|Nice Question||Question score of 10 or more. This badge can be awarded multiple times.|
Stefano Borini earned this badge 6 times
jan 24 at 17:33The speed of gravity?
jun 3 '12 at 23:33Lenses (refractor) or mirrors (reflector) telescope?
may 4 '12 at 20:35(post deleted or otherwise unavailable)
may 4 '12 at 20:35Why is M42 red in the pictures, but green when observed at the eyepiece?
dec 23 '10 at 21:04Experimental observation of matter/antimatter in the universe