Concentrating the Sun with mirrors facing each other What will happen if the sun is concentrated by directing sunlight to mirrors that are facing each other? i know that mirrors absorb light and dont reflect 100% but will the efficiency increase due to the multiplication of the sunlight over the multitudes of reflections? if this can be done with arrays of micro heliostats with programmable motion controllers, the reflection of the sun can be tracked and the beams within the reflections also tracked to produce an enormous amount of heat.......wont it? Isnt it going to be more efficient than this: http://www.youtube.com/watch?v=LMWIgwvbrcM  ?
 A: This is a variation on a theme which has been discussed many times. For example, see Strength of moonlight
The short answer is no; you cannot heat an object hotter than the temperature of the source.  The advantage of multiple passes with mirrors is that you may be able to extract more energy on each pass of the light - this is often done inside the cavity of a laser, in order to extract the maximum energy from the pump beam.
But for sunlight you might do better by simply improving the absorption rate of your final collector.
A: As far as your theory of the suns rays becoming "trapped"between two mirrors bouncing back and forth gaining in strength with each additional photon added to the already building super power beam,  please don't even try that, it may get so hot in cuts the planet in half!  Please look up the first law of thermodynamics Sir.   Gosh,  you're no Alfred Eisenstein are you?
No,  I actually thought of very similar contraptions when I was a youngster in high school.  The particle of light has a certain energy level and either it will be absorbed by the mirrors or it will forever bounce back and forth kind of building up as more sunlight gets added to the parallel mirrors.  So what you are thinking is that the device will be able to act like a sun capacitor,  building up to a great level and then releasing it at some object and incinerating it instantly!  Forget your method because it has some difficulties.
Just get a field of mirrors and concentrate the sun at a focal point of your choosing and watch them scatter like ants on the sidewalk from you and your magnifying lens.
There are no bad ideas and no stupid questions! But does that mean there are no stupid answers?  Obviously not! 
