The minimum number of photons per second?

AI Thread Summary
An owl's eyes can detect a light intensity as low as 4.5 x 10^-13 W/m2, and the problem involves calculating the minimum number of photons it can detect per second with a pupil diameter of 7.5 mm and a light wavelength of 503 nm. The initial approach suggests using the formula for photons per second, which is energy per second divided by energy per photon. To solve this, one must first calculate the energy per second based on the given intensity and the area of the pupil. The discussion emphasizes the need for a step-by-step solution to arrive at the final answer.
girlygirl55
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Homework Statement



An owl has good night vision because its eyes can detect a light intensity as small as 4.5 10-13 W/m2. What is the minimum number of photons per second that an owl eye can detect if its pupil has a diameter of 7.5 mm and the light has a wavelength of 503 nm?



Homework Equations



I'm not really sure how to begin. Can you help me solve this step by step?

Photons per sec= Energy per sec/Energy per photon ??


The Attempt at a Solution

 
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girlygirl55 said:
Photons per sec= Energy per sec/Energy per photon
Sure, that'd be a good start.
 

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