Whatever you do, don't kill grandma!
A new concept for a time machine could possibly enable distant future generations to travel into the past, research now suggests.
Unlike past ideas for time machines, this new concept does not require exotic, theoretical forms of matter. Still, this new idea requires technology far more advanced than anything existing today, and major questions remain as to whether any time machine would ever prove stable enough to enable actual travel back in time.
Time machine researchers often investigate gravity, which essentially arises when matter bends space and time. Time travel research is based on bending space-time so far that time lines actually turn back on themselves to form a loop, technically known as a "closed time-like curve."
"We know that bending does happen all the time, but we want the bending to be strong enough and to take a special form where the lines of time make closed loops," said theoretical physicist Amos Ori at the Technion-Israel Institute of Technology in Haifa. "We are trying to find out if it is possible to manipulate space-time to develop in such a way."
Many scientists are skeptical as to whether or not time travel is possible. For instance, time machines often are thought to need an exotic form of matter with so-called "negative energy density." Such exotic matter has bizarre properties, including moving in the opposite direction of normal matter when pushed. Such matter could theoretically exist, but if it did, it might be present only in quantities too small for the construction of a time machine.
Ori's latest research suggests time machines are possible without exotic matter, eliminating a barrier to time travel. His work begins with a donut-shaped hole enveloped within a sphere of normal matter.
"We're talking about these closed loops of time, and the simplest kind of closed loops are circles, which is why we have this ring-shaped hole," Ori explained.
Inside this donut-shaped vacuum, space-time could get bent upon itself using focused gravitational fields to form a closed time-like curve. To go back in time, a traveler would race around inside the donut, going further back into the past with each lap.
"The machine is space-time itself," Ori said. "If we were to create an area with a warp like this in space that would enable time lines to close on themselves, it might enable future generations to return to visit our time."
Ori emphasized one significant limitation of this time machine"it can't be used to travel to a time before the time machine was constructed." His findings are detailed in the Aug. 3 issue of the journal Physical Review D.
A number of obstacles remain, however. The gravitational fields required to make such a closed time-like curve would have to be very strong, "on the order of what you might find close to a black hole," Ori told LiveScience. "We don't have any way of creating such strong gravitational fields today, and we certainly have no way of manipulating any such gravitational fields."
Even if time machines were technically feasible, the gravitational fields involved need to be manipulated in very specific, accurate ways, and Ori said his calculations suggest any time machine could be very unstable, meaning "the tiniest deviations might keep one from working. We need to explore the problem of stability of time machines further."
Theoretical physicist Ken Olum of Tufts University in Medford, Mass., who did not participate in this study, was skeptical concerning how this new model claimed to sidestep prior theoretical objections to time travel.
Still, Olum noted, "It's important if it's rightthat there really is some kind of loophole. So this should be scrutinized very closely." The point of such work, he added, was to "expand the bounds of what's possible, what kind of things we can have and what kinds of things we cannot have."
Thoughts?
GREAT SCOTT!
It's for distant/future generations. Unless they come back and go public with their experience... then. Yeah "we're building something and you wont live to see it" isn't exciting to me.
Especially when that thing is time travel, which can prove itself possible at any time yet never does (alternate timelines?).
Wake me up when something's being built that I'll eventually see.
Man, the first time future kids start walking around, I'm so offering them antiques worth a fortune in exchange to bring me to the future.
People come back from the future all the time, they just kill the witnesses and take the bodies with them.
I'm really stretching my turn.
Yea time travel is surely possible. I've looked into alot. And not even so much time travel as the more commonly experienced reduction of time. The faster you go[the closer you are to the speed of light], the slower you age. So Neil Armstrong took off like 10 picoseconds off his life. Sure it's not much, but time travel could surely be possible. I'm all for it. =]
What is it with Armstrong and success/fame
i thought it was impossible to make a time machine that can go back in time any further then when it was first built? or was that just the type of time machine that was made with black and white holes? oo; argh, i can't remember!
*flings one of the science of diskworld books at you all and retreats under a pillow before her brain tries to implode* ><;
Well if the machine travelled with you, I guess you could go someplace (time) where it didn't exist. I guess that wouldn't be the case with this method, as if you travel to a time the machine is not in working order, you stop right there.
If it will exist, wouldn't time travelers have already come back in time?
Maybe they have but we just don't know it. :O
Or they can only return to when the first time machine was built. So when the first time machine is built, someone will come through it from the future and congratulate us.
But hey, who knows.
Nothing will ever take my Delorean away from me.
>> Umm instead of just building the machine to bend the timelanes...(thereby eliminating the ability of the machine to be useful until hundreds of years from when it was built and completed...
why don't they just figure out a way to bend the space lanes by using mirrors and an acceleration field in the shape of a donut hole-and using radiation waves.
That way--we have the tiniest particles of matter, may be able to create a mini black hole type energy and bend the time lanes onto themselves.
>> Don't you DARE make sense of this >>
Forgive me if I'm wrong, but doesn't such an anomaly already exist? I could've sworn her name was Haruhi Suzumiya.
Quote:
Ori emphasized one significant limitation of this time machine"it can't be used to travel to a time before the time machine was constructed."
Bull. Time is relative to the observer's position in space, so you can't make a universal law that something is permissible only after a certain specific fixed point in time.
Let's say John Q Alien over in Galaxy Abel 1835 IR1918 wants to travel into his past. How can he, who's living in his own local relative time flow, determine what's "before" or "after" the point in which we develop this machine in our completely separate time flow?
Answer: he can't. Because time isn't a straight line.
I have no idea whether time travel is possible or how it would work if it did. But I know the universe doesn't work in the way he's suggesting.
As you all know, if it went back before it was constructed, it would not have existed and you would be trapped from that time, and possibly would'nt live long enough to the time you left and/or was born.
But, I don't have any proof to back me up here, but if they went beck before it was constructed, wouldn't it sorta kinda change time so that the machine WAS constructed then, Oh wait! If it was, it would sorta kinda change the future a bit. Cuz then kids from the time he traveled to, could possibly get one and go off to the time of when he other traveler left, resulting in possible minor and major changes to the future.
but first they would have to experiment, so we'd get a ton of time-travelling mice and other animals before people started appearing at random.
*just read 'the time traveller's wife' by audrey niffenegger. it certainly had an interesting concept of time travel*
This never happened.
Trust me. I know.
