singularity

How Supermassive Black Holes Work

/ Emma / Leave a comment

We first took a peek at supermassive black holes back in our discussion of galaxies. But now that we’ve covered a few types of active galaxies, it’s time to take a deeper dive.

Okay, I guess we won’t really be diving into a black hole…sorry to disappoint!

(Honestly, though, you really wouldn’t want to. It would be very uncomfortable, to say the least…and, of course, it’s a one-way trip.)

Supermassive holes are thought to lie at the hearts of most galaxies, including our own. They seem to be key to galactic structure. Most of them–including our own–are quiet. But a few percent of the galaxies in the universe emit titanic amounts of energy from their nuclei, and supermassive black holes are the ultimate culprit.

But how?

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A Peek at Supermassive Black Holes

/ Emma / 11 Comments

There are few things in the universe quite as exciting as black holes.

They’re in all the movies–I even wrote a post a few years ago on what the movies get wrong about them! Though some movies, like Interstellar, do a pretty good job of capturing the relativistic effects.

There are also plenty of popular misconceptions floating about–probably thanks to those fictional portrayals!

Most of the time, when we geek out over black holes, we’re talking about stellar-mass black holes. That is, the remains of massive stars.

Wait a second…most of the time? What other kind of black hole could we be talking about?

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How to Find a Black Hole

/ Emma / 5 Comments

Okay, good question. How the heck do you find an object that emits no radiation? Astronomers find—and study—just about everything in the universe using the radiation it emits or reflects. So…what happens when the object we’re looking for has such a strong gravitational pull that even light can’t escape?

Well, that’s when we need to turn to the theoretical science behind black holes. What measurable effects do they have on objects in their vicinity? Can we detect them indirectly?

Of course, some of you might be screaming at me that we’ve already photographed a black hole—in visual wavelengths! Yes, astronomers did make that achievement—we now have visual proof that what we’ve been theorizing all along is indeed real.

But that black hole was so faint, it took an interferometer the size of the Earth to image. We had to know exactly where to look in order to get that picture.

So how the heck do we find one in the first place?

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Black Holes: What the Movies Get Wrong

/ Emma / 13 Comments

Any of you recognize this?

To those who don’t, it probably looks like a pretty unimpressive, blurry ring. In fact, this is the first ever image of a black hole, taken with an interferometer the size of the Earth.

If you’re a science geek, you’ve no doubt seen tons of artists’ conceptions of black holes on the internet. Most use a great deal of artistic license. Some of my favorite “images” of black holes used to be the ones that look like ripples in the fabric of space. Imagine my disappointment when I realized that’s not the case at all.

Black holes are singularities—infinitely dense places of zero radius with at least 3 M☉ (solar masses) of star stuff—surrounded by an event horizon, inside of which gravity is so strong that even light cannot escape. That’s why it’s called a black hole.

But they are not “holes” in the usual sense. They are not giant space potholes that you can easily stumble into, and you certainly don’t fall into them the same way you would a pothole.

So…what are black holes really like?

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What is a Black Hole, Really?

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If you’re a sci-fi fan, you’ve probably seen these in movies. And I’m guessing you’ve heard a lot about them in pop culture. The problem is, pop culture and movies don’t do a very good job of describing black holes.

First off, let me clear up a common misconception: Black holes do not act like giant space vacuum cleaners, sucking in everything around them. Describing them as “gobbling up” anything is inaccurate.

The representation in movies that bugs me the most is in J.J. Abrams’ Star Trek reboot, when the bad guy falls into a black hole and the good guys almost get pulled in with him. First of all, please…black holes do not growl. And basically none of what happens in that scene is accurate.

So…what are black holes, really?

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