posted on May, 16 2006 @ 07:33 PM
Quantum Tunnelling is the quantum mechanical effect which permits a particle to escape through a barrier when it does not have enough energy to do so
classically. You can do a calculation of the time it takes a particle to tunnel through. The answer you get can come out less than the time it takes
light to cover the distance at speed c. Does this provide a means of FTL communication?
ref:T. E. Hartman, J. Appl. Phys. 33, 3427 (1962).
The answer must surely be "No!" otherwise our understanding of QED is very suspect. Yet a group of physicists have performed experiments which seem
to suggest that FTL communication by quantum tunneling is possible. They claim to have transmitted Mozart's 40th Symphony through a barrier 11.4cm
wide at a speed of 4.7c. Their interpretation is, of course, very controversial. Most physicists say this is a quantum effect where no information
can actually be passed at FTL speeds because of the Heisenberg uncertainty principle. If the effect is real it is difficult to see why it should not
be possible to transmit signals into the past by placing the apparatus in a fast moving frame of reference.
W. Heitmann and G. Nimtz, Phys Lett A196, 154 (1994);
A. Enders and G. Nimtz, Phys Rev E48, 632 (1993).
Terence Tao has pointed out that apparent FTL transmission of an audio signal over such a short distance is not very impressive. The signal takes
less than 0.4ns to travel the 11.4cm at light speed, but it is quite easy to anticipate an audio signal ahead of time by up to 1000ns simply by
extrapolating the signal waveform. Although this is not what is being done in the above experiments it does illustrate that they will have to use a
much higher frequency random signal or transmit over much larger distances if they are to convincingly demonstrate FTL information transfer.
The likely conclusion is that there is no real FTL communication taking place and that the effect is another manifestation of the Heisenberg
Also couldnt you possible transfer information through pulsating gravity waves? since they go faster than the speed of light one could rig a time
device that would be able to transfer information faster than the speed of light.