the rule. a clock at distance r from a mass runs at √(1 − r_s/r) of a clock far away. r_s = 2GM/c² is the size at which light can't leave (8.9 mm for Earth, 3 km for the Sun, 4.1 km for 1.4 Suns). measured, not assumed: clocks a few floors apart disagree, and GPS satellites are corrected for it every day. the seats. Earth's surface runs 7 × 10⁻¹⁰ slow: 9.6 years lost over 13.8 billion. the Sun's surface: 29,000 years. a white dwarf: 3.6 million years. a neutron star: 2.6 billion years; it is 19% slow. hovering at 1.5 × the black-hole size costs 42%; at 1.01 ×, 90%. at the edge itself the clock stops, and the lap never turns. your today moves. the lap from the last pages is 521 million far-away years. a slow clock does fewer laps, so its "now" sits at a different station: the neutron-star seat is still mid-collapse (163°) when far-away reaches element 0 (180°). the black-hole seat at 1.01 rs is at 229° of its third lap, two dead stars spiralling toward the merge. relative to everyone else. nobody's clock is wrong. each runs one second per second for its owner, so none of them is the true one. far-away is just the seat with no gravity to subtract. seen across the universe. there's a second kind of slowing: light from a galaxy seen as it was 13.2 billion years ago has been stretched by the expanding universe (redshift ~8.4), so we watch its clocks run 9.4× slow. stamps. the formula and the Earth, Sun, white dwarf and neutron star numbers are LIT. the black-hole seats need a rocket to hover, and "sat there for 13.8 billion years" is a thought experiment: AMBER. the lap stations carry over from the last page: AMBER.