davev
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Can someone please explain why the are used is 4∏D2? Shouldn't it just be ∏r2?
Why is light intensity 4πD² and not πr²?
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Can someone please explain why the are used is 4∏D2? Shouldn't it just be ∏r2?
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sandy.bridge
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The intensity spreads out over the surface of a sphere. Your formula is for the area of a circle.
davev
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sandy.bridge said:
That makes much more sense! Can't believe I totally missed that. Thank you!