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yungman
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I understand the surface of the sphere is [itex]4\pi [/itex] sr. where the area of one sr is [itex]r^2[/itex].
My question is why [itex] d\Omega = sin \theta \;d \theta \;d\phi[/itex]? Can anyone show me how to derive this.
Is it because surface area [itex]dS = (Rd\theta)(R\; sin\;\theta\;d\phi)\;\hbox { so if }\; \Omega = \frac S {R^2} \;\Rightarrow \; d\Omega = \frac {d\;S}{R^2}= sin \theta d\theta d \phi[/itex]
My question is why [itex] d\Omega = sin \theta \;d \theta \;d\phi[/itex]? Can anyone show me how to derive this.
Is it because surface area [itex]dS = (Rd\theta)(R\; sin\;\theta\;d\phi)\;\hbox { so if }\; \Omega = \frac S {R^2} \;\Rightarrow \; d\Omega = \frac {d\;S}{R^2}= sin \theta d\theta d \phi[/itex]
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