3 ms·
Good question! I can't find a truly authoritative source, but a few calculations on the web put photon flux at the earth's surface at 10^21/m^2/s, give or take.
by ericbarrett 5y ago
Good question! I can't find a truly authoritative source, but a few calculations on the web put photon flux at the earth's surface at 10^21/m^2/s, give or take. Assuming your thumbnail is one square centimeter, that would be 10^17 photons per second, or 100,000,000,000,000,000, but only during the day :)
- alok-g 5y agoInteresting! So much higher than for neutrinos. One follow up question. When reading about low-light cameras, the number of photons per pixel seem much smaller. I guess the following factors are involved: Several orders of magnitude reduction under low light. Pixel area likewise much smaller than thumb. Exposure time less than a second. Visible light vs. all spectrum. Well, the question: Do the numbers fit? :-)