The ladderTwenty speeds, each rung about ten times the one below it. Where a number is arithmetic off somebody's measurement, the arithmetic is printed under it and the measurement is linked.
Eighteen powers of ten separate the slowest thing here from the fastest. That is the same gap as between a second and thirty billion years, which is why the picture needs a log scale and why your gut is no use above about the third rung.
- 7.9e-10 m/sslower than the eye sees
The ground under the house[1]
The Atlantic gets wider about as fast as a fingernail grows. You have been movin' this whole time and nobody spilled their coffee.
2.5 cm a year ÷ 31,557,600 s
- 0.00275 m/s9.9 mm/s
A racin' snail[2]
That is the course record at Congham, and the snail that set it was named Archie. Thirteen inches, two minutes, downhill in spirit only.
13 in (0.330 m) in 2 min (120 s)
- 1.2 m/s2.7 mph · 4.3 km/h
A body walkin'[3]
Every WALK light in the country is timed off this number. When the hand starts blinkin' early, the argument is with a federal table.
3.5 ft/s, the figure the crosswalk timer is set by
- 12.27 m/s27 mph · 44 km/h
Usain Bolt, flat out[4]
Fastest a human body has been measured movin' under its own steam. He was not goin' that fast at the gun and he was slowin' at the tape.
peak over the 60–80 m split; the whole 100 m averaged 10.44 m/s
- 25.9 m/s58 mph · 93 km/h · Mach 0.08
A cheetah, hunting[5]
Twice Bolt and change. The collar caught 25.9 m/s over a single stride — not a zoo sprint down a straight lane, but a turn-and-burn after dinner.
measured on wild cheetahs wearin' a collar, in the hunt
- 31.3 m/s70 mph · 113 km/h · Mach 0.09
Pickup on the interstate[6]
You beat the cheetah in third gear and it cost you a gallon every eighteen miles or so.
70 mph × 0.44704
- 108 m/s242 mph · 389 km/h · Mach 0.31
A peregrine, stooping[7]
Ken Franklin jumped out of the plane with the bird and they fell together so the speed could be read. Fastest anything alive has been measured goin'.
242 mph, clocked off a skydiver's meter
- 341.1 m/s763 mph · 1,228 km/h · Mach 0.99
ThrustSSC, on the salt[9]
Andy Green, Black Rock Desert, 15 October 1997 — 1.9 m/s under the speed of sound on the salt that day only because the desert air was cold. First car to go supersonic, and still the record, which tells you somethin' about how hard the next mile an hour is.
763.035 mph, two runs inside an hour, averaged
- 343 m/s767 mph · 1,235 km/h · Mach 1.00
Sound, in the air out front[8]
The rung everything else on this page gets measured against. Count the seconds after the flash and divide by three for kilometres, by five for miles.
dry air at 20 °C; colder air is slower
- 686 m/s1,535 mph · 2,470 km/h · Mach 2.00
The tip of a bullwhip[10]
The crack is a sonic boom. A whip was the first thing a person ever made go faster than sound, and it was doin' it for centuries before anybody worked out why.
about twice the speed of sound at the tip
- 853 m/s1,908 mph · 3,071 km/h · Mach 2.49
A .30-06, leavin' the muzzle[11]
Two and a half times the speed of sound before it clears the porch rail. The crack you hear downrange is the bullet's own boom, not the powder.
2,800 ft/s, 150-grain factory load
- 980.4 m/s2,193 mph · 3,529 km/h · Mach 2.86
An SR-71, in a straight line[12]
Eldon Joersz and George Morgan, 28 July 1976. Fifty years on, nothin' with a person in it and an air intake has gone quicker and had it certified.
3,529.56 km/h, the standin' record for an air-breathin' aeroplane
- 2,021 m/s4,521 mph · 7,276 km/h · Mach 5.89
The X-15, with the rocket lit[13]
Pete Knight, 3 October 1967. The paint burned off. The airframe came home warped and that airplane never flew again.
Mach 6.7, 4,520 mph
- 7,660 m/s17,135 mph · 27,576 km/h · Mach 22.33
The space station, goin' around[14]
Sunrise every ninety-two minutes. It is not up there because it went up. It is up there because it is goin' sideways this fast and keeps missin'.
√(GM/r) at 420 km up
- 11,186 m/s25,022 mph · 40,270 km/h · Mach 32.61
Quittin' the Earth entirely[15]
Throw somethin' this fast and straight up and it does not come back down. Ever. No engine needed after the throw.
√(2GM/R) at the ground, air not counted
- 17,000 m/s38,028 mph · 61,200 km/h · Mach 49.56
Voyager 1, still leavin'[16]
Launched in 1977, out past the edge of the Sun's wind, and still talkin' back on a transmitter weaker than a refrigerator bulb.
about 61,000 km/h away from the Sun
- 29,780 m/s66,616 mph · 107,208 km/h · Mach 86.82
This whole planet, orbitin'[15]
Sittin' on the porch, you are doin' this. Sixty-seven thousand miles an hour and the sweet tea does not slosh.
the Earth's mean orbital speed
- 192,000 m/s429,492 mph · 691,200 km/h · Mach 559.77
The Parker Solar Probe, at the bottom[17]
Fastest thing people have ever built. The Sun did most of the work — the probe fell, the way anything falls, and the Sun is a long way down.
about 692,000 km/h at closest approach, 24 December 2024
- 230,000 m/s514,495 mph · 828,000 km/h · Mach 670.55
The Sun, haulin' the lot of us[18]
One lap takes about 230 million years. Last time we were here, the dinosaurs had not started.
around the centre of the Milky Way
- 299.8 million m/s670,616,629 mph · 1,079,252,849 km/h
Light[19]
Not measured any more. Fixed. The metre is defined as how far light goes in 1/299,792,458 of a second, so the number cannot be wrong — the ruler moves instead.
exact, by definition
What the numbers do not say
A record is a measured run, under rules, witnessed. A cheetah does not care about rules, so its number came off a collar in the field and is the best anyone has caught, not the best there is. A bullwhip tip has been filmed past Mach 2 in a laboratory and the number depends on the whip and the arm. Take the rungs as the order of things, which is solid, rather than as the last word on any one line.