TECHNOLOGY
When was
the hot-air
balloon invented?
Find out on
page 254What is the
range of
the Venturi
Astrolab?
Find out
on page
259Technology began about 3 million years ago when people invented the first tools.
Computers work at least a million times faster than they did in the 1940s.
A single DVD can store as many words as over 10,000 thick books.
There are over 600 million cars on the planet—roughly one for every 11 people.
A space rocket makes 10 times more power at liftoff than an airplane’s jet engines.
TECHNOLOGY