johannes1

Imaging with a time resolution of few 10's picoseconds and sometimes even faster is principally possible. There are different techniques. I do not see a direct reference in the video description, but it looks very much like a single-photon avalanche diode (SPAD) camera, similar to this paper: https://www.nature.com/articles/ncomms7021 SPAD cameras are intriguing, because they can be made in standard CMOS processes and could potentially in a few years be available in a format and cost that might be in reach for amateur astronomy. However, there are some catches. If taking images at say 50 picoseconds/frame, you have a couple of challenges: You need to have some form of shutter that goes at picosecond rate - this is solved by SPADs You have the photon flux problem pointed out above: there will on average be very few photons in the integration interval and thus gigantic shot noise You somehow need to get your image data off the chip into some form of memory before the next frame In the light-in-flight demo, problems 2&3 are solved by using a periodic process (pulsed laser), and accumulating data over many many pulses. I.e. you synchronise your SPAD camera with the laser, for each individual pulse you only get a few photon detections, and hence little data to deal with, and under the assumption that each pulse has the same effect, you fill your frames bit by bit - timed in reference to your trigger pulse. Not exactly the same as actual live trillion fps, but rather trillion fps for very specific processes. Whether that translates to astronomy in any way that is not accessible to more traditional cameras, not sure about that but perhaps someone comes up with a clever idea some day. (the exploitation of periodicity makes me think about pulsars, but since they are point sources I am not clear why you would need imaging capability for those)