Could the Universe Have Another Kind of Light We’ve Never Detected?

Hey guys! We’re now live on Spotify🎧 Listen here: https://open.spotify.com/show/5rqQFYd... Right now, a kind of light you cannot see may be passing straight through you, through the walls, through the planet itself. The light your eyes can catch is a thin sliver of all the light there is — so how would we ever know if the universe held one more kind we have never detected? Tonight we follow that question from the discovery of invisible light, into the dark ninety-five percent of the cosmos, out to the experiments hunting a light that would rather slip through solid walls than be seen. Get cozy and let this slow walk through the physics of hidden light keep you company tonight. Subscribe to Sundown Science if you enjoy taking the long way around the universe. CHAPTERS 0:00 Introduction 1:52 The Light You Cannot See 11:48 Every Time We Built a New Eye 21:26 The Ninety-Five Percent That Is Dark 31:21 A Second, Hidden Photon 42:09 The Crack of Kinetic Mixing 52:57 Shining Light Through a Wall 63:22 Making Hidden Light in a Machine 73:31 The Graveyard of Almost-Discoveries 83:28 A Second Light Inside You 94:15 The Other Dark Photon 105:50 What Is Actually at Stake 115:28 Another Kind of Light SOURCES The Shadow Existence of Photons (Max Planck Institute of Quantum Optics) — https://www.mpq.mpg.de/7110233/10-the... Famous Double-Slit Experiment Holds Up When Stripped to Its Quantum Essentials (MIT News) — https://news.mit.edu/2025/famous-doub... Famous Double-Slit Experiment Gets Its Cleanest Test Yet (Physics World) — https://physicsworld.com/a/famous-dou... New "Dark Photon" Theory Would Completely Upend Quantum Physics (Earth.com) — https://www.earth.com/news/dark-photo... The Dark Photon (Fabbrichesi, Gabrielli, Lanfranchi — arXiv review) — https://arxiv.org/abs/2005.01515 The Dark Photon: a 2026 Perspective (arXiv) — https://arxiv.org/abs/2603.08430 Dark Photon (Wikipedia) — https://en.wikipedia.org/wiki/Dark_ph... Dark SRF Experiment at Fermilab Demonstrates Ultra-Sensitivity for Dark Photon Searches (Fermilab News) — https://news.fnal.gov/2023/07/dark-sr... New Dark Photon Results from the FASER Experiment (CERN / FASER) — https://faser.web.cern.ch/briefing-20... Searching for Light Dark Matter and Dark Sectors with the NA64 Experiment at the CERN SPS (arXiv) — https://arxiv.org/abs/2505.14291 Dark Photon Dark Matter Constraints at the Taiwan Axion Search Experiment with Haloscope (arXiv) — https://arxiv.org/abs/2507.00784 New Constraints on Dark Photon Dark Matter with a Millimeter-Wave Dielectric Haloscope (arXiv) — https://arxiv.org/abs/2503.23354 — Disclaimer: All videos are produced for entertainment and education. Factual claims are sourced from peer-reviewed research and official scientific institutions. Where a video explores speculation, fringe theories, or the creator's own analysis, it is clearly labeled as such. Sundown Science is not a news outlet. Watch at your own discretion. #DarkPhoton #KineticMixing