Below is a short summary and detailed review of this video written by FutureFactual:
Why Mirrors Flip, Hamster Black Holes, and Fulgurites: The Rest Is Science Explains Everyday Physics
Overview
Join The Rest Is Science as they unpack three quirky physics questions from audience mailbag and a jaw‑dropping object reveal. They explain why mirrors do not flip left-right but reveal you inside out, how dense a hamster would have to be to become a black hole, and what fossilized lightning (fulgurites) reveals about Earth's atmosphere and ancient weather. The hosts weave intuition with calculations, humor, and real‑world context, including a quick aside on Hawking radiation and the cosmic ray seeds behind lightning. Packed with demonstrations and surprising numbers, this episode invites viewers to rethink everyday physics. It also plugs into future episodes and emphasizes science communication.
Earth as a Pool Ball: Smoothness, Texture, and Fingerprints
The episode then shifts to Edward's question about whether shrinking Earth to the size of a pool ball would make it smoother than any man-made object. The host team explains that Earth’s Schwarzschild radius would be about 0.8 centimeters, so shrinking to a pool-ball size would still leave a rough texture on the order of 320 to 360 grit. They compare this to real pool balls, which have micro-scratches and sub-m micron texture that are far finer than any surface texture described by a crude 28-kilometer mountain scale. They discuss how the regulation diameter speaks to spherical regularity rather than smoothness, and reveal that even a pool ball’s texture hides micro-scale roughness. The conversation also touches a popular belief about fingerprints being detectable at different scales, noting that human touch can detect features down to about 13 nanometers and that a giant Earth-sized finger would sense differences between everyday objects like houses and cars. The segment concludes that the Earth is not smoother than a pool ball, but rather carries its own micro-scale texture. The hosts then shift to a hands-on demonstration with a fossilized lightning specimen, foreshadowing a deeper dive into the geologic time record of lightning and the atmosphere.
