how many of you have watched a movie or
a series and ended up asking yourself
whether or not what you’ve just watched
is physically possible well I do this
all the time
after watching avatar I always just try
to airbend and I horribly fail then
there’s Back to the Future which
captivates us with the idea of time
travel moving going to your past or to
your future now time is a concept were
very very familiar with it governs our
lives doesn’t it it gives meaning to the
words early and late but what is time
itself and is time travel just science
fiction well today together we’re going
to unravel one of the most important
insights into the fabric of this
universe made by an extraordinary mind
yeah that’s the face of extraordinary
Albert Einstein together we’re going to
see that time travel is no science
fiction instead is the reality that lies
all around us
now other Einsteins foundation for his
theory was an experiment called the
Michelson and Morley experiment now what
this experiment determined was pretty
simple no matter who you are where you
are what you’re doing whether you’re
moving or not the speed of light will
always be constant it will always be 299
million 700 thousand four hundred fifty
eight meters per second okay so to
explain his theory let’s play out a
scenario imagine two people let’s call
them Peter and Jane
Peter is on a train while Jane is
outside observing Peter for purposes of
the explanation let’s say Peter has a
device which bounces a beam of light up
and down between two mirrors
now when the train is not moving both
Peter and Jane see the same thing which
is the light bounce up and down now what
do you think would happen when the train
starts moving well
Peter still sees the light being moved
up and down between the two mirrors but
Jane the other hand sees something
completely different it so happens that
the vertical mount vertical motion of
the light beam and the horizontal motion
of the Train merged together and she
sees something like this she sees the
light move at an angle diagonally in a
triangular path now keeping in mind that
the light that the speed of light is
always constant let’s do some math
simple math I promise will be simple
well simple I know we do in class so
we’ll start with speed distance divided
by time
simple enough yeah now what we’ll now
we’re talking about the speed of light
so C is equal to distance divided by
time that’s how light is denoted now
what would Peter’s equation be let’s say
he measures the light cover a distance D
in time T his equation would be simply D
over T what about James equation she saw
the light beam move in a triangular path
therefore the distance sheets she
measures the light cover is greater than
what Peter measured for simplistic
purposes we’ll say it’s twice the
distance so 2d her equation will be 2d
divided by what what will her time be it
can’t be T otherwise the time the speed
of light both Peter and Jane will
calculate will not be the same so
realize that Jane’s time must also be 2t
now you may not realize this right now
but what this means is something
mind-blowing it means that for every one
second that Peter spends on the train
two seconds will have passed by for Jane
this means that Peter just effectively
time traveled to the future by one
second I know it’s mind-blowing isn’t it
you see to keep the speed of light the
same the universe works in a way that it
rips time and space off of their
definite nature time begins to move at a
different rate for someone in motion and
this is called time dilation
this is Einstein’s theory of special
relativity and you can most definitely
be used to time travel to the future now
I know by the looks of most of your
faces you’re probably wondering this is
just a pretty neat theory isn’t it well
just like any other theory in science
it’s not it’s not just a theory it was
tested in 1971 a couple of atomic clocks
were synchronized and just to give you a
picture of how accurate this method is
here’s a fact and that the most accurate
atomic clocks lose one second every 15
billion years that’s older than the age
of the universe this is mind-boggling
accuracy so a couple of these clocks
were loaded on a jet plane and flown
around the world and when they landed
their time was compared to a few clocks
that were left on the ground and what
the experiment found is that the clocks
that were flown around the world their
time was ahead by a few nanoseconds now
and a few nanoseconds you may say isn’t
a lot but in this case it’s enough
evidence for the theory of relativity
that theory works now when I think of
all of this when I think of all of this
it’s just mind-blowing stunning
confusing all those emotions at once
I mean imagine traveling to the future
time travel has opened up so many
doorways that were closed till now
imagine witnessing the technology that
today right now we call impossible
flying cars for example lightsabers
imagine going to the future and bringing
back the cure to
so how many lives will be saved the
possibilities simply explode and they’re
simply just limitless now many of you
may be asking what about time travel to
the past because I said go to the future
and bring back the cure to cancer well
my friends I’m afraid that’s a story for
another day
well and if someone if mankind ever
makes time travel possible in the future
remember the vows Choji first thank you
[Applause] [Music]