Which Way Is Down?

Vsauce

1 год назад

BRAIN CANDY LIVE http://www.braincandylive.com/tickets THE VSAUCE CURIOSITY BOX: https://www.curiositybox.com/ Links to sources and to learn more below! my twitter https://twitter.com/tweetsauce my instagram https://www.instagram.com/electricpants Thanks to Eric Langlay (https://www.youtube.com/user/ericdraven30) for producing, editing, and animating this episode with me. Thanks also to Henry Reich (https://www.youtube.com/user/minutephysics) for his advice and guidance. Universe Sandbox² : http://universesandbox.com/ Mass vs weight: https://en.wikipedia.org/wiki/Mass_versus_weight Great Veritasium video: https://www.youtube.com/watch?v=_Z0X0yE8Ioc two other great videos: https://www.youtube.com/watch?v=6ccIjRwYO9U and https://www.youtube.com/watch?v=aCqQzrPCcFM baseballs coming together under gravitational attraction can be simulated in Universe Sandbox 2. More math behind it can be found here: https://www.reddit.com/r/explainlikeimfive/comments/2vyxl7/eli5_will_two_baseballs_a_foot_apart_in_deep/ Weight to mass (on surface of Earth) convertor: https://www.convertunits.com/from/kilograms/to/newton pencil and Earth falling numbers: https://www.quora.com/When-we-drop-a-pencil-the-earth-attracts-it-and-it-seems-that-the-pencil-is-falling-towards-earth-Why-doesnt-the-earth-come-up-towards-the-pencil NASA HD footage: https://archive.org/details/NASA-Ultra-High-Definition Buoyancy: https://en.wikipedia.org/wiki/Buoyancy Earth’s spin and its effect on ‘down’: http://www.freemars.org/jeff/Earth/down.htm The measurement of Earth and its gravity: https://en.wikipedia.org/wiki/Geodesy https://en.wikipedia.org/wiki/Physical_geodesy Movement of Earth’s center of mass: http://www.aiub.unibe.ch/research/slr_data_analysis/estimating_the_geocenter_and_earth_rotation_parameter/index_eng.html http://www.massentransporte.de/index.php?id=307 http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.650.4392&rep=rep1&type=pdf you get heavier before you get lighter as you descend into Earth: https://www.reddit.com/r/askscience/comments/4qfl52/do_you_get_lighter_the_further_underground_that/ vertical deflection: https://en.wikipedia.org/wiki/Vertical_deflection practical uses of measuring gravity: https://en.wikipedia.org/wiki/Gravimetry geoid: https://en.wikipedia.org/wiki/Geoid https://oceanservice.noaa.gov/facts/geoid.html https://www.youtube.com/watch?v=jOQl8DRzQks Interactive Earth geoid: https://experiments.withgoogle.com/chrome/geoid-viewer your weight when moon is overhead: https://www.thenakedscientists.com/forum/index.php?topic=11639.0 Hammer and feather drop on moon: https://nssdc.gsfc.nasa.gov/planetary/lunar/apollo_15_feather_drop.html Why things fall at the same rate: https://www.quora.com/If-an-object-has-more-mass-then-its-pull-on-earth-would-be-greater-than-an-object-with-less-mass-and-therefore-should-fall-to-earth-faster-Why-do-objects-of-different-mass-fall-to-earth-at-the-same-speed Wolfram Alpha cone geodesic tool: http://demonstrations.wolfram.com/ConeGeodesics/ General Relativity: simple animation showing geodesic on cone and how it causes motion DOWN in space: https://www.youtube.com/watch?v=DdC0QN6f3G4 GREAT pbs spacetime video (watch the whole channel): https://www.youtube.com/watch?v=AwhKZ3fd9JA http://www.askamathematician.com/2009/10/q-why-does-curved-space-time-cause-gravity/ https://www.av8n.com/physics/geodesics.htm#sec-straight http://www.pitt.edu/~jdnorton/teaching/HPS_0410/chapters/spacetime/ http://www.einstein-online.info/spotlights/geometry_force time and gravity: https://www.youtube.com/watch?v=jlTVIMOix3I https://youtu.be/1ENkP0h8nAg https://youtu.be/gcvq1DAM-DE https://www.reddit.com/r/askscience/comments/30lt1o/bending_of_space_not_responsible_for_objects/ https://www.reddit.com/r/AskScienceDiscussion/comments/3rfmtl/does_time_dilation_cause_gravity_or_the_other_way/ tests of general relativity: https://en.wikipedia.org/wiki/Tests_of_general_relativity RECOMENDED BOOKS: great introductory texts: “Relativity Visualized” by Lewis Carroll Epstein https://www.amazon.com/Relativity-Explained-Classics-Science-Mathematics/dp/0486293157 There’s also this PDF that takes Epstein’s diagrams into more detail: http://www.relativity.li/uploads/pdf/English/Epstein_en.pdf “Relativity Simply Explained” by Martin Gardener https://www.amazon.com/Relativity-Explained-Classics-Science-Mathematics/dp/0486293157 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 https://www.amazon.com/Most-Incomprehensible-Thing-Introduction-Mathematics/dp/0957389469/ Requires some background in relevant math topics (see above) but very very good: “Spacetime And Geometry: An Introduction To General Relativity” by Sean Carrol https://www.amazon.com/gp/product/9332571651/