3 ms·
I would never have guessed this result, because it seems like a vast overoptimization for light detection: in what circumstances would a human being need to see
by appleflaxen 9y ago
I would never have guessed this result, because it seems like a vast overoptimization for light detection: in what circumstances would a human being need to see a single photon? And if those circumstances are rare, then what is the cost (in fitness, energy, etc) that we pay to maintain that ability?
- baking 9y agoRods can respond to individual photons, that is pretty much accepted. The issue is what can we perceive. The first nerve synapse screens out about 50% of isolated photons (ones that are not correlated from other rods) which has been estimated from modeling. Which means that some of those singular photons are getting through (perceived) and can be isolated from the background noise through careful experiments. I don't think we evolved to see single photons, but that we evolved to be very sensitive to light while reducing the noise and that sweet spot means that we can quite possibly, under ideal conditions, see individual photons slightly more than we think we see non-existent photons.