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: 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: 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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