Why Not Use Empirical Adjustments for Solar Death Rays?

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mr henry said:
now I'm no physicist, beyond my A-level, but maintain an interest, so feel free to laugh if required!
No laughing here...
mr henry said:
Wouldn't the size of focal area be dependent on the size of the mirrors and one's accuracy at lining them up? If they were, say, an inch square, and you had them perfectly lined up (a near impossible feat, i understand), would it not be only an inch square, rather than a cumulative total of the area?

Am going to try and build one myself, just to see if i can, so these little nuggets of info could prove useful and determine whether it works or not.
Yep. Three foot mirrors (the size of a soldier's shield) will make a three foot spot.

See http://www.solardeathray.com/about.html (as in the initial post) who did it with 3.5" mirrors.

Personally, I think he did it the hard way - he calcualted the angle of every mirror. Seems to me, all you need to do is set it one place, point a light at it (parallel), and move it until it reflects the light at the focus. Who cares what the numerical angle is.
 
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aaaahhh, sorry, a simple misunderstanding. I imagined a comma ("3, foot round mirrors...") that blatantly wasn't there!

Thanks for the link, i stumbled across that site about a month ago, hence wanting to build one. Fancy the challenge of a longer range one (although my garden wouldn't quite accommodate 100'!) Clearly levels of observation and attention to detail will need to be improved if I am to stand a chance!
I do prefer the idea of doing the mirrors empirically though, the calculations seem a bit heath robinson, and more open to error.

Thanks
 
mr henry said:
...the calculations seem a bit heath robinson

Ah, what??
 
well, flat mirrors don't reflect 100% of sun energy, do they? Ordinary metalised mirror is lucky to reflect about 50% of visible light, but shoudn't they hunt for more like infrared side of spectrum?