The Crash That Broke Physics Records.

On 17 August 2017, we heard two neutron stars collide, saw the flash 1.7 seconds later, watched gold being forged, and used it all to measure the expansion of the universe, with no distance ladder at all. We read the three papers. ⏮️ Previous episodes: Hubble 1929 [link] · Baade 1956 [link] 📄 Papers (free) Abbott et al. 2017, A gravitational-wave standard siren measurement of the Hubble constant. Nature 551, 85. https://arxiv.org/abs/1710.05835 Abbott et al. 2017, GW170817: Observation of Gravitational Waves from a Binary Neutron Star Inspiral. PRL 119, 161101. https://doi.org/10.1103/PhysRevLett.1... Abbott et al. 2017, Multi-messenger Observations of a Binary Neutron Star Merger. ApJL 848, L12. https://doi.org/10.3847/2041-8213/aa91c9 ⏱️ Chapters [0:00] Listen [0:43] What is a gravitational wave? [2:17] 17 August 2017 [4:52] The hunt for the flash [8:12] A ruler made of sound [10:21] The answer: 70 [11:16] What's next [11:56] Vote. Actually. 🗳️ Which paper next? Vote in the pinned comment. 🎙️ Narration: AI voice (Kokoro-82M, Apache-2.0). Animations: Manim Community Edition. #gravitationalwaves #neutronstars #HubbleTension