Glass fiber that brings light to standstill
Now, here's the question for fun.
If light always travels at the speed of light when free in vacuum and you can now stop it, what re-accelerates it back to the velocity of light?
"Light is an extremely useful tool for quantum communication, but it has one major disadvantage: it usually travels at the speed of light and cannot be kept in place. A team of scientists at the Vienna University of Technology has now demonstrated that this problem can be solved - not only in strange, unusual quantum systems, but in the glass fiber networks we are already using today.
By coupling atoms to glass fibers light was slowed down to a speed of 180 km/h. The team even managed to bring the light to a complete stop and to retrieve it again later. This technology is an important prerequisite for a future glassfiber-based quantum-internet, in which quantum information can be teleported over great distances."
If light always travels at the speed of light when free in vacuum and you can now stop it, what re-accelerates it back to the velocity of light?
"Light is an extremely useful tool for quantum communication, but it has one major disadvantage: it usually travels at the speed of light and cannot be kept in place. A team of scientists at the Vienna University of Technology has now demonstrated that this problem can be solved - not only in strange, unusual quantum systems, but in the glass fiber networks we are already using today.
By coupling atoms to glass fibers light was slowed down to a speed of 180 km/h. The team even managed to bring the light to a complete stop and to retrieve it again later. This technology is an important prerequisite for a future glassfiber-based quantum-internet, in which quantum information can be teleported over great distances."
