Quote: Originally Posted by Reverend Blair
The speed of sound changes depending on conditions. It is possible that the speed of light changes as well.
I thought they had demonstrated time travel a couple of years ago using sub-atomic particles or something. I know that they demonstrated teleportation and I think it was based on the same basic theories and experiments.
All this talk regarding time/speed travel (being a race fan) really is fascinating!
Transporting humans through teleportation would be very very unlikey. Teleportation is a disembodied form of transport. It can not be instataneous, otherwise the theory of relativety goes out the window. A device required to measure our atoms for teleportation would require slicing us apart to do that. We require about 10 Gigabytes (that's about 10^11 = 100,000,000,000 bits) to give the full three dimensional details of a human down to one millimeter resolution in each direction. If we forget about recognizing atoms and measuring their velocities and just scale that to a resolution of one-atomic length in each direction that's about 10^32 bits (a one followed by thirty two zeros). This is so much information that even with the best optical fibers conceivable it would take over one hundred million centuries to transmit all that information! So it would no be feasible.
An area of interest that would provide insight into possible time travel would include rotating Kerr Black Holes, if they exist. Black Holes resemble an ice cream cone. In these types of black holes, it would theoretically be possible to enter, go through and exit a black hole (the exit would be a white hole with the reverse effect of a black hole). Dying stars would collapse into a rotating ring of neutrons that would produce sufficient centrifugal force to prevent being crushed by the infinite gravitational force at its center. This would obviously not be possible for non-rotating black holes.
The cosmic strings theory is another scenario. Thsi is based on string-like objects that some scientists believe were formed in the early universe. These strings may line the entire length of the universe and are under immense pressure -- millions upon millions of tons. These cosmic strings, which are thinner than an atom, would generate an enormous amount of gravitational pull on any objects that pass near them. Objects attached to a cosmic string could travel at incredible speeds, and because their gravitational force distorts spacetime, they could be used for time travel.
The best hope for ever succeeding in time travel would probalby lie with wormholes. If they do exist, not only would they allow us to travel through time, they could allow us to travel many light-years from earth in only a fraction of the amount of time that it would take us with conventional space travel methods. As the velocity of an object nears the speed of light, time slows down. Scientists have discovered that even at the speeds of the space shuttle, astronauts can travel a few nanoseconds into the future.
A wormhole is a tunnel-like image and is formed by two masses applying enough force on spacetime to create a tunnel connecting distant points in the universe.
As an example to how this wormhole might be formed, if we take a sheet and fold it over and leave a space between the top and bottom. If we then Place a baseball on the top side, it will cause a curvature to form. If an equal mass were placed on the bottom part of the sheet at a point that corresponds with the location of the baseball on the top, the second mass would eventually meet with the baseball.
As to how a wormhole might work, picture two people, person A and person B. Person A stays on Earth, while person B takes off in a spacecraft. At takeoff, their watches are in perfect syncronization. The closer person B's spacecraft travels to the speed of light, the slower time will pass for person B (relative to person A). If person B travels for just a few hours at 50 percent the speed of light and returns to Earth, it will be obvious to both people that person A has aged much faster than person B. This difference in aging is because time passed much faster for person A than person B, who was traveling closer to the speed of light. Many years might have passed for person A, while person B experienced a time lapse of just a few hours.
If we picture a scenario in which we would want to travel to Sirius, a star that's seen in the Canis Major constellation just below Orion. Sirius is about 9 light-years from Earth, which is about 54 trillion miles (90 trillion km). Obviously, this distance would be far too great for space travelers to traverse and return in time to tell us about what they saw there. So far, the farthest people have traveled into space is to the moon, which is only about 248,548 miles (about 400,000 km) away from Earth. If we could find a wormhole that connected us to the space around Sirius, then we could cut the time considerably by avoiding the trillions of miles that we would have to cross with traditional space travel.