I didn't see a post on this yet, so here it is.
A fresnel lens from a large projection TV will burn through a pop can in less then 7 seconds (700-900watts-about 800Deg C) just from the suns power.
So get one of those next time some one tosses one out. You could boil water with this and if you know how to make a small steam engine, you could get
power from it as well. There are also fresnel lenses that can be rolled up but they are much smaller.
You can also make a lens from plastic wrap, a 4-8" wooden ring and water. You hold the wrap around the edge of the ring and pour water into it and
allow the plastic to deform to become almost spherical and hold it over what ever you want to burn. You might be able to do the same with water filled
condoms, not that they will really have another use if you need to repopulate the earth.
You cand make solar ovens too. They trap heat and light to cook things and can reach 150Deg. C. They can be made with aluminium foil and glass!
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Good tip!
You can get Fresnel lenses at many science museums and they are readily available online fairly cheaply. I have melted asphalt with a Fresnel lens so
be careful as they can generate a surprising amount of heat.
I dont think your water filled condom idea would work. Save the condom to keep your rifle clean.
Perhaps this thread belongs over in "Random Survival Tips" where it will get more attention.
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Indeed!
This was the name of the lense I was trying to think of whist shining a laser through it.
No doubt the intense light of a laser would be refracted and concentrated by a frensel lense...lol, might make that laser pointer you got at the
county fair worthwhille!
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LOL no, a fresnel lens won't make a laser more powerful. A small lens from a CD player/drive will focus it to a tiny dot, but it will not burn/melt
anything. You would need a 20mW laser and above for any effect after focusing, they don't sell them in the store.
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If you have a new Brillo pad and a nine volt Battery you can stick the battery to the brillo pad and it will ignite.
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Originally posted by Terapin
Perhaps this thread belongs over in "Random Survival Tips" where it will get more attention. 
I agree. Since we have a thread on random survival tips you should consider reposting this information there.
Thread closed.
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