Time travelling paradoxes

[Snusmumriken]

Maybe a stupid question... Maybe something broke inside my head as I was thinking about time travel earlier... but... IF you were to go back in time, to before your father was born, to kill your grand father, etc... WHY would you expect to find your grandfather there ??

Why would you expect to find anything at all there ?? Other than what you brought with you of course...

Why would the earth, the sun, the moon, etc... be there ??

Shouldn't they all be lightyears away in the future... moving away from you at or near the speed of light ??

My physics are a bit rusty, and I might be confused about something... Maybe I have mixed some stuff up... But, I seem to recall that ALL the stuff in this universe is constantly moving, and everything is always moving at the same speed... The speed of light... Only the direction is changing... When you're going faster through space, you're going slower through time, and vice versa...

But IF there were an earth for you to arrive at in the past, and a grand father for you to kill, etc... Wouldn't that imply that things aren't actually moving through space and time in this universe at all ?? , but rather different frames or time-slices of a completely static universe are somehow being "activated" one after another ??

Life is not a movie, is it ??

Not a stupid question at all. And quite correct too.

The reason it is omitted most often is that degree of realism: you are stepping into a zone where you are pretty much a single step away from realising why the travel to the past is impossible - as it needs you to travel faster than the speed of causality.

So People who already broken that rule (and assumed time travel is possible) usually break the next one and assume you will end up in the spot you need to end up at rather than the actual spot.


BTW this is the reason that dinosaurs actually lived across the galaxy - when they were alive our solar system was way over there.

 

[RepresentingCaution]

My child comes to interrupt Husband and me while we are copulating. Surprise causes Husband to ejaculate a little earlier or later, and a different sperm reaches my egg. Now my child has a second X chromosome instead of a Y chromosome!

 

[expentio]

If time travel would be a thing, like an accepted technology there would be no way to safely contain it. At one point it's so known that anyone could theoretically have access to it. This would soon lead to too many people using time travel at once.
Now it may work for the first epoch, but people wouldn't stop. This means an indefinitely long future of people who time travel, cramping the time line up like a highway at rush hour.
At one point people might even migrate to safer times. Maybe dinosaurs age, fleeing from our exploding sun. Since those wouldn't simply die there's the question how the timeline can progress from this point on without leading to completely different way things happen. Yet that means all the migrated people would lose their cause of existence. And eventually time is again at its end and people escape to the dinosaurs age.
But this cannot work as there are already people. And this means that all these people cannot exist in their same timeline since their parents never were born due to different future-past.
With time so many different timelines push their people into the past that there's no space left.
And this all doesn't make any sense, which means that time travel within the same timeline cannot work as I don't know about billions of superadvanced dinosaur civilizations in the past.

 

[Agentt]

Maybe a stupid question... Maybe something broke inside my head as I was thinking about time travel earlier... but... IF you were to go back in time, to before your father was born, to kill your grand father, etc... WHY would you expect to find your grandfather there ??

Why would you expect to find anything at all there ?? Other than what you brought with you of course...

Why would the earth, the sun, the moon, etc... be there ??

Shouldn't they all be lightyears away in the future... moving away from you at or near the speed of light ??

My physics are a bit rusty, and I might be confused about something... Maybe I have mixed some stuff up... But, I seem to recall that ALL the stuff in this universe is constantly moving, and everything is always moving at the same speed... The speed of light... Only the direction is changing... When you're going faster through space, you're going slower through time, and vice versa...

But IF there were an earth for you to arrive at in the past, and a grand father for you to kill, etc... Wouldn't that imply that things aren't actually moving through space and time in this universe at all ?? , but rather different frames or time-slices of a completely static universe are somehow being "activated" one after another ??

Life is not a movie, is it ??

Well, not lightyears, that is too big, but yes, they have displaced through space too. If I just go through time, I would find myself in outer space

 

[AryaX]

If I just go through time, I would find myself in outer space

But... It won't matter where you go in space... if you go to the past, it will all be empty space, no?

Every particle of matter (or most... some might have been brushed away by solar winds and such) that was where earth was in space and time a year ago, is here and now today, so if you hop into a time machine and go back to the exact location is both space and time where you were year ago... while your time machine "might" be able to take you to that location in space-time, all you will find there is empty space, no? With every particle of matter being located lightyear away (in the direction towards the future...) or further... depending how fast the time machine is...

 

[TheTrinary]

But... It won't matter where you go in space... if you go to the past, it will all be empty space, no?

Every particle of matter (or most... some might have been brushed away by solar winds and such) that was where earth was in space and time a year ago, is here and now today, so if you hop into a time machine and go back to the exact location is both space and time where you were year ago... while your time machine "might" be able to take you to that location in space-time, all you will find there is empty space, no? With every particle of matter being located lightyear away (in the direction towards the future...) or further... depending how fast the time machine is...

I'm sure someone has written about it somewhere, but a time machine would have to be a space-time machine, able to also change points in space. Given how time travel is so ridiculous on it's own, people don't' treat it with that level of seriousness though. If you're writing about one impossible thing, might as well ignore the whole absolute point in space thing too.