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This can purify water, instantly start a fire, melt metal, cook food and even melt concrete…..This can melt a padlock if you needed to get in somewhere too … just saying.
This is made from a simple lens called a Fresnel lens… These are commonly found in old rear projection big screen TVs ….
WHAT IS A FRESNEL LENS – The basic idea behind a Fresnel lens is simple. Imagine taking a plastic magnifying glass lens and slicing it into a hundred concentric rings (like the rings of a tree).
Each ring is slightly thinner than the next and focuses the light toward the center. Now take each ring, modify it so that it’s flat on one side, and make it the same thickness as the others.
To retain the rings’ ability to focus the light toward the center, the angle of each ring’s angled face will be different. Now if you stack all the rings back together, you have a Fresnel lens.
You can make the lens extremely large if you like. Large Fresnel lenses are often used as solar concentrators.