Paragraph 1
Today,
are getting shorter. Scientists just measured the
unit of time ever recorded. It is a zeptosecond. This is
- a trillionth of a billionth of a
. It is a decimal
followed by 20 zeros and then a 1. The
study atomic physics. They used
tools to measure how long it takes a
to cross a hydrogen molecule. The scientists said it took 247 zeptoseconds for
to happen. This is too
for humans to see.
