What if you fell through the Earth? We simulated it

Gravity experiments, run for real: we drop S.I.M., our Simulated Impact Mannequin (a crash-test dummy), through the Earth, throw a ball into orbit by hand, stand it in the rain on Titan, take a ski jump to the Moon, and finish on a neutron star. This is the full test behind our four gravity Shorts. Each chapter replays one test and pushes it further with a new simulation: • A tunnel through the Earth takes 38 minutes. Through the Moon: 53. Through tiny Deimos: 82, at the speed of a jog. Size doesn't matter, only how tightly the mass is packed. • Orbit speed on Earth is 7.9 km/s, and in air a cannonball would lose almost all of it in about a second. On Deimos it's 3.94 m/s, a gentle toss. Why doesn't the ball come down? It falls the whole time, and keeps missing the ground. A fall through a tunnel keeps pace with the orbiting ball. • On Titan, thick air and weak gravity make a raindrop fall 7 times slower than on Earth, and a skydiver without a parachute falls at about 36 km/h. • On the Moon, the same ski jump takes off at only 39 km/h, floats for 8 seconds and lands at 100 m. • On a neutron star, a pebble dropped from 1 m hits at 1,606 km/s, and a jump rises 1/28 of a hydrogen atom. Chapters 0:00 What if you jumped into a hole through the Earth? 0:50 Test 001: the tunnel 1:34 Tunnels through the Moon, Mars and Deimos 2:48 Test 002: the jump on seven worlds 3:24 Throwing a ball into orbit 4:45 Why an orbit never comes down 6:07 Test 003: rain without air 6:38 Rain on Titan 7:59 Test 004: ski jumping without air 8:36 A ski jump on the Moon 9:52 Finale: the strongest gravity 10:22 A neutron star 11:17 What pushes back How we simulated it: the Earth tunnel uses the Preliminary Reference Earth Model; the Moon and Mars use layered models from seismic and gravity data (GRAIL, InSight); Deimos is treated as a smooth, round, non-spinning ball. Orbits are integrated with Newton's gravity. Raindrop speeds come from measured drag (Gunn & Kinzer) and, for Titan, the Huygens probe's measurements of its air. The ski jump uses the real Snowflake Ski Jump (Westby, Wisconsin, HS 118) from its FIS certificate and the flight model FIS uses, with air forces measured by ETH Zurich on the world's top jumpers. Neutron-star numbers are Newtonian and rough: Einstein's gravity makes the pull about a quarter stronger there. Visuals are code-generated simulations; the narration uses a synthetic voice and the background music is AI-generated. Sources: Dziewonski & Anderson 1981 (PREM) · Klotz 2015, Am. J. Phys. 83, 231 · Cooper 1966, Am. J. Phys. 34, 68 · Weber et al. 2011, Science 331, 309 (lunar core) · Wieczorek et al. 2013, Science 339, 671 (GRAIL crust) · Stähler et al. 2021, Science 373, 443 (Mars core) · NASA planetary fact sheets · JPL Solar System Dynamics (Deimos, Ceres, 67P) · Newton, A Treatise of the System of the World (1728) · Gunn & Kinzer 1949, J. Meteorology 6, 243 · Fulchignoni et al. 2005, Nature 438, 785 (Huygens) · Lorenz 1993, Planet. Space Sci. 41, 647 · Graves et al. 2008, Planet. Space Sci. 56, 346 · Loftus & Wordsworth 2021, JGR Planets 126 · FIS Standards for the Construction of Jumping Hills (2012) and Gasser 2008 (FIS/ETH Zurich flight model) · Bond et al. 2017, ApJ 840, 70 (Sirius B) · Riley et al. 2019 and Miller et al. 2019, ApJL (NICER neutron-star radius). Run The Sim Lab · Gravity: the full test #Gravity #NeutronStar #RunTheSimLab #RunTheSim