It seems that electrical engineers at the University of Maryland may have been a bit hasty, in April, when they announced findings that they said showed time travel impossible. Light, they said, could not be steered in a circle so that photons could not return to where they started.
But according to a Wired blog article:
(you can demonstrate this to yourself by taking a broomstick say and wrapping your fingers around it. Your fingers then, are the lines of electric force that are generated when voltage is applied. Now extend your thumb and first finger. The thumb is parallel to the conductor and points in the direction of motion. The first finger extended points away from the conductor at 90 degrees. As you can now clearly see, the electric and magnetic fields are out of phase 90 degrees. I know this is gross over-simplification, but current, voltage and magnetic lines of force are the exact same forces at play in Maryland's experiment. Their error was taking into account the electrical forces straight off the meta-materials and that showed that light could not be curved back on itself)
From the article again:
Read the complete article in Wired here
But according to a Wired blog article:
- physicist Ulf Leonhardt of the University of St Andrews in Scotland disagrees. “They considered the wrong polarization,” he said. “Making a loop in space is perfectly possible in their model. Therefore, for this model, time travel is possible.”
(you can demonstrate this to yourself by taking a broomstick say and wrapping your fingers around it. Your fingers then, are the lines of electric force that are generated when voltage is applied. Now extend your thumb and first finger. The thumb is parallel to the conductor and points in the direction of motion. The first finger extended points away from the conductor at 90 degrees. As you can now clearly see, the electric and magnetic fields are out of phase 90 degrees. I know this is gross over-simplification, but current, voltage and magnetic lines of force are the exact same forces at play in Maryland's experiment. Their error was taking into account the electrical forces straight off the meta-materials and that showed that light could not be curved back on itself)
From the article again:
- According to Leonhardt, the equations used by (University of Maryland) are valid when the magnetic field — not the electric field — points upwards. Make the necessary correction, and the barrier to creating time-like loops in the meta-material disappears.
Read the complete article in Wired here
