[ATM] Re:Extended Object Brightness

["Vladimir Galogaza" <vladimir.galogaza@zg.tel.hr>]

Daniel,

>: why is it so dangerous to look at the sun
> through a telescope

Insolation is the rate of solar energy arriving on a specific flat surface
perpendicular to the line of the sun. At sea level, the least possible loss is
29 to 30 percent. The maximum possible insolation is therefore about 70 to 71
percent of the solar constant which is 1367 W per sq meter outside the Earth
atmosphere.
On sea level this is about 1KW/m^2 or 1mW/mm^2.
Looking with unaided eye at the Sun, pupil will be cca 3mm^2 allowing 3mW into
the eye.
8" telescope primary mirror will collect approximately 30 W  ( something like
soldering iron consumption). If this power will enter the eye even without
focusing there will be
permanent damage to the eye.
Please do not check my calculations by performing experiment and looking  at the
Sun.
Burn the hole in the paper.
Vladimir.





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