that he uses a different - supposedly secret, faster, and higher-yielding than the Cennini method.
I'll warn you that the later half of the video is mostly about the politics and economics of the mining in Taliban-controlled Afghanistan. It's interesting, but it's not so much about the material production but more about material sourcing.
I was not expecting an excellent explanation of stress-strain curves (2:30), toughness (6:00), environmental costs of polymer production (7:00), amorphous vs (nano)crystalline regions (6:45), hydrophobicity (and hydrophilicity) (12:45), and CRISPR/Cas9 technology (20:30), but that's what you get in today's Veritasium video.
As an aside, I want to rant and rave about the investment in Veritasium by Electrify, but the quality of the videos, the topics being covered, and the volume of output have stayed at least as high and might in fact have improved.
If you rely on one source for a material, you run the risk of that one source either holding you hostage or that source simply drying up.
Note, this is just about the clay source for Wallace & Gromit (or rather for Aardman animators) - not about anything to do with material needs in the production of rare earth magnets and electric motors.
I make glass with some regularity in my material science class. We batch glass and add in manganese oxide (purple), chromium oxide (green), copper oxide (light blue), and cobalt oxide (dark blue) to produce colors.
From watching this video, I'm thinking I may need to buy some new crucibles and try other oxides to check out more colors. I'm not as worried about their color under UV light - though that is kind of gorgeous - but rather under various visible light sources.
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.
Found on reddit...(my apologies for the subreddit's name)...
Wear your PPE, folks.
I hear people lamenting 'government regulation' all the time, but I recognize that most government regulations were put in place at the cost of somebody's life.
I've seen the reverse spherification technique of using sodium alginate and calcium chloride solutions to produce edible, gelled products (Kool Aid worms, gelled drink spheres, cocktail pods). Sometimes the calcium chloride is swapped out for calcium lactate because it's really the calcium ions that are necessary for the process.
But using that process to make gelled glass which can be shaped in ways that glass normally couldn't be shaped is pretty amazing. All respect to Karen Lise Krabbe for developing this technique. If you want to learn more, you can check out her ebook on the technique.
The materials in our world are rarely pure. Our steels are alloys. Our polymers contain dyes and plasticizers. And apparently our food packaging - like chip bags - are composed of nearly a dozen different polymer and aluminum foil layers glued together.
Trying to get those materials apart again to recycle them is currently all but impossible to recycle.
In our summer camp (more info here, natch) we have an awesome demonstration that heats an iron wire via a variac that demonstrates the solid state phase transition from BCC iron (at room temp) to FCC iron (at higher temperatures).
This video heats wires of various metals at - I think - constant voltages - and observes a few interesting things:
copper wire produces a green flash at the moment of melting
magnesium ribbon rose as it heated and expanded (rather than sagging) at first
molybdenum wire produced a series of evenly spaced 'balls' (unduloids) before melting and breaking
I've seen something somewhat similar to the molybdenum balls when the iron wire melts and fails. Each end of the iron wire creates one single ball of iron on its end where the wire failed. We don't get the repeated drops like molybdenum, but the metal balls are familiar to me.
I appreciate the explanation of the formation of unduloids forming via partial melting and surface tension pulling the molten surface together. Sounds good enough to me.
I do wish they had repeated the 90 degree turned experiment with the molybdenum wire - not just with the copper wires.
We were talking about the expandable, polyurethane foam in class after doing the lab, and I wanted to hunt down some uses of the foams outside the classroom. I figured if I'm looking for them, some of you might be interested in them, too.
If you have any other good videos of uses of expandable foam, please link to them in the comments.
I'm far from an expert when it comes to firing ceramics. I've been using the same programs on the same kilns in my classroom at Princeton HS for almost twenty years now, and as I've learned from the actual ceramics teacher in my school, that likely means my elements and thermocouples aren't anywhere near optimal working condition anymore. She offered to replace the elements for me, and I think I'm going to take her up on that this year.
I've also learned that I should probably be using some pyrometric cones to confirm some of the temperatures that I think we're getting to according to the thermocouples and the digital controllers on the various kilns.
I can admit to having not seen the movie Tower Heist. I'm okay with that fact since the reviews generally weren't all that positive.
To give you the relevant summary, a bad Alan Alda has stolen money from lots of people including the employees of the building in which he lives via a ponzi scheme. The employees break into his apartment to steal back the money only to find the safe empty. Luckily, they happen to scratch the paint job on vintage Ferrari in the apartment and find that it's made of solid gold.
Bad science ensues.
In the above clip, nebbishy Matthew Broderick does some quick math and states that the car weighs 2000 lb at $1872 per ounce of gold which makes for about $45 million.
The math doesn't even check out as 2000 lb x 16oz/lb x $1872/oz = $59.9 million...even allowing the 'give or take ten million,' that's lazily off.
But the issue here is that a 2000lb car made of steel, rubber, and glass wouldn't translate to the same weight in gold since steel, rubber, and glass have different densities than gold.
2000 lb of gold would make for a cube roughly 14 inches on a side because gold is way more dense than steel, rubber, or glass. If the Ferrari were actually made of gold, it wouldn't be 2000 lb; it would be more like more than - according to one article I found - 10,000 lb...because gold is very dense.
Which would lead to so many problems in the subsequent scenes when the team tries to lower the Ferrari down on a rope, swing it into an apartment being renovated, and then has to pull the Ferrari back up the roof where a single person unhooks it and drops it into the rooftop pool.
Oh, spoilers...
None of that would be possible with a solid gold Ferrari weighing in excess of five tons.
Then, in the touching end scene, each of the building's employees gets a chunk of the solid gold mailed to them - a grill, a wheel, a bumper - all of which are easily delivered by a friendly UPS-type man...and each of which would weight hundreds and hundreds of pounds.
I've been waiting to post this video until the construction was fully completed.
Nate From the Internet has been building a 'life-sized' Lego castle for nearly a year now. I'm pretty sure it's set 6080 - Kings Castle from 1984.
He's had to figure out how to 3d print the individual bricks which meant designing digital files for the initial 1x1 bricks and also for interlocking pieces to make each of the bricks, plates, and tiles that were too large to fit into a single 3d printer. Along the way he ran into problems with the interlocking mechanism, the fit of the pieces together, the strength of the plates on which he would hopefully be able to walk, how to 3d print the big ugly wall panels, and lots more.
The above video shows the assembly of the final castle, but Nate has a full playlist of the work in progress videos. They're all worth checking out, and I'm half tempted to look into going to Utah in August to see the final product.
A little while ago, I went looking for a video to explain the oxidation/reduction aspects of raku so I could assign it for my students to watch while I was out of the classroom for a day.
Sadly I didn't find one, but I did come across this video from the inaugural ASM teacher camp in Butte, Montana. It doesn't explain the redox aspects of raku - though the title suggests that it might - but it does include your friendly, neighborhood blogger in his orange polo shirt (ASM-branded, natch), and jeans.
Because the video doesn't explain the science, I'll give a quick version...
We use a clear glaze into which we mix oxidized metals (cobalt oxide, iron oxide, copper carbonate, nickel oxide, etc). Each glaze gets just one of those oxidized metals.
The pottery is taken out of the kiln while it's hot - somewhere around 1050 oC. At that point the glaze is molten, allowing oxygen to leave the glaze.
The hot pottery is placed into a metal can with something flammable. In this situation we're using torn up newspaper.
The torn up newspaper catches fire and starts to consume the oxygen in the now-sealed can.
The carbon and hydrogen from the paper continues to 'search' for more oxygen, so it reduces the metal in the glaze and takes the oxygen from the oxidized metals. (This only works if the pot is hot enough for the glaze to stay molten in the reduction environment.)
The glaze cools, sealing in the now-reduced metal within it, leaving - hopefully, if everything works right - reduced, shiny metal in the glaze.
The pottery is quenched in water to lock in the final version of the metal within the glaze - either reduced or oxidized metal.
You can see lots of versions of raku pottery on other blog posts.
Most years, I give my students some freedom after the AP chemistry exam. There's still so much more chemistry to learn, but I've completed the required curriculum for the year, so we can explore a few cul de sacs of chemistry.
We've played Minecraft because they told me there was a bunch of actual chemistry involved - which turned out to be kind of true. There's certainly a whole bunch of material science involved.
I've also had them research chemistry programs as universities around the midwest, practice and perform a demonstration for my non-AP course, and honestly - write a blog post for my chemistry blog.
Today's post, however, is about the time my students asked if they could just make slime. We make polyvinyl alcohol slime in first year chemistry, but they wanted to make glue (which I recognize is often PVA-based) slime. One of the students said she had a gallon of Elmer's school glue at home from her Covid lockdown slime days (apparently slime-making was a thing for many school-age students during Covid lockdown?)
In discussing what they could bring in, other students in the class offered to provide shaving cream (apparently to make 'cloud' slime - a fluffy variation), small fruit-shaped slime charms, glitter, and non-staining food coloring. I, generous sort that I am, offered my leftover borax solution from the crystal making experiment early in our matsci curriculum. It's a little more than the 4% concentration called for in most slime recipes, but it's close enough.
One of the students asked me if the borax solution took the place of the activator. I'd never heard of an 'activator' solution before, so I started looking around online.
Apparently the borax solution + PVA/glue solution with which I am most familiar has some alternatives - sort of. There's the 'borax-free' variety using baking soda and contact solution, but the contact solution has to contain boric acid - which would be neutralized into...um...sodium borate (aka borax) with the addition of sodium bicarbonate (baking soda). There's also the option to just purchase pre-mixed activators, one of which - shown in the image - is Elmer's Magical Liquid.
With a quick check of the Magical Liquid's SDS, I see that it's a solution of boric acid, sodium bicarbonate, sodium chloride (?), and a couple ofanti-microbial agents. The various concentrations seem lower than I would have thought: <1% boric acid, 1-5% sodium bicarbonate, <1% sodium chloride, and <0.5% of each of the preservatives. I'm feeling too lazy to do the math to do actual calculations, but I'm pretty sure the combined percentages - discounting the bicarbonate and the chloride masses - would come out decently below the 4% of the borax solution I'm used. Wonder if that's just a case of commerce allowing for the lower concentration leading to more needing to be purchased.
At $17 per quart (from Amazon as of 6/7/26 when I'm typing this up), the magical liquid has to be a high margin item for Elmer's. It's more expensive if you want your slime to be green-apple-scented. Sadly the cherry limeade scent looks to be sold out and might be out of production now - even though Elmer's still has it listed on their website.
