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:

Relativity: you can't choose your family, but you can pick your physics.
Relativity: you can’t choose your family, but you can pick your physics.

I’ve learned a little about the theory — actually, theories — of relativity.

(Obviously only “a little”; I’ve never learned a lot about anything.)

Of course, I got a little confused about the word “relativity”. Seeing as how it sounds like “relatives”, I initially thought the physics professor was talking about my family. The parallels are so strong, in fact, it took me three lectures to figure out the problem. Maybe your relatives are different. Judge for yourself:

First, there are two kinds. You’ve got “general” relativity, and then there’s relativity that’s… “special”. Like Aunt Eunice, who leaves her girdle by the table after family dinners. Or cousin Gene, whose clan has watched “A Christmas Story” several thousand too many times.

(Apparently, there’s now a new-ish thing called “doubly special relativity” or “extra-special relativity”. Some physicists must have talked to Nana after her three helpings of rum fruitcake.)

Just as families make no sense, neither do the two names for types of relativity. “General” relativity actually only covers one specific thing: gravity. I thought this meant the gravitation of parents and grandparents around you when you visit for Christmas, asking things like, “You’re not wearing that, are you?” And “When are you going to find a job?” And “Who ate all my damned fruitcake?

I found out later it was a different kind of gravitation, and apparently it doesn’t work the way Isaac Newton or anyone else thought it did. The way Einstein figured gravity led to some pretty oddball predictions about the universe: spacetime must be curved rather than consistent, gravity can slow time and bend light, and black holes could exist that suck up all matter and light nearby.

These were all pretty outlandish notions when they were hypothesized back in the early 20th century. But as we’ve sorted out ways to precisely measure and explore such things, they’ve all turned out to be real. Who’s loopy on fruitcake now, classical physicists?

Of course, that leaves “special” relativity to explain everything else — a common occurrence at my family’s holiday parties. If you want to hear what’s wrong with kids today, where you ought to put your money or how the “gubment” ought to be run, just pull up a chair (and a tall stiff eggnog) and listen to the “special” relatives dish out a dose of “wisdom”.

(Naturally, they know as much about these topics as I know about… well, science. Which is scary. I’m surprised most of them manage to put on their pants in the morning.)

As I’ve mentioned before, special relativity isn’t about such things, though. (Thank goodness.) Instead, it’s a description of how spacetime — the woven-together fabric of time and three-dimensional space — works, and how things we used to believe were fundamental actually change based on perspective. Like an event happening at the same time according to two people, but sometime else to an observer in relative motion. Time slows down and objects seem shorter, the faster they go. And the big one that ties mass and energy and the speed of light (squared) all together: E = mc2.

Physicists glommed onto special relativity soon after Einstein first proposed it in 1905, because it fit with certain experimental observations better than Newton’s old laws — and it was useful in the bizarro, whacked-out, very “special relative” worlds of nuclear physics and quantum mechanics. General relativity took longer, but finding black holes and pulsars and other weird cosmic schmutz it predicted helped to solidify it, too.

So relativity isn’t about relatives, really. But a lot of it is strange, much of it is “special”, and most of it is, like, a hundred years old. So it’s really not that different. And it’s all around us in the form of spacetime and gravitation, so keep an eye out for relativity at your family gatherings over the holidays.

Just watch out for Nana. She’s a mean fruitcake drunk.

Image sources: Science News (relativity clocks), Southern Belle View (the family that Ralphies together…), Daily Mail UK (drunk grandma), Sur Fisika (Einstein v. Newton)

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· 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: 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.

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

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