The Bizarre Market for Old Battleship Steel

Oddly, I had heard that old battleship steel - from before the development of atomic/nuclear weapons - was highly valuable for non-radioactive shielding material.

This video does a great job explaining how the Trinity explosion - and subsequent open-air, atmospheric testing of nuclear weapons - polluted any steel made after those tests via the Bessemer process for producing steel from pig iron and using atmospheric air.

I did not know, however, that the battleships scuttled at Scapa Flow had subsequently been salvaged and some of the steel used in this way. (As an aside, your friendly, neighborhood blogger has visited Scapa Flow. It's gorgeous.)

And I also didn't know that the demand for this low-background steel has mostly been superseded because of the switch from Bessemer to basic oxygen steel production.

Marbling Paper with Oil Paints | Teaching Chemistry (and more)

Man, how pretty is that?

I'm talking about the first half of the above video, during which Chris Rowlatt shows us how he produces marbled papers for eventual book binding. The marbling involves putting a nonpolar ink (or maybe dye, I'm not sure the technical distinction there) onto polar water. The two materials don't mix, so the nonpolar ink can be lifted from the surface of the water with paper.

The end product is gorgeous.

And it's been done in all sorts of places.

Mystery blue & white beads

I can't remember where I first saw this density bottle. It might've been from Educational Innovations at one of our ASM summer camps...or maybe from Flinn Scientific at one of their NSTA workshops.

Either way, I have one of those bottles in my classroom, and nearly every student who plays with it love and is fascinated by it. 

There's so much goin on with the bottle (the full video of which you can watchin real time at 4:30).

There's solubility concepts - salt water and isopropyl alcohol being immiscible.

There's polarity concepts - food coloring being differently attracted to the two liquids (I recommend green food coloring not the red that Mould uses here. Just add green food coloring and see what happens.)

There's density concepts - the five substances in the bottle (air, isopropyl alcohol, salt water, white/translucent beads, blue beads) line themselves up by density.

There's polymer concepts - the two beads are made of different polymers (the company wouldn't tell me what polymers, and I've asked). The blue beads are sold as pony beads. The top beads - at least the ones in my bottle from Ed Inn - are sold as UV-detecting beads.

There's electromagnetic wave concepts - turns out that the less dense beads are UV beads. I'd had the bottle for years without knowing that because my classroom at the time had no windows, so I hadn't noticed that. Now that I know it, though, it's pretty cool.

There's IMF concepts - the bottle is shrinking a bit as liquid evaporates even through the bottle over the course of years. That's stunning to me, but I swear that I haven't opened the bottle even once in those years. Something must be going on.

Fact-Checking this Viral Bottle Trick

Cavitation bubbles are stunning. (rim-shot)

Wait, you didn't get the joke?

But, see the mantis (murder) shrimp moves its...um...pedipalps, I think...so fast that they create cavitation bubbles which end up stunning its prey before the killing strike.

Didn't you watch PhysicaGirl's previous video about all that?

You should check it out.

I love that much of the video here is about fact checking a viral video - because the science we get from many of those videos is a whole bunch of bunk.

The science in this video mostly isn't about the bottle at all but rather about cavitation, a fascinating phenomenon that has all sorts of ramifications - like with corrosion, for example, or biology.

I love the slow-mo video of the bottle smacks - even down to the shockwave and soniluminescence.

Hand Sanitizer Fires Are Invisible

Yeah, I guess hand sanitizer - mostly ethanol - fires are pretty hard to see, but I'm really glad that Steve Mould here goes into the dangers of methanol for the second part of his video.

If I haven't mentioned methanol to you yet, you should check out all of my methanol videos.

Piezoelectricity - why hitting crystals makes electricity

Piezoelectricity is so cool.

The fact that if you deform crystals, you can produce a voltage difference to get a spark...or that you can introduce a voltage difference to deform a crystal (like how a fan is a generator but in reverse or how LEDs are solar cells but in reverse) is amazing to me.

And Steve Mould's explanation of why that works - with the crunchy and smooth peanut butter lids - is just brilliant.

I'd known that piezo crystals were the guts of a grill lighter for a long time, but it was a long time before I found out other uses like the 'speakers' within greeting cards or microphones and guitar pickups.

The Curious Case of the Xenon Balloon - Periodic Table of Videos

There's an AP chemistry problem that I vaguely remember. The problem showed four balloons, each with initially identical volumes, temperatures, and pressures. The balloons were filled with helium, oxygen, nitrogen, and xenon gases respectively. (This is entirely from memory, but the details aren't 100% relevant to where I'm going with this.)

The questions underneath the prompt and diagram then asked something about which... 

• particles had the greatest average kinetic energy (they're the same because temp is proportional to average kinetic energy)
• particles had the fastest moving particles (helium because Graham's Law of Effusion says that the smallest particles - if all are at identical temperatures - move the fastest to make up for the lower mass)
• balloon had the greatest mass (xenon because they're at the same temp, pressure, and volume, so they have the same number of moles and xenon has the greatest molar mass)
• balloon would be expected to be the smallest after a day

It's that last one that's relevant to this video.

In the answer I remember, the helium balloon would be the smallest because its particles are the least massive, so they're moving the fastest at the same temperature. That means they'll randomly hit the microscopic holes in the balloon (all latex balloons have tiny holes we can't see with our naked eyes - imagine a rubber band ball inflated), so the helium would get out of the balloon the fastest (it would effuse through the tiny holes) leaving the helium balloon the smallest after some amount of time.

But it seems like xenon might be the correct answer for a much more complicated intermolecular force reason.

Vlad, I think I owe you a point retroactively.

Chemistry is dangerous.

If you're not aware, NileRed - Nigel Braun - posts some really fascinating chemistry videos over on YouTube. 

I'm tempted to blog pretty much everything that he posts because the reactions are brilliant and often are things that I wouldn't remotely feel confident in doing myself. He's a chemist, and I'm clearly a chemistry teacher - very different training and levels of confidence with chemicals.

Recently, on his alternate channel NileBlue, Nigel posted a great video about the safety precautions that he takes in all of his work. The above video is long - twenty-four minutes long - but covers a great breadth of safety concerns from what clothing to wear to how to minimize risks by never working alone.

If ever you're tempted to do any chemistry at home - Nolan, I'm looking at you - you should watch this entire video and buy yourself a lab coat and some high quality goggles.

Aluminum =/= aluminium

When I was a college student at the University of Aberdeen (I spent my junior year from Wabash overseas in Scotland, doncha know) I was admonished by one of my professors for misspelling the element aluminum. 

See, he didn't know I was an American, and I didn't know - at the time - that the Brits spelled aluminum with an extra i - aluminium.

So, just why do we spell that element differently than they do?

For a few years now I've been telling a story of the Aluminum Company of America (Alcoa) changing the name because it sounded better in their advertising back in the 1880's.

The story that Michael Quinion tells in his book about the etymology of words and phrases in the English language is somewhat similar to that but isn't quite the same.

Check out the story in his book - or on Google Books here.

Extracting gold from computer parts

I hope it goes without saying but, "do not try this at home."

I'd read somewhere that the process of 'mining' gold from electronic waste was - at this point in time - more profitable than actual mining from the ground.

After watching these two videos in which NileRed tried to recover gold from electronic scrap, I'm not sure how I feel about the veracity of that statement.

You CAN melt glass in a microwave (microwaves explained) - Filmed from the inside #3

The concept that you can melt glass in a microwave oven - as long as you heat the area to near-melting with a blow torch first - seems like a bit of a cheat.

Steve Mould does go on to explain how microwave radiation works to heat food - causing the water molecules in the liquid state to vibrate in the microwave field. This is based on the polarity of the water molecule as well as its ability to freely move.

If the water were locked in a solid lattice (like in ice), those molecules aren't able to vibrate back and forth nearly as easily, hence why ice doesn't heat - or defrost - well in a microwave.

And Mould uses that to his advantage to take glass to the nearly-molten stage, allowing the molecules to move freely and absorb the microwave radiation causing them to heat more and move more freely. He doesn't, sadly, explain why the glass molecules - a network of SiO₂ as far as I know - respond to the microwave field similarly to how water does.

Stand-up comedy routine about bad science

(Heads up, non-school appropriate word at 6:37...and another at 7:21)

So, I was watching a stupid cooking video recently in which the 'chef' made a jiggly cake.

And this shot came up on the video at 1:14...

...and I got bothered.

First off, multiplying three dimensions should give you cubic units not squared units.

Secondly, converting from inches to centimeters requires you to multiply by 2.54. Like 22 inches times 2.54 gives you 55.88 centimeters. It's not quite the 53, but it's close enough. Unless you have the units squared (or, more correctly, cubed). In that case you have to multiply by 2.54 squared (or, more correctly, cubed). 

See, if you're going to make a frivolous cooking video, you should at least get the math right. Sheesh...

If you're with me on that, then the video up top might be for you. In it, Steve Mould - he of the two instance potty mouth - goes through analyzing a statement, "The temperature outside an aeroplane is 6 times colder than the temperature inside a freezer."

And he analyzes the heck out of it, trying to figure out what '6 times colder' means and whether there is some objective temperature at which 'colder' begins - particularly for Canadians.

I enjoyed it, but it might not be everybody's cup of tea.

Non-Traditional Careers for Science Majors | Dr. Dwight Randle | TEDxMountainViewCollege

"Hey Mr Dusch, I really like chemistry. I'm thinking about becoming a chemical engineer."

Replace that last part with "becoming a chemist", and you have nearly every beginning of a career conversation that I have with my students.

See, chemistry leads to being a chemist or a chemical engineer. That's about it as far as the students know. 

I'm always happy to have a few other suggested paths available for my students.

I've had former students go into labware glass blowing, illustrations for science textbooks, digging up dinosaur bones in Wyoming, counting birds along the upper Mississippi River, and nuclear submarine engineering.

I was really hoping that I would get a few more suggestions for chemistry-adjacent careers paths that I could provide for my students. Sadly, that's not what the above video provides - in spite of the title of the video. Instead, we get told that scientists have historically been portrayed as loner white guys. Scientists don't all look like that now. And then we get advice to follow the career path that fits you.

Overall, meh...

The below video, however, is a bit of that science-adjacent career exploration. It's a speech by a scientific illustrator explaining how her career combines art and science and why it's better than just taking photos to illustrate the text.

How Microwaving Grapes Makes Plasma

Go ahead...do it at home.

Butterfly some grapes and throw them in the microwave.

It's fun. I've done it.

Here's a bit of a how-to...

I always assumed that the water just vaporized which then superheated as the microwaves went through the cloud. That doesn't explain, though, why grapes are so good at doing this.

Apparently it can be done without grapes. They tested using sodium polyacrylate (water gel) beads, and it worked, too.

Turns out there's a lot more to the phenomenon than just superheating the vapor. Apparently the microwaves change wavelength as they pass through the grape/water gel to just the right wavelength to almost exactly match the grape's length.

Fascinating stuff

Can you light a match with water?

My first teaching job was at Terre Haute South Vigo High School in Terre Haute, Indiana.

At THS (we pretty much just called it Terre Haute South), one of the other science teachers gave me a coiled copper tube that looks pretty much like what's shown in the video and was used for exactly what it's used for in the video.

I think I set the demonstration up once...maybe twice ever...and had that copper tube in my storage drawers at three separate schools. I can't remember offhand whether I brought it over to the new building. I think I'll check, though.

But, that's not what the video is about. The video shows how water can be heated to vapor which can then be superheated to a high enough temperature to set a match aflame.

The video also goes on to explain why the copper corrodes so thoroughly.

Kind of cool neat.

An Actually Good Explanation of Moles

This video is brilliant, and the title is surprisingly accurate.

I've been defining a mole for two and a half decades now, and I've never quite approached it from this angle. The mole is simply a quantity that relates the mass of different elements that react together.

I like that.

The rare property of pumpkin seed oil - dichromatism

(Warning: almost dirty word at 1:35)

Is pumpkin seed oil something that any of you have around your house?

I think we have vegetable oil, olive oil, peanut oil, baby oil, motor oil, and safflower oil. I'm pretty sure we don't have pumpkin seed oil.

In this video, Steve Mould breaks down how we see color (three cone cells in your eyes) and how translucent liquids show the colors that they show...especially how pumpkin seed oil shows two totally different colors depending on how deep the puddle of liquid is.

I wonder if there are any artistic uses for pumpkin seed oil.

(By the by, you can see a more accurate version of the pumpkin seed oil spectrum on wikipedia.)

Why all solar panels are secretly LEDs (and all LEDs are secretly solar panels)

In the fall of 1995, Professor Arthur B Ellis of UWisconsin came to Wabash College - where I was then a senior chemistry major - and gave a presentation about LEDs. At the time I knew of LEDs as the little red or green light bulbs that were pretty much used as power indicators on electronic devices. I didn't - before his talk - have much of an idea how they worked or how important they would come to be in our world now twenty-five years later.

Coincidentally, Dr Ellis had just written Teaching General Chemistry: a materials science companion, a book that my cooperating teacher bought for me after my student teaching semester later that academic year and that I accidentally re-purchased twenty years or so later. (I realize now that I've told this story on the blog before.)

But I digress...I have come to realize that Dr Ellis's lecture at Wabash really laid out the chemistry of LEDs marvelously well because I watched the above video - showing the LEDs and solar panels are of a kind - and the below video - in which Steve Mould explains the science of LEDs and how they turn electricity into light (and the reverse in solar panels) - and realized that I already knew that information...even down to the P- and N-type semiconductor information.

I've never had a chance to thank Dr Ellis for his lecture, so maybe - if I'm lucky - he'll come across one of these blog posts and realize that he's appreciated.

Hiding a Nobel Prize From the Nazis

So much chemistry here.

Great explanation of a famous story of Neil Bohr's lab - particularly George de Hevesy - dissolving two gold Nobel prize medals to hide them from the Nazis...and then precipitating the gold back out of solution a decade or so later once the Nazis had been defeated.

It's a great story, and the science - full d-shells, equilibrium, Le Chatelier's principle - is outstanding. The story itself is better told in this NPR post from Same Kean's The Disappearing Spoon book, but Kean doesn't go into the science as well as Hank Green does here. 

Why our sewers are plagued by fatbergs

Don't pour grease and oil down the drain...pretty much ever.

See, sewage is washed down the pipes by the way of water. 

Water takes along with it things that are soluble in water...like salt...food coloring...the eventual product of goldfish 'sent back to the sea'...

...but not things that are NOT soluble in water...like oil...grease...

But it's even worse (as Hank Green tells us in the above video) because of the hydrogen sulfide created by bacteria in human waste. The hydrogen sulfide eventually turns to sulfuric acid which reacts with lime in concrete (which most of our sewers are made of) which eventually crumbles the concrete and releases calcium sulfate. The calcium sulfate then reacts with fatty acids (oils, grease) and turns them into soaps (a la Fight Club).

And whatever non-waste stuff you're flushing down the toilet ('flushable' wipes, tampons, whatever) is just making that stuff stick to the walls even worse.

Sewage stuff is gross, man...gross.

So, don't pour oil and fat down the drain.

Don't flush anything but poop, pee, and toilet paper.

Water in Boiling Oil

Do NOT ever pour water on an oil or grease fire!

Ever!

NEVER EVER!

See - as the above video shows - if the oil is hot enough to burn, it's probably hot enough to boil the water you're splashing on it. If the water is hot enough to boil, then its volume will increase about 1600 times meaning that even a tiny drop of water will expand massively and push the oil above it out of the way.

If enough water drops do that, the oil splashes out of the put and will often turn into tiny liquid droplets in the air. That's called aerosolizing (like how liquid droplets come out of an aerosol can).

Those tiny oil droplets then can ALL catch fire at once, turning a tiny fire into a conflagration. (That's a big fire, donchaknow).

Let's let the Slo Mo Guys (and a few other folks) show us that happening.

Large Number Formats

Source - https://xkcd.com/2319/

See, it's funny because the distance from Earth to Jupiter (a constantly changing distance, admittedly) is a really big number (citation needed), and really big numbers can be written in different ways.

First, as a normal person would write the number, it's 25,259,974,097,204 inches (not the most practical of units for this) from Earth to Jupiter. Admittedly, if we're using inches, your location on Earth very much matters as to the precision (14 significant figures???) of that measurement.

Rounding that off, that would be about 25 trillion inches. That's the same number but to only two digits of precision.

In British numbers - at least a while ago - a billion meant a 'million million' whereas in American English a billion meant a 'thousand million'. Hence the confusion there.

The 2.526 x 10¹³ is the same but to four significant digits and using proper scientific notation (something some of my students struggle with but that I continue to insist that they use, especially when we're dealing with numbers of atoms).

The scientist trying to avoid rounding up just kept everything until he or she got to a zero. Forget sig figs.

The software developer doesn't have superscripts. I don't get that, but I see students try to write that all the time - especially if they're just using a calculator with an E display.

I really don't understand floating point numbers, though I understand that programmers do.

The astronomer only cares about the order of magnitude involved. Everything else is just rounding at that level.

The set theorist includes every number underneath the actual number starting with the empty set.

And Abe would just divide the number by twenty and add the remainder. 

See, funny...

Spooky

Source - http://www.threepanelsoul.com/comic/spooky

See, it's funny because Schrödinger's (the umlaut is important, don't forget it) cat is a famous thought experiment in which a hypothetical cat is placed in a hypothetical box along with a flask of poison, a radioactive source, and some kind of monitor that detects radioactivity. If the monitor detects radioactivity (something that happens with 50% frequency in a certain amount of time), the monitor breaks the flask with the poison, killing the cat. If not, the flask remains unbroken, and the cat lives.

Until the box is opened, however, the cat's fate is unknown, leading to a quantum superposition in which the cat is both alive and dead until the box is opened, collapsing the two possibilities into one reality.

It's a thing that shows up in popular culture from time to time, most famously on the AWFUL SERIES The Big Bang Theory.

But here's the deal, yo...

Schrödinger wasn't in favor of the thought experiment. He didn't like it. He was using it to suggest that the idea of quantum superposition was absurd.

From wikipedia...

Schrödinger did not wish to promote the idea of dead-and-alive cats as a serious possibility; on the contrary, he intended the example to illustrate the absurdity of the existing view of quantum mechanics.

...

It is typical of these cases that an indeterminacy originally restricted to the atomic domain becomes transformed into macroscopic indeterminacy, which can then be resolved by direct observation. That prevents us from so naïvely accepting as valid a "blurred model" for representing reality. In itself, it would not embody anything unclear or contradictory. There is a difference between a shaky or out-of-focus photograph and a snapshot of clouds and fog banks.

...

(Written by Einstein to Schrödinger) You are the only contemporary physicist, besides Laue, who sees that one cannot get around the assumption of reality, if only one is honest. Most of them simply do not see what sort of risky game they are playing with reality—reality as something independent of what is experimentally established. Their interpretation is, however, refuted most elegantly by your system of radioactive atom + amplifier + charge of gun powder + cat in a box, in which the psi-function of the system contains both the cat alive and blown to bits. Nobody really doubts that the presence or absence of the cat is something independent of the act of observation.

So, I would imagine that Schrödinger would be appalled that his non-scientific legacy has come down to people knowing him for a theoretical experiment that he came up with in an attempt to point out how ludicrous quantum superpositions are.

And I love the idea that Schrödinger's ghost haunts the world embracing anyone who recognizes that 'his experiment' is ridiculous and stupid.

That was his point.

(Though I would be remiss if I didn't point out that quantum superpositions have turned out probably to be 100% true and real.)

on Good Water

Source - http://www.threepanelsoul.com/comic/on-good-water

See, it's funny because hucksters say all sorts of crazy stuff about the water that they sell.

Whether they're selling ionized water...



...or anti-oxidizing, micro-clustering, alkalinized water...



These claims are bunk...hokum...pseudoscience. They would fail any psuedoscience test readily. Their 'scientific' evidence is anything but.

And the fact that Ian (the artist of Three Panel Soul - sometimes snsfw, you've been warned) mocks these claims by saying that the pitchman's (kind of looks like the Shamwow guy to me) water uses magnets to make the water molecules 25% smaller (impossible, atoms cannot be shrunk) and more efficient (at doing what, huh?).

See, it's funny...once you understand the science and explain it all to heck.

Tasks at Hand

Source - http://www.threepanelsoul.com/comic/tasks-at-hand

See, it's funny because you might think that a mountain made of rock candy would dissolve into the alcohol streams.

For those of you who aren't aware, "Big Rock Candy Mountain" is a song first recorded by Harry McClintock in 1928 based partially on older hobo ballads telling tales of a more perfect world just a little further down the road.



That's Harry there singing the song.

In the chorus, you can hear the lines...

In the Big Rock Candy Mountain
You never change your socks
And the little streams of alcohol
Come trickling down the rocks
...
There ain't no short-handled shovels,
No axes, saws, nor picks,
I'ma goin' to stay
Where you sleep all day
Where they hung the Turk
That invented work
In the Big Rock Candy Mountain

Most of it isn't about chemistry but rather about a fantasy world where hobos were always heading to.

But would those alcohol streams really have such deleterious effects on a Big Rock Candy Mountain?

Well, assuming the rock candy is primarily sucrose and that alcohol streams are pure ethanol, not so much. See, the literature value for solubility of sucrose in ethanol is 0.6g / 100mL. That's much lower than sucrose's solubility in water (210g / 100mL). You can see that here.



If the 'little streams of alcohol' were actually spirits that you could purchase from a liquor store, though, they would be mixtures of alcohol and water (the percentage of alcohol is roughly equal to half the proof of the alcohol - 80 proof ~ 40% ethanol in water), then you'd have a much bigger problem.

But not as bad an erosion problem as you would have with just little steams of water.

Who knew?

What Causes Beef Rainbows?

Source - https://9gag.com/gag/anj1VRV/should-i-be-concerned-if-this-prepackaged-meat-is-shiny

I've seen those roast beef rainbows before, and I'll admit to having been a little freaked out by them.

I assumed that any greenish - even if it was iridescent greenish - wasn't good on meat. Turns out it's nothing to be worried about.

See, there are a few ways to make colors.

One is for there to be a light-absorbing dye. Like if you have a red shirt, it's been soaked in a chemical (a dye) that absorbs most of the colors of light except for the red wavelengths. That means that white light shone upon the shirt will reflect only the red light.

That's not what causes the roast beef rainbows.

Instead, they're formed by interference of light waves - as slightly explained in this Atlantic article or this Daily Mail article.

Source - https://www.dailymail.co.uk/news/article-2287287/Why-beef-rainbow-NOT-tainted-Popular-myth-debunked-Department-Agriculture.html

When light is reflected off of a wet surface, some of the light reflects from different depths of the liquid. As the same white light reflects from different depths, the reflected light comes back slightly out of phase from the other light. This causes a diffraction pattern which leads to shimmering, shifting colors - like the rainbow from an oil slick on a puddle or a butterfly's wing.

Apparently the rainbow on roast beef is common enough that the USDA even has a page answering the following...

Meat contains iron, fat, and other compounds. When light hits a slice of meat, it splits into colors like a rainbow. There are various pigments in meat compounds that can give it an iridescent or greenish cast when exposed to heat and processing. Wrapping the meat in airtight packages and storing it away from light will help prevent this situation. Iridescence does not represent decreased quality or safety of the meat.

So, as Pink Floyd told us, you should eat your [rainbow] meat...how can you have any pudding if you don't eat your meat?

I guess that's one way to wash your glassware

That's my upload of a video I originally found here (warning, adult word in the link - video is school-appropriate, though).

So, what's happening here (I think)...

Clearly, something is burning. I don't see any fire, but the lighter lights 'something' inside the beaker. Because the fire is 'invisible', I'm assuming the inside of the beaker is coated in methanol. It might be ethanol or some other alcohol, but the fire isn't visible enough for me to think it's anything else.

The vapors burn, momentarily heating the inside of the beaker and pushing lots of gas out. Depending on the stoichiometry, it also uses up more moles of gas than it produces. If the water vapor then cools quickly enough, there's an even greater drop in moles of gas.

If the moles of gas inside the beaker decrease and the temperature decreases, the pressure is going to drop. That lets the outside air push the blue water into the beaker.

It's sort of like the ammonia fountain or the can crush demo, but this drop in gas moles is due primarily to combustion and temperature changes (I think.)

All that being said, the idea of igniting methanol vapors just seems stupid.

When you burn steel wool, it gets heavier

Anti-phlogiston at work, clearly!

Back in the day (primarily the 1700s), one of the prevailing theories of chemistry was that as materials burned, they released phlogiston, a gas that was somehow stored in the material (the wood, paper, whatever). That release of phlogiston made the material lighter.

It makes sense, right.

Sure, until you look at something like what you see above. The burning metal gets heavier as it burns. Maybe phlogiston has negative mass...or there's anti-phlogiston...or phlogiston just doesn't exist.

Along came Antoine Lavoisier in the 1770s and the discovery of oxygen. Now we know that the metallic oxide has metal AND oxygen, so it has more mass, more stuff, more weight.

But that took a looooong while to figure out.

SMBC: PuCube

Source - SMBC

See, it's funny because plutonium kind of would do all those things (as Randall Munroe pointed out previously).

Working downward from the top...

• The plutonium would give off energy for way more than just "2+ generations", and it would heat the tea around it. From Randall's calculations, though, it seems like it would keep the tea warm but not hot.
• Plutonium in water would emit Chernekov radiation which glows a very pleasing blue.
• 1.5 cubic centimeters of plutonium would certainly fit in your pocket. It would be about 1.14 cm on each side of the cube. 
• The plutonium would certainly sterilize your tea for you...if that's a problem you normally have with your tea.
• You likely would get to meet your local FBI agent - possibly an IAEA agent.
• You should not swallow PuCube. To get an idea of what could happen, read about this former Soviet spy poisoned via polonium.
• As to the $400,000 cost, the only reliable sources I could find put the price of plutonium between $4000 and $6000 per gram (though I prefer this answer). 1.5 cubic centimeters at 19.84 grams per cubic centimeter at $5000 (an average) per gram, that would be closer to $150,000. My math doesn't jibe with Zach's. I'd need to see his sources.
• PuCube certainly would be heavier than you would expect. 1.5 cubic centimeters of water (a fairly dense material) would have a mass of 1.5 g (at 4 degrees Celsius, natch). Osmium and iridium would be the most dense (at 22.6 and 22.4 g/mL respectively - source), but I'm guessing the plutonium would be much heavier than you would expect. I've picked up mercury (13.546 g/mL compared to plutonium's 19.84 g/ml), and it was surprisingly heavy.
• The repeated warning not to swallow PuCube make me think of Happy Fun Ball. Do not taunt PuCube.

And the rollover joke...

See, because americium is radioactive, too.

Household chemicals and a dubious infographic

Source - James Kennedy's blog

I searched James Kennedy's blog for the original source of this graphic, and I can't find it at all.

I searched for bleach and vinegar and household and a whole bunch of other terms that are listed here, but the graphic - still hosted on his site - and its original post is entirely missing from his site. The graphic's host address suggests that it was posted sometime in 2013, and I've been through every on of his 2013 posts (he claims to have read and reviewed 103 books in that year, and I scanned every single one of this review posts, blech).

I'm curious as to why he might've taken the graphic down, and I have an idea.

The graphic is woefully undersourced and possibly dangerous.

To quote the graphic...

This chart summarizes how people in internet forums are using various combinations of household chemicals to make stuff on their own. Sources include YouTube, Yahoo! Answers, and countless niche internet forums. Because all the information was gleaned from the Internet, I cannot accept any responsibility for its accuracy or efficacy.

This table is provided for viewing only. Do not use attempt [sic] any of the household chemistry on this chart. I accept no responsibility for damage incurred as a result of using the information provided in this chart.

Admittedly that's a much easier way to post an infographic: say that it might or might not be correct and claim that nobody can sue you if they get hurt using the information you provided. That seems incredibly irresponsible and foolish coming from someone who claims to be somewhat of an expert in the chemistry field (and whose work I've posted before).

I'm not going to make any claims as to the veracity of the infographic up there. In fact, I'm going to say flatly that I don't trust it because there aren't any sources presented.

Some of the 'answers' - the water line, the bleach/ammonia combo, the bleach/soap combo - are most assuredly correct. Others - the hydrogen peroxide/liquid soap, salt/vinegar, whatever 'washing up liquid' is - are partially but certainly not entirely correct. And others are almost assuredly wrong - rubbing alcohol/cornstarch makes shampoo?

Today's lesson is that just because something is written and presented neatly, it isn't automatically correct.

CERAMIC COATINGS - How It Works | SCIENCE GARAGE

First off, thanks to Eric Moorman who sent me this video. Mad love for Eric.

Let's go through the material science awesomeness in this video about how to get the most durable, prettiest finish on your car.

• The first four minutes or so are all about the causes of the tiny scratches on car surfaces and how to clean the car before applying a finish coating of either wax or ceramic.
• At 4:10 we get a discussion of wax, and the host even uses the word hydrophobic, explaining how the water beads up because of the hydrophobic nature of the wax.
• At 5:10, we finally get to the ceramics, "a non-metallic solid material making up an inorganic compound of metal and nonmetal (or metalloid) atoms primarily held in ionic and covalent (?) bonds." The host explains that those atoms can be crystalline (in various ways) or even vitrified.
• There's an explanation of the Moh's hardness scale, and a mention that there are other ways to measure hardness like via measuring scratch resistance.
• Heck, he even shows a very simplified version of covalent bonding with shared pairs of electrons.
• We get into using nanotextures to increase the hydrophobic character of a surface, increasing the contact angle between a drop and the surface - with a nice diagram, too - explaining super hydrophobic coatings.

Admittedly, I had no idea such coatings existed for cars.

Things not to mix

TL; DR - The first two are bad. The third and fourth are very minor worries.

I came across this graphic online and thought I'd take a moment to check the chemistry involved.

Let's go in order, and I'll cite sources as I find them...

From ThoughtCo.com...regarding bleach + vinegar

What Happens When Bleach and Vinegar Are Mixed 

Chlorine bleach contains sodium hypochlorite or NaOCl. Because bleach is sodium hypochlorite dissolved in water, the sodium hypochlorite in bleach actually exists as hypochlorous acid: 

NaOCl + H₂O ↔ HOCl + Na⁺ + OH^-

Hypochlorous acid is a strong oxidizer. This is what makes it so good at bleaching and disinfecting. If you mix bleach with an acid, chlorine gas will be produced. For example, mixing bleach with toilet bowl cleaner, which contains hydrochloric acid, yields chlorine gas: 

HOCl + HCl ↔ H₂O + Cl₂ 

Although pure chlorine gas is greenish-yellow, gas produced by mixing chemicals is diluted in air. This makes it invisible, so the only way to know it's there is by the smell and negative effects. Chlorine gas attacks mucous membranes in the eyes, throat, and lungs—these attacks can be deadly. Mixing bleach with another acid, such as the acetic acid found in vinegar, yields essentially the same result: 

2HOCl + 2HAc ↔ Cl₂ + 2H₂O + 2Ac^- (Ac : CH₃COO) 

There is an equilibrium between the chlorine species that is influenced by pH. When the pH is lowered, as when adding toilet bowl cleaner or vinegar, the ratio of chlorine gas is increased. When the pH is raised, the ratio of hypochlorite ion is increased. Hypochlorite ion is a less efficient oxidizer than hypochlorous acid, so some people will intentionally lower the pH of bleach to increase the oxidizing power of the chemical even though chlorine gas is produced as a result.

So, I'd say that one checks out.

Next up, bleach and ammonia...again, from h2g2.com...

When these two compounds are combined, the following reaction takes place:

2 NaOCl + 2 NH₃ --> 2 NaONH₃ + Cl₂

...

Another potential reaction, which occurs when a greater amount of bleach is added than ammonia, is this:

3 NaOCl + NH₃ --> 3 NaOH + NCl₃

That's sodium hydroxide and nitrogen trichloride. Nitrogen trichloride is a very toxic chemical to humans, and even if you did get close enough to ingest it, it would probably explode in your face first, as it is also a very volatile explosive.

...

Still another reaction - in three parts this time - can occur, producing hydrazine, N₂H₄, a component of rocket fuel) if you have more ammonia than bleach:

NH₃ + NaOCl --> NaOH + NH₂Cl

These two products then react with ammonia as follows:

NH₃ + NH₂Cl + NaOH --> N₂H₄ + NaCl + H₂O

One last reaction occurs to stabalise the reagents:

2 NH₂Cl + N₂H₄ --> 2 NH₄Cl + N₂

That last equation is of particular interest because of the amount of heat it produces. The heat is so great that it usually leads to an explosion.

Again, I'm okay with staying you definitely shouldn't mix those two. I did, however, struggle to find a source with reactions that I trusted. The first two I found - this and this - didn't make sense in a few places, having missing mass in various places in their reactions.

Now, bleach + rubbing alcohol...

I'm a little less sure about this one. I found a lot of sources that say this one produces "chloroform, (CHCl₃), hydrochloric acid (HCl), and other compounds, such as chloroacetone or dichloroacetate." but I can't find the exact chemistry anywhere.

The only reaction I could find, however, in all of the articles was of acetone with bleach.

3 NaClO + C₃H₆O --> CHCl₃ + 2 NaOH + NaOCOCH₃

Acetone and isopropyl (rubbing) alcohol certainly aren't the same thing. So I'm going to leave this one as a maybe as I also found a fair number of sources that said any reaction between isopropyl alcohol and bleach would be fairly slow and likely would need a catalyst to see significant product production at room temperature.

The last combo is hydrogen peroxide with vinegar (acetic acid). From wikipedia...

[Peracetic acid] forms upon treatment of acetic acid with hydrogen peroxide with a strong acid catalyst.

H₂O₂ + CH₃CO₂H ⇌ CH₃CO₃H + H₂O

From cooksinfo.com

If you mix the two together in one bottle, a weak form of peracetic acid is formed. Peracetic Acid ( aka peroxyacetic acid) is a mixture of acetic acid and hydrogen peroxide. Peracetic Acid is primarily used for deactivation of a large variety of pathogenic micro-organisms in the industrial food industry, medical supplies and to prevent biofilm formation in paper pulp industries. It is usually produced in concentrations of 5 – 15%. This industrial formulation is toxic by inhalation, ingestion or if absorbed through skin; caustic and corrosive at concentrations > 10%; irritant at concentrations below 2%. Retail vinegar is a mixture of acetic acid and water composed of 4 to 8% acetic acid. Hydrogen peroxide at 3 % and retail versions of vinegar are an extremely diluted form of peracetic acid. Mixing the diluted form of acetic acid (known as vinegar) with 3% hydrogen peroxide forms a weak form of peracetic acid that may cause some reaction to those who are very sensitive to it – another reason, besides effectiveness, that applying the two solutions separately is recommended.

So this one I'm going to say is true but a minor issue.

Seriously, though, the first two combos - bleach with either vinegar or ammonia - are bad combos and are to be avoided. The other two, maybe less so...maybe.

Fire in ZERO-G!!

Dr Derek, please stop using multiple exclamation points and all caps in your video titles.

I get that you're trying to game the YouTube algorithm, but it's kind of off-putting for me.

(Ok, rant over, back to the science content...)

I would love to ride the vomit comet. It's certainly a secondary dream to actually getting to go into space, but I'm pretty sure the 'space' goal has entirely left the building at this point.

Apparently having a really successful YouTube science education channel offers a few more opportunities, and Dr Derek got to ride the parabolic flights simulating weightlessness, something that let him explore fire in 'zero-gravity' environments.

Once he explains the why of his experiments (without weight, the isn't a buoyancy force to move less dense objects like hot air upward and more dense objects like cold air downward), everything makes sense, but I absolutely couldn't have come up with that explanation.

Luckily, I don't have to teach this...and if I ever do, I plan to just show this video.

You rock, Dr D.

(Oh, the fire doesn't actually show up until about 3:40 in the above video. Before that it's explaining how the plane work to simulate zero gravity and some playing around inside the plane.)

In case you're curious, here's Physics Girl's video from the same flight.

Luca Parmitano and Chris Cassidy explain what happened during EVA 23

tl; dw - Luca almost drown in his spacesuit...but he didn't.

Water does some freaky stuff in space. Apparently, some of that freaky behavior edges toward being deadly to astronauts.

In this case, Luca Parmitano was on an extra-vehicular activity (EVA - a thing most folks might call a spacewalk) and had a small water leak into the air flow refreshing the air into his spacesuit's helmet. (Skip to 2:45 to get the explanation from astronaut Chris Cassidy) The small leak began to build up behind the plastic shield behind his head. When the water built up enough, it started to leak around the plastic shield and touched his snoopy cap. I guess the snoopy cap is hydrophilic, because the water then quickly headed forward, covering his head, filling his ears, and eventually drenching his eyes.

The next stop for the water would have been to cover and fill his mouth, leading nicely to - as all involved feared - death...in space...from drowning.

Turns out water's IMFs really matter because the molecules hold together well enough that they're hard to get off of a head in space without hands or towels - both well on the outside of the helmet.

I did appreciate seeing (at 1:30) the other astronauts (Russian, American, everybody on the ISS) at the ready to help save Luca once he got back into the airlock.

Plus seeing Karen Nyberg's hair in space is just outstanding.

Elephant toothpaste

Today's topic is the reaction typically known as elephant toothpaste.

It's a pretty simple reaction, the decomposition of hydrogen peroxide solution into water and oxygen gas.

H₂O_{2 (aq)} --> H₂O _(l) + O_{2 (g)}

This reaction happens all the time, most commonly in your home in that brown bottle of 3% hydrogen peroxide solution that somebody bought years ago and that goes 'pfsssst' whenever you open the cap.

The 'pfsssst' is the built-up oxygen gas.

In the demonstrations below (and after the jump with much bigger volumes), that reaction is catalyzed (sped up) by the addition of various things - typically sodium or potassium iodide but also yeast. And the oxygen gas is contained within soap bubbles.

Add that all together - maybe add in some food coloring - and you get a foamy mess.

...on Jimmy Kimmle's show...



...on The Big Bang Theory...



...a supposed world record volume...



...another supposed world record volume...



...another supposed world record volume...

A better description of entropy

I open my discussion of entropy in AP chemistry by saying that I'm going to offer an incorrect definition of entropy, that it's the same incorrect definition I was taught in high school and that my students will likely be told in college - as I was - that the high school definition isn't correct...that it's a drastic simplification.

I've said this for years, and I've had other people who study chemistry in college confirm that same story having happened to them, too.

I also will admit that I tried to read PF Atkins's The Second Law without much success.

So, let's try to be a little more precise and correct by watching Steve Mould's video up above - it's a video explaining how a Sterling engine works - and try to be better about what entropy really is.

Why do Pineapple and Kiwi Ruin Gelatin?

As far as I'm concerned, the video could just as easily be asking why thumbtacks or dog poo ruin gelatin because I'm about as likely to put them in my gelatin as I am to put pineapple or kiwi.

...because those fruits are nasty.

Sure, these acidic fruits denature the proteins that hold together gelatin meaning that they ruin the collagen network that keep the gelatin jiggly. That's what acids do, donchaknow.

I assume that highly basic foods would do that some thing, too.

Shocking Pickled Pumpkins! Halloween Science

Don't electrocute pumpkins at home.

And especially don't set up two forks with electricity running to and through them onto which you mount random produce...like pumpkins or pickles or jalapenos...that would be stupid.

But if you were to do that, soaking the pickles...or pumpkins...or whatever, I'd be okay if you soaked the produce in various ionic compound solutions so you could check to see if the ions produced different colors.

You know, if you wanted to do something totally stupid...just if...

We're Running Out of These Elements - Here's How

We need elements.

Lots of them.

Lots of lots of different ones of them.

Some of those elements aren't quite as plentiful as we might like them to be.

Actually, some of them are plentiful enough in total, but they're hard to recover...or they're only found in a very few places.

Either way, we're in danger of running out of a whole lot of elements - or at least in danger of not being able to get to those elements when we need them.

You may want to stock up on your cerium, ladies and gents.

Oxy-Acetylene Explosions at 330 000 fps | Fastest High Speed Camera on Youtube!

"I think this is bad idea," is my favorite quote from, I think, Lauri.

This video certainly isn't as bad an idea as heating a jackhammer up past its BCC -> FCC phase change. In fact, I think this video's a pretty great idea.

The video is a super slow motion look at the combustion of acetylene gas, producing a gorgeous, bright blue flame that I can't even see in real time.