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Speed of Light Inconstant?
DHR writes "Australian scientists have discovered that light isn't quite as fast as it used to be." We've done previous stories on these findings. Those of you with subscriptions to Nature can read the actual paper, the rest of us will just have to suffer.
One possibility, though, is that the structure of the vacuum in space has changed. This is where we get into the rather spooky world of quantum physics. When light travels through a medium other than a vacuum, such as glass or water, it slows down. A vacuum, far from being empty, is teeming with quantum "virtual" particles that flit in and out of existence.
Sometimes those particles become real, such as under a strong electric charge, Lineweaver says. If the vacuum of space is changing uniformly across the universe, just as the universe is expanding uniformly, it could affect the speed of light.
Well... this was the hypothesis that was given in the article... and from the looks of this, it seems that there is a possibility that light didn't slow down at all. Here he explains that it is the medium that light is travelling in that is slowing it down. So light's top speed in a vacuum may still be the same... c, but the medium, the universe, is changing. Who knows.
But if light is slowing down, then that faster than light travel maybe possible. However, how the hell do you see anything when your going faster than any signal? Well... maybe you can communicate with the spooky particles and get instant communication while travelling at faster than light speeds. Of course you'd best be sure your data arrived promptly, as you'll never see the planet you just rammed.