The Unknow Phase of Matter

God lord but Steve Mould is a brilliant communicator of science.

I've never really understood super critical fluids - even though I've posted about them before, but today's video - especially the part from about 10:20 through 14:20 or so - makes for a brilliant explanation of why fluids go supercritical at higher temperatures.

The use of the entropy and potential energy graphs in combination lays out the argument for supercriticality brilliantly.

Thanks, Steve...thteve.

This 200-Year-Old Lighter Ignites Without a Spark

I understand that the act of creating fire at this point in our lives is trivial. 

I have a couple of piezoelectric grill lighters and a flint-based lighter in the a drawer in my kitchen. The 'pilot lights' in my gas stove, hot water heater, and furnace are all piezoelectric. If I need fire, I can have it in about two seconds.

That hasn't always been the case, of course. From prehistoric times when fire meant warmth and digestible food, the act of fire creation was miraculous and to be protected.

So the development of a 'safe' lighter that could create fire at the whims of the lighter's owner was an important step toward taming that fire.

But I certainly wouldn't want to carry around Steve Mould's Döbereiner's lamp (yes, the same Döbreiner as the periodic triads) in my pocket.

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.

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).

Why November is the most dangerous month for trains

Heya, Steve. Good to have you back.

I'll fully admit that I assumed this was going to be a dead simple explanation. Leaf cover decreases friction because leaf-on-leaf friction is less than train-on-rails friction.

Turns out it's a lot more complicated than that, needing to look at pectin and the creation of a natural 'jam' on the rails.

Who would've guessed that the chemistry of leaf litter would result in longer travel times in the month of November in England?

Homochirality: Why Nature Never Makes Mirror Molecules

Chirality is incredibly simple on the surface, but the effects of chirality are incredibly complicated and important in the biological world.

Our world - our universe - favors one handed-ness over the other, and we sometimes get in big trouble when we interact with the wrong version of a molecule.

If you want to know more about just how right- or left-handed molecules rotate light waves, check out more from Steve Mould.

Pop-Pop Boats Are Weirder Than You Think

I've never heard of a Pop-Pop Boat before, so it's really not any weirder than I thought it was because I'd never thought of it at all.

Turns out the science of a pop-pop boat isn't all that different from the drinking bird. There's a contained amount of gas that is warmer than another amount of gas. That warmness causes the gas to expand and pushes liquid blocking that gas. In the case of the drinking bird, that unbalances the bird and makes it tip over. In the case of the pop-pop boat that liquid pushes the boat forward in a halting way.

Steve Mould's see-through model of the pop-pop boat doesn't, sadly, make the same pop-pop sound because there's no metal to snap back and forth, but it is a great way to see the inner workings of the boat.

Will a Kettle Full Of Alcohol Stay On Forever?

Lots of interesting stuff from Steve Mould today.

He looks at two different designs of electric kettles and tries to explore how they work, making a few predictions along the way involving the boiling points of water and ethanol. He then takes the kettles apart and explains why the two kettles behave differently and why they don't behave the ways he expected.

What Do Protons Taste Like?

Steve takes a long while to get to the interesting chemistry part of the video, spending a whole lot of time explaining our sense of taste and how each taste aspect (sweet, sour, savory, etc) work.

It's really interesting, and it's really great applications of macromolecule chemistry.

Admittedly, the answer to the video's title question turns out to be less interesting and more obvious (once Steve explains it) than it might have.

Piezoelectricity - why hitting crystals makes electricity

Heya, Steve. Good to see you back again.

The part of this video that I think I most appreciate is the actual look at the guts of a piezo electric safety lighter. I've used them for a long time and never quite been sure how they work on the inside.

I also appreciate Steve's comments on quarts 'healing crystals' around 1:40. "Don't know if you take it orally or..."

And then we get into the fact that piezoelectricity is dependent on the electronegativity differences in a quart crystal (admittedly simplified in Steve's peanut-butter-jar model). I'm totally duplicating this post for my material science blog because of that explanation.

Mystery Blue and White Beads

The blue and white bead bottle up there might look familiar to a lot of science teachers, especially the ones who have taken our ASM summer camps. The bottle can be bought from Educational Innovations or from Flinn Scientific (though Flinn's version is green and white).

The bottle is a spectacular demonstration of density and of solubility, both of which are explained by Steve Mould in the above video.

We do a similar activity in a lab in our material science course at Princeton (one we certainly didn't develop but have tweeked to our needs) using preforms and polymer pellets. An extension we particularly like is related to the food coloring demo that Mould mentions in passing near the end. I especially recommend green food coloring. The effects are far more dramatic than the red that Mould shows.

Another extension involves shining ultraviolet light at the bottle. It turns out that - as one of our Utah campers pointed out to me after I'd had the bottle for a decade or so - that the white beads are actually the UV beads that Ed Inn sells. Apparently having a classroom with no windows blocked me from seeing that happen until she pointed it out to me.

I did also find a video showing how you can make one of your own - without the UV beads, however. The YouTuber's full instructions with quantities can be found in the video description.

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.

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.