We Accidentally Discovered A RARE Scientific Phenomenon (10,000fps Collisions)

Most of this video - as is typical of videos from these ridiculous Aussies - can be skipped. It's primarily just repeated, slow motion footage of two giant air cannons firing random things (plastic dinosaurs, basketballs, cola cans, pumpkins, rubber band balls, spray paint cans, and such) at each other and ridiculous mugging for the camera.

But then - at 16:30 - they fire two glass balls at each other and something really interesting happens.

Well, at 16:30 they load the two glass balls and mug around for two and a half minutes before showing us the scientifically interesting slow motion video. Go ahead and skip to 19:00 to see the science.

I'll wait for you...

At 19:24 we get a flash of light when the two highly accelerated glass balls hit each other.

The flash of light certainly wasn't something that I expected to see and seems to be an example of triboluminescence (light produced from force or movement).

The initial science explanation (at 20:00 about IMFs being broken) seems a bit dodgy, and I'm really happy that they come back around 21:00 with something that sounds more correct to me.

I've never heard of glass causing triboluminescence (nor fractoluminescence which is a subset of triboluminescence, I guess), but I'd like to see somebody with way more science knowledge than I have explain what's happening here.

Thanks, by the way, to reddit for the gif.

Boxed cake vs scratch cake — Why bakers can't beat SCIENCE

A few years back - when we were still in the previous iteration of Princeton High School - I had my AP chemistry students make cupcakes with three separate leavening methods: baking soda, baking powder & soda, and mechanical leavening (whipping egg whites). The three methods are fascinatingly different and produce very different results.

In this video Adam and his baker friend look at the differences between box cake mix and from-scratch cakes. They're not quite looking at just the leavenings, but the science behind the differences are fascinating.

I'm sometimes sad that we went with material science rather than food science as one of our science electives at Princeton. I wish I had a good curriculum for high school students to explore food science, but that would also require a cooking classroom - something that our principal at the time of the building of new Princeton High School wasn't interested in building anything that practical.

Aluminum and mercury

I'm thinking that the dangers of mercury thermometers on aluminum-skinned airplanes has mostly passed us by - both because home mercury thermometers are all but outlawed and have been replaced by digital thermometers and because so little of a commercial airplane is being made out of aluminum at this point.

But the demonstration of the formation of mercury-aluminum amalgam is still really cool to watch.

Pee-riodic tables

The source of this image is a reddit post which included only the following explanation, "The bathroom in our science building has the periodic table in tiles".

I need more info. 

Where's the building? I assume it's a university science building, but there's no info provided.

Why do the metalloids seem to continue diagonally down from the table itself?

How old is the bathroom design? Nihonium (element 113) is the last element shown, and that was created in 2003 or 2004 with the discovery not adjudicated until 2015.

Why do the metalloids, halogens, and noble gases get to continue upward into the border design?

(Oh, and I can't take credit for the title joke. That came from the first comment on the reddit post.)

Modeling a Gas With Magnets

That works surprisingly well, though I'm terrified of magnets as large as Cody is using to vibrate the individual 'molecules'.

Floating stick man explained

I know, long-time blog followers have seen the floating stick man phenomenon before.

...but they haven't had Steve Mould explain why it works before, nor have they seen it used to animate an alien abduction.

How Do Dry Cleaners Clean Clothing

tl;dr - They use solvents with weaker IMFs that water - some of which are nonpolar.

It's been a big improvement over the ancient Roman 'dry scouring' which was based on fuller's earth, lye, and urine-sourced ammonia.

The solvents used have varied over time from turpentine, gasoline, benzene, and kerosene (all highly flammable, carcinogenic, and stinky leading most dry cleaning facilities to be located outside of densely populated cities) to tetrachlorethylene (which is less flammable but toxic to plants and animals and can lead to neurological issues like Parkinson's disease).

So, dry cleaning isn't remotely 'dry.' It's just cleaning with gentler machines using solvents that evaporate more quickly and readily than does water.

Liars...

Hypercolor, the most 90s of colors

That ad is so 90s that it should've been parodied on the Bill Nye show.

Hypercolor - a brand of thermochromic clothing that changed color when it warmed up - was a very narrow slice of popular culture, lasting only about a year in the popular culture of the time.

The science behind the thermochromic dye was pretty cool, similar to that used in touch-sensitive thermometers, but the fabric and its dye wasn't built for long-term wear.

Sadly, though, after a handful of washes, or one laundering misstep in too-hot water, the magic powers faded and the shirt froze permanently into a purple-brown mushy color. (source)

If you want a hypercolor shirt, the easiest way is probably to make one of your own.

Caption this...

I've sat this that shade, maybe not at that specific stadium but certainly at tennis matches where I've followed the sun and moved with the shade. In fact, if we started school a week or two later in the year, I'd likely be doing it for a week in August at the Cincinnati Open.

Sadly the picture isn't quite right in that the second row would need to be eight seats wide compared to only two seats for the first row. Or maybe four seats compared to one with people sitting on each other's laps to represent the Pauli Exclusion Principle. 

All that would need the shadow line to be shallower, more of a 15 or 20 degree angle rather than the 45 that's in this picture.

But then the sun wouldn't be as bright and harsh when it was that low in the sky meaning that the people likely wouldn't be seeking out the sun as overtly and urgently.

So maybe it's best not to question this but rather to chuckle at it and move on.

And definitely don't go listening to the "Electron Configuration Polka" by Michael Offutt.

Exposing the Color Blind Glasses Scam

Take what this YouTuber has to say with a grain of salt. I will admit that I haven't researched and confirmed his claims, though I have watched all of the videos I'm posting today. I can say that they confirm something I've long been skeptical of: it seems unlikely that glorified sunglasses could produce colors in the eyes/brains of people who genetically can't see (or maybe can't differentiate) colors.

The enchroma glasses (and other, similar brands) seem to block a narrow band of colors leading to a greater differentiation between green and red meaning 'color blind' people can distinguish those colors more easily and can pass various 'color blind' tests like the classic numbers inside a circle. What the glasses seem incapable of, however, is actually letting those people see different colors that they inherently cannot see.

The science behind 'color blindness' is well explained here as is the science of what the glasses actually can do. The videos also explore common issues with scientific research - both conflicts of interest and confirmation biases as well as social pressure leading people to report results that may or may not actually be there. 

I've been captcha-ed.

See, it's funny because there's no way to know where the electrons likely are in the quantum mechanical model of the atom. The best we can do is predict where the electrons will likely be found.

So, I'm going to fail that captcha.

Light sucking flames look like magic

I've posted about this black fire on the blog before.

This one - from Steve Mould - doesn't add a whole lot new to the basic technique of shining a sodium vapor light on a methanol (stay safe out there, folks) flame that has been doped with sodium chloride. It does add in some more information on how the spectra are created and some info about enchroma glasses (more on them next week).

Can I lick it?

As Q-Tip once asked us...

Can I lick it?

Carl Wilhelm Scheele was likely the first person to isolate and prepare pure oxygen gas - though sadly for his historical reputation, not the first to publish his results.

Scheele also has gone down in history as a chemist known for tasting many of the chemicals that he experimented with in his laboratory.

So, can - or should - you lick the various elements? 

Some -the green ones - would probably be okay. Go ahead, for example, and lick a penny. It might be germy, but the metal itself isn't going to be a problem.

Other - the yellow ones - wouldn't be great, though they're not going to immediately kill you.

The red ones will likely immediately kill you or seriously harm you without much of a doubt.

The purple ones are radioactive and will kill you quickly.

So, can you lick it?

Maybe you can.

Water jokes

I promise these will be the last few joke posts for a while. I'll go back to more informative content next week.

See, it's funny because this is the easiest joke for any chemistry teacher or student to make. We build plastic water molecules for lots of purposes. The ones I use in class are magnetic to show the IMFs appropriately. 

At some point, a student spills the water molecules, and I almost automatically tell the other students to be careful, that there's water spilled on the floor.

It's funny the first time, and I keep making the joke year in and year out because it works for the students who are hearing it for the first time.

See, it's funny because 'my water broke' is a phrase that pregnant women use when their amniotic sac ruptures, typically suggesting that labor is beginning.

Here, however, the water breaking doesn't mean that at all; it sets up an expectation and then subverts that expectation. Hence, comedy!

Run! It's fluorine!

See, it's funny because fluorine has the highest electronegativity of any element on the periodic table meaning that it's great at taking electrons from every other element.

Fluorine would be Henry J. Waternoose III trying to take Boo from Sully in Monsters Inc except that Sully eventually is able to get Boo back. 

No element would get its electron back from Fluorine.

True facts...but not quite obvious at first...

See, it's funny because my first reaction - as I'm assuming many people's reaction is - was to say, "no, that's wrong...there are only two hydrogen atoms in a molecule of water, and there are way more than two stars in the galaxy."

Then I read it a little more closely and saw that it's claiming there are more hydrogens in a molecule or water than there are stars in the entire Solar System which is flatly true since there's only one star (the sun) at the center of our solar system.

It's misleading because "more _______ than there are stars in the galaxy" is a common phrase, and "more ______ than there are stars in the Solar System" is not a common phrase because it's dumb. It's just saying there's more than one of something.

XKCD - Classical Periodic Table

Source - xkcd

See, the ancient Greeks believed that the world was composed of four elements: Earth, Air, Fire, and Water.

Here Randall Munroe has classified the modern elements on the periodic table into airs (elements that are gaseous at room temperature), waters (elements that are liquid at room temperature - Br and Hg), earth (solids at room temperature), and fire (the radioactive elements).

Not a lot to figure out there, though there is still an explainxkcd article on it.

Oh, and congratulations if you figured out why I posted this today.

Covalent bonds > hydrogen bonds

See, it's funny because covalent bonds are stronger than hydrogen bonds, and this 'cartoon' is using the weak versus strong password box that most of us are familiar with to comment on this strength difference.

Hydrogen bonds are usually considered to be intermolecular forces attracting separate molecules to each other (or parts of one molecule to different parts of the same molecule as in DNA and proteins' tertiary structures).

Covalent bonds, on the other hand, are intramolecular forces holding atoms together within molecules. They aren't usually considered IMFs unless we get into the grey area of covalent network solids.

I hope this goes chiral.

So, a little background...

There are certain molecules that exist in two mirror forms of each other. They have the same four functional groups around a single atom but arranged in such a way that they are mirror images of each other but cannot be rotated in such a way so as to superimpose one molecule onto the other.

These molecules are called chiral. They show chirality.

This is the opposite of achiral structures that are identical to their mirror image but can be rotated in such a way so as to superimpose one molecule on the other. A sphere, for example is achiral. It's identical to its mirror image, but the sphere can be rotated so that it matches its mirror image, too.

Samuel L Jackson is chiral, however, because he is identical to his mirror image, but there is no way to rotate him so that he is identical to his mirror image.

That's the first part.

The second bit of background is that the two forms of chiral molecules in chemistry are referred to as being levorotary and dextrorotary because they each rotate the polarization plane of light either left (levo-) or right (dextro-). To shorthand this, the molecules are labeled as L- or D- such as L-alanine and D-alanine. 

So, after all that, this is funny because it's Samuel L. Jackson would be an enantiomer (the chiral version) of Samuel D. Jackson.

Weirdly this chirality has been hypothesized to present a problem to life from 'our world' as the opposite chiral version of molecules such as protein from a 'mirror world' would likely not be useful in cellular processes if brought into our world. Just this past year I read an admittedly not great run of the Fantastic Four that used this concept as a problem that the First Family of Marvel had to solve.

A painfully incorrect graphic

Source - macosicons.com/#/u/antonin1802

The reddit thread on which I found today's graphic saw quite a few comments pointing out the horrific incorrectnesses (sp?) in the folder graphic found to the right.

Amongst the many issues...

• The chemical reaction as written eschews an arrow (or even equilibrium arrows) in favor of an equal sign. For people who don't know chemistry, those symbols might seem equivalent, but they are not - in spite of what some of my students have dismissively claimed over the years.
• The reactants in the reaction includes monatomic oxygen, a drastically and dangerously unstable form of oxygen. Typically, diatomic oxygen is written in the reactions because that's the stable form of elemental oxygen.
• The structural formula as drawn contains a carbon at the center top of the 'molecule' that has six bonds, expanding the octet of carbon which - to my understanding - is rather impossible.

There is some suggestion in a few of the comments that this figure might be generated by artificial intelligence. I can't speak to that, but if it was created by a human - assumedly antonin1802 - then it was clearly created by a human who didn't know how organic chemistry works.

Australia

 

See, it's funny because Au is the symbol for the element gold, so Au-stralia would be a stralia made of (or maybe colored) gold.

Ag-stralia would be a stralia made of silver because Ag is the symbol for silver.

Cu-stralia then would be a copper stralia because Cu is the symbol for copper.

You can read more about these element's - and eight more elements - symbol origins in this infographic from Compound Interest.

Science in an Art Museum, Part 1: The Science (and parts 2, 3, and 4, too)

As I mentioned last week, I toured the Indianapolis Art Museum's conservation lab as part of our summer ASM materials camp a decade or so ago. It was a great tour given by Dr Gregory Smith, star of this series of videos through which he explains the process of verifying the age and pedigree of an Uzbek Coat of Many Colors.

The rest of the four-part series is after the jump.

Lunch & Learn: The Science Behind Art, with the Indianapolis Museum of Art

Give 'em a break, alright?

It was the pandemic. People were trapped in their houses. They were doing their best to create content that was interesting and that could be enjoyed remotely.

No, a video of two people talking remotely to each other while narrating a slide show isn't necessarily the most exciting of presentations, but I can vouch for Dr Smith being an entertaining guy. He gave me and our summer ASM campers a tour of the Indianapolis Museum of Art's conservation lab about ten years ago, and it is one of the more unexpectedly great tours that I've been on through those summer workshops.

Take some time and see what Dr Smith has to teach us about art conservation and forgery detection today.

Pothole patch - some updates

Source - link

We've been showing videos about the Case Western Reserve students who invented a better pothole patch for years in our summer camps and in our material science courses at Princeton.

I usually add the fact that most of those videos, however, are now a decade old, and I haven't seen the product being used. Thankfully one of my campers last summer took that as a challenge and went hunting for an update. 

Here's what he and I have been able to find...

• Feb 2017 - Cleveland.com - "It has been more than five years since Okoye and three other students created the product, which received entrepreneurship recognition in 2012. Okoye said the idea never died, but attending college and finding a job while refining the product and seeking funding, took time." 
• U-Patch Canada (YouTube) - 20 short, non-narrated test videos of the Thumper Pad in potholes, all from January 2018
• Yeu Patch (Facebook) - No new posts since Feb 2019
• KMBC.com - "KC uses thump pads as temporary fix to potholes" 
• KMBC.com - The same story as above but as video.

There are a bunch of other, similar stories from those time periods, but the websites that the company website that I found - http://yeupatchtechnologies.com/ - doesn't seem to be registered anymore.

Flash photography used to be pretty wild

I remember having flash cubes in cameras when I was growing up, but I had no idea how literally explosive they really were.

There's a lot of build up and explanation, but the money shot really shows up around 20:30 and onward. It's then that they get the right resolution and exposure time to see what's really happening within the flash bulbs when they ignite.

Our phones are miraculous, but their flash isn't nearly as cool as a flash bulb ever was - much less the original limelight.

Periodic Table...unstable bench

Source - Reddit

 The bench looks to be sturdily enough installed to me.

Though the table needs to be updated with the newest elements and the names for elements 110 and 111.

See, it's funny, though, because many - but not all - of the inner transition metals are radioactive meaning that their nuclei are unstable and will decay into more stable nuclei.

It's a joke that requires a little chemical knowledge but that falls apart if you have a lot of chemical knowledge.

Why on Earth is Depleted Uranium Used for Military Ammunition?

Depleted uranium just sounds terrifying. Sure, you can pick up some uranium ore and yellowcake from United Nuclear, but trying to buy depleted uranium is going to likely be a little dodgier.

With that being said, the US military has used depleted uranium (DU) as a source of armor penetrating ammunition over the years. I thought - wrongly from the video above - that the DU was simply used because of its high density and nature otherwise as nuclear waste. Today's video posits that there are quite a few other advantages of DU in high-caliber munitions applications.

There are also some seemingly obvious health risks involved in living in an area where spent DU shells are peppering the ground or having been in a tank where DU rounds entered and as least slightly vaporized. The video also goes through those health risks and says that they have largely been disproven, though I would be skeptical and appreciate that many military branches are "not considering depleted uranium anymore because of the environmental problems associated with it, be [they] real or perceived."

I think I'll stick to good ol' tungsten for my armor piercing needs.

The weird ways the elements got their names

I'll admit that I knew most of the name origins of the elements in this video. 

There were a couple of that I'd either forgotten or hadn't known. Tellurium, antimony, argon, and a few others on the list at 13:25 surprised me.

In the end, I don't know that's it's the most helpful thing to know the origin of an element's name. It's historically interesting and might tell you something about the element, but it's also possibly a misnomer, oxygen, for example doesn't necessarily for acids, but its name suggests that it does.

Why is glass transparent? - Mark Miodownik

Mark Miodownik is the author of one of the better materials science books written for a popular audience, Stuff Matters. 

In that book he takes a chapter to explore each of the various material categories and some of that category's most common exemplars.

Here, however, Miodownik looks at glass to see why light can pass through it. Turns out it's all about electron transitions.

The life and achievements of chemist Stephanie Kwolek, inventor of Kevlar

Stephanie Kwolek absolutely belongs in the inventors hall of fame, in the women's hall of fame, on the American Chemical Society's website, and on lots of other lists of honorees.

Stephanie Kwolek, you see, invented Kevlar at DuPont in 1965.

Paraffin Wax Autoignition

I've posted a couple of videos of this demonstration before, but this one does a better job explaining how to do the demo than those others did.

As always, let's be careful out there, folks.

What Do Baking Soda and Baking Powder Do? | Kenji's Cooking Show

I've posted before about the importance of pH on food preparation, but the increase in browning is one of the easiest ones for home cooks to exploit.

Want something to brown better without having to increase the heat? Increase its pH.

With that being said, I personally can't stand big, fluffy pancakes. Give me thin pancakes any day of the week.

If you're interested in food chemistry, check out On Food and Cooking by Harold McGee, How to Read a French Fry by Russ Parsons, or The Food Lab by J Kenji Lopez-Alt. I own them all and have read through and cooked out of some of each of them.

You can mix 10 marbles until they sort themselves. Why not 100?

This Monday's post was a little light on the science, so I thought I'd add in a heavily-sciencey video to make up for it.

The concept of entropy is a big, dang deal, but it's often reduced - at a high school level, at least - to being defined as 'disorder' or 'randomness'. I try to explain to my students a slight bit of the subtlety, but I'm not entirely sure how much sinks in for them.

Thankfully, AlphaPohenix has a video explaining entropy really well. 

What’s the most expensive piece of glassware you ever broke?

My son texted me a bit upset this morning because he broke a beaker in his high school chemistry lab and brother can all we chemists tell him some stories

What’s the biggest / most expensive piece of glassware you’ve ever broken? pic.twitter.com/tIujO4qGCm

— Keith Hornberger (@KRHornberger) March 6, 2024

Source - Buchi

And from there the chemists happily obliged, telling tales of broken 20L flasks (like the one shown to the right from Buchi which doesn't look like much until you realize that it's 20 liters (or about 9 gallons) in size and costs about $1500.)

I don't have anything remotely approaching that in my career, but I also didn't do that much lab work beyond undergrad at Wabash. During that time, the biggest break I had was probably a pyrex (note, not Pyrex) casserole that was being used as a sand bath for heating a round-bottom flask at the time.

What happens if you don’t put your phone in airplane mode? - Lindsay DeMarchi

No, you're not going to cause the plane to crash, but you might screw up the cell reception for some folks on the ground as you pass by.

...and your phone's battery is going to die a whole lot faster, so be a gallant not a goofus, ok?

Why Melted Bugs On Candy And Lemons Fuel A $167 Million Industry | Big Business | Business Insider

That is amazing...and gross...and sad...and a marvelous encapsulation of our world.

I had no idea that the stuff grandpa used to put on some of his wordworks - or at least the etymological origin of what he called what was probably varnish or polyurethane by then - had its origins in bug secretions meant to protect them while they nibbled on trees. 

This yellow is toxic | How To Cook That Ann Reardon

There's so much to say about the dyes that are used in our food from whether artificial or natural dyes are better, why certain red dyes aren't vegan friendly, whether some dyes can cause or affect ADHD, why we need to dye our food at all, why Aldi isn't using artificial dyes in any of their products, and much more.

This video is a bit long at twenty minutes, but it covers a whole lot of ground.

Periodic Table Regions

Source - xkcd

There's a whole lot of jokes there - my favorite of which is the "You Are Here" triangle.

Enough jokes, in fact, that I'm going to let explainxkcd explain why it's funny.

Bigger Periodic Table - Periodic Table of Videos

This video is, admittedly, from 2011, so the "just published" article (read it for free here or here or a summary here) that's mentioned in the beginning is well past its newness by now.

At some point the periodic law isn't nearly as neat and clean as I teach my students, and I kind of love that fact. The fact that the edge cases of superheavy elements start to stress our understanding of the quantum mechanical model is fascinating and to me shows that there are more things in Heaven and Earth...

Source - wikipedia

Making an apple that tastes like a grape

That just doesn't seem right.

I get that esters like methyl anthranilate are pretty typical in the artificial flavor and smell world. In fact, when I was a high school student, we made a banana ester (isoamyl acetate - hmm, I wonder if I could bring that back for my chemistry classes next year.)

But the soaking of an apple in something that's used as a bird repellant to make a grape-flavored apple (check the Grāpple website via the internet archive) seems...problematic.

Does Anything Radioactive Actually Glow Bright Green?

I was cleaning up my bookmarks this summer and found that I have a whole bunch of backed up videos and articles for my two blogs.

My first step was to post ahead one video or article per week until the end of the calendar year 2024. Now that I've gone ahead and done that and still have a ridiculous number of saved bookmarks.

The next step was to ready a second post per week (Fridays this time to balance the already-ready Mondays), and this is the first of those Friday posts.

There won't be any particularly difference focus of the Friday posts, but you'll just get twice the content from me.

This video explores why most people think that radioactive materials give off a green glow (they don't) through the history of radioactivity's discovery including the radium girls' sad story.

Thankfully the video closes by pointing out that there is actual Cherenkov radiation that causes a light blue glow from radioactive materials in water.

Why American Cheese Makes the Best (and Easiest) Mac and Cheese | What's Eating Dan?

American cheese is sort of cheese. 

Well, it's cheese with some sodium citrate added to it, anyway, stabilizing the emulsion of fat and water that normally breaks when any aged cheese is heated and melted.

And it's tasty and heck, so shut up.

(I'm tempted to buy that sweatshirt that Dan's wearing - but more likely in maroon than in yellow.)

Making American cheese to debunk a conspiracy

Ah, NileRed eating and 'cooking' in lab again...

American cheese cannot legally be called cheese. Cheese is legally defined as...

The fresh or matured product obtained by draining after coagulation of milk, cream, skimmed, or partly skimmed milk or a combination of some or all of these products and including any cheese that conforms to the requirements of the Food and Drug Administration for cheeses and related cheese products

...and American cheese contains ingredients added to that to encourage emulsification of the fat and water so that the cheese won't break when it melts, meaning the fat and the water won't separate and create the oily puddles that you get from melting cheese.

So American cheese is technically a processed cheese product.

...which NileRed explains and demonstrates in today's video.

Iron? Like iron?

Maybe maybe maybe
byu/Make-this-popular inmaybemaybemaybe

Yes, like iron.

I'm reminded of a question that one of my former students asked me quite a few years ago. We were two thirds of the way through the year of honors chemistry, and she said that she had been reading the ingredients on her toothpaste the day before and found sodium fluoride. She asked if that was the same sodium and the same fluorine that we'd been talking about all year.

"Yes," I said, "it's the same elements."

She followed up, "so, are there other things in my house that are made of elements?"

"Yeah," I answered, "everything in your house - and the house itself - is made of elements."

"Like, the same elements on the periodic table?"

Clearly, Sarah (or maybe it was Sara - it's been a while since this conversation) was one of the lucky ten thousand that day.

I've done the iron demonstration below in class before - though I used a blender to get even more iron particles out of the cereal by chopping it finer.

The video at the top, of course, also shows one of the lucky ten thousand today.

Hell...and a miscommunication...

Source - Cyanide & Happiness

See, it's funny because Joe doesn't seem to understand that warm gases expand, lowering their density and causing them to rise to higher levels. So I guess the first - assumedly top level from the diagram that the devil points at - would be the hottest level just like how the upper stories of a building are usually warmer than the lower stories.

Then again, the circles of hell as described by Dante Alighieri in his Inferno suggest that the lower levels are for the greater sinners where greater punishment is meted out, and that image seems to have permeated the popular consciousness, so Joe's thinking seems to be reasonable.

Maybe this is another example of two people both being correct but simply not communicating with each other.

Just talk it out, Devil and Joe.

Then again, if we assume that hell is somewhere underground - maybe under Turkmenistan, maybe somewhere else - then the geothermal gradient should likely be considered.

The Real Story of Oppenheimer

In case there's anybody out there who hasn't seen Oppenheimer at this point, I strongly recommend it.

Critics have been raving about it. It was half of a cultural event last summer. It's not 100% accurate - though it is largely factual. It isn't without criticism, but it's a great film.

With all that being said, there's so much more to the story of Robert Oppenheimer and the Manhattan Project. Do yourself a favor and watch the above video from the Veritasium YouTube channel.

And, if you want to know more, move onward to Fallout by Jim Ottaviani and American Prometheus by Bird and Sherwin.

Oppenheimer was a fascinating, brilliant man whose effect on our world is almost immeasurable, and he is a compelling source for a movie, a graphic novel, or a biography.

Great use of spaces on a building

 

Source - Reddit

I would 100% study in that building. 

It took me a while, but I was able to find that it's at UNAM (Universidad Nacional Autónoma de México) in Mexico City. Here's a Google Map link.

And I appreciate that it's up to date.

No idea what they'll do when the eighth period has to be populated, though.

Dihydrogen Monoxide!

Source - Reddit

OMG, that solution is so basic.

No, not basic, basic.

Outdated Periodic Table

 

Source - XKCD

That would be so much easier to memorize.

As you can see if you look at the timeline of the Big Bang, that's about right that half an hour after the big bang, the only elements would have been hydrogen (75% of the universe's mass), helium (25%), lithium (trace amounts), and radioactive beryllium.

Of course, I'm not sure what this periodic table could've been printed on - or by whom, but that's not the point.

The rollover joke - Researchers claim to have synthesized six additional elements in the second row, temporarily named 'pentium' through 'unnilium'. - is also outstanding.

Freezing liquid nitrogen

I've done that.

Quite a few years ago, in class, I had some liquid nitrogen thanks to the parent of one of my students, and I was able - with the help of a vacuum pump - to repeat this demonstration in class.

I'm not sure my students were nearly as amazed as I was, but it's a singular occurrence for me.

Very cool...(pun intended)...

How To Make Drawings Float With A Magic Water Marker

That's pretty cool, man.

It's no Animator v Animation or anything, but it's a neat way to show that polar and nonpolar substances typically don't mix.

Burning diamonds

As they say, "Diamonds are forever."

That's what they say, anyway, but chemically it's not remotely true.

Diamonds are just a covalent network of carbon atoms and occasional impurities. Those covalent bonds are fairly easily broken in a combustion reaction at a high enough temperature.

That's why I tried to convince my wife that cubic zirconia was the fare more durable, stable, long-lasting choice to show the permanence of our love.

She wanted a diamond, though.

Green hands and green horns

A couple of years back, one of my AP chemistry students asked me if I knew why her hand turned green when she played the French horn.

It wasn't something I was familiar with, but I had a decent guess that green on the hand was a reaction with something copper-based...and brass is certainly copper based.

With a little looking up and finding the various brass compositions used in brass instrumentation - 67-89% copper in the brass used, I feel pretty certain that it's the copper corroding and creating that green residue - on the instrument and on the hand.

My student - MK of the Eastman School nowadays - said that she tried one of the suggested solutions -  lacquer on the horn - and didn't care for how it changed the tone of the instrument. If anybody has a better suggestion, I'll pass it along to MK.

Carbide cannons and lamps, oh my

Simple enough, eh?

I remember my dad saying that he used to play around with toy carbide cannons when he was growing up. By the time I was a kid, however, carbide cannons as children's toys had gone well by the wayside because of the danger involved.

The Rose Hulman Fighting Engineers (seriously), however, still fired one off in their quonset hut of a gym (since replaced) back when I was a student at Wabash College and occasionally travelling to watch the basketball team. I can't remember exactly why they were firing off the cannon. Maybe it was for their football team and I'm misremembering things. I can't find proof on the internet either way.

Check out some more carbide toys after the jump - including a far safer way to demonstrate this reaction thanks to Steve Spangler and Bob Becker.

Is NON-BUOYANT WATER Deadly?

Yes...sort of...

The video above explains that aerated water in sewage treatment plants - the ones with warning signs saying 'non-buoyant water' - might not be as deadly and non-buoyant as advertised.

From a 1985 study in Indiana, a Mythbusters episode (see below), and a Facebook/LinkedIn post, it looks like aerated water isn't quite as deadly as the signs say.

People do drown in aeration tanks from time to time, and I'm sure it's a very unpleasant way to die, but it appears that the drop in buoyancy - while very real - is apparently counteracted by the upward flow of the bubbles in those tanks. There is also a current caused by the upwelling that can create a circulation pushing any object toward the pool's walls and then downward (sort of like the bubbles in a pint of Guinness).

So, should you ignore the non-buoyant water signs? Not at all.

But is the risk not quite as risky as it's been made out to be? Probably.

Enter the crystalverse

 

In our material science class at Princeton - and in most of the matsci classes that originated from the ASM summer camps, I would imagine - we grow copper (II) sulfate crystals from solution.

It's a fairly easy lab to do, and the students have a high success rate.

For most students, that crystal growing experience is an end, but for others it's just a beginning, a taste of a much richer world of crystal growth.

For those students, crystalverse would be a great resource as it provides instructions for the diy crystal farmer whether they want to grow crystals of copper acetate, monoammonium phosphate, sucrose, alum, sodium chloride, potassium ferrioxalate, or even pyramidal crystals of sodium chloride.

In every case, the procedure is largely the same - make a solution, let the solution cool and evaporate to form seed crystals, continue to let the solution evaporate to grow the seed crystals larger. The great things about the crystalverse website is that it has loads of tips and faqs to help you troubleshoot your growing.

Making salt

Today you get a whole bunch of videos about making salt.

It seems like such a simple thing - talk salt water from the ocean and boil it down - but there's a lot more to the science of making salt including removing the calcium and magnesium impurities, allowing the crystals to grow to the desired size, and sorting those different crystal sizes.

Who knew that the rate of crystal growth would affect the size of the crystals?

More after the jump...

How cooks put their fingers in hot sauce without burning themselves

Heat =/= temperature

Temperature is the average kinetic energy of the particles in a substance.

Heat is energy transferred from one body to another due to a difference in temperature.

Hot things - like boiling water or simmering sauce - conduct energy to cool things - like your finger.

The amount of energy you get from that hot sauce depends on way more than the temperature of the sauce. More mass of sauce that you get on your finger means more molecules with that same average kinetic energy, so more total energy, so more pain.

In this video Adam switches mass out for time in contact with the sauce, but in this case that seems a fair swap.

Don't dunk your finger in hot fryer oil or hot sugar syrup. According to Adam, go ahead and dunk (or flick) your finger in hot, water- or oil-based sauces.

As always, vinegar leg on the right.

How To Accidentally Invent A Color

I've posted about Phoenician Purple before - the dye mentioned in this video as coming from snail shells. That's an amazing story, too.

The early part of this video defines pigments versus dyes. I'll admit that I didn't have any idea there was an actual distinction between those two. I am curious, though, as to whether the insoluble and soluble designation depends on the nature of the solvent. Like are some chemicals pigments in oil but dyes in water-based solutions?

Maybe I'll hunt down that in a different video.

Why dutched cocoa is different from natural cocoa

"It's Dutching time!"

Thanks, Adam.

Turns out there's some serious chemistry happening in the kitchen when you're making - and especially when you're dutching - some chocolate from scratch.

The Most Reflective Mirror In The World

Arrggghhh, Action Lab again.

I want to hunt down some of those dialectric mirrors. Their non-isotropic reflective materials sound pretty cool.

I am amazed that there is no metal in the material. It's just made of transparent polymer layers in alternating materials with different indices of refraction.

Best Rust Converter? POR-15, Eastwood, Rust-oleum Rust Reformer, Gempler's

One of my coworkers recommended this video to me, and I respect the video host's adherence to the scientific method. He tests metal from the same source, prepared in the same way, and has multiple test samples for each coating.

I'm not so sure, however, what these rust convertors actually do. I found this in the wikipedia article on rust converters...

Commercial rust converters are water-based and contain two primary active ingredients: tannic acid and an organic polymer. Tannic acid chemically converts the reddish iron oxides into bluish-black ferric tannate, a more stable material. The second active ingredient is an organic solvent such as 2-butoxyethanol (ethylene glycol monobutyl ether, trade name butyl cellosolve) that acts as a wetting agent and provides a protective primer layer in conjunction with an organic polymer emulsion. 

 

Some rust converters may contain additional acids to speed up the chemical reaction by lowering the pH of the solution. A common example is phosphoric acid, which additionally converts some iron oxide into an inert layer of ferric phosphate. Most of the rust converters contain special additives. They support the rust transformation and improve the wetting of the surface.

Looks like they're primarily tannic acid with some organic solvents.

The science seems pretty interesting, and I might show this video to my students when we discuss experimental design methods.

Reusable handwarmers that get hot by freezing

The title of this video is wrong.

There is no freezing happening. There is recrystallization happening from sodium acetate dissolved in solution.

That's not freezing - a pure liquid turning into a solid like ice turning into water. The host seems to understand that distinction, but he's sloppy on using the term freezing and freezing point somewhat misleadingly. He also is sloppy on liquid versus solution and melted versus dissolved.

Most of this video is an explanation and comparison of the two types of hand warmers - the reusable sodium acetate solution and the single-use iron rusting type. The video host explains the science behind what's happening and judges the single-use to be the better choice - something that I'll leave up to you.

I use both in class for different purposes and different chapters.

Decay Modes

Source - xkcd
Rollover text - Unlike an Iron Age collapse, a Bronze Age collapse releases energy, since copper and tin are past the iron peak on the curve of binding energy.

...so, it's funny because...

We haven't taught nuclear decay or nuclear chemistry in my first year chemistry class at Princeton in quite a few years since it was taken out of the Ohio chemistry curriculum and off of the AP exam quite a few years ago. We leave that nuclear stuff to the PHS physics department.

With all that being said, I remember the top row of decay mechanisms, and they're real. 

• Alpha decay sees the nucleus shedding two protons and two neutrons.
• Beta decay shows a neutron turning into a proton while the nucleus ejects an high-energy electron, aka a beta particle. That drawing helps us to know that Randall is drawing neutrons as shaded-in circles and protons as the 'white' or 'hollow' spheres.
• Gamma has the nucleus rearrange its particles - protons and neutrons, known collectively as baryons (though there are more baryons than just protons and neutrons.)
• Electron capture is just what it says: an electron is drawn into the nucleus, turning a proton into a neutron.
• Positron emission is also a proton turning into a neutron, but in this case it releases a position, effectively an electron with a positive charge.
• Neutron emission is pretty self-explanatory as a neutron leaves the nucleus.

Then we get to the made-up ones which lead to the jokes. For some of these, I did rely on explainxkcd to get the gist.

• Baryon panic would be insanely energetic, requiring all of the protons and neutrons to spontaneously separate, requiring a massive amount of energy to be absorbed by the nucleus.
• Omega decay is the assumed progression of alpha, beta, and gamma decay - omega being the last Greek letter in the alphabet. I guess since alpha, beta, and gamma decay give off increasingly energetic particles, omega decay would somehow give off the most energetic particle and cause death?
• Electron wilt seems to show the electrons just stopping their motion around the nucleus, wilting like a flower.
• One big nucleon shows all of the protons and neutrons 'congealing' into a single nucleon, the generic term for a particle in the nucleus. The is, I guess, kind of like a Bose-Einstein condensate but for the nucleus.
• Fungal decay gets nuclear decay and biological decay muddled up with the nucleus sprouting mushrooms.
• Collapse due to invasion by the sea peoples seems to refer to something that supposedly happened to the eastern Mediterranean during the late Bronze Age. I dunno. I had to look it up.

The rollover makes reference to the fact that the nuclear binding energy for iron-56 is the highest on the periodic table (at least among common isotopes). This is why large stars never make anything beyond iron-56 in their life cycle until they go supernova. And since bronze is made of tin and copper - both beyond iron-56 on the periodic table - a collapse of those elements releases energy according to Randall.

It's all some pretty esoteric stuff today.

Don't worry if you don't get it.