If one asked me to believe that some researchers have developed an imaging system to capture light in slow motion, say about five years ahead from now, then I would probably believe it with a blink of an eye.
I was told about the same technique today (by a friend of mine) that researchers at MIT have created a camera that rendered the speed of light in slow motion. Believe me, I literally kept blinking after I heard about it.
I was filled with awe when I read about the New York Times report, which stated that “scientists at MIT have created an ultrafast camera that captures light as it passes through liquids and objects, creating a snapshot in less than two-trillionths of a second.”
Well, if you still haven’t got the idea on why I’m so surprised, or if this news hasn’t really blown your mind away, then consider this – The video you see below would require an entire lifetime to watch one tenth of a second of footage on this camera. Hence, it is actually delayed down to 30 frames per second, so that you can actually watch the speed of light in slow motion.
The light source used in the demonstration is a Titanium Sapphire laser that emits pulses at regular intervals every ~13 nanoseconds.
According to Raskar –
A laser pulse that lasts less than one trillionth of a second is used as a flash and the light returning from the scene is collected by a camera at a rate equivalent to roughly half a trillion frames per second. However, due to very short exposure times (roughly two trillionth of a second) and a narrow field of view of the camera, the video is captured over several minutes by repeated and periodic sampling.
The recording is done at roughly 480 frames and each frame has a roughly 1.71 picosecond exposure time. A fixed delay is maintained between the laser pulse and the movie start time. After all the process, an algorithm uses the captured data to compose a single 2D movie of about 480 frames.
Raskar also notes that the use of such cameras can be done in “Medical Imaging, Industrial or Scientific use, and the future for even consumer photography.” He also explains that one can use this technique in Industrial Imaging to analyze defects in objects and materials, while in consumer photography, people are generally fascinated about lighting effects, and with this we can create photos showing how photons move through space and analyze their movements.