**February 4**: Professor Spencer Dowdall

**Title**: Horror of horoballs! The Möbiusville rational riddle.

**Abstract**: Möbiusville has a horoball dilemma! A mysterious chain reaction is causing subterranean noxious gas to bubble to the surface through every rational point! The only hope is to launch a neutralizer directly into the poisoned earth. But with billowing biohazardous bubbles everywhere, how can this palliative payload reach the surface without bursting a bubble and releasing the deadly gas? Can Möbiusville’s much-maligned mayor muster of a mathematical miracle? To find out we’ll embark on a hyperbolic journey that bends lines into circles and reveals the secret of continued fractions.

**February 11**: Hayden Jananthan

**Title**: This Title is False (Part II)

**Abstract**: In 1931 Kurt Gödel proved his Incompleteness Theorems, which put strong bounds on the expressiveness of arithmetic and mathematics more generally. In 1936, Tarski used Gödel’s methods to prove another stark limitation on the expressiveness of mathematics, and language more generally. Merriam-Webster’s Dictionary defines “Truth” as, “A judgement, proposition, or idea that is true or accepted as true.” But… does this actually *define* truth in a way that explains what it is in a non-circular fashion? We will see that any sufficiently expressive language cannot, in a particular sense, define truth.

**February 18**: Professor Jose Gil-ferez

**Title**: Rainbows

**Abstract**: Rainbows are these colorful arrangements of light that appear in the sky, sometimes, after the rain; marvelous phenomena that make everyone’s heart happier. Remarkable as they are, every culture has stories and myths about them, and even today they are very present in our lives as symbols of beauty, peace, covenants with the gods, human rights, technology, … We will take a closer look, from a mathematical perspective, to these gorgeous shows that Nature puts out there only for your eyes.