If you want to get a good scare for Halloween but you’re not interested in anything gory, maybe math is right for you. A lot of people seem to find it scary, and for good reason. Over the past few years, I've written about some pretty spooky topics. Enjoy...if you dare!

Zombies! Actual zombies are too gross for me, but I can handle a mathematical model of zombies as a pop culture phenomenon. Don’t expect people to stop making zombie movies any time soon.

Angels! Devils! Cantor’s function, also known as the devil’s staircase, sneaks up on you like a weeping angel. Don’t blink.

Mummies! Or at least how to do math the way they did. I mean, before they became mummies.

Measles! This disease is scary, and so is its basic reproduction number.

Misuse of statistics in criminal cases! No explanation necessary.

Obsolete trig functions! The stuff of nightmares. Specifically the nightmares where you show up to class naked and have to take a test on material you never learned.

Big numbers! A post about Graham’s number, which is so big that attempts to explain how big it is fail.

Epsilon-delta proofs! Based on my experiences teaching calculus, epsilon-delta proofs are plenty scary to many people.

Higher homotopy groups! Because it’s just not right for a two-dimensional sphere to have a three-dimensional hole.

A cost function that doesn’t obey the triangle inequality! You and your friend buy your British Rail tickets at the same time and ride the train together, but one of you pays more. 

Assigning “sums” to non-convergent series! You're moving into a land where the positive integers add up to a negative number. You've just crossed over into the Twilight Zone.

If you're looking for a scary mathematical flick, Anna Haensch recommends Cube, "quite eaasily the best low-budget Canadian horror movie to come out of the last millennium." Personally, I don't think Halloween would be complete without a viewing of Vi Hart’s Scary Sierpinski Skull Time. “Forget skull fractures, you’re about to get a skull fractal!”

Has math scared you lately?

Help us do science! I’ve teamed up with researcher Paige Brown Jarreau to create a survey of Roots of Unity readers. By participating, you’ll be helping me improve Roots of Unity and contributing to research on blog readership. You will also get FREE science art from Paige's Photography for participating, as well as a chance to win a $50 Amazon gift card or other perks! It should only take 10-15 minutes to complete. You can find the survey here: http://bit.ly/mysciblogreaders. The survey end date has been extended to November 20, 2015.