More physics

[securespark]

This thread is very "Sliding Doors"...

 

[Mickymoody]

It's a very interesting theory, and no matter what I say, some might agree, and others not, and in an alternative reality, everyone agreed, I went on to win the world cup, singlehandedly, and became president of the UK Euroland state.

But I believe time travel, to some extent does happen at a more basic level. If you are having fun, or are excited, then doesn't 'time-fly' as they say?

But if you are bored, and waiting for a delivery for example, 'time drags', so by this example, if you are in a 'time drag' scenario, you know that the phone is about to ring, and who it is? Possibly because your internal clock is going slower than the person that rang you, and as the data travelled at the speed of light, you knew the outcome?

OK it's BS, but worth considering in the order of things, as obviously the 'kill your Grandad' type timetravel cannot occur. What about timetravel, but with no interaction, like A christmas carol?

 

[mikhailfaradayski]

i think some people have been watching too many star trek re-runs

If there are an infinite number of parallel universes (or is that universii, universa??) in which an infinite number of possibilities exist, then ive just watched Dannii and Cheryl going at it like hedonistic drug fuelled rabbits and they've just asked me to join in. (whoop whoop )

However, in the reality that im currently aware of, im actually just sat at my pc typing this pointless response. I sharn't be holding my breath waiting for some transient fissure in the time space continium to transport me to the universe i think i'd rather be in

True knowledge is knowing that there is no answer.

As i (in my perception) have some answers, i therefore am not truely knowledgeable. So, until i have the answer to nothing at all, i will never understand anything.

The estate of Gene Rodenberry know this, but are happy to see the confused people struggle to come to terms with it.

c'mon England!!

 

[lifesagasman]

tranquility is thinking that you're not confused...

 

[Space cat]

Because everything is moving about, if you travelled back in time one year, you'd be zillions of miles away from where the Earth was one year ago.

It's not immediately obvious that 'the past' even exists! Treating time like an extra dimension through which you could move, if you only knew how, is a bad idea. Physicists like to talk about space-time because, if you multiply time by c, it fits into equations as if it was a fourth space dimension. It's nothing more than a mathematical convenience.

time travel DOES exist.. you're doing it right now.. you are traveling into the future, albeit at the leisirely pace of 1 day/day.

And you'll get to tomorrow a tiny bit quicker if you run round the block very fast. That's how you can travel into the future. Of course running round the block is not a very effective means of time travel. To do it properly, you have to jump into the space ship with an engine we haven't invented yet, powered by anti-matter we can't easily contain, and take a year off work streaking across the galaxy at c/3.

When you get back you'll find that it's a bit later than you think. There is no question about whether the future exists yet because you watched it evolve. What happens is that you get to June 18th 2011 a week or two ahead of everybody else. You'll also be able to see the lottery results ahead of time - by your own clock - but that won't do you any good. There is no way back to June 11th here on Earth to buy a ticket.

they proved this by splitting some sub atomic particle in 2 and taking the 2 halves a long way from each other..
they then manipulated one half and the other half did the same thing despite being a long way apart.

Maybe the 'particle' is really a wave. If you disturbed one part of a wavefront you wouldn't be too surprized if it changed somewhere else as well. It's an idea I've been toying with for years. I don't entirely believe in photons. What kind of particle comes in an infinite range of sizes (energies).

What if a wave really is a wave but our emitters and detectors - which are made of particles - can only disgorge and pick up wave energy in discrete bites? The single photon double slit paradox becomes trivial. Look at it another way. You want to know what the sea is made of so you run into it with a bucket. But you can only bring it back either full or empty. Would you conclude that the sea was made from discrete lumps of water?

 

[maltaron]

All this proves that too many people have nothing better to do than think up rubbish.

 

[lifesagasman]

compelling and fascinating simultaneously

 

[sooey]

It's not immediately obvious that 'the past' even exists!

That's hardly a revelation, I would have thought that the idea of a time machine was to take you to when it did exist.
Personally, I can't bring myself to believe in the possibility of time travel, but it does make for some good films.

 

[HOGGY952]

for every choice a single person makes, another universe ( or universes if it's multiple choice ) is created where the oposite choice(s) are taken

Which is why, if time travel were possible it would be impossible to change anything due to the knock-on effect.

To use your example of hitler, (I refuse to use a capital h), if someone went back in time and assassinated him in the late 30's early 40's then the course of the war would be different. Some people may die that didn't and some may live that didn't. This in turn would alter the structure of various families, maybe even yours. Would you have been born? Would you have an extra sister or brother? Would the time traveller have been born? If not then time travel may not have occured for another 200 years, in which case by altering the past the time traveller would be the cause of his own demise by not being born in the first place and consequently not been able to time travel.

this is why most scientists now think it is possible only to travel into the future.
the faster you travel, the slower time runs (this can actually be measured and clocks on sattelites have to be adjusted to compensate)
so if you travel almost at the speed of light, time will almost stop for you, but carry on at same rate for everyone else.
you wont notice anything unusual until you stop as it will seem to "you" as time is running at normal rate.

as time has been passing faster for everyone else, when you stop, more time will have passed for everyone else and you will have travelled into the future.
the nearer to speed of light and the longer you sustain the speed will determine how far into the future you travel.
if anyone could travel at speed of light, then time would stand still (so they say)
therefore, if you could break it, time would run backwards and opposite effect would take place.
this would apppear to be the reason nothing can reach speed of light, because it doesn't make sense and can't happen...
i think... brain fried....

 

[Space cat]

if anyone could travel at speed of light, then time would stand still (so they say)

One thing that does travel at the speed of light is light itself and so that hypothetical particle, the photon, doesn't age. It is created and destroyed at the same instant by its own clock.

therefore, if you could break it, time would run backwards and opposite effect would take place

It's not that simple. The time dilation effect comes from the term SQRT[1 - (u/c)^2] where u is your speed. When u = c, this is zero - and so your clock appears to stop - but what happens if u > c? The answer is the square root of a negative number and the logical conclusion is that time ceases to be real.

 

[skitzee2k]

OK, how about this one.

You get a time machine that can transport you through space and time. You go back to kill Hitler. You do so, then pop out of existence (because you weren't born) so Hitler ISN'T killed, because you never existed...so things go back to normal, without any changes, so you go back and kill Hitler...etc continual loop forever.

Even if it WAS possible, you can't ever change anything you know about..because it already happened. You may find that you were involved in history but didn't know about it.

Like you could go back in time to try and shoot lee harvey oswald before he kills JFK, but, when you are hiding behind the grassy knoll, your gun goes off and kills he president. Without knowing it, if you had done nothing Oswald would have missed...

 

[Space cat]

Time machines are good for movie plots but I would suggest that backward time travel is simply not possible. Our reasons for thinking otherwise are mostly derived from fiction, notably The Time Machine and, later on, Dr Who. Phrases like 'space-time' and 'the fourth dimension' have fuelled such speculation but time is nothing like space. It only becomes space-like in relativity calculations when multiplied by c. As I said earlier, it's just a mathematical convenience.

What do we actually think time is? Our concept of passing time is based on the common observation that actions cause things to happen afterwards, never before. The number of other things that happen around us after the cause but before the event gives us a crude sense of how much time has passed. To get a better measure, we construct clocks which generate regularly spaced events that we can count. That's all a clock is.

In order to reverse time we would have to undo all the events that have already happened. That is to say, we would have to restore the universe to an earlier state, something that the second law of thermodynamics will not allow. That's what I meant when I said that 'the past' might no longer exist.

 

[EddieM]

There proved !!

 

[EddieM]

I invented the first time machine.

 

[lifesagasman]

When?