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:

Oort cloud: Go way, way Oort -- then Oort a little further.
“Oort cloud: Go way, way Oort — then Oort a little further.”

If you’ve ever played pinball — which you’ve probably only done ironically, if you’re under the age of thirty — then you’re familiar with the concept of “multiball”. You lock balls by making certain shots, and then there’s some way to unlock them, so a bunch of balls all come flying out at once. Sometimes there’s more than you locked. Often, they come from different places than you put them. They fly around higgledy-piggledy from all directions, until you lose them or you tilt the machine or you get bored and remember that video games and the internet and Netflix exist.

But maybe you’ve wondered, while the multiball madness ensues: where are all of these balls coming from? I always assumed there were some nifty mechanics inside the machine, pulling balls from a reservoir and gliding them around. Either that, or gnomes. Very small hippie gnomes. But then I learned something about astronomy, and found there’s another place those balls might be coming from: the Oort cloud.

Mind you, the Oort cloud is purely theoretical. But its existence has been predicted based on questions about our solar system’s own version of multiball — namely, comets. Some comets swing past the sun every few years. The orbits of these “short-period” comets aren’t so large, and most of them originate in either the Kuiper belt, around 30-50 AU (astronomical units; 1 AU is roughly the distance from the earth to the sun) or the overlapping “scattered disc”, which extends from around 30-100 AU.

These regions begin right around the distance of Neptune from the sun, and they’re not so mysterious. Definitely not “multiball mysterious”. Astronomers see Kuiper Belt objects all the time — probably with a decent pair of opera glasses. New Horizons, the space probe that buzzed Pluto a while back, is swooping through the Kuiper Belt right now. It’s practically down the block.

The Oort cloud is a leeeeetle cooler than that. First, it’s just slightly further away, occupying the space somewhere between around 2,000 – 100,000 AU, give or take a light year. (Which, as it happens, is about 50,000 AU. So it’s true!)

For perspective, that Voyager I probe launched back in 1977? You know, back when people actually played pinball (because it was either that or Pong, those poor primitive saps)? That craft has traveled further than any other we’ve made, it’s technically in interstellar space, and is traveling at around 38,000 miles per hour (a shade faster than New Horizons; don’t tell the Space Highway Patrol). Voyager is expected to enter the Oort cloud in roughly 300 years — or about 290 years after its radioisotope-powered generators are expected to fail, leaving it a silent hunk of space rubble.

So the Oort Cloud is a big ol’ faraway ball of space, is what I’m saying. Inside it are theorized to be trillions — that’s trillions, with a ‘truh-‘ — of objects at least one kilometer across. Most of these are icy bodies, but there are few (meaning few billion) rocky asteroids sprinkled in, just for fun. It’s thought that Oort cloud objects mostly come from debris left over from the formation of the solar system, when the original “protoplanetary disc” swirled into Saturn and Jupiter and Earth and the rest of the planetary gang. Some even theorize that part of the Oort cloud — up to 90%, at the upper end — comes from “sister stars” that were closer by during the sun’s early days, and spewing pre-planetary spittle all over the cosmos themselves.

But if we’ve never seen the Oort cloud, then why would we think it’s out there? Why don’t we just assume there’s nothing there, or space gnomes, and be done with it? Because of long-period comets, that’s why. When astronomers track the orbits of these comets, they see some that make a circuit in hundreds or even thousands of years. And unlike comets from the Kuiper belt or scattered disc, which lie flat in the same plane as the planets, these long-period take-your-time-grandpa comets come from everywhere.

So that’s the Oort cloud. Further out than we can see, surrounding our whole solar system and occasionally raining some of its trillions of balls of ice and rocks down on our pinball machines. Ding ding ding. Multiball, indeed.

Image sources: Universe Today (Oort cloud), Zazzle (MULTIBAAAAAAALL!), French Vocabulary Illustrated (opera-glassed stargazing), Drawception (space gnome [artist’s rendering])

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

Fast radio burst: and you thought Sex Pistols songs were short and confusing.
“Fast radio burst: and you thought Sex Pistols songs were short and confusing.”

If you’re like Fox Mulder, you believe the truth is out there.

That’s great and all, but what happens if you’re not fast enough to read it when “the truth” finally whizzes by?

That’s the sort of problem astronomers have faced since 2006, when the first “fast radio burst” (or FRB) was detected in radio telescope data recorded five years earlier. Poring over archived pulsar survey data, they found a brief spike in the signal across a range of wavelengths. It lasted less than five milliseconds, quick as a Ruby Rhod *bzzzzzz*. And then it was gone.

That may seem weird. But pulsar-hunting astronomers are used to this sort of now-you-see-it, now-you-don’t radio signal Whack-a-Mole. Pulsars are rapidly spinning neutron stars that emit radio signals, and their twirling makes the detectable signal come and go at regular intervals. Only with this particular fast radio burst, it came once… and it never came back.

Kind of like Jesus. Or Nelson Muntz’s dad.

Oh, no, wait. Nelson’s dad did come back eventually. Scratch him.

That was just the beginning of the mystery, though. The spread of the signal across wavelengths suggested that this fast radio burst had traveled across space and through interstellar gas, which can spread signal out, the way a prism does with light. Based on the spread, astronomers calculated that the signal had come from more than five billion light years away. Which meant whatever had created it must have been ginormously powerful, for the signal to make it so far through the cosmos.

That opened up a whole new can of WTFs. So far as we can tell — meaning as far as we can see with our various telescoping gadgets — there’s nothing in the region where the fast radio burst came from. No stars. No black holes. No outposts with Marvin the Martian plotting our destruction. Nada. If there’s something — or somethings — there, we’re not able to see it with our equipment. And we have no idea why it would scream at volume 11 for an instant, and then stop seemingly forever.

I mean, sure — Obi-Wan would tell you it was Alderaan. But what does he know? He doesn’t have an astrophysics degree.

The first fast radio burst was weird enough to make people skeptical. When we didn’t see another one for a few years — and when one team discovered they could make similar signals by opening a microwave door just right — astronomers wondered whether it was a technical glitch. Flying bird farts. Space voodoo. Something.

But in the past few years, ten more fast radio bursts have been detected. Now, there’s corroboration from a second radio telescope — and the last one, in 2014, was detected live as it happened. Now, scientists calculate that if we could point radio telescopes at the entire sky, full-time, we’d see hundreds — maybe even ten thousand — of these fast radio bursts per day.

That still doesn’t tell us what causes them — but there are some pretty cool theories. Each source is calculated to be no more than a few hundred kilometers wide, so these big (and quick) things are coming from some pretty celestially small packages. Some think it might be colliding black holes, or neutron stars collapsing together. Or black holes exploding, if that can even happen. Others blame them on blitzars — though why we have to bring Santa’s reindeer into this, I don’t know. We’re trying to do real science over here.

Whatever it is making fast radio bursts, astronomers are now agreed that they exist and are doggedly looking for more. Someday, with enough evidence, no doubt they’ll finally find “the truth” behind these weird astronomical aberrations.

Or they’ll find the Death Star. And I’m pretty sure Mulder wasn’t looking for that.

Image sources: PBS (fast radio burst [artist’s rendition, apparently]), QuickMeme (truthy Fox), Simpsons Wiki (Nelson and papa, haw haw!), Giant Bomb (Alderaan, we hardly knew ye)

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· Categories: Physics
What I’ve Learned:

Love wave: It's DEFINITELY not the motion of the ocean.
“Love wave: It’s DEFINITELY not the motion of the ocean.”

When you see the term “Love wave”, you might think it’s any number of pleasant things. Some kind of humanitarian pay-it-forward deal. A page for really flexible people from the Kama Sutra. How hippies say hello.

Hey, I said “pleasant”. I never said “freshly showered”.

As it happens, a Love wave is none of these things. A bunch of physicists got to the phrase first, so now it means something much more serious — and not nearly so pleasant. Or in any way love-ly.

The Love wave is actually named for Augustus Edward Hough Love.

(And with a name like that, it seems unlikely he was familiar with either the Kama Sutra or hippiedom. I bet he never even went to Burning Man.)

Love was a British mathematician who in 1911 made a prediction about waves traveling along a surface. Not all surface waves, though — just one specific type, on a very particular sort of surface. You wouldn’t see these waves where the usual surface waves show up — on ponds, or in glasses of water when T. rexes are nearby, or when somebody farts on a waterbed. Those waves are boring; they just travel in a straight line away from the origin, moving the surface up and down as they pass with no razzle-dazzle at all.

But Love had another surface in mind. He imagined waves not on water, but on a surface sitting atop other layers of material. If the top layer is “low-velocity” — that is, a material the wave moves through more slowly, compared to the layer(s) below — Love predicted a different sort of wave could form. A sexy wave that wouldn’t rock the surface up and down, but instead would shake it side to side, like a Polaroid picture.

Only Polaroids weren’t invented yet when Love worked out the math for all this, so the analogy probably wouldn’t have occurred to him.

(Possibly he said his waves “shake like a quick-drying daguerreotype”, but that’s way harder to work into song lyrics, so what’s even the point, really?)

If you live on a pond — or, say, Waterworld — then Love waves probably aren’t of much interest. But if you’re a landlubber, then you’re living on a low-velocity layer atop a bunch of other layers. Most of us call that “earth”, and when it shakes around a lot, we call that an “earthquake”. And Love waves are one of four major types of wave that spread out from earthquake events, just as A.E.H. Love predicted.

In fact, Love waves can be the most damaging type of seismic wave produced by earthquakes. Two of the types — P-waves and S-waves — are “body waves”, which travel quickly through the solid body of the earth and may affect the surface less if they’re sufficiently deep. The “boring” sort of surface wave — called Rayleigh waves after Lord Rayleigh, pip pip, indeed, Bob’s your uncle — undulates the ground as it passes. That’s no picnic for buildings and bridges and such, but at least the movement is fairly regular, and relatively slow.

Love waves, on the other hand, are transverse surface waves, so they shear the surface in layers, side to side — and they’re a little faster than Rayleigh waves, too. In culinary terms, if Rayleigh is a “rough chop”, Love is a fine mince. And considering all the waves come at you during an earthquake, it’s no surprise the aftermath often looks like it’s been through a blender.

So there’s no reason to love Love waves, though it might be helpful to know about them. They’re the side-to-side jostling most people feel during an earthquake — and the best you can hope for at that point is that you’re sharing a bed with someone you love, and hoping that’s why “the earth just moved”.

Preferably with the Kama Sutra. But not an unwashed hippie.

Actual Science:
Michigan Tech UPSeisWhat is seismology?
PSU Department of GeosciencesSeismic waves and Earth’s interior
AllShookUp.orgTypes of earthquake waves
ABC Science (Australia)Earth hums while making ‘Love’ waves

Image sources: Earthquakes blog (Love wave schematic), Laurie Conseils (“Aw, C’mon Sutra”), Gizmodo (T. rex water), Complex (The Love Haters, shakin’ it)

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

Very Large Array: My, what a big telescoping instrument you have!
“Very Large Array: My, what a big telescoping instrument you have!”

Reasonable men and women can disagree — and lord, they often do — about what qualifies as “very large”. Reasonable astronomers, however, agree that the Karl G. Jansky Very Large Array of radiotelescopes in the plains of New Mexico is indeed “very large”.

It’s right there in the name. No debate or overcompensation or embarrassing pumping equipment necessary.

To be fair, 27 x 25 sounds pretty darned big, and the Very Large Array backs those numbers up: it’s comprised of 27 separate telescopes, each with a 25-meter diameter dish. The antennae are arranged in a Y-shaped formation, with a total collection area covering more than thirteen square miles. That’s some girthy science.

What’s more, the Very Large Array dishes sit on tracks, so they can be moved around into many different configurations. Given that the array is located in New Mexico, I assume several of those configurations spell out “BEAT ARIZONA” — but still. Moving the component parts around is pretty nifty. It’s like Puppetry of the Radio Antennae over there.

All of those dishes and formations give the Very Large Array remarkable telescoping power. The data from each dish is combined and calibrated to give the resolution of a single dish 22 miles across, and the sensitivity of a dish more than 400 feet in diameter. Some people say that “big things come in small packages”. Clearly, these people aren’t packing a Very Large Array in their arsenal. Because with these telescopes, a bunch of reasonably small packages add up to find some really big things.

How do they do that? By multiplying the radio wave signals captured by each antenna and studying the interference patterns that emerge from the combined data. This technique of interferometry relies on the Fourier transform — which sounds very French and very complicated — to accurately find and track radio sources throughout near and deep space.

And by “radio sources”, I don’t mean Bill and Marty on the KBBL morning show.

Rather, the Very Large Array has been used to study star formation at the center of our galaxy, explore galactic gas clouds, track electron beam bursts in the sun and investigate black holes, quasars, pulsars, gamma ray bursts and more. In 1989, the array was even tuned to listen to radio signals coming from the Voyager 2 space probe as it zoomed past Neptune. I wasn’t even aware NASA had imprisoned a ham radio buff on Voyager 2, but apparently so. Hey, good for them.

But being “very large” doesn’t help you do everything. Even though the Very Large Array featured prominently in the movie Contact, it’s not actually used on a regular basis in the search for extraterrestrial intelligence (SETI).

(That’s okay, though. I’m starting to suspect Jodie Foster isn’t a real astronomer, either. We know she’s not a poet, obviously. But past that, I have my doubts.)

Limitations aside, the Very Large Array’s radio-based interferometry has uncovered a number of fascinating scientific discoveries since coming online in 1980, from the presence of water ice on Mercury to the first detection of radio waves accompanying a gamma ray burst to the discovery of the first “Einstein ring” gravitational lens. A complete overhaul and digital upgrade in 2012 — when it also added the Jansky name to the official title — prompted the National Radio Astronomy Observatory (NRAO) overseers to declare the system significantly improved, and dub it the Expanded Very Large Array.

Me, I would have gone with “MAGNUM“. But what do I know? My array isn’t nearly as large, and can’t even pick up local FM stations.

I’m blaming shrinkage.

Image sources: Big History Project (Very Large Array), Portigal (“Giiiiiirthy!”), QuotesGram (Jodie, not a poet), The Ruddy Duck (shrinkage!)

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