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 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)

· 1 comment
· Tags: , , , , , , ,

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

Hypervelocity stars: what happens in the galaxy doesn't always stay there.
“Hypervelocity stars: what happens in the galaxy doesn’t always stay there.”

Many things move at a proverbial “million miles an hour”. Vacation days. Your heart, when a hot-bodied stranger in a swimsuit walks by. And your gossipy friends’ mouths, telling everyone how you drool over hot-bodied swimsuited strangers on your vacation.

You knew you should have never invited them to Cancun. Live and learn, gringo caliente. Live and learn.

Some things that don’t literally move that fast are stars. Sure, stars are usually clustered into galaxies, and galaxies zoom around the void at a million miles an hour or more — depending on which other bits of celestial fluff you measure them against. But the stars are just along for the ride; relative to their host galaxies, they don’t reach those insane kinds of speeds.

Except when they do.

The universe is full of exceptions — even Keanu Reeves made that one good movie once — and turbocharged stars are interesting examples. Known as hypervelocity stars, they whip around at speeds up to two million miles per hour, relative to galactic speed.

That’s like gunning a Ferrari down the highway and being overtaken by a cruise missile. Even your motormouth vacation friends can’t keep up that pace.

Hypervelocity stars are fairly new to astrophysics — predicted in 1988, and first observed in 2005. There are only a handful known to exist, mostly because confirming their speed requires measurements over a period of decades. We can’t exactly set up a speed trap and flash these things with a radar gun as they zoom past.

The really interesting thing about hypervelocity stars is that they move so fast, they can reach the escape velocity of their galaxies. Meaning, instead of swirling around in a galactic spiral forever like our boring old sun, these stars break completely free of galactic gravity and ping off into interstellar space, never to be heard from again.

(Maybe somebody could have pitched that to Keanu Reeves after the first Matrix. I’m just saying.)

What we don’t know for sure is how these stars get all hypervelocitized in the first place. But two theories explain the current observations pretty well.

It’s thought that some hypervelocity stars are formed near our galactic center, where a supermassive black hole looms. Computer models say if a binary system — two stars closely orbiting each other — got caught in the black hole’s clutches, one could be sucked in while the other is flung outward at ridiculous speed. Like a marble fired from a slingshot shot out of a cannon mounted on a jet plane. Times a lot.

The other, equally violent, theory also involves binary systems. Only in this scenario, the partner star isn’t stuffed into a black hole; instead, it goes supernova — exploding so catastrophically that it accelerates the surviving star to supergalactic speeds.

Either way, the presence of a hypervelocity star means that things went terribly, terribly wrong for that star’s old flame. So basically, if your sweetie ever tells you he or she wants to become a hypervelocity star some day, you should pack your bags and leave. Like, yesterday.

You can always take a rebound trip to Cancun. Your friends may gossip, but at least none of those swimsuited hotties are going to explode you or unceremoniously stuff you down a black hole. That kind of shit only happens in Las Vegas.

And apparently, all around the Milky Way. Stellar breakups are a bitch, yo.

Image sources: Tech Guru Daily (hypervelocity star), El Horizonte (beach bods), Oh No They Didn’t! (fast Keanu), Universe Today (binary breakup)

· Write a comment
· Tags: , , , , , , , , ,