Paragraph 2
In 1999, a
measured the speed at which
change their shape. He found this was
femtosecond, which is a millionth of a billionth of one
. One millisecond is a thousandth of one second. This is the
it takes a neuron in our
to fire. One nanosecond is one billionth of one second. The
unit of time it may be
to measure is one Planck. This is a
point followed by 44
and a 1.
