what if the dimension of time was no

different from the three dimensions of

space we live in what if you could

travel to the past and to the future the

same way you can move right or left up

or down would you be able to change the

past and if you did would it create a

time paradox what kind of time machine

would you need to build anyway this is

what if and here's what would happen if

you could travel two times how many

times have you wished you could jump in

a time machine and skip that boring

meeting or choose a bitter comeback in

that argument last week time travel

sounds like some wild fantasy that only

happens in sci-fi movies but we're

actually traveling in time every day

Albert Einstein found that time is not a

constant but it's continually moving

forward and we're moving forward with it

according to Einstein time is the fourth

dimension together with

three-dimensional space it's fused into

a single four-dimensional continuum

space-time if you think of traveling in

space moving upwards is a bit of a

challenge unless we get on a plane or at

least take the stairs so maybe we just

haven't come up with a proper machine to

travel in time yet theoretically

building a time machine is possible but

it wouldn't look like this or like this

rather more like this because the secret

to time travel isn't in some exotic form

of matter what you'd need is a spaceship

that could travel almost as fast as

light

Einstein's theory of relativity taught

us that the faster we move through space

the slower we move in time let's assume

you were in a spaceship traveling at

99.9 percent the speed of light to a

potentially habitable exoplanet some 40

light years away you find some primitive

life-forms and speed back to earth to

share your discovery but when you

finally make it back to earth you

discover that all your colleagues are

now very very old from your perspective

you'd only been gone for about two years

for people on earth you'd been gone for

80 this phenomenon is known as time

dilation it's not likely to happen to

you though because traveling at the

speed of light isn't quite possible with

the technology we have now the fastest

piloted vehicle we've ever created

Apollo 10 reached a speed of 11,000

meters per second the speed needed for

time travel is somewhere near 299

million meters per second on top of that

accelerating at that speed would cause

an enormous centrifugal force a force

that would rip you apart before you came

anywhere close to light speed but hey we

still have wormholes Einstein predicted

that these theoretical tunnels linked

two separate places and two different

times a shortcut to another universe and

another time

the problem with wormholes is they're

extremely tiny just a billion trillion

trillionth of a centimeter across no

human would be able to fit through

I can barely fit in my jeans from last

year if only we could capture a wormhole

we might be able to enlarge it imagine a

giant tunnel above the earth leading to

another planet and theoretically if we

put both ends of a wormhole in the same

place but in different times we could

step into a wormhole and come out in the

distant past but wormholes have their

issues they're very short-lived and

traveling into the past would create

paradoxes like the one in which you go

back in time and convinced your

grandmother never to get married then

your grandmother doesn't give birth to

your dad

he doesn't have you but if you didn't

exist who went back in time to talk your

grandmother out of marrying your

grandfather time is linear it only goes

forward for that reason we can only

travel into the future not to the past

in fact astronauts that spent about a

year on the International Space Station

are now living in the future compared to

us even though it's just 13 milliseconds

in the future they're proof that

traveling a time is possible and maybe

wormholes could open up a whole

different world where the laws of

physics work in different ways and

traveling to the past is possible would

you dare step into a time machine not

knowing where it would take you and if

you had the choice where would you go

and when