What If You Kept Shrinking and Couldn’t Stop?

You're 1.75 meters tall. Then, every few seconds, a little less. You shrink past your cat, past an ant, past the limit of the human eye. Past bacteria, viruses, your own DNA. Into an atom, a proton, a quark — and then into the place where physics runs out. The only made-up thing in this video is the premise. All sizes are real and rounded. CHAPTERS 0:00 An ordinary morning 0:15 Smaller than a child 0:55 Smaller than the cat 1:48 Ant-sized 2:20 Invisible 3:06 The microbes 3:39 Lights out 4:21 Molecules 5:08 Inside the atom 5:46 The nucleus 6:16 Quarks 7:03 The unknown 7:41 The Planck length SOURCES Garden ant (Lasius niger) worker length: 3–5 mm House dust mite (Dermatophagoides): about 0.3 mm long; no eyes Resolution of the naked eye: about 0.1 mm at reading distance Human hair diameter: about 17–180 µm (typical ~70 µm) Pollen grains: about 10–100 µm Skin cells (corneocytes): about 30–50 µm across; humans shed hundreds of millions per day Escherichia coli: about 2 µm long Bacteria in the human body (~3.8 × 10¹³): Sender, Fuchs & Milo, PLOS Biology, 2016 Visible light: about 380–700 nm Coronaviruses / influenza: about 100 nm across Mean free path of air molecules at sea level: about 68 nm; mean spacing: about 3.3 nm DNA double helix: 2 nm wide, 3.4 nm per turn Water molecule: about 0.28 nm Oxygen atom: about 0.1 nm; nucleus about 100,000 times smaller Nuclear density: about 2.3 × 10¹⁷ kg/m³ (a teaspoon ≈ a billion tonnes) Proton charge radius: 0.84 fm (CODATA) Proton mass mostly from QCD binding energy (quark masses ~1%) Quark size: no measured size; LHC limits below ~10⁻¹⁹ m Etruscan shrew: ~4 cm body, eats up to ~2× its body weight per day Planck length: 1.616 × 10⁻³⁵ m (CODATA)