Over the years, there have been several memory and display technologies that served a particular niche for a while, only to be replaced and forgotten when a more suitable technology came along. One of ...

You can buy all kinds of conventional clocks that have hands and numbers for easy reading. Or, like [Fabio Ricci], you could build yourself something a little more esoteric, like this neat shadow ...

O'clock is a way of telling the exact hour on a clock. We say "o'clock" when the minute hand (the long hand) points to the number 12 on the clock. When the minute hand points straight up to 12, it ...