in theory time travel would provide us
with endless possibilities
but what happens when you rearrange
space-time and it goes wrong
really wrong this is unveiled and today
we're answering the extraordinary
question
what if you die during time travel
are you a fiend for facts are you
constantly curious
then why not subscribe to unvailed for
more clips like this one and ring the
bell for more fascinating content
there have been various representations
of time travel in the media
and various ideas put forward by
academics about how we might one day
achieve it in the real world
but at its core the concept of time
travel is quite an easy one to follow
it's the ability to move through time to
jump to and
from any two points on any given
timeline where now we can all travel to
say the train station and then the movie
theater and then back home
with time travel we could journey to
1820s europe and then 1920s america and
then
2120s mars the past and the future are
ours to visit as we please
but that apparent freedom is actually
riddled with problems and paradoxes
probably the most famous time travel
conundrum is the grandfather paradox
which asks what would happen if you
traveled back in time and caused the
death of your own grandfather
before they parent either your mother or
father if time travel to the past were
ever possible
then this would naturally be a
possibility but if your grandfather dies
before one of your parents is born then
you're never born either which
means you'd never be alive to travel
back in time to cause your grandfather's
death in the first place
there are variations on the paradox too
where you might want to travel back in
time to kill any individual
one that you're not directly related to
only to find that the gun
inexplicably doesn't shoot the general
idea is that if you were motivated to go
back in time to kill someone then you'd
never actually be able to do it
because if you did then you'd never have
that motivation to spur you on
the same applies to any action to change
the past too
it doesn't always have to be killing in
theory time travel is simple
in practice it's really not but what
about you as an individual
in regular everyday non-time travel life
there are countless ways you could die
and seeing as you'd still be inside that
same organic perilously killable body
even if you were to travel backwards or
forwards in time x number of years
you'd still be just as vulnerable to
fatal accidents in the past and future
as you are in the present
this isn't about cutting down your
family tree anymore your grandfather
lives
your parents live and you live up until
the moment that you time travel
someplace else and
well you don't live say you zap to just
a regular day
in 19th century london crossed the
street without looking
and got trampled by a horse and carriage
or you popped up inside a moon base in
the year 2296
took a wrong turn down the wrong
corridor and got ejected out into space
both times you die despite the fact that
you weren't meant to be there
but is that really true would you really
be not meant to be there
one of the more straightforward ways to
contemplate traveling through time is
just to accept it as a part of life
as far as we know it isn't a part of
life right now but
one day it might be and if we do reach
that stage any place or time we travel
to
only actually accounts for one moment on
the overall timeline of our own
individual existences
so from this point of view any time
travel destination we happen to die at
is simply the last location in a long
series of locations we visited
much like how it is for any death
despite the fact that their timeline
would move all over the place
a time traveler would simply look back
at this list of locations as having been
their life
they can't possibly have been or died
anywhere they weren't meant to be
because their route through that life
had simply led them to that point
the repercussions get a little foggier
however we're a time traveler to meet
their past or future selves
if they met their past selves and
somehow caused them to die
maybe their past self double takes at
the sudden appearance of their apparent
doppelganger
and because of that gets hit by a
passing car well we're back into
grandfather paradox type territory
where present day you in the past causes
present day you and the present not to
exist
if a time traveler met their future self
and somehow caused them to die however
it's probably an even bleaker prospect
now more than ever
time travel theories become wrapped up
in ideas on fate determinism and
retrocausality
retrocausality is the idea of an effect
preceding its cause
that something only happens because
something else happens after it
it's linked to something called
newcomb's paradox too where one person's
ability to see into the future
affects the actions of someone else in
the present in the case of meeting your
future self and causing them to die then
retro causality relates to the time in
between that moment as seen by your
younger self
the one causing the death and that
moment as seen by your older self the
one
dying say you travel six months into the
future knock a piano down some stairs
and that piano kills older you at the
bottom
for the rest of that six months on earth
whatever happens you'd know with
certainty what was about to unfold
one day you'll find yourself at the
bottom of a staircase when a piano
pushed by a younger you ends your life
in the meantime in a world where time
travel is obviously possible
you might jet here there and everywhere
in a bid to extend the time you're alive
between now and then
doctor who fans will recall clara oswald
taking the long way round to her death
like i said
[Music]
but the moment of your death would still
be inevitable no matter how strongly you
resolved never to go to that particular
staircase to be crushed by that
particular piano
it would be predetermined and
inescapable it's why many debates about
time travel argue that if time travel
exists
then free will can't just think of all
the things that have to happen just to
get the piano to the top of the stairs
the lives of manufacturers music
teachers buddy pianists
and removal companies all have to align
and interweave
to ensure the object that you know will
kill you is at just the right place at
the right time
there'd be nothing you or anyone else
could do about it in this version of
reality it might seem like we make
choices but we really don't
so time travel death essentially raises
three main possibilities
you either die as you were always meant
to just not in traditional chronological
order
or you erase yourself from existing in
the first place even if that is
problematic
or you set an inescapable future moment
at which you definitely will die
but you at least get to live a
predetermined life before then
of course the other possibility is that
you died during the time travel process
itself
not in the past or the future but whilst
you're traveling to the past
or future one aspect of time travel
that's often overlooked
is the apparent rematerialization of a
traveler at their destination
clearly we don't yet know how time
travel would actually physically work
or if it ever could but there's some
argument that even if we had viable time
machines
simply arriving in the right place would
be an impossible feat in itself
the earth rotates while orbiting the sun
which orbits a black hole at the center
of a galaxy
which is one of billions of galaxies in
the universe fast forward or rewind just
one year then
and it would take some incredible
mathematics to land in exactly the right
spot
rather than getting cast off into the
oblivion of space
like drops of rain in the ocean time
travelers could find themselves lost and
absorbed into the void
and even if there was no chance of a
spatial error like this
it's a sure bet that any hypothetical
means of time travel
would place the human body under
incredible strain
until we have working time machines it's
really impossible to predict how they
might immediately affect time travelers
but we do know that just the idea of
time travel opens up a wealth of
philosophical thought experiments and
temporal puzzles to solve
if anyone could ever be in the past
present and future then that person's
death could truly occur at any time
but does that mean it could be avoided
probably not
because that's what would happen if you
died during time travel
what do you think is there anything we
missed let us know in the comments check
out these other clips from unveiled and
make sure you subscribe and ring the
bell for our latest content