## Zepto-Moon

I have a thing for crazy units. The first crazy unit I found was the femto-lightfortnight. You may be familiar with the lightyear which is how far light travels (at 186,000 miles per second) in a year. A femto-lightfortnight is the distance that light travels in a quadrillionth (10^{-15}) of a fortnight. If you work out the maths, it turns out to be a length of about 36 cm (just over 14 inches). Quite useful for measuring the heights of people. My latest crazy unit is the zepto-Moon, or in other words, a sextillionth (10^{-21}) of the mass of the Moon. The Moon has a mass of 7.36 10^{22} kg, so a zepto-Moon works out at a handy 73.6 kg (162 lbs for those still using old money) which just happens to be about the same mass as me. Utterly pointless.