Hank Green: So there's science, and then there's science fiction, and then there's just outright hoaxes, and with December 21st 2012 coming up, it seems like we're just gonna have to tell you outright, right now, what is not going to happen. [intro music] December 21st, 2012. As you may have heard, from some people's perspective it's pretty much D-Day for Earth. You're probably familiar with the Mayan apocalypse scenario, which I covered in a different episode of this show (you can go watch it right now -- it's quite interesting) which basically is saying, "The world is going to end because the Mayan long calendar is reaching this somewhat roundish number." That's basically all that's happening. It happens every 400 years or so, and every time it's happened before, nothing impressive has happened. That was your end-of-the-world hoax primer. Now we can truly let the debunking begin. 1. Myth: Nibiru, the rogue planet that was discovered by the Sumerians (let's not get into how they discovered it while we can't see it). It's nearing the end of its 3,600 year orbit, and it's going to come round and smash into the Earth -- when? Oh, December 2012, of course. Of course, NASA knows about this, but they're covering it up. Everyone with a telescope of any size can see this planet by now, but they're covering it up, the massive planet, and it's coming to get us in a year's time. But, you know, you might as well keep it to yourself. There's no reason to induce mass hysteria; we're all just gonna die anyway. Fact: Sumerians? Great at a lot of things, like creating agriculture, civilization as we know it, writing down things... that was super awesome. Not particularly great at astronomy. For example, they were not aware of the concept of planets orbiting stars, right, and also, there is no planet Nibiru. If you go to any of the websites that are advocating this disaster scenario, they all look like they were designed in 1996. The date of Nibiru's arrival keeps changing -- it was supposed to get here originally in 2003, they're just not very good at math. 2. Myth: We're just gonna combine two here -- one, the Earth is headed for the equator of the galaxy, and also the sun is going to be pointing directly at the center of the galaxy, and this is going to create a gravitational vortex and everything will wobble out of sync and will flip over and shoot off the side and drop down and the whole... pancake the Earth. We'll all be dead. Fact: I don't even know where to begin with this one. So, the galactic equator... I think what they probably mean is the galactic plane, which is like midway through the thickness of the galaxy. That doesn't have any, you know, special significance except that it's, you know, kind of a cool idea for it to have. Also, we're, like, dozens of light years away from being aligned with the galactic plane, and we're currently hurtling away from it as part of our 64 million year cycle of wobbling around within the galactic plane. As far as the sun lining up with the center of the galaxy, I mean, that's sort of a cool idea to think, "Ah, the sun is lining up with the center of the galaxy..." Doesn't mean anything. 3. This episode is giving me David Tennant hair. Final myth: On December 21st, 2012, the Earth's magnetic sphere is going to turn inside out and it's going to tear our planet apart, or possibly we'll just be killed by lethal doses of radiation. Fact: Actually, this happens sometimes, so you're allowed to freak out a little bit. It's really interesting, actually, that the Earth's magnetic sphere occasionally turns inside out. And that doesn't mean that south becomes north and north becomes south. Actually, I'll put a graphic of that up -- it's weird. It goes from, like, being a normal looking magnetic sphere to being, like, what the frick is that? The last of these reversals was about 780,000 years ago. The time between the reversals varies wildly, and it's estimated to take between 1,000 and 10,000 years for the reversal to actually take place. But yeah. This happens, and if it had happened during, like, the age of exploration, people's compass needles started pointing the wrong way, that would have been really weird, but it didn't. If it does start to happen, though -- if our magnetic field starts to weaken and flip -- that could have some potential consequences for our lifestyles. We'd probably have to use more sunscreen. But there's nothing in the fossil record that indicates that these hundreds of flips that our magnetic field has gone through over the course of history has resulted in anything like the kinds of mass extinctions that we see for, like, for the dinosaurs, for example. I'm getting my blood pressure all worked up over this, but let's just give a shout-out to David Morrison, who has the thankless job of responding to these weirdos at NASA. He's just such an earnest and patient guy, and he's constantly responding to the questions of freaked-out teenagers and adults alike, and I'm just gonna give him the final word for this video.

David Morrison: There is NO threat to Earth in 2012. There is no danger. All of the talk about a doomsday is a big hoax perpetuated on the Internet and with people trying to make money, so please don't worry about it.

Hank Green: I hope you're less freaked out now. In the comments, please go ahead and respond to crazy people who are telling me why I'm stupid. I really appreciate your help in dealing with those people, 'cause I can't respond to them all, but you can respond to us on Facebook and Twitter, give us suggestions for what we should talk about in the future, and ask us any questions that you have, and we'll do our best to answer. Thank you for watching SciShow. [outro music]