# ESP Biography

## JOSHUA HOROWITZ, thinker, dreamer, occasional eater

Major: Physics, Mathematics

College/Employer: Stanford

## Brief Biographical Sketch:

I can wholeheartedly endorse the following: pasta, books (in general), inquiring into the nature of the world around you (in general), dance parties, statistical physics, DIY music scenes, getting a good night's sleep.

## Past Classes

(Look at the class archive for more.)

Linkages: The Steampunkest Math Class at Spark in Spark! 2011 (Mar. 12, 2011)
Take a bunch of pieces of metal, and attach them together with hinges. What do you get? * Some of the greatest engineering challenges of the 19th century. * Beautiful geometry that helps you build mechanical computers. * A nifty introduction to the concepts behind topology. And, of course, The Steampunkest Math Class at Spark.

Processing: Making Programs That Make Art [l33t version] in Spark! 2011 (Mar. 12, 2011)
"Processing" is a Java-based programming environment designed to help artists express themselves with computer programs. If that sounds exciting to you, stop by and give it a try! I'll show you what Processing can do and give you some ideas to get you started exploring your own projects. Procedural generation, interactivity, physics simulations, video processing, sound, and many more possibilities are all on the table. (And if you think "computer programs as art" sounds crazy, visit http://complexification.net/gallery/, whose artist uses mostly Processing!)

Processing: Making Programs That Make Art [n00b version] in Spark! 2011 (Mar. 12, 2011)
"Processing" is a programming environment designed to help artists express themselves with computer programs. If that sounds exciting to you, stop by and give it a try! Even if you've never programmed before, I'll show you the basics and you'll leave with a better idea of how all this stuff works. (And if you think "computer programs as art" sounds crazy, visit http://complexification.net/gallery/, whose artist uses mostly Processing!)

Computational Photography: A Survey in Spark! 2011 (Mar. 12, 2011)
Ever heard of HDR (High Dynamic Range) photography? It's just one example of the exciting work being done in the field of computational photography. "Computational photography" is all about extending the power of normal cameras using sophisticated algorithms and a lot of clever ideas. While we don't have the time to go into details about the algorithms, I'd like to show you what sort of things are possible using a camera plus a computer. I expect you will be surprised!

Critical Phenomena & Phase Transitions in Spark! 2011 (Mar. 12, 2011)
If you take a water molecule and cool it down, not much will happen. You can make a nice smooth graph of energy vs. temperature, but that's just about it. Put a bunch of water molecules together, though, and you get a completely different story. At some specific temperature, the way in which the water organizes itself suddenly changes, and we have solid ice instead of liquid water. How can interesting behavior come out of uninteresting pieces? How can a discontinuous jump come out of continuous physical laws? The freezing of ice is a critical phenomenon. Other systems which exhibit critical phenomena include magnets, superconductors, liquid crystal displays, and the universe itself (especially in its early days). Weirdly enough, it seems that problems we give computers to solve may also exhibit "phase transitions". Phase transitions are usually reserved for upper-level physics courses. I hope to give you a small taste of them, because I think they're the coolest things ever.

Urban Exploration in Splash! 2009 (Nov. 21 - 22, 2009)
High places, low places, hidden places, and secret places -- urban explorers seek out the nooks and crannies of the built environment which most people don't even know exist. Among their ranks are adventurers, photographers, spelunkers, historians, and amateur archaeologists. What unites these characters is their sense of wonder at the world around them, and their desire to push the typical boundaries to discover what lies under their feet, or though that door. Come learn about what makes "urbex" special. Fantastic images and stories will be presented, along with the more serious side: Where did urban exploration come from? What sorts of exploration exist? Why in the world do people do it? And the age-old philosophical question: What does it all mean?

Ukuleles? Ukuleles! in Splash! 2009 (Nov. 21 - 22, 2009)
Holy cow, have you ever played a ukulele? Come play a ukulele RIGHT NOW.

Teach anything! - How to fake a presentation in Splash! 2009 (Nov. 21 - 22, 2009)
Consider: It's a nice day out, and you're dozing off in the back of your class. Suddenly you get jolted awake by the kid sitting next to you, and you wake up to find everyone in the class and the teacher staring at you, waiting for you to give a surprise presentation. About import regulations on Afghani rugs. And you're in physics class! Clearly, you don't stand a chance. Or do you? Well, just because you don't know anything, doesn't mean you can't be prepared. In this class, we will teach you how to explain and present topics without concern for such trifling matters as prior knowledge or preparation. By the end of this class, you'll be happily presenting your Nobel Prize-winning chemistry research alongside the story of your grueling climb up Mount Everest to fulfill your kung fu master's dying wishes. Learn to demonstrate expertise that you may or may not have! All skill levels welcome.

The Physics of Siege Weapons in Splash! 2008 (Nov. 22 - 23, 2008)
For centuries, nations have made war using all manner of weapons and armament. Among the most frightening and dangerous of these in medieval times were siege weapons, designed to break even the most fortified of defenses. In this class, we will look at the physical principles behind some of these weapons, aided by practical demonstrations and activities.

Complex Numbers and Trigonometry in Splash! 2008 (Nov. 22 - 23, 2008)
So you know trig functions, like $$\cos(x)$$, and you know exponential functions, like $$e^x$$. Now would you believe me if I told you that they were (almost) exactly the same thing? And that you could use this connection to prove (almost) every trig identity known to man through simple algebra? Best thing is, all of this comes out of one of the many beautiful connection between complex numbers and geometry, which have far more implications than I could possibly talk about here. But I'll explain a bit about where they come from, and leave you with, at the very least, a nifty trick to use on your exam when you've forgotten what $$\cos(x+y)$$ is supposed to be.

Teacher-Taunting Tricks: Math Edition in Spark! Spring 2008 (Mar. 08, 2008)
Learn to derive trig identities from scratch, solve calculus problems without calculus, and generally annoy the living daylights out of your math teacher. Note: I am not your math teacher.

The Physics of Siege Weapons in Spark! Spring 2008 (Mar. 08, 2008)
For centuries, nations have made war using all manner of weapons and armament. Among the most frightening and dangerous of these in medieval times were siege weapons, designed to break even the most fortified of defenses. In this class, we will look at the physical principles behind some of these weapons, aided by practical demonstrations and activities.