Science Fiction

[upholder]

Originally posted by Jon

Watch Donnie Darko

 

Watched it last night and really enjoyed it, very good film.

 

However, I did feel that the ending was a bit of as cop out as he travels back in time and dies in an accident thus avoiding all the major questions relating to time travel once it has been achieved.

 

As posted above;

You could meet yourself.

You could kill your parents.

 

Being now dead what happens to all the events from the time he is killed to the time he decides to go back in time.(If you know what I mean). Doesn't everyones life change that he came into contact with and wouldn't they know that something weird was happening?

 

Need a lie down.

[Hodge]

Fascinating stuff, physics. In a way, we already time travel. The fact that we move through time (as a dimension), and also the fact that We only ever see the past - we don't even see the present, unless we are recieving light from exactly the same point in space as the original source of the photons.

 

If, for example, you are sitting talking to someone, 1 metre away from you, you're not actually seeing them as they are now, but as they were approximately 3.33 x 10^-9 seconds ago - the time it takes for light to reflect off the object (person) and reach us (we see because of light) 1 metre away:

 

speed(s) = distance(d)/time(t)

 

Therefore, t = d/s

 

distance = 1 metre

speed (of light) = 3x10^8 m/s

 

t = 1/3x10^8

 

t = 3.33x10^-9 seconds

 

In the same principle that we only see the Sun as it was approximately 8 minutes ago, and stars millions, or billions of years ago, and so on.

 

This, for me, throws up dozens of other equally fascinating questions - especially with regards to our universe, and what/where/when we can see. It's generally thought that the Big Bang occured between 12 and 15 billion years ago, and that the universe has possibly been expanding at almost the speed of light. So, theoretically, if we have a telescope powerful enough to 'collect' light from a distance of 12 - 15 billion light years, we may be able to see the Big Bang, and since the universe has been expanding in all directions, we may therefore theoretically be encased in a "shell" of the Big Bang - i.e. whichever direction we look in, at that distance, all we will see is the Big Bang. Further, it may be so that we cannot see any distance greater than 12 - 15 billion light years, since we are i) possibly encased in this "shell", and ii) nothing, it is thought, existed before the Big Bang, so there is nothing to look at even if we could see past the barrier.

 

But... nothing is infinite - quite literally - you can't have no nothing (a vacuum, if you like), so to speak, so the only infinite thing in the universe is nothing.

 

What if this universe is not the only one too? What if there were dozens, thousands, billions, centillions of Big Bangs accross the expanse of infinite nothing?

 

The mind boggles.

[upholder]

 

 

Just kidding, I envy your knowledge:D

[woolyhead]

OK Hodge. You say the universe has been expanding for 15 billion years so we may be in the centre of a big bang "shell." How and why the centre? Suppose our bit of spacetime occurred on the outside edge of spacetime at some point and so the exact point of creation for the universe is in only one direction from us as we are now? In other words we could be on the edge of spacetime, not in its centre.

[woodview]

This proves time travel is possible. A 16 year old post has just had a reply!!!

 

The time travel to the past thing is based on travelling faster than light, and just looking back at what happened in the past. You would have overtook the images, and be able to look at them. Handy if you don't have VAR set up.

As far as I know theoretically impossible, with our current understanding.

 

'Travel' to the future is possible, and proven. The closer you get to the speed of light, the more time dilation happens. i.e time in your locality 'passes slower' than time at the stationary locality.

e.g if you were at a funfair and could get a go on a spaceship that went 99% speed of light, and had a 10 minute ride, then years would have passed at the kiosk when you got back.

Sadly, and scarily, that is a one way ticket.

[woolyhead]

OK Woodview, are you referring to my post? I reckon you're being sarcastic when you say time travel is proven but look again at the meaning behind what I actually said. I meant that as spacetime expanded we appeared at some point. Why was that point necessarily at the centre of everything? Can you explain?  And by the way spacetime is not expanding at or even close to the speed of light, either, but much less. And the initial expansion was faster than c and it's called inflation. But my idea was about us appearing after inflation and within spacetime.

Edited March 14, 2019 by woolyhead

[woodview]

12 minutes ago, woolyhead said:

OK Woodview, are you referring to my post? I reckon you're being sarcastic when you say time travel is proven but look again at the meaning behind what I actually said. I meant that as spacetime expanded we appeared at some point. Why was that point necessarily at the centre of everything? Can you explain?  And by the way spacetime is not expanding at or even close to the speed of light, either, but much less. And the initial expansion was faster than c and it's called inflation. But my idea was about us appearing after inflation and within spacetime.

The 'time travel is possible' was a joke, referring to replying to a post from 2003..........

 

The rest of my post was about the OP, not your message.

[woolyhead]

I see, Woodview. Sorry.

[Cyclone]

1 hour ago, woolyhead said:

OK Hodge. You say the universe has been expanding for 15 billion years so we may be in the centre of a big bang "shell." How and why the centre? Suppose our bit of spacetime occurred on the outside edge of spacetime at some point and so the exact point of creation for the universe is in only one direction from us as we are now? In other words we could be on the edge of spacetime, not in its centre.

Only the centre as we observe it, not a true "centre" at all.

Also, you're replying to a thread 15 years after the fact, so I guess time travel does happen.

1 hour ago, woodview said:

This proves time travel is possible. A 16 year old post has just had a reply!!!

 

The time travel to the past thing is based on travelling faster than light, and just looking back at what happened in the past. You would have overtook the images, and be able to look at them. Handy if you don't have VAR set up.

As far as I know theoretically impossible, with our current understanding.

 

'Travel' to the future is possible, and proven. The closer you get to the speed of light, the more time dilation happens. i.e time in your locality 'passes slower' than time at the stationary locality.

e.g if you were at a funfair and could get a go on a spaceship that went 99% speed of light, and had a 10 minute ride, then years would have passed at the kiosk when you got back.

Sadly, and scarily, that is a one way ticket.

Observing the past doesn't mean you've gone to the past though.

We observe the past all the time, and when we listen it's even further behind!

[woodview]

36 minutes ago, Cyclone said:

Only the centre as we observe it, not a true "centre" at all.

Also, you're replying to a thread 15 years after the fact, so I guess time travel does happen.

Observing the past doesn't mean you've gone to the past though.

We observe the past all the time, and when we listen it's even further behind!

I know, that's why i talked about just looking at images of what happened. I think you also traveled in time and knicked my joke btw.......