The Born Loser by Art and Chip Sansom for November 12, 2014
November 11, 2014
November 13, 2014
Transcript:
Wilberforce: My science teacher showed how you can start a fire using a pair of glasses and the sun's rays! Gladys: It's good to know, if you ever have to wear glasses, they can come in handy in an emergency! Wilberforce: Are you kidding? I'm never gonna wear glasses - I don't want my eyes catchin' fire!
The Glasses: There are two main types of corrective lenses: Converging lenses and diverging lenses. Diverging lenses, which are used to correct nearsightedness, bend the light further away from the focal point, while converging lenses, which correct farsightedness, bend the light towards the focal point.
As a result, if you are nearsighted, your glasses won’t help you start a fire, because they are actually dispersing the light instead of focusing it.
If you are farsighted, however, you are in luck, because your glasses will bend the light inward towards a focal point. And it’s this focal point that will allow you to create fire.
Though, ironically, you may need some water to do it.
The Water: Starting fire with your glasses is essentially the same as starting a fire in your back yard with a magnifying glass when you were a little kid. But there’s one major difference: Magnifying glasses are biconvex.
That’s a fancy way of saying that the lens of a magnifying glass is curved in both directions, as opposed to your glasses, which are only curved in one direction. Being biconvex means that a magnifying glass bends the light twice, once when it enters the lens and again when it leaves. This produces a more focused beam of light, which in turn creates more heat and makes it easier to start a fire.
Most glasses aren’t powerful enough on their own to create fire, as the light isn’t focused quite enough. But there’s a simple solution: A drop of water on the inside of the lens. Placed in the middle of the lens, this drop of water will also bend the light, turning your glasses biconvex – and allowing you to start a fire.
The Fire: Now the fun part. After preparing your target – tinder, kindling or other suitable material for a fire – hold your glasses up between the sun and the target. The light will appear as a small circle or dot. Your goal is to find the proper height and angle for your glasses to make this circle of light as small and as focused – perfectly round is best – as you can.
If it’s a sunny day and you’re working with dry tinder, you should start to see smoke within 20-30 seconds. Congratulations! You’ve just made fire with your glasses.
If you are in the Desert good luck with finding water, because you may need water more than a fire.