The answer to time travel? in The AnswerBank: Science

As proved in 'King Arthur and the Spaceman', travelling close to the speed of light will take you back in time....

The phenomenon with the clocks, people are referring to is again relative. The one that has travelled, has aged less than the other, and therefore nows exists in the past (relative to the stationary clock).

bernardo

The most-travelled time traveller is a Russian cosmonaut who has spent about 2 years in space goes round and round the world thopusands of times at 18000 mph. He was going so far so fast for so long that he has actually travelled approximately one-fiftieth of a second into the future compared with the rest of us.

IndieSinger

Wow, did he ever tell us what it was like? Were we all travelling around on hoverboards and having cups of tea made by robots? That must have been amazing.

trilobite

jenky dearest, 'King Arthur and the Spaceman' is fictional I'm afraid, and as such offers no proof of anything.

jenky

WHAT! Fictional - Never.... next you'll be telling me that Father Christmas was really my parents.

Gef

Sincere apologies to trilobite - a few beers too many last night. Perhaps instead of finishing with "I am now in the past", I should have written "I am now pxssxd".

slimfandango

No, I wasn't drunk, what I was trying to illustrate with my ferging and farging is what I consider to be one of the hardest nuts to crack in science/philosophy: the ACTUAL relationship between the terms we use and the actual thing to which they refer. Example: time. Everyone (ish) before 1900 believed that it really referred to a real thing worth talking about. Now we know that the real thing is probably spacetime.

Relativity dictates that it is difficult to find things to talk about independently of other things. Eg. oh, let's say if my mass was x, what would my speed be if I added energy z? Well, your mass changes with speed, etc etc. So my problem is that we talk of speed (ie of light) as the one thing that is absolute, but to me it seems that speed, within the confines of our description, derives its meaning from time....and space. So does this mean that when you put together two things that are relative like that you get an absolute? Or is it because it's a property of light, ie energy. Which travels. Just trying to fix this all before I start indulging in a bit of light bbc docuscience watching...

Pinotage, that's the old chestnut...they may be around you, LOL. Best answer I heard so far is that you can come back, but only to a time when time machines already exist. And delorians also probably...

stoo_pid

Pinotage, according to The Flipside of Dominic Hyde they do come back from the future but are only allowed to observe us. Things can go wrong though & Mr Hyde accidentally ended up being his own grandfather.

Tiesto

Question Author

Your still going way over my head with that one Slimfandango.

I think i'll stick to Dna reproduction to make another one of me in a 100 years if i want to go into the future!!

asallen

Relative to what?

If two spacecraft speed towards each other at half the speed of light, (possible in theory!)

then they are relatively approching each other at the speed of light.(impossible!).

slimfandango

Geff, you meant 'I will be pi***d'. Einstein's work is commonly misinterpreted. What he said was that the only absolute is the speed of light ale.

magicdice

ahhh relativity. think about this:

i'm travelling AT the speed of light towards the sun. i throw a ball in the direction i'm going. so the ball is travelling faster than me, which by extension means it's travelling faster than the speed of light. which it can't. hmmmmm.....

stoo_pid

Or, as Steven Wright asked, if you're travelling in a car at the speed of light & you turn your headlights on - would anything happen?

bernardo

Wow, did he ever tell us what it was like? Were we all travelling around on hoverboards and having cups of tea made by robots? That must have been amazing.

*HB* IndieSinger - A fiftieth of a second is nothing. I know someone who has travelled a whole year into the future only since yesterday.

bernardo

If two spacecraft speed towards each other at half the speed of light, (possible in theory!)

then they are relatively approching each other at the speed of light.(impossible!).

Actually, if one thingy is travelling eastwards at half the speed of light, and a second thingy is travelling westwards at half the speed of light, the speed of the two thingies relative to each other will be only four-fifths of the speed of light.

Phantaxus

you all need to read Richard Gott: Time Travel in Einsteins universe

http://www.amazon.co.uk/exec/obidos/ASIN/0753813491/qid=1101484943/ref=sr_8_xs_ap_i1_xgl/202-2240677-5694243

Andrew_2004

time travel is possible in this day and age!

here we are in 2004 pop down the shop buy yourself a Hebrew calendar and hey presto your in the year 5765! :o)

or if you want to travel backwards in time, simply take a trip to a remote town in the yorksire dales, hey presto your back in the 1930s! :o)

Andrew_2004

but on a serious note, if you were to tie a person / space craft to a piece of rope and start rotaing it about a point at a constant speed, as you increased the length of rope the velocity (angular velocity) at which the person is travelling would increase , therefore, if you had an infintite length of rope you would, and you constantly increased its length you would get to a point where the person will be travelling at an angular velocity exceeding the speed of light.

Well

Andrew_2004

but on a serious note, if you were to tie a person / space craft to a piece of rope and start rotaing it about a point at a constant speed, as you increased the length of rope the velocity (angular velocity) at which the person is travelling would increase , therefore, if you had an infintite length of rope you would, and you constantly increased its length you would get to a point where the person will be travelling at an angular velocity exceeding the speed of light.

Well

the

Andrew_2004

but on a serious note, if you were to tie a person / space craft to a piece of rope and start rotaing it about a point at a constant speed, as you increased the length of rope the velocity (angular velocity) at which the person is travelling would increase , therefore, if you had an infintite length of rope you would, and you constantly increased its length you would get to a point where the person will be travelling at an angular velocity exceeding the speed of light.

Well

the theory is sound

The answer to time travel?

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