Speed Compare

[Please note first] This app cannot measure speed. It uses no GPS and no motion sensors. You enter a figure you already know, and it is compared against everyday things. ────────── » Speed Compare — how fast is that, really? "107,000 km/h" does not tell you much on its own. That is 26,750 times a walking pace. The speed of sound, 1,225 km/h, is 306 times a walking pace, and a cheetah runs 2.46 times a human sprint. Enter one speed and compare it against 24 things, from a snail to the orbit of the Earth. ■ Two views ▪ Compare — the things closest to your figure, slowest first ▪ How many times — your figure as a multiple of each thing The same 24 entries are used both ways — searched by nearness in one view, divided in the other. ■ Three units to choose from The same speed gets said three different ways. km/h / m/s / knots (kt) Switch with the chips under the input box; the figure converts as you go. One metre per second is exactly 3.6 km/h; one knot is exactly 1.852 km/h. Both come straight from the definitions, with no rounding. Changing the unit never changes the order or the multiples. A ratio of speeds is the same whichever unit you measure it in. ■ The twenty-four A snail (0.05), blood in the aorta, walking (4), walking briskly, jogging, cycling (15), a moped at the legal limit in Japan (30), a car in town (40), a human sprint (44.7), a galloping horse (60), a car on the expressway (100), a cheetah (110), the maximum sustained wind of a violent typhoon (194.4), the Tokaido Shinkansen (285), a peregrine falcon diving (320), a Formula 1 car (370), Japan's SCMaglev record run (603), a tsunami over deep ocean (713), an airliner at cruise (900), the speed of sound (1,225), the rotation of the Earth (1,674), the International Space Station (27,600), escape velocity (40,270) and the orbit of the Earth (107,000). All in km/h. Tap any row to load its speed. ■ Fixed figures and ranges are kept apart Japan's moped speed limit is set by law, and the Tokaido Shinkansen service speed by the timetable. The tsunami and the two motions of the Earth are calculated, and the working is shown on screen. Animals and vehicles vary, so a range is shown as well as a typical figure: 0.02 to 0.08 for a snail, 80 to 120 for a car on the expressway. The range is shown only for reading; comparison uses the typical figure. ■ Nearness is measured as a ratio Those two figures are 2,140,000 times apart. Measured by difference, everything slow collapses into one clump. This app compares by ratio, so the nearest thing to 1,440 km/h is the spin of the Earth at 1,674 — not the speed of sound at 1,225, which a difference would pick. ■ Good for ▪ Making sense of a speed quoted in the news ▪ Turning meters per second or knots into something you can picture ▪ Explaining to a child what fast actually means ▪ Any moment you see a number and wonder whether it is fast ■ Things worth knowing (included in the app) ▪ There are exactly 3.6 km/h in a meter per second: one meter a second is 3,600 meters an hour ▪ A knot is one nautical mile an hour, and the nautical mile is now defined as exactly 1,852 meters ▪ The speed of sound is not fixed; it falls to about 1,062 km/h at 11,000 meters ▪ A tsunami runs faster over deep water, and the speed it loses in the shallows turns into height ▪ The Earth spins at 1,674 km/h at the equator and orbits at 107,000; you feel none of it because people sense changes in speed, not speed itself ▪ A cheetah holds its top speed for about 20 seconds. Speed and stamina are different things ■ How the app is built ▪ One screen with two views. No settings page ▪ Your last five entries are kept, and a tap restores one ▪ Japanese and English, following your device language ▪ No account needed. The comparison runs on your device and your figures are never sent anywhere ────────── Note: all speeds are typical guides, and animals and vehicles vary with conditions. This app cannot measure speed.