Does greater light intensity imply greater energy?

AI Thread Summary
Light intensity, defined by the number of photons, is directly related to energy, suggesting that greater light intensity implies greater energy. Additionally, energy is inversely proportional to the wavelength of light, indicating that higher intensity correlates with shorter wavelengths. In the context of the problem regarding Star A and Star B, the observed brightness depends on both energy output and distance. Although Star A radiates more energy, its increased distance diminishes its apparent brightness, leading to the conclusion that Star B appears brighter. The discussion emphasizes the importance of considering both energy and distance when assessing brightness.
navalava
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Since light intensity increases with the number of photons, and the photon can be viewed as energy, would energy be proportional to intensity of light? Also since energy is inversely proportional to the wavelength of light, this would mean that the intensity of light is also inversely proportional to the wavelength of light.

The reason I'm asking this is because I saw this problem:

Star A is radiating two times as much energy as Star B, but it
is two times the distance from us. Which star will appear
brighter, and by how much?

a. Star A will be 2 times brighter
b. Star B will be 2 times brighter
c. Star A will be 4 times brighter
d. Star B will be 4 times brighter
e. they will both have the same observed brightness

Since brightness increases with intensity of light, and intensity is proportional to energy, brightness should also be proportional to energy, which means that Star A would be 2 times brighter (if they are at equal distances). Since brightness is inversely proportional to distance, wouldn't both stars have the same observed brightness? But the answer is b., which I don't understand...I would really appreciate it if someone could clear this up for me. Thank you so much!
 
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navalava said:
Since brightness is inversely proportional to distance...

Hint. Re-examine your assumptions.
 
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