Eclipse cycle
The saros is a measurement of time equal to 6585 days (plus one third of a day). It is the time between identical eclipses.
Electoral fairness
The Gallagher Index measures how well the makeup of a legislative body represents the proportion of votes cast to elect it. Some countries do this much better than others.
Kilometre zero
All roads lead to Rome… but where in Rome do they lead?
The Year 6000
In classical Jewish tradition, the Messianic Age – a thousand years of peace and harmony – must begin no later than 220 years from now: the Hebrew Year 6000.
The equation of time
When a day is longer or shorter than 24 hours you need to use the equation of time to bring it back into sync.
Pirates hate metric
Who keeps the metric system down? In the United States, pirates do.
One lifetime
The saeculum was a measurement of time used by the Etruscans and Romans to represent a single lifetime: no-one who witnessed the beginning of a saeculum would see its end, by definition.
Shake and barn
In nuclear physics terminology, first you need to hit the barn, and next you need to wait for 50 to 100 shakes. And then the bomb blows up.
Counting prayers
Worshippers of many different religious use beads on a string to count prayers: Catholic Christians, Muslims, Buddhists, Sikhs, Hindus, and Baháʼís.
Largest ocean current
How do you measure ocean flow? One sverdrup equals a million cubic metres of water per second. All of the world’s rivers emptying into the ocean is 1.2 sverdrups; the largest current in the world is more than a hundred times larger.
Decimal time
1000 metres in a kilometre, 1000 grams in a kilogram, and 1000 minutes in a day?
Double time
Almost all of China uses only one time zone. In the extreme west of China, the Xinjiang region uses two time zones at the same time. This is very confusing.
Australian tablespoons
If you’re using an Australian recipe book, watch out for the tablespoon, or your baking will turn out all wrong.
Metric martians
The Mars Climate Orbiter space probe cost 327 million US dollars – and it crashed because of a mix-up between the metric and imperial systems.
Most painful sting
Justin O. Schmidt, an entomologist from the United States, has ranked the relative pain caused by bee, wasp, and ant stings. How do you find that out, though? Easy enough, you just sting yourself.
