Imagine what your history class would be like if time travel
were possible. You could travel back to 1620 and
watch the Pilgrims land at Plymouth Rock, or set your time
machine for July 4, 1776, and watch Thomas Jefferson sign the
Declaration of Independence, or even see the Wright Brothers on
December 17, 1903 make their historic flight over the sands of
Kitty Hawk, NC. History would no longer be trapped in our
textbooks. We could live through the important moments of the
past and see what really happened! You might be amazed that time
travel already exists in some ways. One day, we might even be
able to travel far into the future!
To understand time travel, you must first know how to define
time. Take a few minutes and try to write down a simple
definition. It isn’t that easy is it? You may be surprised, but
even the best scientists find it hard to put time into words.
We all think we know what time is. Probably the easiest way to
see time is to watch the ticking hands of a clock. One clever
teacher even put this message above the clock in her English
class: "A note to clock watchers: Time passes... will you?"
There are lots and lots of clues about time in our daily lives.
Have you ever seen a newspaper after it sat a few days in the
light and turned yellow? Your body also shows the effects of
time. In fact, you've probably even grown a little taller this
You'll find many definitions of time in the dictionary. The
simplest one is that it is a series of events with a past,
present and future. In fact, we are all time travelers of a sort.
Even as you read this, you are traveling into the future at a
rate of 60 seconds per minute, 60 minutes per hour and 24 hours
Any event that has not happened yet is in the future. Once we
reach an event, we've traveled forward through time. When you
wake up tomorrow morning, you will have traveled a few hours
through time to reach that point. But there's another way that
may be possible for us to travel hundreds or thousands of years
into the future. Time Rockets!
key to speeding up time travel and allowing us to jump into the
future is to build vehicles that can travel at the speed of
light - or at least near light speed. Light speed equals 186,000
miles per second! That is about 11 million times faster than a
car traveling at 60 mph! Scientists claim that time actually
slows down for you as you near light speed. So, if you had a
time machine that allowed you to travel at the speed of light,
time would slow down for you - but it would remain the same for
those not in the time machine.
But, here's the hitch. Scientists don't believe that matter can
actually reach the speed of light. The good news is that we
don't need to travel at the speed of light to travel through
time. In fact, we already have spaceships that can jump into the
The space shuttle travels at about 17,500 miles per hour. That's
40,000 times slower than the speed of light speed. But, even at
that speed, scientists calculate that astronauts aboard the
space shuttle travel a few nanoseconds into the future. A
nanosecond is a tiny speck of time - only a billionth of a
second. It is so fast that, by the time you can blink your eye,
400,000 nanoseconds have gone by! If we could build a spaceship
that is thousands of times faster than the space shuttle, then
we could travel weeks or years into the future.