# Splash Biography

## KAI XU, Yale Junior, Computer Science & Applied Math

Major: Computer Science & Applied Math

College/Employer: Yale

## Brief Biographical Sketch:

I'm Kai Xu, a junior from the San Francisco Bay Area studying Computer Science and Applied Math. For the past year and a half, I've conducted independent research on new ways of measuring mountains and surface area on Earth and other planets. Some of my other interests include music production, outdoor adventures, and web development. Behind me is Jobs Peak, a mountain in the Sierra Nevada with a jut of 750 meters. (You'll learn what jut is in my class!)

## Past Classes

(Clicking a class title will bring you to the course's section of the corresponding course catalog)

M4725: The Art of Measuring a Mountain in Splash Spring 2023 (Apr. 01, 2023)
This is a tale of three mountain measures: elevation, prominence, and jut. Let us journey back in time to ancient Greece, where the brilliant minds of the day pondered a question that had inspired adventurers for centuries: "how high is this mountain?" And so, they invented elevation, allowing them to measure the height of these majestic peaks. Fast forward a few centuries to the early 20th century, and we find ourselves in the midst of an exploration boom. But as explorers ventured into uncharted territories, they encountered a new challenge: "is this a mountain?" And so, the measure of prominence was born, allowing us to distinguish true mountains from mere hills. But the story doesn't end there. In the year 2021, a new measure was born - jut. Now, we could answer the question that had always lingered in the back of our minds: "how impressive is this mountain?" With jut, we can finally quantify the awe-inspiring beauty and magnificence of these towering giants, not only on Earth, but even on the Moon, Mars, and beyond. Learn about why erosion is like the hand of a sculptor, turning flat mountaintops into razor edges and spires. Learn about mountains on Earth and other planets that dwarf Everest in size. And learn about why there is no right way to measure a mountain, and no wrong way either.

S4556: Measuring Mountains on Earth, Mars, and Beyond in Splash Spring 2022 (Apr. 16, 2022)
On Earth, the height of mountains and other physical features is represented by elevation, or distance above sea level. But what about a physical feature on a planet without a sea levelâ€”how should you represent its height? Last summer, I tackled this problem and invented a solutionâ€”designed to be physically meaningful, conceptually intuitive, and universally applicable to any planetary body. This new approach is currently known to less than 100 people in the world, so by taking this course, you will be embarking on the forefront of scientific research. Get ready to travel to many fascinating places, including a volcano on Earth taller than Mt. Everest, the Apollo 15 Moon landing site, and a Martian valley five times deeper than the Grand Canyon. Along the way, you will find yourself learning more about creative problem-solving, mathematical modeling, and scientific principles of measurement.

E4531: Digitally Change the Gender, Age, and Pitch of Your Voice in Sprout Spring 2022 (Feb. 19 - Mar. 05, 2022)
Ever wondered what you would sound like as an adult? As someone of a different gender? Want to sound like Batman or SpongeBob? I will be showing you how to set up the world's most realistic voice changer. You will be using the REAPER digital audio workstation, a software used by professional audio engineers and music producers. Along the way, you will learn the fascinating science behind the human voice. Once your voice changer is set up, you can use it in future Zoom meetings.