It's Halloween and time to scare yourself silly, so why not do so with a little bit of science. Users of Reddit have been discussing what the "scariest thing that science has proven real" is. Here are some of the best, and as ever we will jump in if something needs explaining or elaborating.
This is entirely true. Called teratomas, they typically form in the ovaries, testicles, and tailbone, though they can be found all around the body. They aren't limited to skin, hair, and teeth – in one 16-year-old girl, surgeons found "a skull-like, bony shell" in a particularly developed teratoma.
Some found in others have contained bone and elements of a nervous system. Though they may cause discomfort (as you'd imagine), typically mature teratomas like this one aren't all that dangerous, and can be removed via surgery with minimal complications for the patient.
Yep, gamma ray bursts could theoretically destroy Earth if one was emitted from a near enough source. Though incredibly unlikely, one binary star system just 5,000-8,000 light-years away – WR 104 – contains a giant star on the brink of boom time. Should it explode as a gamma ray burst, and we're unlucky enough for the rays to head in our direction, it could cause a mass extinction event. As well as the possibility it could deplete the ozone layer by about 25 percent, it could break apart nitrogen molecules in our atmosphere and reform as nitrogen dioxide, red-brown smog that could block out sunlight and cool the planet.
So, is it pointed at us? Well, maybe. It certainly seems to be facing us based on the spiral it is creating, but estimates put it at being tilted anything from between 16 and 0 degrees from our perspective, a range between "ooh look an interesting gamma ray to study" and "what's that weird red smog that's blocking out the Sun".
With space already full of terrifying objects, and the fact that we still don't know how the star will explode, nor when, astronomers aren't majorly concerned, though a few are a bit wary.
"I used to appreciate this spiral just for its beautiful form," Peter Tuthill, an astronomer at the University of Sydney told Space.com, "but now I can't help a twinge of feeling that it is uncannily like looking down a rifle barrel".
Yep, it doesn't get much more terrifying than amoebas eating your brain. Except, of course, for prions.
Prions are indeed scary. Take for example this unfortunate researcher who worked in a lab in France. She accidentally cut her finger while handling mouse brains during lab work. Seven years later she began to feel burning pains in her neck and shoulder. She then developed depression, anxiety, and experienced hallucinations, before dying 19 months after her symptoms began.
The cause of death was variant Creutzfeldt-Jakob disease, a rare disease where prions begin to fold in your brain, before changing the shape of neighboring proteins, turning them into misfolded prions and so on, spreading around the brain.
That isn't even the worst disease caused by prions, with that title going to fatal familial insomnia. Check out more about that one here, but probably not before bed.
This one is grim, but abuse during childhood has been linked to structural changes in the brain.
Yep, according to one study hearing is the last sense to go, though this could also be seen as reassuring as well as terrifying.
And finally, the spoopiest fact of all.
Even worse: your bones are wet. Sleep soundly.