Always wear eye protection during science experiments. Never handle sharp objects, open flames, chemicals, or other dangerous objects without adult permission and supervision.
Hope you brought your appetite, because today we're cooking... with science! A solar cooker is a type of oven that captures and heats food using only the energy from the sun. Most solar cookers are pretty low tech, but some technologically-advanced cookers can actually cook for hundreds of people. Solar cookers are super cool because they reduce the need for electricity, the burning of fuels, and deforestation (from firewood).
Solar cookers work by concentrating sunlight, converting the light into heat, and then trapping the heat. In this demonstration, we're going to see exactly how we can accomplish all three and, if it's sunny enough, make some lunch in the process.
To start off, we need to cut a hole in the side of the Pringles can. Use the picture to get an idea of how big your hole should be. It's a good idea to draw where you want to cut on the can first, then use the scissors to cut it out. The shiny, curved inside of the can is going to redirect the sunlight towards what we want to cook.
Being extra careful, poke a small hole in the centers of both the lid and the bottom of the Pringles can. You may need to ask an adult for help with this part.
Push the skewer through the hole in the lid and into the hole in the bottom of the can.
Next, we're going to create something called glazing, the part of our cooker that will allow sunlight to come in, but prevent heat from going out. Tape a piece of plastic wrap over the hole in your cooker. The idea is to prevent outside air from easily entering the can and cooling it down through convection (although it doesn't have to be perfectly air tight!).
And now, the part you've been waiting for: we're ready too cook! On a sunny day, take your cooker outside and place it so that the hole is directly facing the sun (you may need to place it on something, so it doesn't roll away). We're going to start with the marshmallows. Remove the skewer from your cooker and use it to skewer a couple marshmallows, lengthwise.
Place the skewer, with marshmallows in the middle, inside of your cooker and close it up. The marshmallows should start heating up pretty quickly if it's sunny enough outside. Check back in about ten to fifteen minutes.
Take the marshmallows out of the can, and while you're enjoying your solar-cooked treat, use the thermometer to measure the inside temperature of your cooker. If possible, the best way to do this is to put the thermometer into your cooker, close it up again, and wait a few minutes. If your thermometer is reading 70°C or more (this takes a very hot day, so don't feel bad if it isn't), you're ready to try cooking a hot dog!
Like in the picture, again take the skewer from your cooker and skewer a hot dog right down the middle. Put the skewered hot dog into your cooker and let the sun work its magic (err, science). Check on your hot dog in about thirty minutes. To make sure it's safe to eat, it's best to heat your hot dog to at least 60°C.