# ESP Biography

## CHELSEA VOSS, MIT '15, computer scientist

Major: Computer Science

College/Employer: Wave

## Brief Biographical Sketch:

I graduated from MIT in '15 and graduated with my master's degree in computer science in '16. These days, I work as a software engineer at a startup called Wave. I'm a nerd about computer science, linguistics, math, and biology.

Ask me about: linguistics puzzles, doodling fractals, writing programs that output themselves, catching and identifying insects, catching and identifying plants, why letters and numbers are colorful, why 142857 is a cool number, doing math research for fun, how to make pearl milk tea, what I've been thinking about recently, and what I've been programming recently.

## Past Classes

(Look at the class archive for more.)

Spectrograms: What Does Sound "Look" Like? in Spark 2017
What is sound? How do our ears hear the information in sound and send it to our brain to be processed into language? And how might we teach a computer to do the same thing? We'll investigate all of this by diving into phonology and phonetics, the study of the audible components of language. We'll explore what sound is, and look at some ways it can be visualized. We'll talk about all of the different sounds that human languages can use, in English and beyond. Finally, we'll look at patterns in sounds by converting them into pictures called spectrograms. With this tool at our disposal, we can investigate how both computer systems and human brains might tackle the problem of speech recognition. Come learn what you never knew you never knew about sounds!

Insect Identification! in Splash 2016
Is that an orchid, or a mantis? What's the difference between a bug and a beetle? Why does EVERYTHING seem to want to pretend to be an ant? Why do bees cooperate with each other like that? Come learn about insects, the fascinating animals with more than a million species on Earth and a majority of ALL the species we know about! This class will present a whirlwind tour of insects of all sorts. You'll learn how each group is related and how to recognize each group's unique features, as well as some random cool examples of camouflage, symbiosis, and parasitism among insects. As we go, you'll apply your newly-learned identification skills to identify insects yourself!

Linguistics Problem Solving in Splash 2016
Do you enjoy unraveling logic puzzles, want to learn about other languages, or crave the feeling of a good riddle? Come solve fun problems from the Linguistics Olympiads, NACLO and IOL! A variety of languages, problem styles, and difficulty levels will be provided for you to solve. Logic and reasoning are your main weapon here – no prior linguistics knowledge required!

Unsolvable Problems in Splash 2016
What can philosophers learn from computer scientists? Even though computer science is an applied discipline, its theoretical foundations are rich and fascinating. For example, many problems are *impossible* to solve by writing a computer program. Why are these problems unsolvable? I'll prove it to you -- and along the way we'll learn some unexpected facts about infinity. In order to talk about computer science formally, we'll learn about Turing machines. We'll decide on what it means for something to be powerful enough to be called a "computer", and we'll investigate whether systems such as Minecraft or the Game of Life make the cut. Finally, we'll discuss some philosophical puzzles and paradoxes relating to the study of minds and machines and artificial intelligence. Come learn about uncomputability, about Turing machines, and about code that loops forever. We will explore the limit of the mathematically possible.

Arithmetic, Ancient Egyptian Style in Spark 2016
This class will be a blast from the past. Okay, sure, we're traveling back in time to learn about Ancient Egypt. But that's not the only time travel we'll be doing. In this class, we'll also be traveling back in time – to first grade. Imagine that you are a young Ancient Egyptian scribe-to-be, going through the equivalent of Ancient Egyptian elementary school. You need to learn reading, writing, and ... arithmetic. What happens when two separate cultures independently discover the ideas of mathematics? Are there other ways we can multiply numbers, and other ways we can think about decimals and fractions? The answer is yes, and the details are strange and fascinating! Through a variety of hands-on exercises, we will cover how the Ancient Egyptians wrote down their numbers, carried out addition and subtraction, represented multiplication and division, and manipulated fractions. Inspired by the book "Count Like an Egyptian" by David Reimer.

Insects: Classification and Camouflage in Spark 2016
Is that an orchid, or a mantis? What's the difference between a bug and a beetle? Why does EVERYTHING seem to want to pretend to be an ant? Why do bees cooperate with each other like that? Come learn about insects, the fascinating animals with more than a million species on Earth and a majority of ALL the species we know about! This class will present a whirlwind tour of insects of all sorts. You'll learn how each group is related and how to recognize each group's unique features, as well as some random cool things about camouflage and parasitism among insects. At the end, you'll apply your newly-learned identification skills to identify some real insects!

Spontaneous 5-Minute Classes on Whatever You Want in Splash 2015
You choose the title, we improvise a 5-minute lesson on it! Bring your wackiest topic suggestions, and watch us embarrass ourselves as we teach you about them on the spur of the moment.

Robots! Space! Time! Stories! in Splash 2015
Interested in science fiction, futuristic engineering, artificial intelligence or interplanetary empires? Ever wondered what would happen if people lived forever? What would happen if the world split in two every time you had to make a choice, and both options happened? What would happen if there was a center of time where time stood still? Come read a few of the short stories of Isaac Asimov, one of the most prolific science fiction writers of all time. We'll spend an hour devouring tales of robots, space, and time!

Stack Hacks: Programming Recursion in the TI-84 in Splash 2015
You've got a TI calculator. It does math. Yet, somehow, that's always felt... unsatisfying. Only math? You want it to do more! With only 27 basic variables available to you, TI-BASIC is one of the more Fun(TM) programming languages out there. Yet, with certain tricks, you can wield the awesome power of lists, graphing, matrices, and more in order to write your own programs for any purpose. As an appetizer, we'll cover the basics of TI-BASIC in class. For our main course, we will use the concept of a "stack" in order to implement recursion in your TI calculator. This is the same way recursion is done by code running on real computers! With this tool in hand, our ultimate goal will be to create a program to draw fractals on the calculator's screen. There will be opportunities to write and run code in class -- so if you have a TI calculator, please bring it. If you do not, you can download a TI calculator emulator to your phone (yes, there's an app for that) or to your computer, or you can write code with paper and pencil -- you'll still be able to follow along and learn.

Spectrograms: What Does Sound "Look" Like? in Splash 2015
What is sound? How do our ears hear the information in sound and send it to our brain to be processed into language? And how might we teach a computer to do the same thing? We'll investigate all of this by diving into phonology and phonetics, the study of the audible components of language. We'll explore what sound even is, and look at some ways it can be visualized. We'll talk about all of the different sounds that human languages can use, in English and beyond. Finally, we'll look at patterns in sounds by converting them into pictures called "spectrograms". With this tool at our disposal, we can actually think about how both computer systems and human brains might tackle the problem of speech recognition. Come learn what you never knew you never knew about sounds!

Splash Hackathon in Splash 2015
Whether you're new to programming or have experience, we'll help you learn new things and get better! This will be a self-paced programming workshop, where you get to work on whatever you want -- either pursue your own idea, or let us suggest a project. We'll be here to guide you if you get stuck. If you've never programmed before, we'll have suggestions for resources to use to get started. We'll be in a computer lab, but feel free to bring your own laptop (just make sure to keep an eye on it – Splash is hectic, and it's easy to lose things!).

Spark Hackathon in Spark 2015
Whether you're new to programming or have experience, we'll help you learn new things and get better! This will be a self-paced programming workshop, where you get to work on whatever you want -- either pursue your own idea, or let us suggest a project. We'll be here to guide you if you get stuck. If you've never programmed before, we'll have suggestions for resources to use to get started. We'll be in a computer lab, but feel free to bring your own laptop.

Insects: Classification and Camouflage in Spark 2015
Is that an orchid, or a mantis? What's the difference between a bug and a beetle? Why does EVERYTHING seem to want to pretend to be an ant? Why do bees cooperate with each other like that? Come learn about insects, the fascinating animals with more than a million species on Earth and a majority of ALL the species we know about! This class will present a whirlwind tour of insects of all sorts. You'll learn how each group is related and how to recognize each group's unique features, as well as some random cool things about camouflage and parasitism among insects. At the end, you'll apply your newly-learned identification skills to identify some real insects!

Arithmetic, Ancient Egyptian Style in Spark 2015
This class will be a blast from the past. Okay, sure, we're traveling back in time to find out how things were done in Ancient Egypt. But that's not all. In this class, we'll also be traveling back in time -- to when you were in first grade. Imagine that you are a young Ancient Egyptian scribe-to-be, going through the equivalent of Ancient Egyptian elementary school. You need to learn reading, writing, and ... arithmetic. What happens when two separate cultures independently discover the ideas of mathematics? Are there other ways we can multiply numbers, other ways we can think about decimals? The answer is yes, and the details are strange and fascinating! Through a variety of hands-on exercises, we will cover how the Ancient Egyptians wrote down their numbers, carried out addition and subtraction, represented multiplication and division, and manipulated fractions. Inspired by the book "Count Like an Egyptian" by David Reimer.

Insects: Classification and Camouflage in Splash 2014
**This class was previously two hours; it has been reduced to one hour** Is that an orchid, or a mantis? What's the difference between a bug and a beetle? Why does EVERYTHING seem to want to pretend to be an ant? Why do bees cooperate with each other like that? Come learn about insects, the fascinating animals with more than a million species on Earth and a majority of ALL the species we know about! This class will present a whirlwind tour of insects of all sorts. You'll learn how each group is related and how to recognize each group's unique features, as well as some random cool things about camoflage and parasitism among insects. At the end, you'll apply your newly-learned identification skills to identify some real insects!

Spectrograms: What Does Sound "Look" Like? in Splash 2014
What is sound? How do our ears hear the information in sound and send it to our brain to be processed into language? And how might we teach a computer to do the same thing? We'll investigate all of this by diving into phonology and phonetics, the study of the audible components of language. In the first half, we'll talk about all of the different sounds that human languages can use, in English and beyond. In the second half, we'll look at patterns in sounds by converting them into pictures called "spectrograms". With this tool at our disposal, we can actually think about how both computer systems and human brains might tackle the problem of speech recognition. Come learn what you never knew you never knew about sounds!

Stack Hacking: Programming Recursion in the TI-84 in Splash 2014
You've got a TI calculator. It does math. Yet, somehow, that's always felt... unsatisfying. Only math? You want it to do more! With only 27 basic variables available to you, TI-BASIC is one of the more Fun(TM) programming languages out there. Yet, with certain tricks, you can wield the awesome power of lists, graphing, matrices, and more in order to write your own programs for any purpose. In this class, we will use the concept of a "stack" in order to implement recursion in your TI calculator. This is the same way recursion is done by code running on real computers! With this tool in hand, our ultimate goal will be to create a program to draw fractals on the calculator's screen. In class, I will teach you what you need to know, and leave you to try it out on your own time afterwards. Therefore, if you do not have a TI calculator, you will be able to participate and learn from the class just fine. However, if you do have a TI calculator, please bring it so you can get more practice.

Arithmetic, Ancient Egyptian Style in Splash 2014
This class will be a blast from the past. Okay, sure, we're traveling back in time to find out how things were done in Ancient Egypt. But that's not all. In this class, we'll also be traveling back in time -- to when you were in first grade. Imagine that you are a young Ancient Egyptian scribe-to-be, going through the equivalent of Ancient Egyptian elementary school. You need to learn reading, writing, and ... arithmetic. What happens when two separate cultures independently discover the ideas of mathematics? Are there other ways we can multiply numbers, other ways we can think about decimals? The answer is yes, and the details are strange and fascinating! Through a variety of hands-on exercises, we will cover how the Ancient Egyptians wrote down their numbers, carried out addition and subtraction, represented multiplication and division, and manipulated fractions. Inspired by the book "Count Like an Egyptian" by David Reimer.

Programming Recursion in the TI-84 -- Blitz Edition in Splash 2014
**This is a one-hour shortened version of C8538. It was not open during the lottery phase.** You've got a TI calculator. It does math. Yet, somehow, that's always felt... unsatisfying. Only math? You want it to do more! With only 27 basic variables available to you, TI-BASIC is one of the more Fun(TM) programming languages out there. Yet, with certain tricks, you can wield the awesome power of lists, graphing, matrices, and more in order to write your own programs for any purpose. In this class, we will use the concept of a "stack" in order to implement recursion in your TI calculator. This is the same way recursion is done by code running on real computers! With this tool in hand, our ultimate goal will be to create a program to draw fractals on the calculator's screen. I will teach you what you need to know, and leave you to try it out on your own time afterwards. Therefore, if you do not have a TI calculator, you will be able to participate and learn from the class just fine. However, if you do have a TI calculator, please bring it so you can get more practice.

Mathematical Insights in Computing in Junction 2014
Problem-solving meets philosophy as we explore mind-blowing ideas from the theoretical study of complex systems: computers, minds, and beyond.

Linguistics Problem Solving in Spark 2014
Do you enjoy unraveling logic puzzles, want to learn about other languages, or crave the feeling of a good riddle? Come solve fun problems from the Linguistics Olympiads, NACLO and IOL! A variety of languages, problem styles, and difficulty levels will be provided for you to solve. Logic and reasoning are your main weapon here – no prior linguistics knowledge required!

Insects! in Spark 2014
Is that an orchid, or a mantis? What's the difference between a bug and a beetle? Why does EVERYTHING seem to want to pretend to be an ant? Why do bees cooperate with each other like that? Come learn about insects, the fascinating animals with more than a million species on Earth and a majority of ALL the species we know about! This class will present a whirlwind tour of insects of all sorts. You'll learn how each group is related and how to recognize each group's unique features, as well as some random cool things about camoflage and parasitism among insects. Real insects are promised! Really!

Math and Art: Geometric Constructions in Spark 2014
Come use math to create works of art! Learn basic and advanced geometric constructions, from bisecting an angle to constructing a pentagon, and even approximating a heptagon! Draw fractals with precision, acquire a useful mathematical skill, and invent your own elaborate geometric pieces of art!

Insects! in Splash! 2013
Is that an orchid, or a mantis? What's the difference between a bug and a beetle? Why does EVERYTHING seem to want to pretend to be an ant? Why do bees cooperate with each other like that? Come learn about insects, the fascinating animals with more than a million species on Earth and a majority of ALL the species we know about! This class will present a whirlwind tour of insects of all sorts. You'll learn how each group is related and how to recognize each group's unique features, as well as some random cool things about camoflage and parasitism among insects. Real insects are promised! Really! This class is two hours, but there will be a ten-minute break in the middle.

Sounds and Language in Splash! 2013
Ever wonder how humans create, hear, and understand the sounds of language? What actual, measurable properties of sound are we sending when we speak? How our ears can decipher all of the information in sound, and send it to our brain to be processed into language? To figure all of this out, we'll dive into phonology and phonetics, the study of the audible components of language. Come learn what you never knew you never knew about sounds! This class is two hours, but there will be a ten-minute break in the middle.

Problems We Will Never Solve in Splash! 2013
Many problems are "uncomputable" -- we will never be able to write a computer program that can solve them. Ludicrous!, you say. Crazy! Never? That can't be true! But it's true. And I'll prove it to you. Come learn the lore of uncomputability, of Turing machines, and of code that loops forever. We will explore the limit of the mathematically possible.

Linguistics Problem Solving in Splash! 2013
Do you enjoy unraveling logic puzzles, want to learn about other languages, or crave the feeling of a good riddle? Come solve fun problems from the Linguistics Olympiads, NACLO and IOL! A variety of languages, problem styles, and difficulty levels will be provided for you to solve. Logic and reasoning are your main weapon here – no prior linguistics knowledge required!

Writing Systems in Splash! 2013
How are the worlds' writing systems different, beyond just using different characters? What writing systems are more similar to each other than others, and why? Why is Hangul (the Korean writing system) the best in the world, and Chinese characters the worst?

Linguistics Problem Solving in Splash! 2013
Do you enjoy unraveling logic puzzles, want to learn about other languages, or crave the feeling of a good riddle? Come solve fun problems from the Linguistics Olympiads, NACLO and IOL! A variety of languages, problem styles, and difficulty levels will be provided for you to solve. Logic and reasoning are your main weapon here – no prior linguistics knowledge required!

Crayfish: Take It Apart! in Splash! 2013
Dissections are a fun (and messy) way to figure out how things work! Crayfish are adorable arthropods, and relatives to shrimps and lobsters. Though they are also animals, their anatomy is vastly different from a human’s. A crayfish has a grand total of NINETEEN pairs of appendages – can you find them all? Come dissect crayfish specimens in pairs, and learn all about the internal and external anatomy of arthropods!

Introduction to Programming in HSSP Summer 2013
Do you want to create adventureful text games, have your computer solve ALL the math, or write scripts to automatically get things done? Learn programming! This will be a course for students who have no prior experience with programming, but want to learn. It will be taught in Python. By the end of this course, you will know some of the basic tools of Python, you will have programmed a final project on a topic that interests you, and you will learn how continue improving your Python skills even after the class ends.

The Building Blocks of Languages in HSSP Spring 2013
Explore the many human languages, piece apart their puzzles, and even create your own! This class will be an in-depth introduction to linguistics, the scientific study of human languages. We'll solve logic puzzles that don't require any linguistics knowledge, but that, in answering, should lead to insights about what sounds languages can be made of, how we put them together to form meaning, and how the world's languages have developed and changed. We will discuss a sampling of these aspects of languages over the course of HSSP. The central theme of this class will be for you, the students, to create your own conlangs (constructed languages) by the end of the class. Building the parts of your conlang will be assigned as light homework. Come expecting to learn, to decipher, and to create.

Insects! in Spark! 2013
What are insects? It turns out there's a whole lot more to them than just the basic "head, thorax, abdomen, 6 legs" you might already know. With more than a million species on Earth representing more than half of ALL the living things we know about, insects are fascinating creatures with widely-varying lifestyles. This class will present a whirlwind tour of insects of all sorts. You'll learn how to classify them and recognize each type's unique features, how they are related, and how they survive in their plethora of habitats. Actual insects are promised!

Crayfish: Take It Apart! in Spark! 2013
Dissections are a fun (and messy) way to figure out how things work! Crayfish are adorable arthropods, and relatives to shrimps and lobsters. Though they are also animals, their anatomy is vastly different from a human’s. A crayfish has a grand total of NINETEEN pairs of appendages – can you find them all? Come dissect crayfish specimens in pairs, and learn all about the internal and external anatomy of arthropods!

Sea Urchin: Take it Apart! in Spark! 2013
Dissections are a fun (and messy) way to figure out how things work! Sea urchins are round and full of spikes -- it's hard to see how anything so weirdly shaped could be an animal. Find out firsthan how they survive with such an unusual and unique body structure. Come dissect sea urchin specimens in pairs, and learn all about the internal and external anatomy of echinoderms!

Mathematical Doodling in Spark! 2013
Do you find <a href="www.youtube.com/watch?v=v-pyuaThp-c">Vi Hart's</a> doodles awesome? Now you can draw fractals, spirals, and knots, too! Come learn new ways to doodle, mathematically! Spend an hour learning how to draw compass constructions, dragon curves, Celtic knots, fractals, Mobius strips, Fibonacci spirals, Koch snowflakes, 3D buildings, and much more! Your math class notes will never be the same again. Generalized drawing supplies will be provided.

Crayfish: Take It Apart! in Splash! 2012
Dissections are a fun (and messy) way to figure out how things work! Crayfish are adorable arthropods, and relatives to shrimps and lobsters. Though they are also animals, their anatomy is vastly different from a human's. A crayfish has a grand total of NINETEEN pairs of appendages -- can you find them all? Come dissect crayfish specimens in pairs, and learn all about the internal and external anatomy of arthropods! Middle school edition. Nitrile gloves, forceps, dissecting scissors, and crayfish will be provided.

Crayfish: Take It Apart! in Splash! 2012
Dissections are a fun (and messy) way to figure out how things work! Crayfish are adorable arthropods, and relatives to shrimps and lobsters. Though they are also animals, their anatomy is vastly different from a human's. A crayfish has a grand total of NINETEEN pairs of appendages -- can you find them all? Come dissect crayfish specimens in pairs, and learn all about the internal and external anatomy of arthropods! High school edition. Nitrile gloves, forceps, dissecting scissors, and crayfish will be provided.

Linguistics Problem Solving in Splash! 2012
اللسانيات! Мовазнаўства! भाषाविज्ञान! 언어학! Γλωσσολογία! Ngôn ngữ học! Linguistics! Do you enjoy unraveling logic puzzles, want to learn about other languages, or crave the feeling of thinking about a good riddle? Come solve fun problems from the Linguistics Olympiads, NACLO and IOL! A variety of languages, problem styles, and difficulty levels will be provided for you to solve. Logic and reasoning are your main weapon here – no prior linguistics knowledge required!

Phonetics in Splash! 2012
Ever wonder how humans create, hear, and understand the sounds of language? What the difference between a /$$s$$/ and a /$$z$$/ is in terms of actual measurable properties of sound? How we can decipher all of the information in sound, and give it linguistic meaning? To figure all of this out, we'll look at phonetics, the study of the audible components of language. Come learn a whole bunch of things you never knew about sounds, and the computational tools that we can use to study them! (High school edition.)

The Science of Talking in Splash! 2012
Ever wonder how humans create, hear, and understand the sounds of language? What the difference between a /$$s$$/ and a /$$z$$/ is in terms of actual measurable properties of sound? How we can decipher all of the information in sound, and give it linguistic meaning? To figure all of this out, we'll look at phonetics, the study of the audible components of language. Come learn a whole bunch of things you never knew about sounds, and the computational tools that we can use to study them!

Robots! Space! Time! Stories! in Splash! 2012
Interested in science fiction, futuristic engineering, artificial intelligence or interplanetary empires? Ever wondered what would happen if people lived forever? What would happen if the world split in two every time you had to make a choice, and both options happened? What would happen if there was a center of time where time stood still? Come read a few of the short stories of Isaac Asimov, one of the most prolific science fiction writers of all time and excerpts from the book Einstein's Dreams, which describes numerous different ways in which time could work. Come spend an hour devouring tales of robots, space, and time!

Synthetic Biology in Splash! 2012
What would you do if you had the power to make bacteria smell like bananas, destroy environmental poisons, or glow fluorescent green? Synthetic biology is the new and exciting science of using biology's toolkit to engineer new and useful systems. We're the MIT team competing in the 2012 International Genetically Engineered Machine competition, here to show you why synthetic biology is awesome and what we can do with it.

Riddles In Another Language in ESPrinkler Summer 2012
Toki Pona is a remarkably simple language, but it can be tricky to decipher at times. Come learn the vocabulary of this constructed language, and try your hand at deciphering a set of riddles in Toki Pona from last year's MIT Mystery Hunt!

Make a Writing System! in ESPrinkler Spring 2012
We'll take a look at some of the world's interesting writing systems, and learn how to write in them. Then, we as a class will develop our own writing system!

Math and Art: Shiny Geometric Constructions in Spark! 2012
Come use math to create works of art! Learn basic and advanced geometric constructions, from bisecting an angle to constructing a pentagon, and even approximating a heptagon! Draw fractals with precision, acquire a useful mathematical skill, and invent your own elaborate geometric pieces of art!

Probability and Genetics in Spark! 2012
Think biology is all memorizing and no math? Come learn a few of the more mathematical details behind genetics! Topics to be covered include pedigrees, recombination, conditional probability, binomial distributions, modes of inheritance, and calculating probabilities of all sorts. With sample problems and probability demonstrations!

Intro to TI-84 BASIC Programming in Splash! 2011
Learn how to program your TI-84 calculator using BASIC, and come code some projects yourself! TI-BASIC is an immensely useful programming utility -- it's more portable than your laptop, plus quick and easy to use. This skill will provide endless uses in math classes, as well as personal enjoyment. Cope with only 27 variables! Draw slope fields! Prove that 2+2=5! Graph radii of curvature! Impress your friends! Convert numbers between bases! Make simple text games!

Probability and Genetics in Splash! 2011
Think biology is all memorizing and no math? Come learn a few of the more mathematical details behind genetics! Topics to be covered include pedigrees, recombination, genetic markers, modes of inheritance, and calculating probabilities of all sorts. With sample problems!

Linguistics Problem Solving in Splash! 2011
اللسانيات! Мовазнаўства! भाषाविज्ञान! 언어학! Γλωσσολογία! Ngôn ngữ học! Linguistics! Come solve fun problems from the Linguistics Olympiads, NACLO and IOL! A variety of languages, problem styles, and difficulty levels will be provided for you to solve. Logic and reasoning are your main weapon here -- no prior linguistics knowledge required!

What are imaginary numbers, and -- if they're so "imaginary" -- what are they actually useful for? Why could $$e^i\pi$$ ...