A team of scientists at Cornell University in the US has demonstrated a way to bend light in such a way that it effectively hides an event from happening – what they call a "spatio-temporal cloaking" scheme.
The team, which is funded by DARPA, has built on work by Imperial College London, which showed that it was theoretically possible to split light and hide actions in the ensuing invisible area.
“This approach is based on accelerating the front part of a probe light beam and slowing down its rear part to create a well controlled temporal gap – inside which an event occurs – such that the probe beam is not modified in any way by the event,” the team writes. “The probe beam is then restored to its original form by the reverse manipulation of the dispersion. These results are a significant step towards the development of full spatio-temporal cloaking.”
Light bending opens time hole
If the period of time during which the effect can be achieved is extended, the system may provide a new way for computer networks to be monitored and attacked. The team estimates the effect could be stretched to a single second, long enough to allow code injection, most effectively in a quantum-computing system. One catch: the machinery needed to accomplish this feat using their current scheme would have to be 18,600 miles long.
This may well be the case, but the team has taken barely a year after the original 2010 discovery of the phenomenon to come up with a functioning device – much faster than the originators expected. Given the steady progress that technology has made in advancing efficiencies of existing techniques, the time-cloaking device could be in operation a lot sooner than we think. ®