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!

· Categories: Physics
What I’ve Learned:

Nucleation: Once you start, you REALLY can't stop.
“Nucleation: Once you start, you REALLY can’t stop.”

Everybody has to start somewhere. If you’re a corporate lackey, you start at the bottom. If you’re a gravedigger, you start at the top. And if you’re a phase transition, you start with nucleation.

Phase transitions are the change of a substance from gas to liquid, or from liquid to solid. But transitions don’t magically happen everywhere at once; you never see a swimming pool full of water freeze in an instant.

Not outside of a Vegas Penn and Teller show, anyway. Preferably with David Blaine chained down in the deep end.

Instead, the process — in this case, the formation of ice crystals — starts in one or more places called nucleation sites. In pure substances, these sites may occur randomly; where materials are mixed or in an irregular container, the nucleation sites usually form where different surfaces meet. Like by a leaf floating in the swimming pool. Or the tip of David Blaine’s nose. Just for instance.

Once formed, the nucleation sites provide an anchor for the transition process. That process speeds up, piling onto the sites like tacklers on a running back, until the entire team is on the pig pile and the system comes back into equilibrium. In the example above, that would be when all the water on the surface that’s cold enough has frozen into solid ice. Or when they fish the David Blaine-cicle out with a pool noodle.

The magic-but-actually-science of nucleation is not limited to freezing water, however. It’s also a crucial part of other natural processes, like crystallization, cloud formation and elongation of biological polymers like actin filaments. Some quantum cosmologists have even hypothesized that our entire universe is the result of a sort of bubble nucleation in the vacuum of whatever it is that lies outside the universe we observe.

(My guess for what’s out there? That girl from the Wendy’s commercials. Because she seems to be every-fricking-where else these days.)

Speaking of bubbles, a lot of people have been having fun with nucleation, possibly without realizing it. The key to the explosive foaming mess you can make by dropping a Mentos candy into a bottle of diet soda is indeed nucleation. Small pores in the Mentos allow bubbles of gas from the soda to form, which attract more bubbles and more bubbles — and they tell two friends, and so on and so on until there’s foam all over your kitchen and mom’s asking why there’s half a dissolved mint embedded in the ceiling.

Of course, bubble nucleation doesn’t require all those theatrics to be useful. Microscopic irregularities in champagne glasses nucleate those nose-tickling bubbles in the bubbly everyone loves. Nucleation also explains why it’s harder to pour a beer into a used glass without foaming up the place; the remnants of the previous pint’s suds provide sites for bubble-making that a fresh clean glass would not.

So that’s nucleation in a nutshell. It’ll help you pour a good beer, it makes Mentos much more interesting, and it might help us get rid of David Blaine. Honestly, what more could you ask of science?

Image sources: ASEPTEC (nucleation diagram), YouTube (cold, wet but sadly unfrozen David Blaine), Examiner.com (football pig pile), New York Times (science ‘n’ Mentos)

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

Bioluminescence: where 'fight or flight' meets light.
“Bioluminescence: where ‘fight or flight’ meets light.”

Have you ever fumbled around in the dark, maybe in an unlit alley or a strange bathroom or in a basement with a burned-out bulb? If so, you should probably stop living your life like an expendable in a horror movie, before something terrifying happens to you.

Seriously. At this rate, you’ll be dead before the slutty girl or the dumb jock boyfriend who brought her out to this isolated cabin built on an Indian burial ground next to the haunted lake infested with vampire sharks. Get a grip, already.

Or you could grow a pair (of extra genes) and make your own light, using the time-tested strategy of bioluminescence. Humans aren’t capable of such things just now, but bacteria, fireflies, deep-ocean critters and some fungi have been doing it for millennia. And no one’s ever chainsaw-massacred them, so it must be doing the trick.

Here’s how it works: bioluminescent organisms produce two chemicals, known as luciferin and luciferase.

Don’t worry; this isn’t a pair of demons coming to get you in that dark alleyway. Chemistry may be many things, but it’s not the debbil.

In this case, the “lucifer” part of the name comes from the Latin word meaning “light-bringer”. And that’s just what these two molecules do. Luciferin undergoes a reaction — typically with oxygen — which produces a new molecule in a chemically excited state.

Because who wouldn’t be thrilled with a fresh batch of oxygen? I get socks for my birthday, and that’s not nearly as exciting.

When this excited molecule settles down (or chemically speaking, decays to its ground state), it emits a photon — in other words, a teeny little speck of light. String enough of these reactions together, and you’ve got yourself a light-up firefly butt. Or glow-in-the-dark mushrooms. Or a vampire squid with flashbulb arms.

(And yes, vampire squid do exist, unlike the vampire sharks I mentioned earlier. Which proves once again that nature is actually way more scary than whatever shit we make up.)

Luciferase catalyzes, or speeds up, this luciferin transformation in cells, so a bioluminescent creature can light up like Las Vegas whenever it likes. This comes in handy for, say, a firefly trying to attract a mate, an anglerfish trying to attract lunch or a mushroom trying to attract… actually, I’m not sure what it is the mushrooms are after. Mario Kart players? Phish fans? The ghost of Jerry Garcia?

At any rate, organisms use bioluminescence for self-protection, camouflage, communication, as a warning and for lighting up some of Mother Nature’s darkest metaphorical alleys, like the bottom of the ocean. Some non-bioluminescent species, like the Hawaiian bobtail squid, even form symbiotic relationships with those that have the “gift” — in this case, a bacterial species whose light helps hide the squid from predators. Basically, when your body parts light up, you can always make a friend. Just ask a certain wrinkly extraterrestrial.

And now that scientists understand the mechanisms of bioluminescence, they’re using it in all sorts of research. Luciferase genes have been cloned into experimental cells, often as a “reporter gene” — or an indicator that other genes cloned in during the same test are present. If the cells light up, everything’s good; if not, it’s back to the drawing board.

Bioluminescent materials have also been used for medical imaging, for exploring “living lighting” in various scenarios, and even as an experimental treatment for cancer.

It’s just too bad you can’t use bioluminescence yet to light up the dark section of those haunted woods. Because it’s a long way back to the cabin. And those footsteps. Are. Right. BEHIND. YOU!

Oh, whew, never mind. It’s just a vampire squid.

AAAAAAAAAAHHHHHHHHH!!

Image sources: It’s Okay to Be Smart (bioluminescent [but non-vampire] squid), Bitch Flicks (slutty girl / dumb jock in a cabin), QuickMeme (“Science is the debbil!”), The Abstractionist (E.T.’s glowy finger)

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· Categories: Chemistry
What I’ve Learned:

Ionic liquids: When all the little ants go chemical-warfaring.
“Ionic liquids: When all the little ants go chemical-warfaring.”

An ionic liquid is a salt that’s in the liquid state. But let’s define “salt”, because in this context, it’s not just for shakers and hot buttered popcorn.

Chemically, a salt is any mixture of positively-charged ions (called “cations”) and negatively-charged ions (aka “anions”). Salts form when an acid (which contains positive ions) and a base (chock full of negative ions) mix and neutralize each other. The best-known salt is made of sodium cations and chloride anions, and it’s so common it gets the saltiest name possible: “salt”. Or “table salt”. Or “that stuff the chef forgot to put on the bean salad, and that’s why the dude got Chopped”.

Any salt can be an ionic liquid, under the right conditions — even sodium chloride. You just have to heat it to fifteen hundred degrees or so Fahrenheit.

And then pay twelve bucks at some upscale Euro-gastro-bistro to have it ladled over your artisinal free-range pommes frites, probably. Which just goes to show, you don’t really want an ionic liquid made of table salt.

Some ionic liquids are more useful, however. Most are poor electrical conductors, highly viscous and some are even liquid at room temperature. These tend to have names like 1-alkyl-3-methylimidazolium tetrafluoroborate, which is somewhat harder to pronounce than “salt”.

It’s also harder to pronounce than the name of that Kyrgyzstani guy who plays on your favorite hockey team. Barely.

What are ionic liquids good for? Lots of stuff! Industries like cellulose processing, industrial gas storage, nuclear fuel reprocessing and waste recycling use (or are researching) ionic liquids. They’re also being tested as electrolytes in batteries, treating wounds infected with bacterial biofilms and for heat transfer in solar energy systems. All of these things are pretty important — and also kind of boring, unless you’re a chemist or a drug-resistant biofilm.

So let’s talk about ants instead.

All the ionic liquids mentioned above are artificial, created in the laboratory. In fact, not a single naturally-occurring ionic liquid had ever been observed — until scientists took a closer look at ants.

But not with a magnifying glass on a sunny day, because that’s cruel.

South American fire ants invaded the U.S. several years ago, and it’s known that their “fire” comes from a vicious burny venom made of toxic alkaloids, which are bases. They’ve recently been joined by another South American ant species called tawny crazy ants — not to be confused with Tawny crazy Kitaen, which is a whoooole other sort of ecological hazard.

These ants have been fighting over territory for ages, and the tawny ants are one of very few species that can survive the fire ant’s flesh-melting juice. Scientists only recently discovered how they do it — by secreting and coating themselves with formic acid. The acid mixes with the fire ants’ alkaloids, neutralizing it to produce a harmless ionic liquid.

With chemical defenses in place, the tawny crazy ants survive the fire ants’ onslaught 98% of the time. And they do it with the only ionic liquid known (so far) in nature. That’s one “salt of the earth” species, there.

Image sources: University of Glasgow (ionic liquid model), Troy Nunes Is an Absolute Magician (Chopped chef), Cuz Dads Are Still People Too (hockey tongue-twister), Write a comment

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

Gravitational lensing: mirror, mirror in the sky; show me what's behind this guy
“Gravitational lensing: mirror, mirror in the sky; show me what’s behind this guy.”

If you’ve ever sat behind a really tall person at a movie, then you know the infuriating problem of not being able to see something on the other side of a solid object. At the theater, you probably deal with this in the usual ways — hoping the heighty person slouches in their seat, or spontaneously loses six inches of height, or their head explodes like in that Scanners movie.

But astronomy tells us there’s another viable option, known as gravitational lensing. All you have to do is push the movie a few million light years away, and make that big fat head in front of you as dense as a ten-billion star galaxy.

It’s a little complicated. I’ll explain.

One of the (now-famous) predictions of Albert Einstein’s general theory of relativity is that space (really spacetime, but who’s counting?) is curved, and that hugely massive objects with lots of gravitational force will further warp that curving. So if a celestial light source — like, say, a quasar — lies behind an enormous gravitational well such as a galaxy, the light from the quasar would get curved around the galaxy and slingshot out the other side.

It might appear that the light source lies beside the big heavy thing in the way, because the light doesn’t bend all the way back to the middle. And if the source is directly behind the obstacle, the light could take more multiple paths around it — left, right, up, down, south by southwest — and appear more than once on our side. It could even form a full ring of light all around the object in the middle, weirdly indicating that the thing producing the light isn’t anywhere around the obstacle at all, but directly behind it.

I know, right? It’s spooky. Real call is coming from inside the house stuff.

Because Einstein described relativity, and was a generally awesome dude, the light rings caused by gravitational lensing are called “Einstein rings”. There are very few complete rings — caused by a massive energy source directly behind a star or galaxy — but hundreds of partial rings, multiple-image systems and other gravitational lensing events have been observed. One of the most impressive, called Einstein’s Cross — because, again, cool smart guy — consists of four “bent” images of a way-distant quasar curved around a still-way-distant-but-not-as-way-distant galaxy in between.

It’s like having a head in the way, but still seeing the movie in double-stereo-vision. Because astronomy makes everything better.

So what do you need to make gravitational lensing work? First, a source of some kind of energy. Many of the known ones work in visible light, but any kind of electromagnetic energy will do in a pinch. The universe isn’t picky.

The energy source has to be ridiculously strong, though, because you’ll need to see the signal from way far away. Not just from down the block, or from that window in your attic, either. Instead, from billions of light years away. Which is kind of a big deal.

Why so far? Because you then need to find an incredibly massive object to plop between you and the energy source to produce the gravitational lensing. A bowling ball isn’t going to do it. A star might, if it’s in precisely the right orientation. A whole galaxy of stars would be better. Or you could try Nicki Minaj’s ass. It’s big enough to attract most of the pop culture paparazzi into a close orbit, apparently. Maybe it could work; I don’t know.

The point is, you’ll only see gravitational lensing by throwing that hypermassive whatever between you and and the signal. And then you can watch that gravity well bend electromagnetic waves like Beckham, off a straight line and down to your eyes.

So maybe it won’t help you the next time you’re blocked at the movies. But gravitational lensing could show you a star behind another star some day. And really, isn’t that how the movie industry works in the first place?

Image sources: Cosmic Chatter (Einstein ring), Slate (big head at movie theater), Disease Prone (Scanners head), SlamXHype (rocket-powered Minaj)

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

DNA methylation: it's like a chastity belt for your chromosomes.
“DNA methylation: it’s like a chastity belt for your chromosomes.”

We humans have a lot of genes — twenty or thirty thousand, give or take a chromosome. But we also have a problem. All those genes are packed into the DNA of each and every one of our cells. You’ve got genes for hemoglobin next to genes for neurotransmitters next to liver enzyme genes next to the ones that tell your left foot to grow toenails. The whole caboodle, in every single cell.

You can’t have all those genes turned on at once, in all the cells. It’d be a disaster. Think of your DNA as a big walk-in closet full of clothes. Some things go together, some things clash, and other things you only wear for holidays — or when senile-assed Aunt Clara shows up to see the stupid lop-eared bunny suit she bought you. But you don’t wear everything you own all at once. That would make you a crazy person.

So it goes with your cells. Depending on where they live — in a little row house along the spinal column, maybe, or a brownstone in the colon — they want to fit in with the neighbors and express the right set of genes. When in Rome, do as the Romans. And when in the respiratory system, don’t spew out growth hormones. That’s not your job, bunnybutt.

There are several ways that cells can shut down or “silence” genes, but one of the most common is DNA methylation. It sounds complicated, but it’s actually pretty simple. To make a protein in a cell, a bunch of enzymes have to get at the bit of DNA coding for it. Those enzymes read the code into RNA, and the protein is built from that. “Methylation” means taking a methyl group, a single-carbon molecule similar to methane, and glomming it onto that DNA structure like a wad of used chewing gum.

Slap enough methyl groups onto a stretch of DNA, and those RNA-making enzymes can’t get at it. Any genes in the neighborhood get completely shut down, like a Honda running out of gas or a dudebro wearing Axe cologne. Even better, when the cell divides, the DNA methylation pattern gets passed down the line. So it’s a great way for specialized cells to shut off genes they have no business fiddling with — basically a permanent genetic cock block.

Though critical for development in mammals — pssssst, that’s us — DNA methylation isn’t used in the same way by all species. Fruit flies, for instance, apparently have better things to do with most of their DNA, and yeast haughtily looks down its nose at DNA methylation.

Or would, if yeast had a nose. Or eyes. Or the genes for being haughty.

In other organisms, DNA methylation comes up a lot. Some — humans and tomatoes, for two — use it to silence potentially harmful genes inserted by viruses into the genome. DNA methylation tends to decrease over time, so it can be used as an indicator of aging. And it’s been linked to diseases like cancer, Alzheimer’s and atherosclerosis, and could offer clues about how those conditions develop.

So DNA methylation is pretty important. Without it, all our cells would crap out all the possible human proteins and we’d be big unregulated oozing blobs of cytoplasm. Like a certain amorphously-shaped cartoon character with a distinct lack of impulse control.

And that’s not attractive. I don’t care how cute a bunny suit you slap on it.

Image sources: UIUC TCB Group (DNA methylation), The Berry (Ralphie bunny), GenTwenty (dudebro shutdown), UnderScoopFire! (Homer, unregulated)

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