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Old February 23rd 09, 09:56 PM posted to sci.environment,sci.physics,alt.culture.alaska,sci.geo.meteorology
kiloVolts[_30_] kiloVolts[_30_] is offline
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First recorded activity by Weather-Banter: Feb 2009
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Default Power density of the Sun

Duh.

"Eric Gisse" wrote in message
...
On Feb 23, 8:23 am, "kiloVolts"
mant...@4u3t7s0s5A6s1e7F3G6rH3h5d4q3a3s2aX7A2D5y6 j1z.com wrote:
Dimensional analysis yields an understanding of the power density of the
Sun. All of the power generated within the Sun is radiated from the
photosphere, whose area scales as the radius of the Sun, which scales as
4*Pi*R^2 while the volume scales as 4/3*Pi*R^3. Hence, the power density
of
the Sun per unit volume or per unit mass, scales as 3/R. From a human
perspective, since the radius of the Sun R, is almost infinite, the power
density per unit mass is infinitesimal. In fact, when the Sun is active,
the
power density of the Sun is less than that of the human body:


The solar constant at Earth's orbit is 1380W/m^2. Integrate over the
whole volume enclosed by a 1 AU sphere and tell me again how
infintesimal the power output is.


http://en.wikipedia.org/wiki/Sun

The power density of the Sun per unit mass could go from infinitesimal of
zero and we would not notice, because we are mortal.