[chp]

NEWS ARTICLE FOR DISCUSSION

Are Wormholes Tunnels For Time Travel?

As any self-respecting science fiction fan knows, wormholes???theoretical shortcuts through space and time???make for excellent time travel portals. The latest movie to transport people into the past is this summer's A Sound of Thunder, based on the classic 1952 Ray Bradbury novella. In it, a group of hunters build a time machine, which looks like a wormhole of sorts, to travel back to the dinosaur era. There, things go awry when one hunter kills a butterfly, which completely changes the course of history. The movie was widely panned by critics and seems to have quickly slipped out of theaters. But the questions it raises???the mystery of time and the possibilities of traveling through it???remain among the thorniest in physics, keeping a growing number of scientists occupied. It's not like scientists are looking for a way to actually travel through time. But some believe that theorizing about how it could be done???maybe by using a wormhole in space???will help them understand and perhaps even revise the laws of physics.

"Traversable wormholes are extremely useful as gedanken experiments"???the term describes experiments that can be reasoned theoretically but are impractical to carry out???"to probe the limitations of general relativity," said Francisco Lobo, an astrophysicist at the University of Lisbon in Portugal.

Albert Einstein's relativity theory set the speed of light as the universal speed limit and showed that distance and time are not absolute but instead are affected by one's motion.

A clock in motion will always appear to run slowly compared with one at rest, because time is relative to the speed at which a body is moving. That fact would, in theory, allow for time travel???at least if you have a very fast spaceship.

Consider this: If an astronaut travels into space for six months at a substantial fraction of light speed and takes another six months to return to Earth, he would land in the future.

While a year will have elapsed on the astronaut's clock, tens of thousands of years may have gone by on Earth, depending on how close to light speed the astronaut traveled.

"The bottom line is that time travel is allowed by the laws of physics," said Brian Greene, a Columbia University physics professor and the author of The Fabric of the Cosmos: Space, Time, and the Texture of Reality.

But the laws of space and time as Einstein laid them out may be revised by the quirky rules of quantum theory. Quantum theory describes the microscopic randomness that fills the universe.

For full article see source:
http://news.nationalgeographic.com/n...imetravel.html

[Nat]

I was almost excited for a second thinking someone had responded to relevant science. No, No Such Luck !!! I see little point in doing a whole speil about it , ...tho I will point out that Einstein disputed his own theory on galaxial speed limits
(eg: E=MC2) with his 1920 (ish) 'Theory of Torsion fields' which blows previous speculation out of the water.

Nat xxx

EDIT: ..ahhh, never mind, ....she unfortunately deleted her post, which is a shame coz the opinion was valid and kickstarted debate, ...dont do that again hun , ..your opinion is as valid and welcome as anyone elses xxxx

Nat

[marcos]

Not a video on worm holes as such but here is a short clip explaining part of Einsteins theory on time travel.

Presented in an easy to understand format.

Marc

[Nat]

You forgot the link

[marcos]

Thats odd because when I posted originaly I did forget the link but edited the post to put the link in!

Never mind lol heres the Link

http://www.youtube.com/watch?v=V7vpw4AH8QQ

Marc

[SemperNox]

Are wormholes portals allowing time travel? Perhaps; of course it's all highly speculative at the moment. It's a moot point though, as the only wormholes known to exist are around the size of the Planck distance (10^-20 the size of a proton, or 1/100,000,000,000,000,000,000th the size of a proton, while a proton is 10^-12 mm (.0,000,000,000,001 millimeters) making the planck distance approximately 10^-32 mm (32 zeroes in front of the 10) and is far too small for most humans to comprehend. This is too small for even an electron to squeeze through, although photons have made the journey in some laboratory tests.

Macroscopic wormholes (large enough for a human or space ship to pass through) are theoretically possible, but we quickly run into a problem: wormholes are extraordinarily unstable and collapse upon themselves in the presence of matter or energy. It's possible to expand a wormhole and potentially stabalize it with 'negative energy', but negative energy is purely hypothetical and has yet to be observed under any conditions. Perhaps sometime in the future we'll have the technology for stable wormhole travel.

Another problem is that while it's possible for a wormhole to be a shortcut in spacetime (think of a worm eating straight through an apple; the distance it travelled is much shorter than if it had crawled around to the other side of the apple), there are no rules to suggest that a wormhole will always be 'straight'. It's possible for the wormhold to twist and meander and double back to such an extent that travelling through the wormhole would be a much longer journey.

If faster-than-light travel is possible through wormholes, it's possible backward time-travel could be achieved, but there are other things to consider. Are wormholes intrinsically tied to specific locations, or simply floating through space occasionally connecting with locations. Is it possible for a wormhole to consistently have the same locations connected (regardless of how much the 'tunnel' it's-self wriggles around)? There are speed and direction issues to consider as well; for example, the earth is rotating at 1600 kph at the equator, and travelling approximately 107,000 kph around the sun. That's not considering the rotational speed of the galaxy, and the directional travel of our galaxy, and the spreading of the universe in general.

So, IF it's possible to secure a wormhole to a start and finish location/time, and we're able to stabilize the wormhole to a size capable of fitting the human body (or vehicle), then yes, wormholes could be used for time travel.

Thank you for putting up with my rant.

[aanonymous]

Okay,

I just noticed this thread as I was checking the one I started...

Let me see if I can clear a few things up...

Though it is theoretically possible to use wormholes to travel back in time, and it is fact that wormholes exist, they are much too small to be used for practical applications, and are seemingly impossible to predict.

And yes, If we were able to "catch" one and make it large enough to travel through, the journey would be less than heroic.

Basically there is no law in physics that says time travel cannot be possible, though even Albert Einstein himself did not believe that it was so. When I say "time travel", I'm talking about traveling into the past. It is very easy to time travel to the future, as we are all constantly doing it. In fact, a mass that is traveling at a greater velocity actually is traveling forward in time faster. One of the best ways to explain this is the Einstein twin paradox, being that if there were a pair of identical twins, and one were so lucky to find himself becoming an astronaut and was sent into space to orbit Earth, he would in the end have traveled forward in time faster than his brother, making him a minuscule amount younger.

Bringing up paradoxes also raised the whole Grandmother paradox thing up...

If someone, a theoretical badguy for this purpose, were to go back in time, and were so rude to kill his own grandmother, he would never be born...

This paradox is easily overcome!

With the multiverse theory, which consists of collection of universes that lay on top of each other like membranes. They are similar to the leaves branching off of the same plant, in that each are somewhat different. Each universe in a multiverse is called a parallel universe, something you SciFi fans should know oh so much about...

Basically, but not too basically, when this theoretical felon goes back in time and kills granny, he has actually traveled to an alternate reality. In this reality, the individual will never be born, as granny kicked the bucket oh so early. The rude individual actually was born in HIS reality, a seemingly different one from the one where he was never born. This also raised the question to whether or not time travel creates an alternate reality, or if a person actually travels to an existing one... Which... I'm too bored to figure out...

Well, I'm just sitting here wondering about this, waiting for the day I come back in time to tell myself the answer. Honestly, if it was possible, I would have done so already...

[drusila]

oooooooooo paradox............cause and effect.........wormholes.

that's it. digging out the red dwarf dvd's, got cold turkey now.


"This also raised the question to whether or not time travel creates an alternate reality, or if a person actually travels to an existing one... Which... I'm too bored to figure out... "

chicken and the egg theory. :wink:

[oktor]

i read in scientfic america a few years back about a theoretical machine made out of a quantum singularity stretched to some crazy size like 300km as a cylinder then span on it's access at speeds approaching that of light, i tried it, didn't work :/
seriously though i tried to look up the article online but i couldn't find it, it mentioned that traveling through time using such a device could only be possible back to the time the machine was made, no earlier. that would explain why we haven't had any visitors popping up infront of tv screens saying boo.
seems like a good safety net, it won't happen till we are ready for it to happen

[carlosspaul]

Scientists are supposed to have proved that time is relative to space. Apparently an experiment was done by placing an atomic clock in a place travelling around the world, another atomic clock was fixed on the ground. Apparently when the plane landed the clocks where out of sync by something like 0.00000000001 of a second. They say the clocks stayed accurate and time had changed by this minute amount on the plane, Eg. Forward or back in time.

I don't know how much of this is true.

With regards to wormholes, I suspect there are wormholes present natually on this planet. In the Burmuda Triangle forinstance, planes have made 1HR trips in 15 minutes after experiencing lots of strange magnetic interferrence Etc. I met someone who claims to have been through a wormhole himself while walking, suddenly finding himself lost, miles from his original location. Unfortunately I've only got his word for it. There are however many accounts of alledged worm hole experiences if you search the Internet.

Earth bound worm holes don't seem to cause time travel, but simply take you to another destination almost instantly, which could give the illusion of time travel. Eg. Travelled 50 miles in 1 minute. It doesn't mean to say that Time Travel through worm holes is impossible, maybe in space.

What I do know is theres lots of things we don't understand.