Time travel possible.

[AztecInca]

Time travel 'possible, not economical'

Sunday Sep 30 09:31 AEST

Building a time machine that travels into the future is not science fiction - if you are a multi-trillionaire, a physics expert says.

Dr Craig Savage, who lectures in relativity and quantum mechanics at the Australian National University, said it was possible for people to travel forward in time but the costs involved were too great.

"If you could build a spaceship that could go three quarters of the speed of light you would time travel one hour into the future for every hour of your time," he said.

"People have designed such spacecrafts at various times but they would just be unimaginably expensive to create.

"It's not an issue of technology, it's one of economics."

The cost of operating a time travelling machine, in relation to the cost of electricity, would be ten trillion dollars, Dr Savage estimates.

"We are talking vasts amounts of wealth that would be involved in doing this, Bill Gates could not even consider this."

Dr Savage said that due to the cost, not the science, people will not be travelling through time in the foreseeable future.

"If an individual was going to time travel into the future they would have to have enough wealth to spend on this that was the same amount as 10 years of Australia's GDP," he said.

"The question is when will individuals be that wealthy? Certainly not in our lifetime."

Dr Savage said people who might be able to muster the resources for time travel in the future would be so advanced they would be unrecognisable.

"It's hard to imagine what the future would be like where something like time travel into the future would be economically feasible.

"It would be an utterly different kind of world that we live in at the moment.

"This kind of question takes science to the limits."

©AAP 2007

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So anyone have 10 trillion dollars lying around?

[Please Explain]

It's easy for me to believe supernatural but...time travel?

I don't believed it.

[northwest]

There is nothing to disbelieve here, because it's not REALLY time travel as in movies.

You don't disappear and appear in future, its just time dilation, as you go faster, your time slows down, making it seem for you that

the time outside of the vehicle accelerates.

You do it every time you drive in your car, it's just that your jump to future is so tiny beyond measurement.

If you can get a REALLY accurate watch, like an atomic clock, and drive around for some hours, you would be able to verify this (and it HAS been verified this way)

it's not anything strange or an anomaly, if you take a look at the physics behind it, if there wasn't any time dilations, THAT would be paranormal

[DarkSide]

Yeah, it is similar to if you were able to visit a black hole, your time would slow down compared to an observer on the outside of the blackhole the deeper you travel into it. YEAH SPACE-TIME!

[Azmr]

If time travel is possible, dont you think we would of met people from the future?

Peace.

[northwest]

If time travel is possible, dont you think we would of met people from the future?

Peace.

have you even read what this topic is about?

[Azmr]

I dont believe in tooth fairies.

Peace.

[JeremyGTS]

if you would of read that it says "FORWARD" time travel is possible which means traveling time speeds up as you approach the speed of light but you wouldnt be able to go back

[Strange F8]

The concept of time has two seperate veins. One is the time we experience as "now". The other is time as it relates to physics. When experiments have been done with atomic clocks that demonstrate time variants between the earth and space shuttles, one thing seems clear to me. Although there is a definite difference in time relating to physics, both observers on earth and in space experience the same "now" regardless of that difference. There is no "Tooth Fairy" story here. There is a question in my mind that if a more extreme time difference is possible (say a full year or a decade) would not the observers still experience the same "now", just from different time perspectives? What do you think?

[northwest]

I dont believe in tooth fairies.

Peace.

It's called uneducated

[667-Neighbor of the Beast]

One thing that is mentioned in the article above that does not make sense to me is the line "If you could build a spaceship that could go three quarters of the speed of light you would time travel one hour into the future for every hour of your time".

One hour into the future for every hour of my time?? That would be one hour into the future for every hour that I would be traveling on the spacecraft. But isn't that the same rate I am traveling into the future right now, as I sit at my desk?? If I wait an hour, then I am one hour farther into the future than I was one hour ago, correct?? Does this statement not make sense to anyone else??

Edited October 2, 2007 by BIGK1974

[Rocket88]

The concept of time has two seperate veins. One is the time we experience as "now". The other is time as it relates to physics. When experiments have been done with atomic clocks that demonstrate time variants between the earth and space shuttles, one thing seems clear to me. Although there is a definite difference in time relating to physics, both observers on earth and in space experience the same "now" regardless of that difference. There is no "Tooth Fairy" story here. There is a question in my mind that if a more extreme time difference is possible (say a full year or a decade) would not the observers still experience the same "now", just from different time perspectives? What do you think?

Hi "Strange F8".

This space/time/speed thing has always tied my head in knots, i just can"t understand it & it"s really frustrating !

My Ma-In-Law, jets all-over the world due to her occupation.

Just this year she"s been to Australia, the USA a few times (mainly New York & Chicago), Paris, Milan & Barcelona.

She"s doing all this jetting about, while i trundle from job to job in my LDV van (top speed 75mph).

Her NOW, is still the same as my NOW.

If i travel very fast, its still the same time, i"m just moving quickly!

Aren"t i ?

[Strange F8]

Hi "Strange F8".

This space/time/speed thing has always tied my head in knots, i just can"t understand it & it"s really frustrating !

My Ma-In-Law, jets all-over the world due to her occupation.

Just this year she"s been to Australia, the USA a few times (mainly New York & Chicago), Paris, Milan & Barcelona.

She"s doing all this jetting about, while i trundle from job to job in my LDV van (top speed 75mph).

Her NOW, is still the same as my NOW.

If i travel very fast, its still the same time, i"m just moving quickly!

Aren"t i ?

Hello Rocket88,

Your MIL traverses time thru zones, but thats not all, there is a time difference (imperceptible as it may be) during

the process of global travel. but to answer your question, I refer to my previous post that even though there is a

difference in the sense of physics, you both experience the same "now" but from different time perspectives.

If I could travel backward or forward in time (obviously at an accelerated rate from what others experience),

I think that to the observers in the time reference that I leave, I would look stationary, like a statue or a wax figure.

But from my accelerated perspective, everyone and everything around me would look accelerated! I would still

experience the same "now" as everyone else, but I would experience everyone differently than they would exp me.

I don't think we would disappear from one another's sight. Ain't time fun? Truth is stranger than fiction.

[Hawkmason]

Time Travel Possible? Maybe but is it effective? no

because the only thing we could do with the power of Time Travel is observe nothing more

people who think they can change events in the past do not know how time travel works

[Azmr]

It's called uneducated

Not precisely, its getting emotional over fantasies.

Peace.

[GreyWeather]

Time Travel Possible? Maybe but is it effective? no

because the only thing we could do with the power of Time Travel is observe nothing more

Not even that. Once you time travel you cannot go back in time. It's a one way street.

NorthWest hit the nail on the head in his first comment

[GreyWeather]

If time travel is possible, dont you think we would of met people from the future?

Peace.

Read NorthWests initial post, you can only go forward in time.

The faster you go, the more you slow down.

You're inside the cockpit of a rocket and traveling at the speed of light, For you, nothing changes inside the cockpit and your watch is ticking normally. Outside of the rocket, time is also normal, however the time outside of the rocket differentiates greatly from that of the rockets cockpit.

Hardly a fairy tale. It's been observed countless times by using atomic clocks.

Edited October 3, 2007 by Chokmah

[northwest]

What's even more interesting is that, when you observe the outside world from your ship, it also appears to slow down.

I think most people assume that if your ship time slows down and you look outside the window, that it would appear that the outside

time would speed up, but it doesn't, it also appears to slow down. It's a bit counterintuitive but when you start drawing graphs and using Lorentz transformations to plan the trip, it all adds up.

The secret is in the fact that there is no universal simultaneity, which is something a human brain can have a hard time

imagining.

[GreyWeather]

What's even more interesting is that, when you observe the outside world from your ship, it also appears to slow down.

I think most people assume that if your ship time slows down and you look outside the window, that it would appear that the outside

time would speed up, but it doesn't, it also appears to slow down. It's a bit counterintuitive but when you start drawing graphs and using Lorentz transformations to plan the trip, it all adds up.

The secret is in the fact that there is no universal simultaneity, which is something a human brain can have a hard time

imagining.

Well it's just common sense really, if you're traveling at almost the speed of light, of course things will appear to slow down outside the rocket. Being as light is reaching you at a lesser frequency.

You only see objects because of the light refracted from the object entering your eye. So while traveling at a speed close to the speed of light, less refracted light from an object enters your eye.

Of course, traveling at the speed of light, everything will appear to stop. Going faster than the speed of light, you'll see hardly anything.

So, time is not slowing down on the outside as light is at the normal frequency. If that makes sense...

Edited October 3, 2007 by Chokmah

[northwest]

Well it's just common sense really, if you're traveling at almost the speed of light, of course things will appear to slow down outside the rocket. Being as light is reaching you at a lesser frequency.

You only see objects because of the light refracted from the object entering your eye. So while traveling at a speed close to the speed of light, less refracted light from an object enters your eye.

Of course, traveling at the speed of light, everything will appear to stop. Going faster than the speed of light, you'll see hardly anything.

So, time is not slowing down on the outside as light is at the normal frequency. If that makes sense...

You are talking about Doppler effect, but that's not really the core of it, because it doesn't matter in which direction you are traveling.

If it were simply because of Doppler effect, then time would speed up for events that are in front of you.

So its still very far from common sense.

The thing is light travels at c, and you are traveling at say 0.99c, and you hit a beam of light, but the speed of collision

is not 1.99c , but still c.

Edited October 3, 2007 by northwest

[GreyWeather]

You are talking about Doppler effect, but that's not really the core of it, because it doesn't matter in which direction you are traveling.

If it were simply because of Doppler effect, then time would speed up for events that are in front of you.

So its still very far from common sense.

The thing is light travels at c, and you are traveling at say 0.99c, and you hit a beam of light, but the speed of collision

is not 1.99c , but still c.

No no, I was referencing light to signify time.

As the frequency of light slows down - which in effect would contribute to the appearence of time slowing down - Everything around you is as normal as it was when you left.

I wonder... If traveling over the speed of light, say 0.5 over the speed of light, the light inside your own rocket would - in effect - dissapear leaving you in darkness. Unless you looked at the light-source.

[capeo]

I wonder... If traveling over the speed of light, say 0.5 over the speed of light, the light inside your own rocket would - in effect - dissapear leaving you in darkness. Unless you looked at the light-source.

No matter the speed you travel up to C light will still travel at C to an observer.

[GreyWeather]

No matter the speed you travel up to C light will still travel at C to an observer.

Ah I see, Interesting.

[capeo]

Ah I see, Interesting.

I know it sounds absurd but such is the case. It all comes down to the inertial frame of reference. When it comes to light the inertial frame always seems like a standstill. A good example is say you're on a spaceship traveling .5 the speed of light and you point a flashlight along your trajectory. The light emited would still be traveling at C not 1.5 the speed of light. Once you start to talk about massive bodies this starts to fall apart though. Not the inertial frame per se but addition of velocity. Say you're in a train going 50 mph and you toss a ball towards the front of the train at 20 mph. If you measured from inside the train the ball would be going 20 mph. If the refernce were outside the train it would appear to be going 70 mph. And if you tossed it out the window forward (in a vacuum) it would hit a stationary object going 70 mph. Particles without mass don't work that way though.

[diceshadow1]

if you travel 1 hr into the future , in one hours time ,you did nothing