6 feet under Berlin's Alexanderplatz, a 40 year old motor drives a Trabant gearbox. The gears, in turn, propel a huge aluminum disc more than 6 feet (2 meters) above the ground.
On the disc, in a bulky sans-serif font, are the numbers from 1 to 24. During a day's course, the numbers pass by city names from around the world arranged on huge 24-sided prisms.
The Urania World Time Clock, still the place to meet in Berlin, makes the world's 24 time zones palpable -- as does Gmail, one could argue, if something goes wrong:
›› The sun rises while the email says it's noon? Chances are the sun is not wrong. Here's how to align your Gmail time zone with it.