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: Astronomy, Physics
What I’ve Learned:

Orbital decay: Life's a drag, and then you burn. Or worse.
“Orbital decay: Life’s a drag, and then you burn. Or worse.”

Gravity is scary. Like, horror movie monster scary.

Think about it; gravity is relentless. Just when you think you’ve lost it, there’s gravity behind you, shaking its chainsaw or hockey mask or Lee Press-On fingerblades at you. And it’s sneaky; even if you make it to the abandoned cabin where the lights don’t work and the caretaker killed a busload of nuns exactly fifty years ago tonight, gravity will be inside, lurking in the shadows. You can hide under the covers, but gravity is already under the bed.

Face it — you’ll never escape gravity. If it weren’t the earth yanking you down, it’d be the sun or Jupiter or a rogue black hole. The pull is inevitable, like iron toward a magnet. Or Paula Deen toward butter.

But you can reach a truce with gravity — temporarily. With just the right velocity, your momentum will exactly counteract the force of gravity toward, say, the planet below. You don’t fly away, and gravity doesn’t splat you onto Earth; instead, you achieve a “stable orbit” and circle around and around.

But like Jenga towers and Facebook relationships, things aren’t really as “stable” as they seem. The truce falls apart over time, leading to something called orbital decay. Gravity wins, and the orbiter takes a nose-dive toward the orbitee.

When orbital decay happens to artificial satellites — like space station Mir or the Hubble telescope — one of two things comes next: some space scientist will push the satellite further up to counteract gravity, or it will plummet toward Earth, incinerating (we hope) in the atmosphere on the way down.

Other bodies experience orbital decay, too. Moons, for instance, can get sucked into their planets and destroyed; no Death Star laser beam required. Stars collide, and really wish they hadn’t. Even galaxies and black holes, circling for millions of years, can eventually experience orbital decay and smush each other stupid.

So what causes orbital decay? And why can’t we have nice things, cosmically speaking?

A few reasons. The balance between “orbiting” and “plunging toward destruction” is precarious; the slightest nudge can throw it off. Near a planet like Earth, tiny molecules of gas making up the sorry excuse for a high-altitude atmosphere will do it.

Satellites plow through these specks of gas, no problem — but they do get slowed down, infinitesimally. Those orbital brake-taps add up, and eventually cause a slight drop in altitude — down to where the atmosphere’s thicker, which leads to more slowing, and further dropping, and so on. It’s a vicious spiral, ending with a satellite faceplant from ten thousand miles high.

But there’s more than one way to decay an orbit. A lumpy orbitee, for instance — if the mass of a planet or star isn’t distributed consistently, orbiting bodies will get whanged around by the irregularities until they finally cut loose. And if the orbiter is large enough, it can bring this fate on itself by creating tidal forces on the larger body that squeeze it out of shape.

(This is why most satellites take spin classes, just to stay trim.)

Really huge orbiters have another problem: gravitational radiation. When supermassive objects like neutron stars orbit each other, Einstein’s general relativity theory predicts that gravitational energy waves streaming away from them should cause orbital decay over time. In recent years, astronomers have found binary stellar systems that appear to behave just the way predicted by the theory, which some didn’t expect. Even dead for sixty years, Einstein’s still smarter than a lot of physicists. But even he couldn’t escape gravity.

And neither can you; even if you negotiate with it, gravity has friends who will sneak up and kneecap you, just so gravity can finish you off. It’s like Freddy Krueger, backed by gremlins. Or Chucky with a nest of facehugging aliens. Or Jason Voorhees with a horde of zombie henchmen. And that’ll put the “decay” in your “orbital decay”, let me tell you.

Image sources: A-Level Physics Tutor (orbital decay), Houston Press (Paula Deen, butterface), Me and My Bread Knife (Facebook relationships), PsychoBabyOnline (Jason with machete, no zombies)

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

Jabba the Deen don't need no hydrogen bonding, y'all
“Hydrogen bonding: If you can’t keep it in your pants, keep it in your electron cloud.”

Hydrogen bonding is one of the most important chemical forces holding molecules and matter and us together. Without the power of hydrogen bonding, we’d all blob out into big piles of disorganized goo like Jabba the Hutt. Or Paula Deen.

(Hey, they’ve never been seen in the same room at the same time. I’m just saying.)

As attractive forces go, hydrogen bonding isn’t especially strong. A molecule could probably pull more electrons with Axe body spray and a couple of subatomic guitar lessons. If covalent bonding — solid, strong, crazy hard to break — is like a marriage, then hydrogen bonding is the “I’ll call you” after hooking up in the alley outside a downtown bar. Not exactly a sign of a committed molecular relationship.

Of course, there are advantages to keeping your options open. I’m not saying it’s a playah, chemical-interactionally-speaking, but hydrogen bonding gets around. Almost every substance critical to life on Earth — proteins, DNA, cronuts, you name it — contains hydrogen atoms. And those things are constantly getting busy rubbing up against each other, switching partners and saying to their hydrogen friends, “well, I ‘bonded’ him, but I didn’t ‘bond him, bond him’, you know?

It’s like Penthouse Letters meets Mr. Wizard. But slightly less disturbing.

The craziest hydrogen bonding of all is in water.

(Because everything is sexier when its wet. Except possibly Mr. Wizard. Try not to think about that too much.)

A water molecule is chemically simple — one oxygen and two hydrogens, bound together in holy covalent matrimony. But like any threesome, even the sparkly vampire ones, nobody in the relationship is really happy. So the atoms all doll up at night and go hydrogen bonding — oxygens prowling for other hydrogens, and hydrogens making the move on every oxygen with a dipole and a pulse. These things make Don Juan look like… well, like Mr. Wizard.

Or Jabba the Hutt. Or Paula Deen. Only wetter.

What’s more, these electrostatic horndogs are good at hooking up, one-night-bonding with up to four other water molecules at a time. That’s good for us, because it’s all this hydro-boinking on the side that gives water its high melting point, high boiling point and makes ice float instead of sink. All of which are pretty important for us to continue to live and maintain mostly-unblobby shapes and eat trendy breakfast-pastry hybrids.

So be glad that hydrogen bonding works the way it does. Life wouldn’t be the same — or probably, wouldn’t be life at all — without it. Just try to forget that there’s basically an atomic-level key party orgy going on in the glass of water you’re drinking.

And don’t even ask what’s going on in that cup of coffee. Trust me, you do not want to know.

Actual Science:
UC Davis ChemwikiHydrogen bonding
Northland CollegeA closer look at water (animation)
NatureChemists re-define hydrogen bond
io9The very first image of a hydrogen bond
DoubleXScienceWhy are snowflakes always six-sided?

Image sources: StudyBlue (hydrogen bonding), Ripoff Report and Gossip Rocks (Jabba the Deen), Laughing Squid (Mr. Wizard), Etsy/KnotworkShop (coffee sex mug)

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