2013-05-22 13:34:53

Thank you for learning.

2013-06-27 22:29:35

Thank you for learning.

2013-06-30 18:05:22

Well written, now I finally understand.

2013-08-01 22:46:02

Safety first

2013-09-17 12:58:20

I agree with the original poster's opinion.

2014-05-03 12:56:23

A jammer to prevent surreptitious filming? Is it meant to interfere with the propagation of light?

2014-05-04 13:47:55

The discussion went very well and was highly practical.