Which Way Is Down?

BRAIN CANDY LIVE THE VSAUCE CURIOSITY BOX: Links to sources and to learn more below! my twitter my instagram Thanks to Eric Langlay () for producing, editing, and animating this episode with me. Thanks also to Henry Reich () for his advice and guidance. Universe Sandbox² : Mass vs weight: Great Veritasium video: two other great videos: and baseballs coming together under gravitational attraction can be simulated in Universe Sandbox 2. More math behind it can be found here: Weight to mass (on surface of Earth) convertor: pencil and Earth falling numbers: NASA HD footage: Buoyancy: Earth’s spin and its effect on ‘down’: The measurement of Earth and its gravity: Movement of Earth’s center of mass: you get heavier before you get lighter as you descend into Earth: vertical deflection: practical uses of measuring gravity: geoid: Interactive Earth geoid: your weight when moon is overhead: Hammer and feather drop on moon: Why things fall at the same rate: Wolfram Alpha cone geodesic tool: General Relativity: simple animation showing geodesic on cone and how it causes motion DOWN in space: GREAT pbs spacetime video (watch the whole channel): #sec-straight ~jdnorton/teaching/HPS_0410/chapters/spacetime/ time and gravity: tests of general relativity: RECOMENDED BOOKS: great introductory texts: “Relativity Visualized” by Lewis Carroll Epstein There’s also this PDF that takes Epstein’s diagrams into more detail: “Relativity Simply Explained” by Martin Gardener great intro to the math of general relativity: “A Most Incomprehensible Thing: Notes Towards a Very Gentle Introduction to the Mathematics of Relativity” by Peter Collier Requires some background in relevant math topics (see above) but very very good: “Spacetime And Geometry: An Introduction To General Relativity” by Sean Carrol