I was rooting around in the online NLS library the other day for something 
new to read.  I have about a dozen books on my phone I am interested in 
reading and about two dozen in my wish list waiting to be downloaded to my 
iPhone when I am ready.  I stumbled on a book called What is a Laser.  It 
was, and is, just 37 minutes long and was recorded back in 1983 but if you 
want a grade school level of how lasers work, it is a great read.  Besides, 
grade school is about my level at my advanced age.  Even then, I didn't 
understand everything.  And to think they could measure the space between 
atoms back then and a laser, even back then, could drill a perfect hole in a 
human hair.  If you still have hair, that is.  In my case, they'd have to 
use my Abraham Lincoln beard.  Right up front, this little book said, if you 
turned on all the light bulbs in the world at the same time, it still 
wouldn't equal the output of the earliest of lasers.  Don't burn yourself. 
Now if the laser could just grow hair.

Phil.
K0NX