Note (12/2015): Hi there! I'm taking some time off here to focus on other projects for a bit. If you dig science (real, actual science), you might like my stuff (and others') on the Meta blog. If you're looking for silliness, I'll continue to update Where the Hell Was I? semi-regularly, and we're 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: Biology, Genetics
What I’ve Learned:

Homeobox: when it comes to transcriptional regulation, it's not clowning around.
Homeobox: when it comes to transcriptional regulation, it’s not clowning around.

A lot of my confusion about science isn’t really my fault. For instance, when I was in college, In Living Color was on Sunday nights, and a must-watch every week.

So when I stumbled into genetics class at ass-early Monday morning, I still had Homey D. Clown on the brain. Can I be blamed for thinking “Homey O’Box” was Clown’s Irish cousin? It’s a mistake anyone could make, if they were a fan of sketch comedy. And it was before nine AM. And they weren’t very bright.

Eventually I learned that a homeobox isn’t a clown, but a conserved DNA sequence. With very little variation, you can find the 180-base pair stretch in the genomes of most every eukaryotic species, from single-celled fungi to duck-billed platypi all the way up to humans. Including clowns.

When a homeobox gene is expressed, the 180-base stretch translates into a 60-amino acid structure in the resulting protein. Those amino acids form a three-helix structure, which is just the right shape to hook onto the double-helix structure of DNA. So the proteins containing this structure, called homeodomain proteins, are able to bind directly to DNA, which comes in very handy.

That’s because binding to DNA near a gene is a good start to controlling whether or not that gene gets translated into proteins. Some homeodomain proteins, like those in the Hox family, are “master regulators” of transcription, turning genes on and off like an old-timey switchboard operator. This regulation can be triggered in all sorts of ways, but it’s especially important during early development.

As an example, consider the fruit fly — where the homeobox sequence was first identified, back in the 1980s. Scientists found a bunch of Hox-family homeobox genes in flies, and discovered that when one or more of them were mutated, the flies grew in wild and freaky ways. Scramble one gene, and the flies made four wings instead of two. Hork up another, and they grow mouths on the outside of their face, rather than the inside. And a famous Hox mutation makes flies grow legs on their heads, where the antennae should be.

This may be similar to a mutation I assume Abe Vigoda has, which caused him to grow woolly caterpillars where his eyebrows should have been.

Homeobox genes appear to have been with us for a very long time — since before there was an “us”, in fact. They’re found in organisms as simple as yeast and sea anemones, suggesting that the homeobox sequence first evolved in some ancestor common to all the species where it’s seen today; that ancestor would be around 600 million years old, or way before humans made the party. Or clowns. Hell, even Abe Vigoda might not have been born yet.

There’s also a chance we swiped our homeobox tricks from some ancient pre-dinosaur Cryogenian-era virus. No modern bacteria or simpler species have homeobox genes themselves, but one bacterial virus called lambda phage does have DNA-binding proteins that look an awful lot like homeobox genes. So maybe some prehistoric proto-sponge yoinked this precious and valuable sequence that every animal, plant and fungus relies on today.

Now that sounds like a heist worthy of Homey O’Box. Maybe Homey do play that, after all.

Image sources: StudyBlue, Genius.com (Homey, not playing that), People in White Coats (antenna-people-pedia), Roscoe Reports (Abe’s bushy brows)

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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: Biology
What I’ve Learned:

Nude mouse: Taking it ALL off for science.
“Nude mouse: Taking it ALL off for science.”

This being the internet, you might think “nude mouse” is the title of a Mickey and Minnie fan erotica script.

And probably it is. Rule 34, after all.

But for biologists — regardless of any disturbing Disney peccadilloes they might harbor — a nude mouse is something else, and something tremendously useful for research. Nude mice have genetic mutations in the FOXN1 gene, an important transcription factor highly conserved among mice, rats and humans, among others.

Knocking out FOXN1 function has two main effects. First, it prevents the proper growth of hair and nails. That’s the “nude” part of “nude mouse”, as FOXN1-deficient mice are a bunch of hairless, wrinkly pink monstrosities. It’s like watching a four-legged horde of that old guy from the Six Flags commercials a while back. Only with less dancing, probably.

That’s because the other effect of disrupting FOXN1 is an underdeveloped or absent thymus. The thymus is the organ where T cells develop, so missing a thymus leaves a nude mouse severely immunodeficient. They’re susceptible to virus infections and tumors, can’t mount cell-mediated immune responses and are unable to reject transplanted tissues.

That’s no picnic, if you’re a nude mouse. But if you’re a researcher studying infections diseases, cancer, immunodeficiency or treatment of human cells in an animal model, then it’s pretty sweet. Nude mice have been used extensively in studies using xenografts, or tissue from one species implanted into another. Human tumor cells, for instance, might be xenotransplanted into a nude mouse, which is then treated with an anti-cancer compound to see how well it works in a live animal.

Which is to say, a live nude animal. Sexay.

The first naturally-occurring nude mouse was discovered in the 1960s. I assume it was easy to spot back then, as it would have been the only lab mouse without an afro. Because there are many possible mutations that can disrupt FOXN1, several distinct strains of nude mouse have been described.

(Described as “wrinkly little E.T.-looking freaks”, I imagine. But still.)

Most nude mouse strains are “leaky”, which is significantly less icky than it sounds. Here, it just means that the mice retain some thymic function, and often low levels of T cells. Because we humans think we always know the best way to do everything, we’ve now developed knockout mice, where genes important for T cell development are completely scrambled, and there’s no pesky leaking.

So the nude mouse isn’t used as often these days in lab research, but these bald mutant rodents have helped make breakthroughs in immunology, oncology, parasitology, pharmaceutical research and more.

But NOT Disney-inspired fan erotica. Get those minds out of the gutter, people.

Image sources: Scanbur Research (nude mouse), Left Wing Libertarian (Mickey and Minnie, bow-chicka-mouse-mouse), Reddit (Six Flags guy gang), Pinterest (He’s a bad mutha mouse… Shaft!)

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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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