Why don’t cars have a guage on the instrument panel which tells you the tyre pressure? People blather on every year about how important tyre pressure is (especially before the holidays) and watching the Salon d’Automobile in Frankfurt and the amazingly futuristic cars, I noticed none of them had a pressure indicator. Mecedes Benz is making cars which basically drive themselves with things like movement detectors, direction correction, anti-sleep programs, night vision…and the list goes on. But what happens if the tyres are flat? Oops.
Or why can’t I have a small thermometer thing which tells me if the fish is fresh or not in the restaurant? Or toothpaste which doesn’t stick to the basin, or why doesn’t a pheremone indicator exist to make it easier for people in nightclubs to hit on each other?
500 000 patents are registered every year and none of these things exist.