Note (12/2015): Hi there! I'm taking some time off here to focus on other projects for a bit. As of October 2016, those other projects include a science book series for kids titled Things That Make You Go Yuck! -- available at Barnes and Noble, Amazon and (hopefully) a bookstore near you!

Co-author Jenn Dlugos and I are also doing some extremely ridiculous things over at Drinkstorm Studios, including our award-winning webseries, Magicland.

There are also a full 100 posts right here in the archives, and feel free to drop me a line at with comments, suggestions or wacky cold fusion ideas. Cheers!

· Categories: Physics
What I’ve Learned:

Mpemba effect: Warm... hot!... HOT! Cold.
“Mpemba effect: Warm… hot!… HOT! Cold.”

Science is sometimes all about observation — particularly when the thing being observed makes no damned sense, and clearly needs some brainy scientist to figure it out and explain it. For instance, take the following observation:

Under certain conditions, warm water will freeze faster than cold water.

I told you it made no damned sense. This is real up-is-doAwn, black-is-white, Tom-and-Jerry-living-together-in-scandalous-nude-beach-sin kind of stuff.

But it’s also true, and the phenomenon has drawn attention for millennia. Some of the greatest minds of the Western world have puzzled over the problem — Aristotle, Sir Francis Bacon and Rene Descartes, for three. They all tried to suss out why hot water can sometimes freeze faster, and all of their explanations had one thing in common:

They were fairly spectacularly wrong.

To be fair, none of these guys was a professional waterologist, or whatever esoteric specialty the question would fall under. Still, that’s a pretty all-star lineup to be stumped by a puddle of warm water. That’s like the Harlem Globetrotters botching a layup. It simply isn’t done — and it’s probably why the phenomenon isn’t named for any of those people.

The person it is named for is Erasto Mpemba, who was neither a famous (yet) scientist nor a globetrotting basketball trickster. Instead, he was a young student in the 1960s in Tanzania when he asked visiting physics lecturer Denis G. Osborne what gives with this quick-freezing hot water business. Between them, they repeated and confirmed the basic observation, published a short paper on the subject in 1969, and the phenomenon has been known as the Mpemba effect ever since.

Which seems a little like cheating, since Mpemba didn’t really explain what was causing it, either. The lesson here seems to be: if you want something named after you in science, you need to wait for a historical period littered with hippies, when maybe the rules for taking credit are relaxed a little bit. If more of Francis Bacon’s peers had smoked weed and played the sitar, maybe the Mpemba effect would be all his, instead. We’ll never know.

(Also, if your last name is “Osborne”, you’re going to have to do some way crazier shit to get people to remember you. That bar’s set pretty high at this point.)

But there’s another lesson (and some actual science) in more recent work on the matter. The lesson is: if some weirdo science thing is already named after someone, doing the work to actually explain it still won’t get your name on it. Happily, that didn’t stop Xi Zhang and colleagues in 2013 from digging in and getting their hands dirty, mechanistically speaking.

They concluded that the Mpemba effect occurs due to hydrogen bonding in water. These hydrogen bonds across water molecules, much weaker than the covalent bonds holding oxygen and hydrogen atoms within the molecules together, can form and stretch and break at will. It’s known that hydrogen bonds in water compress the covalent bonds, and that heating water will push the molecules further apart, stretching the hydrogen bonds — and further squishing the covalent ones.

The idea is that “hotter water”, with its more tightly spring-wound energy tied up in covalent bonds, will release this energy more quickly than cooler water. Losing this energy is a type of cooling, so the heated water really will cool — and freeze — faster. It’s a neat and tidy explanation for a quirky “stupid water trick”.

Is it right? The debate is still out. Some scientists argue that greater evaporation in the heated water is the main force at work, while others attribute Mpemba effects to gases dissolved in the water samples. It’ll take a lot more scientist frostbite — sorry, make that scientists’ graduate student frostbite — before anyone reaches a consensus.

Meanwhile, Erasto Mpemba can rest easy, knowing that he brought to light a puzzle haunting humankind since the time of the ancient Greeks — even if he didn’t bother to explain it. Thanks, hippies!

Image sources: Cool Science Stuff (Mpemba ice), FanPop (T&J, tanning), Sportales (the ‘Trotter split) and Spultured (Ozzy, presumably preparing to bite the head off something)

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· Categories: Biology, Chemistry
What I’ve Learned:

Micelles: when the heart wants what the head hates.
“Micelles: when the heart wants what the head hates.”

Contrary to popular belief, a micelle is neither an expensive French pastry nor that nice lady currently living in the White House. Instead, a micelle is a clump of wishy-washy molecules called surfactants that can’t make the simplest decisions and probably never see any good action movies.

I’ll back up.

We have love-hate relationships with all sorts of things. Semi-sweet chocolate. That non-frozen yogurt full of bacteria that tastes like armpits. Tom Cruise.

Consider the Cruise. He makes some good movies — and a lot of okay movies — but by most accounts, he’s kind of a schmuck. Also, I think he worships Alf from that ’80s TV show; I’m not so clear on the details. The point is, your heart and your head — and any other organ you invite to the discussion — can rightfully disagree on how you feel about Tom Cruise. And they’ll disagree often, because he’s everywhere. You can’t swing a dead thetan without smacking some new movie, rerun, interview, gossip rag or ironic T-shirt featuring wee Mr. Cruise. He’s practically ubiquitous.

And that’s how surfactants feel about water, a substance almost as ubiquitous as Tom Cruise — although Waterworld really hurt its career.

(Oh, let’s face it. Water hasn’t done a really good flick since Splash. It’s been treading itself ever since.)

Back to surfactants. These are stringy little molecules with separate “head” and “tail” regions. They’re amphiphilic, which just means that one end is attracted to water (or is “hydrophilic”) and the other is repelled by water (aka, “hydrophobic”). They’re like schizophrenic Frosted Mini-Wheats, minus the wheat. And the frosting. And the talking commercial mascot.

(It’s not a perfect analogy. Breakfast cereals can only teach us so much.)

If you dropped one surfactant molecule into a pool of water, it might well go crazy. The water-hating end would flop around, trying to get away, while the water-loving side would soak it all in. All confuzzled, it might contort or explode or lock itself in its room and write awful goth poetry.

But dump a whole bunch of surfactant molecules into water, and they make a plan. The water-repelled ends huddle up and glom together, drawing the water-attracted ends around them on the outside. The result is a big ball called a micelle, with all the brave hydrophilic bits exposed to the water, and the tender hydrophobic bits safely tucked inside.

(Yes, that’s basically the plot to the second half of 300. I’m telling you, water is really clutching at straws for good ideas these days.)

So why are micelles important? Well, they’re how detergents work, for starters. Soaps can pull dirt and nasty bits that wouldn’t normally dissolve in water into the center of their micelles and carry them away. From Dawn to Tide to Irish Spring, micelles make things cleaner.

More important, micelles are critical for life. There’s a lipid bilayer forming basically a big micelle (though technically a “liposome”) around every living cell; it’s called a cell membrane, and all our important DNA and enzymes and junk would leak out without it. Smaller micelles are formed in cells to push or pull in materials, including several vitamins (A, D, E and K) that we couldn’t process otherwise. And scientists can create artificial micelles to deliver drugs into cells directly.

So the next time you feel torn about some wacko celebrity, don’t let it get to you. Tom Cruise won’t live forever (probably), and if you had the same inner conflict about water, you’d never leave the house. Or bathe. Or make a decent cup of coffee.

But micelles make wishy-washy work. And they’ve never even seen Top Gun. Respect.

Actual Science:
Elmhurst CollegeMicelles
Frontiers in PharmacologyPolymeric micelles for drug delivery
Chemistry ExplainedSoap
Idaho Milk ProductsWhat is a casein micelle?
Lab MuffinWhat is micellar water and how does it work?

Image sources: University Federico II (micelle model), DC Dental (Tom Cruise), Business Insider (weepy Mini-Wheat), Chemistry in Your Cupboard (hot detergent action)

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