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:

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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· Categories: Physics
What I’ve Learned:

Even when they're plush, neutrinos are badass.
“Neutrinos: never seen, never heard and there’s one behind you RIGHT NOW!”

Scary question: what do neutrinos, ninjas and Bigfoot have in common?

Even scarier answer: Almost everything.

For starters, neutrinos are shrouded in mystery. They were first predicted decades ago, but there’s a lot we still don’t know about them. What’s a neutrino’s mass? How fast do they move? How many types are there? Boxers or briefs? Do they like gladiator movies?

We know none of these things about neutrinos. Just like ninjas and Bigfoot.

Neutrinos are mysterious because they’re extremely hard to detect. They pass right through air, liquid, solids — even the earth itself. Neutrinos make no sound, give no advance warning and make only the slightest disturbance as they pass.

Sound like any feudal Japanese assassins or Sasquatches you know?

Paradoxically, though, neutrinos are basically everywhere. They’re created by processes including nuclear fusion, like in stars or supernovae or a really intense Dave Matthews Band gig. If you put your hand up to the sun, one trillion neutrinos will pass through it every second.

(Of course, if you put your hand anywhere else, they’ll still pass through it. You can put your hand under your butt in the dead of night, if you want; it won’t make a bit of difference.

Neutrinos don’t care. They do what they want.

Like ninjas. Like Bigfoot.)

This abundance does make neutrinos unique, though. If a trillion ninjas were nearby, you’d already be too dead to read this. And a trillion Bigfeet would stack ten thousand deep in the Montana woods, and someone would eventually notice the pile. Or the smell. Plus, there’d be a lot more idiotic beef jerky commercials on TV. Pretty hard to miss.

Neutrinos are hard to detect because they rarely interact. With no electrical charge, tiny mass and near-light speed, neutrinos are a pain in the ass to catch up to. Researchers only find them when one in a hugetillion pings off a molecule in an underground pool of laboratory water, or a detector array built into an Antarctic ice sheet. Short of running smack into the heart of an atomic nucleus, a neutrino could go undetected forever.

Like ninjas’ and Bigfeet’s long lost subatomic brother.

Of course, anything mysterious and spooky needs a nemesis. For ninjas, it’s pirates. Obviously. For Bigfoot, a zoom-lens Nikon. And for neutrinos, it’s the antineutrino — which some theories say is also a neutrino.

So, a particle that rarely interacts, can barely be seen and is also its own opposite. Maybe neutrinos are actually more like Batman. Or the Unabomber. The Batabomber? Possibly not.

Anyway, for such an antisocial particle, neutrinos get invited to an awful lot of physics parties. Scientists use the kind from supernovae as cosmic warning signals. Astronomers want to use them to “see” stars on the other side of light-blocking cosmic dust and gas. Neutrino property measurements could provide evidence for or against competing particle physics models. Neutrinos from the Big Bang could be some (or all) of the “dark matter” cosmologists have been trying to find. They can be used to monitor nuclear reactors. It’s possible (but not so likely — but still possible!) that neutrinos travel faster than the speed of light.

Yeah. They’re kind of a big deal.

In conclusion, neutrinos. A lot like ninjas, and also Bigfoot. And possibly Ted Kaczynski in a Batman mask. Only better.

Image sources: Ars Technica (neutrino event), Particle Zoo (ninja neutrino plushies), AdWeek (Bigfoot posse), Chris Is Why I’m Skinny and Gentleman Sparks (Batabomber)

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