Dan, great lecture as always. By the way I think this looking-at-you detector does have to do with vision. Because the human eye is not just a sphere, it also has a lens which -- if he's looking at you and focused on you, it focuses your image on his retina perfectly. So that will make the eye a perfect retroreflector and correct for any imperfection in the eye's index of refraction, and the glasses he's wearing will only help! Also, you might find this interesting -- E.T. Jaynes points out that the best sensors are optimized to mostly reflect EM waves, rather than to absorb them like a solar panel would. So it's not even a coincidence that the retina is reflective (and so are CCDs). It turns out that you get a better signal-to-noise ratio that way. It's an off-hand remark in his paper "theory of radar target discrimination" (1991).
There's some sort of ancient curse that says that any time Dan Gelbart gives a priceless lecture about sensing small signals, the microphone gives out, and the poor student helplessly editing the video gains a lifelong appreciation for signal-to-noise ratios and distortion.
This guy has me in tears. Engineering is so good.
Dan, great lecture as always. By the way I think this looking-at-you detector does have to do with vision. Because the human eye is not just a sphere, it also has a lens which -- if he's looking at you and focused on you, it focuses your image on his retina perfectly. So that will make the eye a perfect retroreflector and correct for any imperfection in the eye's index of refraction, and the glasses he's wearing will only help!
Also, you might find this interesting -- E.T. Jaynes points out that the best sensors are optimized to mostly reflect EM waves, rather than to absorb them like a solar panel would. So it's not even a coincidence that the retina is reflective (and so are CCDs). It turns out that you get a better signal-to-noise ratio that way. It's an off-hand remark in his paper "theory of radar target discrimination" (1991).
I love watching anything with dan gelbart
The passive-microwave "bug" 27:00 , if you are interested, is explained in detail here: th-cam.com/video/NLDpWrwijE8/w-d-xo.html
Would adding a polarizer and a quarter wave plate to the sniper-scope make it "invisible"?
Very bad audio in some part . Who played volleyball with microphone
There's some sort of ancient curse that says that any time Dan Gelbart gives a priceless lecture about sensing small signals, the microphone gives out, and the poor student helplessly editing the video gains a lifelong appreciation for signal-to-noise ratios and distortion.