Stephen Hawkins Universe - Time Travel

[Angilion]

There's a brilliant book called Tau Zero (fictional) which is about a near-lightspeed ship that ends up out of control and the consequent results.

http://en.wikipedia.org/wiki/Tau_Zero

As far as I'm aware (it's one thing that's in the book and something that people seem to forget) while you might not be able to get to lightspeed, you can get very, very close (forget about the percentages, unless you want to run into millions of decimals) - and the closer you get, the more the time dilation increases. I was under the impression that you could accelerate closer and closer to the speed of light, but never breaking it, but forever increasing the time dilation to ever higher levels?

Your acceleration would decrease at an ever-increasing rate as your speed increased, if my understanding is correct (assuming your engines maintain the same force). So you'd soon get to a state in which you are accelerating closer to the speed of light but by such a small amount that it's not going to matter in your time frame.

 

[Castiel]

Are you sure?

0.99r = 1

Thus

99.99r = 100

So

99.99r % of c = c

Yeah, I'm sure the OP didnt say 0.99r times c, he said 0.99x the speed of light, where x means 'times'.

At 0.99 times c, the equation gives approximately a 7:1 ratio. As I explained the closer you get to c, the closer to infinity and so the greater the ratio.

I wasn't being pedantic like he claims, just pointing out that the 0.09999999r is extremely significant with regards to the math and the resulting ratio.

 

[G-MAN2004]

If a pair of twins are born on the day the ship leaves, and one goes on the journey while the other stays on Earth, they will meet again when the traveler is 5.14 years old and the stay-at-home twin is 10.28 years old.

Surely they'll still be the same age? Meh, I don't get any of this.

 

[stulid]

it should be, the twin on the ship experiences 5.14 years, the one on earth experiences 10.28 years.

 

[G-MAN2004]

it should be, the twin on the ship experiences 5.14 years, the one on earth experiences 10.28 years.

Don't they both just experience exactly the same, but time is just said to be different, therefore not really making any difference at all at the end of the journey? They'll both be the same age, and one will have been away for the same amount of time as the other one has spent on earth.

All sounds a bit pointless tbh.

 

[bigjimmyauk]

really confusing stuff is the program on any kind of catch up tv at all

so again if i went on a 10 year journey when i came back my daughter would be 22(she's 2 now) but would i

a. Be 20 years older, by which i don't mean time as in just time, i mean actual physical time spent ageing
b. Be 10 years older, by which i don't mean time as in just time, i mean actual physical time spent ageing

 

[Castiel]

Surely they'll still be the same age? Meh, I don't get any of this.

Its relative to the individual. For example the hubble telescope is seeing the farthest stars as they were 13billion years ago, so those photos that look so cool are really pictures taken today of 13billion years ago. Right now in that part of the universe, those stars have long since died.

 

[ChroniC]

Simply put, we all experience a time speed of 10, we are moving at a speed of 2, so time is running at 8 for everyone. if we start to move at a speed of 5, then time is running at 5, which is less/slower than 8! We can only ever move at a speed of 9.99, meaning that for everyone moving at 2, time is 8, where for the traveller at nearly light speed it is 0.01

Make sense?

 

[stulid]

hawkins clearly stated that the one on the ship will come back to a future earth, the ship gets to i believe he said 99% the speed of light and travels for say 1 year, when the ship returns to earth, its now 2 years since leaving.

 

[Philtor]

Simply put, we all experience a time speed of 10, we are moving at a speed of 2, so time is running at 8 for everyone. if we start to move at a speed of 5, then time is running at 5, which is less/slower than 8! We can only ever move at a speed of 9.99, meaning that for everyone moving at 2, time is 8, where for the traveller at nearly light speed it is 0.01

Make sense?

Give me some of that stuff your smoking. lol!

 

[Castiel]

Don't they both just experience exactly the same, but time is just said to be different, therefore not really making any difference at all at the end of the journey? They'll both be the same age, and one will have been away for the same amount of time as the other one has spent on earth.

All sounds a bit pointless tbh.

no, because the twin who travelled completed the journey in 5 years, although 10 years passed on earth due to time dilation of relativistic speed.

he basically travelled 10 years in 5.

 

[Angilion]

proof would be sweet but i fear its mathmatics at play or some nerd phyics nab who made a guess

physics is the route of all evil and can prove anything whether true or false

My vague estimate in the middle of the night is that an airline pilot would need to fly about 100 million miles to experience 2 seconds of time dilation.

 

[Castiel]

Simply put, we all experience a time speed of 10, we are moving at a speed of 2, so time is running at 8 for everyone. if we start to move at a speed of 5, then time is running at 5, which is less/slower than 8! We can only ever move at a speed of 9.99, meaning that for everyone moving at 2, time is 8, where for the traveller at nearly light speed it is 0.01

Make sense?

Not really!

 

[Philtor]

Hawkings might be a smart man but as I've said before all of this time travel craic is not possible given it would take an infinite amount of energy to travel at the speed of light. Even to get close to it wouldn't be possible. Even if we did manage to achieve them speeds, the human body could not withstand such a speed. Your organs would be mush.

 

[Castiel]

My vague estimate in the middle of the night is that an airline pilot would need to fly about 100 million miles to experience 2 seconds of time dilation.

90 million would give 8 seconds at c. I worked it out at around 0.004seconds per year for mach 2, I cant find the reference online.

I'll keep looking.

 

[bigjimmyauk]

http://www.yourdiscovery.com/video/playlists/stephen-hawkings-universe/#player

interesting lol
http://www.yourdiscovery.com/video/playlists/stephen-hawkings-universe/#player

 

[stulid]

the human body could not withstand such a speed. Your organs would be mush.

why, theres no gravity in space to act upon your body, no G force to experience?

 

[G-MAN2004]

no, because the twin who travelled completed the journey in 5 years, although 10 years passed on earth due to time dilation of relativistic speed.

he basically travelled 10 years in 5.

Okay, here's a silly scenario. Let's say each twin had a calendar and a clock and both ticked off each day. When the twin gets back to earth, surely they will have ticked off the same amount of days right? Or am I being utterly stupid?

Yes, I'm not a physics person

 

[DavidMarq]

Yeah, I'm sure the OP didnt say 0.99r times c, he said 0.99x the speed of light, where x means 'times'.

At 0.99 times c, the equation gives approximately a 7:1 ratio. As I explained the closer you get to c, the closer to infinity and so the greater the ratio.

I wasn't being pedantic like he claims, just pointing out that the 0.09999999r is extremely significant with regards to the math and the resulting ratio.

You seem to miss the point, I quoted your post not the OP, it is your post that contains 99.99r which is 100

Why not just put 100?

 

[Angilion]

really confusing stuff is the program on any kind of catch up tv at all

so again if i went on a 10 year journey when i came back my daughter would be 22(she's 2 now) but would i

a. Be 20 years older, by which i don't mean time as in just time, i mean actual physical time spent ageing
b. Be 10 years older, by which i don't mean time as in just time, i mean actual physical time spent ageing

b.

There is no absolute time. We pretend there is because it's extremely convenient to do so and time dilation is negligable in normal life, but it is just a pretence. So if you live for 10 years in your frame of reference, then you will have physically aged 10 years because 10 years will have passed for you. The fact that 20 years passed for your daughter would be irrelevant to that - in her frame of reference, 20 years has passed, but that's her frame of reference, not yours.

Headbender, isn't it? We think of time as absolute, an immutable thing that passes at a fixed rate. Our language, our way of thinking, has that idea deeply engrained into it. I know it isn't true, but I still think that way.