In honor of Black Hole Week, we're diving into the world of the bizarre to give you a quick rundown and answer some of your biggest black hole questions! ⚫ But brace yourself, because things are going to get pretty weird...

How to Make a Stellar-Mass Black Hole

There are a few different kinds of black holes, but we're going to talk about the medium-range ones. You probably know that a black hole is an object that has such strong gravity that nothing (including light) can escape once its been pulled in, but did you know many of them were once run-of-the-mill massive stars? Stars spend the majority of their lives fusing hydrogen into helium in what is basically a giant controlled explosion. In addition to heat and light, the fusion creates a lot of outward pressure, but it's balanced by the star's gravity which holds it together — at least for a while.

When a star begins to run out of fuel, everything is thrown out of balance. It's not producing as much energy, so the outward pressure decreases. Now gravity has the upper hand, so it pulls the star in even tighter. If the star is really massive, it doesn't have a way to stop the collapse. There's a bright supernova explosion, and a black hole is born.

Credit: NASA's Goddard Space Flight Center/J. Schnittman, J. Krolik (JHU) and S. Noble (RIT)

Will Our Sun Become a Black Hole?

Don't worry — our Sun will not turn into a black hole! It isn't nearly massive enough. The Sun has another 4 or 5 billion years of fuel left, and then it will eject its outer layers to form a planetary nebula, like these ones:  

Credits: X-ray: NASA/CXC/RIT/J.Kastner et al.; Optical: NASA/STScI

It's a relatively gentle process, but we'll still want to have a secondary stellar home by then since the Sun will have expanded so much that it will either scorch Earth or completely devour it before settling down as a white dwarf star. Like I said though, we've got 4-5 billion years to figure out interstellar travel so we can get out of the danger zone.

Are Black Holes Dangerous?

Yes and no — they're deadly if you wander too close. We don't really have the travel capabilities to get near one right now anyway though, so you have nothing to worry about!

But say you did get close to one...what would happen? You'd experience a pretty exotic form of tides! You know how tides work on Earth, right? The side of Earth that's closer to the Moon gets pulled on a little stronger than the side that's farther away. Since stellar-mass black holes are so massive, the tidal effect would be much stronger!

The result? Spaghettification.

Say you went sailing feet-first toward a black hole. If you got close enough, you'd pass a "point of no return" called the event horizon — no matter how hard you hard you tried or what tech you used, you wouldn't be able to escape. Resign yourself to a one-way journey, and prepare to become spaghetti!

Your body would be stretched like taffy since your feet would be pulled stronger than your head. This really is called "spaghettification," and it's a very appropriate term! But the stretching wouldn't stop when you were as thin as would continue until you were just a stream of atoms.

Conclusion: Steer clear of black holes!

What Happens When Black Holes Collide?

Black holes do collide sometimes, in the case of supermassive black holes — the kind that are believed to reside in the centers of pretty much every galaxy in the universe (including ours!). A NASA simulation shows what it might looks like:

Credit: NASA’s Goddard Space Flight Center

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