Summarized from Science Daily - New Technique Makes Tissues Transparent.
Light scatters as it moves through an object. Even objects like our bodies allow a certain amount of light to pass through. The light is scattered by bumping into things. We're not translucent like jellyfish. Scientists have discovered, however, that if the light that emerges is recorded as it scatters and then sent back through the same pathways in reverse, it bounces back along the same pathways and return to the original source. This is similar to the scattering of pool balls on a table. If you can precisely reverse the path and velocities of the pool balls, you can make them reassemble themselves into a rack.
Hmm, may have to try that at the next Friday night pool
What does this mean? Light activated cancer killing drugs could be injected into diseased tissue. Play back the light path with a strong light source and the drugs would be activated.
Another possible application is using photovoltaic receivers to power implants like pace-makers, shrinking their size significantly.
