Time travelz

Cyrene · January 20, 2008, 2:33am

I remember a thread questioning this, well, a human has time traveled, and the greatest of human time travelers has traveled 1/50th of a second in time. How?

He zoomed around the earth for a long time, fast, on a satelite.

Seriously. 1/50th of a second.

Cyrene · January 20, 2008, 3:15am

Given the unyielding laws of physics, it may come as a surprise that travel into the futureâ€”or at least a restricted form thereofâ€”is a proven fact. Einstein shattered Newton’s view of absolute time, “flowing equably without relation to anything external,” by identifying a “time dilation” effect. Time is stretched by motion, Einstein theorized, and moving objects age more slowly. On a high-speed trip, clocks tick slower: An astronaut’s wristwatch and biological clock, like his pulse rate, would slow down relative to someone who remains on Earth. The net effect is that he gains time on his journey. The higher the velocity, the greater the dilation factor. Consider an example given in Davies’s book: A round-trip flight to a star 10 light-years away at almost the speed of light (180,000 miles per second) would take just over 20 Earth years, but the astronaut would age less than three years on the trip, so upon her return, she has effectively traveled 17 years into the future.

Time dilation has been proven by placing atomic clocks aboard long-haul flights, but, Davies says, “people are often surprised, indeed disbelieving, when you tell them that simply by flying in an airplane you can jump ahead in time.” Not by much, admittedly. Our fastest spacecraft travels at a dismal 0.01 percent of the speed of light, and the resulting time warp is measured in imperceptible microseconds. J. Richard Gott, professor of astrophysics at Princeton, notes in his book Time Travel in Einstein’s Universe (Houghton Mifflin) that the most successful time traveler we know of is the cosmonaut Sergei Avdeyev, who was in orbit aboard the Mir space station for a total of 748 days. Allowing for Einstein’s principle of equivalence, which asserts that gravity slows time (i.e., a clock at a high altitude would tick slightly faster than on the surface of the Earth), Gott calculated that Avdeyev, whizzing around the planet at more than 17,000 miles per hour for more than two years, traveled into the future by approximately 1/50th of a second.

some place

Cyrene · January 20, 2008, 3:17am

I went on a plane, i’m a time traveler!!

MagsJ · January 20, 2008, 3:21am

To travel in time, one would have to pass the ‘here and now’ - just travelling somewhere would not achieve that, no matter how fast.

This reality/the moment would have to be left behind…

Cyrene · January 20, 2008, 3:24am

When you travel faster in space, time and space kinda start to become a twisted mess.

Cyrene · January 20, 2008, 3:26am

If you went fast enough for long enough like the astronaught did, you would end up in ‘the future’ of the people on earth, as in they would have aged and you would not have comparitively. Thats time travel, no?

Just you’d need to go quite fast and probably for awhile.

Eclipse · January 20, 2008, 4:26am

I believe it’s also true that the lower you are (while on Earth), the slower or faster time goes. Don’t remember which, or why.

Anthem · January 20, 2008, 6:20am

Time runs slower in more distorted space time.

IrvingWashington · January 20, 2008, 11:40am

Its not really time travel as such is it? You can’t leave Earth and return back before you left. You may experience less time, and someone on Earth more time, but you don’t share any experiences in common. Time dilation isn’t time travel, its not as exciting.

I found something interesting in a sci-fi short story the other day, as a solution to the problem of going back in time and altering the past. What stopped people doing anything like telling people the future, or having sex with their grandmother, was a psychological block implanted in them. An interesting take on the stories about bananas stopping you changing things in the past!

Fin666 · January 20, 2008, 2:02pm

We don’t travel through space or time we travel through spacetime. Also you can’t travel from one poit in spacetime to another instantly you have to travel through spacetime.

The higher you are the faster time runs or conversly the closser you are to the earth the slower time runs.

Anthem · January 21, 2008, 5:26am

Quite. That was for Eclipse. Sitting on the earth you are in more distored spacetime than sitting in a stationary clocktower on the earth.

Knox · January 22, 2008, 1:24am

If time travel is possible, then humans will inevitably find a way to do it. And, based on the exponential growth of human technology, and the fact that it doesn’t generally take long (in a galactic sense) for us to transform theory into reality, we can assume that we’ll have that ability sometime in the relatively near future.

And if that’s true, then we can assume that future humans will travel back to our time.

Which means either one of two cases is true: 1) That there are time travelers living among us now, or 2) that humanity will not survive very much longer.

Just a thought.

Anthem · January 22, 2008, 5:01am

^^ You’re assuming that time travel is possible for your two cases.

Also, time travel may not be possible past the point in time where the time machine was created.

Almighty Wikipedia:

proposed time-travel machine using a traversable wormhole would (hypothetically) work in the following way: One end of the wormhole is accelerated to some significant fraction of the speed of light, perhaps with some advanced propulsion system, and then brought back to the point of origin. Alternatively, another way is to take one entrance of the wormhole and move it to within the gravitational field of an object that has higher gravity than the other entrance, and then return it to a position near the other entrance. For both of these methods, time dilation causes the end of the wormhole that has been moved to have aged less than the stationary end, as seen by an external observer; however, time connects differently through the wormhole than outside it, so that synchronized clocks at either end of the wormhole will always remain synchronized as seen by an observer passing through the wormhole, no matter how the two ends move around. This means that an observer entering the accelerated end would exit the stationary end when the stationary end was the same age that the accelerated end had been at the moment before entry; for example, if prior to entering the wormhole the observer noted that a clock at the accelerated end read a date of 2007 while a clock at the stationary end read 2012, then the observer would exit the stationary end when its clock also read 2007, a trip backwards in time as seen by other observers outside. One significant limitation of such a time machine is that it is only possible to go as far back in time as the initial creation of the machine; in essence, it is more of a path through time than it is a device that itself moves through time, and it would not allow the technology itself to be moved backwards in time.