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 secondhandscience@gmail.com with comments, suggestions or wacky cold fusion ideas. Cheers!

Mpemba Effect


· 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!

Actual Science:
Phys.org – Mpemba effect: why hot water can freeze faster than cold
Wired – What’s up with that: the mysterious effect that makes hot water freeze faster than cold
Medium / The Physics Arxiv Blog – Why hot water freezes faster than cold – physicists solve the Mpemba effect
Gizmodo – We’ve finally figured out why hot water freezes faster than cold

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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Nanoparticles


· Categories: Physics
What I’ve Learned:

Nanoparticles: Itsy bitsy teeny weeny hella useful science thingies.
“Nanoparticles: Itsy bitsy teeny weeny hella useful science thingies.”

Nanoparticles are little itty bitty things — anywhere from one to one hundred nanometers in size. A nanometer is defined as one billionth of a meter, which is a very European way of saying you can’t see a thing that small, even if you squint.

If you’re having trouble visualizing nanoparticle scale — which is perfectly understandable, since I just told you it’s impossible — maybe this will help: a human hair is roughly 100,000 nanometers wide, or a thousand times bigger than the biggest nanoparticle.

So take some 200-pound person and then think of an animal a thousand times smaller, or roughly three ounces. Like a baby kitten, or a newborn raccoon. Or Ariana Grande. That critter has hair the width of a nanoparticle.

Okay, that’s not actually how hair works. But we’ve established nanoparticles are small. Even compared to squeaky pint-sized pop divas. Which is impressive in itself.

But nanoparticles aren’t just tiny; some of them can also get pretty weird. The physical properties of nanoparticles are impossible to predict, because they’re small enough to feel quantum effects. And everything at the quantum level is weird.

So nanoparticle gold in solution changes color to look black or red. It also melts at much lower temperature. Some nanoparticles absorb radiation (like zinc oxide and UV rays) much better than bigger, beefier versions of the same material. And some magnetic nanoparticles will flip-flop the direction of their magnetism — which is a cute trick for dinner parties, but is pretty lousy if you want to be used for anything practical.

There are all sorts of other complicated things that happen with nanoparticles, most of which sound like they’re from science fiction. Some semiconductors display quantum confinement, which I assume has something to do with how Han Solo got encased in carbonite. There’s also something called surface plasmon resonance, and another called superparamagnetism. Maybe you get those when you’re bitten by a radioactive spider. I don’t know.

Meanwhile, some nanoparticles are incredibly useful, and the basis for whole areas of modern science. In medicine, researchers are exploring using them to deliver vaccines and drugs and detect cancer. Silver nanoparticles in fabrics kill bacteria. Environmental scientists take advantage of certain nanoparticles’ super-reactivity to clean up oil spills and other dangerous pollutants. Plus a thousand other things, like quick-charge batteries and thermal cloaks. Seriously.

And that’s before you even get to the most famous and ridiculously awesome nanoparticle: carbon nanotubes.

Carbon nanotubes are basically straws made of carbon atoms. They can be grown incredibly long (for their nano-sized widths), in a bunch of different configurations, and they’re basically tiny little superhero molecules. Carbon nanotubes are the strongest and stiffest materials currently known, some are harder than diamonds, better thermal conductors (along the straw length) than copper, and possibly (but possibly not) superconductors.

Obviously, scientists want to use carbon nanotubes for basically everything — and they’ve already started. Today, carbon nanotubes are mixed into materials to provide extra strength or other properties, but tomorrow? Synthetic muscles, maybe. Prosthetic retinas for the blind. Space elevators. The sky — or space, actually — may be the limit, when we’ve learned more about carbon nanotubes, and nanoparticles in general. Even if you can’t see them coming.

Actual Science:
Bristol University – What makes nanoparticles different?
Wired – Why Google’s cancer-detecting pill is more than just hype
MIT News – Pills of the future: nanoparticles
IEEE Spectrum – Nanoparticle reduces charge times for Li-ion batteries from hours to minutes
HowStuffWorks – How nanotechnology works

Image sources: AZO Nano (nanoparticles), The Hits (la petite Grande), Wookieepedia (Hansicle), Gizmodo (space elevator [not made of carbon nanotubes, sure, but hey, it’s cool])

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Capillary Action


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

Capillary action: Is that surface tension in your straw, or are you just happy to see me?
“Capillary action: Is that surface tension in your straw, or are you just happy to see me?”

For a long time, I thought “Capillary Action” was a Tom Clancy novel. That’s partly because I never paid attention in physics class, but mostly because I never paid attention to a Tom Clancy book until Harrison Ford got involved.

As it turns out, capillary action is less about espionage, and more about antigravity. And Alabama Slammers. And sometimes, apple bottom jeans. Yeah. It’s kind of a big deal.

Capillary action, or capillarity, describes the movement of fluids in narrow spaces, without any outside force — including gravity. In fact, capillary action often occurs in a direction opposite gravity — like when a bit of your Alabama Slammer climbs up the inside of the straw while it’s resting in the drink, as though the alcohol was trying to claw its way closer to your brain.

(This is why I only drink margaritas. The salted rims keep the alcohol demons at bay, until you decide you’re ready for tequila.

Also: you’re never ready for tequila. No one’s ready for tequila.)

This seemingly-magical uphill slide is actually caused by two physical forces, which are both attractive: the surface tension of the liquid (caused by mutual attraction of its molecules) and the adhesion (again, molecular attraction) of the liquid to the sides of the tube (or straw, or South American monkey-hunting blowgun, if that’s your thing) it’s in.

The combined action of these forces creates a meniscus, or a curve in the surface of the liquid. In fluids like water, the meniscus is concave, meaning the edges touching the walls are higher than the level in the center. As these edges adhere to the tube, the water is pulled further and further up the sides, and voila — capillary action.

It’s like how when some people put on their “skinny jeans”, some of the fluid around their midsections adheres to — and climbs up, and spills over — the sides. The smaller the container, the more climbing up (and out) is going to happen. So basically, capillary action is the muffin top of the physics world.

Except capillary action is caused by attractive forces, and muffin tops are more often caused by Frito pie. Which is far less attractive. Molecularly speaking, of course.

Capillary action is a pretty important phenomenon, though, and scientists have been poking at it for hundreds of years. Leonardo da Vinci first reported it, and some pretty big scientific cheeses — Robert Boyle, Jacob Bernoulli and Lord Kelvin, for instance — have studied and described it. Albert Einstein’s first scientific paper, in fact, was about capillarity. And that guy was pretty smart. He might have even been ready for tequila. Maybe.

Even outside our caipirinhas and our Calvin Kleins (which don’t technically count, but work with me here), capillary action is everywhere. Sponges use capillary action to suck up liquids; so do paper towels. It’s also how trees get moisture to their leaves. Your tear ducts are tiny straws that use capillary action to drain away tears. And those “wicking” fabrics that are all the rage among gym-goers (if somewhat less so among Frito pie fans)? That’s capillary action sucking the sweat off your body and keeping you cool and dry.

So the next time you’re sipping a Sex on the Beach or aerobicizing in Under Armour, take a moment to think about capillary action.

And also Harrison Ford. If they ever make the Capillary Action spy thriller, he’ll make it a lot more interesting.

Actual Science:
USGS – Capillary action
UC Davis ChemWiki – Capillary action
Scientific American – Frost flowers and hot capillary action
ScienceNews – Chemist tackles complex problems with simplicity
Fuck Yeah Fluid Dynamics – (Tears of wine)

Image sources: MIT (capillary action in action), LoveToKnow (Alabammer slammer), Dude I Want That (Muffin tops [you’re welcome]), Star Warped (Harrison, bemused)

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Quantum Fluctuation


· Categories: Physics
What I’ve Learned:

Quantum fluctuation: If you don't see it, you know it's working.
“Quantum fluctuation: If you don’t see it, you know it’s working.”

Space is pretty empty. You might think you’d like it, if you could get out there away from the traffic and the neighbors and the unending stream of Wendy’s commercials. But empty space isn’t all it’s cracked up to be. There aren’t a lot of wifi hotspots in space, for instance. It’s tough to find a decent cheeseburger out there, too. Also, oxygen, which a lot of us like to breathe now and then. Space is woefully lacking in that.

To be fair, there are also a lot fewer Wendy’s commercials. So empty space isn’t all bad.

On the other hand, “empty space” also isn’t all “empty”. That’s because of quantum fluctuation, tiny twitchy changes in energy coming and going in the ether. There’s no chemical reaction or chain of cause and effect going on. It’s just the cosmos playing peek-a-boo to keep itself entertained.

Quantum fluctuation is sometimes described as a constant barrage of “virtual particles” winking into existence, and near-immediately bumping into a bunch of also-just-winked anti-particles, annihilating both back into nothingness. Like two women entering a swank party, seeing they’re both wearing the same “one-of-a-kind” dress, and beating the hell out of each other in the parking lot. Except one of them is made of antimatter, and nobody’s drinking champagne cocktails.

If that all sounds a little weird, then not to worry: this “virtual particle” business isn’t actually the way quantum fluctuation works, exactly. That’s just a trick physicists use to make the math look prettier. Like most things in quantum physics (and pretty much all of quantum field theory, which this also is), the truth is much, much weirder than the model suggests.

(Also, the burgers at Wendy’s don’t look anything like those sandwiches in the commercials. Just in case you’ve been wondering.)

Rather than virtual particles, which you could imagine but don’t exist, quantum fluctuations are more like jitters in the invisible quantum energy fields stretching across the universe. Those do exist, but they don’t look like anything, and make your brain hurt to think about. You might wish for a rogue anti-particle to fling itself out of the ether and put you out of your misery. But no.

Instead, focus on a few basics. Quantum fluctuation is a consequence of the Heisenberg Uncertainty Principle — which sadly (or happily, depending on your point of view) has nothing to do with a certain meth-peddling chem teacher trying to decide on which pair of tighty whities to wear. Instead, the principle states that it is impossible to know both the current energy and the change in energy in a quantum field at the same time. From this, it follows that there’s going to be jitter — and that it’s unpredictable, uncontrollable and inevitable. Where a field exists, there will be static. The entire universe is like a scrambled soft core porn channel.

Which would frankly explain an awful lot. But not the constant Wendy’s commercials.

Why are quantum fluctuations important? For one, random “jitters” in the very, very early moments of the universe may be responsible for the characteristics we enjoy today. For another, though some quantum fluctuation-predicted measurements are spot on, there’s a many-, many-, many-magnitude of order discrepancy between the energy density of empty vacuum and the observed behavior of the universe. This is called the “cosmological constant problem” and theory-wise, something’s got to give. Even Einstein tangled with it. It’s kind of a big deal.

So the next time you’re staring into empty space, just know that there’s a universally crucial fireworks display happening far below the scale that you can see. But if you could, what would you learn? Is it just static? Is there some pattern, a quantum remnant of the cosmos’ birth?

Or is it just playing another goddamned Wendy’s commercial? Because I totally bet that’s it. Figures.

Actual Science:
Of Particular Significance – Quantum fluctuations and their energy
New Scientist – It’s confirmed: matter is merely vacuum fluctuations
A Review of the Universe – Quantum fluctuation
American Physical Society – Quantum fluctuations affect a row of distant ions
Phys.org – Physicists search for new physics in primordial quantum fluctuations
HETDEX – Vacuum energy, or Einstein’s blunder

Image sources: quantum fluctuations, Mooselicker (Wendy’s chomper), Archie dress scandal), Empty Kingdom (scrambly porn)

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Gravity


· Categories: Physics
What I’ve Learned:

Gravity: what goes up... gets pretty complicated on the way down.
“Gravity: what goes up… gets pretty complicated on the way down.”

Gravity is a bitch. This is true for absent-minded skydivers jumping without their parachutes. But it’s also true for theoretical physicists. Because gravity doesn’t make much sense, and it doesn’t care who gets splatted on the ground trying to figure it out.

Gravity seems like it should easy. Everyone feels the pull of gravity — some of us more than we used to, and on body parts that have themselves “splatted” in shameful, horrifying ways. Discovering what’s underneath all that planetary tugging seems like a no-brainer.

But it is a brainer. A very big-brainer, actually.

Scientists recognize gravity as one of four fundamental forces of nature — and frankly, all four are pretty screwy. There’s the strong nuclear force, which may be mighty — but only works at scales smaller than atomic nuclei, so it’s also really tiny and sad. It’s the Rudy of universal forces.

Then there’s the weak nuclear force, which… I don’t know, holds the atoms of weak things together, maybe? Like that skinny kid in gym class, and Ikea furniture, and the Cleveland Browns. I’m just spitballing here.

Then there’s the electromagnetic force. Electromagnetism gives us light to see, radio waves to hear and microwaves to nuke our frozen burritos. It’s everywhere, and moves at the speed of light. Literally, because it is light, and various other wavelengths.

For all these forces, physicists have discovered corresponding elementary particles. Photons, for instance, which mediate the interaction of electric charges. The photons themselves are a pain to nail down — today they’re particles, tomorrow they’re waves — but at least we’ve found them. Likewise, particles called gluons carry the strong nuclear force, and W and Z bosons carry the weak force. It gets pretty complicated, but everything lines up and can all be explained by quantum mechanics.

Until you get to gravity. Because gravity is a bitch.

First of all, no one’s ever observed a particle — or wave, or aura, or Magic freaking 8-Ball — that carries gravitational force. There’s a predicted one, called a “graviton”, but we won’t be seeing those in a lab any time soon, because practical reasons.

(One estimate holds that we could detect one graviton every ten years, if we had a one hundred percent efficient detector the size of Jupiter. Which we don’t. And it only works if we put it near a neutron star, which we can’t. Also, it has to be shielded from cosmic neutrinos, which requires so much extra matter it would fall into itself and form a black hole. Which is bad.

In other words, gravitons are essentially undetectable. Eat your heart out, Higgs boson.)

We do have a shot at detecting gravitational waves, “ripples” in spacetime made up of many gravitons (if they exist) and produced by various astronomical objects. Some such waves may have been produced soon after the Big Bang, and may tell us something about the early origins of the universe. But we haven’t confirmed any discoveries yet, and interference from various electromagnetic sources on Earth make reliable detection tricky. (Stupid delicious microwave burritos.)

The other issue — theoretical gravitons or no — is you can’t jam the equations dealing with gravity into quantum physics. When you try, you wind up with infinities over here and irreconcilable differences over there and everything goes to hell. You might as well try getting Katie Holmes back together with Tom Cruise. It’s not gonna happen.

That leaves gravity as the “odd force out” — and mathematically speaking, completely separate from the rest of the universe. All sorts of strategies have been devised to pull this crazy loner back into the fold, including string theory, superstring theory and loop quantum gravity. So far, nothing (testable) has worked.

So if you’re planning to prank someone by getting them to jump out of a plane without a ‘chute, you’ve got a fair chance of convincing them gravity doesn’t really exist at all. Bonus if they’re a physicist working on quantum gravity — because at this point, they’ll probably want to jump.

Actual Science:
Fermilab / Inquiring Minds – Is gravity a particle or a wave?
PBS / Nova – What are gravitons?
Universe Today – Can you escape the force of gravity?
Quanta – Physicists eye quantum-gravity interface
New York Times – A scientist takes on gravity
Space.com – Einstein’s gravity waves could be found with new method

Image sources: Physics Is Fun (“Curses!”), ILoveSkydiving.org (lounging jumper), CinemaSips (“Rudy! Rudy!”), Today’s Zaman (giggly Katie, tee-hee Tom)

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