View Single Post
  #3  
Old January 5th 04, 02:35 AM
Henry Spencer
external usenet poster
 
Posts: n/a
Default [OT] Looking at the sun - Safe distance?

In article ,
Bruce Palmer wrote:
On some afternoons, depending on clouds and atmospheric dust, the sun
looks like a giant orange ball that you can actually look at without eye
damage as it sets...


A note of caution: safely low visible-light intensity doesn't necessarily
equate to safely low UV and IR intensity (especially the latter, which has
a tendency to penetrate clouds etc. better than visible light). Your eye
is not a reliable guide to what's eye-safe.

(I'll admit to having yielded to the temptation to look in such situations,
especially when there were naked-eye sunspot groups visible... but only in
brief glances, never looking steadily.)
--
MOST launched 30 June; science observations running | Henry Spencer
since Oct; first surprises seen; papers pending. |