The most obvious answer
is – as Aristotle pointed out- that we have 10 fingers,
which we can use for
counting and displaying
the results. This may be
why many cultures have
adopted the decimal system,
but it’s not a watertight argument:
some Native American tribes decided
single hands are enough, resulting in quinary counting systems
based on units of five. RM
Is there life in clouds?
Yes. Up to two million tons of bacteria are lofted by air currents
into the atmosphere each year, along with 55 million tons of fungal
spores and an unknown quantity of algae. These microscopic
life forms are thought to play an important part in the weather by
causing the water vapour in clouds to precipitate into rain more often
than it would in a lifeless atmosphere. LVWhy do we use a decimal
system?
PHOTOS: GETTY X2, SCIENCE PHOTO LIBRARY, ALAMY, PRESS ASSOCIATION
Tunnel Boring Machines are
being used to excavate
beneath London for the city’s
Crossrail project