We’re still in the Dog Days of Summer (at least through August 11) and kids are soaking up the last bit of no-school freedoms in the heat and extra daylight. At some point in the summer, you might have uttered, “It’s so hot you could fry an egg on the sidewalk.” But is that actually a thing? And, did you know there’s a National Sidewalk Egg Frying Day? Really, there is. It’s on the Fourth of July, America’s Independence Day, which also celebrates STEM in its own right.
Celebrated in Arizona
The origins of this holiday are unknown, but it’s a great way for you and others to get out in the summer heat and test ways to cook an egg using solar energy. You might think this holiday doesn’t get celebrated by many people, but you haven’t been to the town of Oatman, Arizona. Oatman holds an annual Solar Egg Frying contest every year, and has since 1991, with 20 contestants trying their hands-on ways to cook an egg within the 15-minute time frame. Participants bring their various contraptions, such as mirrors, aluminum foil, and even frying pans. This event attracts more than 1,500 spectators from all over the country. In the end, prizes and medals are given to contestants for anything from the youngest participant to those who traveled the farthest – and, of course, they earn bragging rights. Next year, that winner could be you!
But, Can You REALLY Do It?
The big question is: Is it even possible to fry an egg on the sidewalk? And the answer is YES (well, kind of) . . . but there are several factors to be aware of before you crack your egg. First off, for the egg to fully cook through, the egg must denature and then coagulate to become firm. This means all the characteristic properties, such as proteins, must be destroyed by heat and be changed to a semisolid state. To get the egg to start this process, it needs to reach a temperature of 158 degrees Fahrenheit and then maintain that temp to fully cook. Yes, that’s going to be a HOT day – ideally it should be at least 100 degrees Fahrenheit outside!
Sidewalks are also a factor that comes into play. Variables include how much direct sunlight they receive, the air temperature, and even the type of sidewalk. Concrete sidewalks usually can only reach up to 140 degrees Fahrenheit on the hottest of days and can’t conduct heat very well. This means they soak up the heat rather than distribute it, leaving the egg uncooked. And after you crack your egg onto the sidewalk, the surface temperature of the sidewalk will cool slightly. Blacktop pavement, however, can absorb more heat due to its dark color, but it might not allocate heat to the whole egg.
To actually make the phrase “it’s so hot you could fry an egg on the sidewalk” true, you might need to add another heat source or use a different conductor to cook on. Cracking your egg onto a piece of aluminum foil or using a magnifying glass can help intensify the Sun’s rays to fully fry your egg. Another idea, which I wouldn’t suggest trying, is using the hood of your car. Metal can absorb heat better than a sidewalk and is similar to a frying pan BUT could ruin the paint on your car. There are many different ways you can test frying an egg on the sidewalk this summer, and if you do manage to cook one, we’d love to hear about it! But I don’t recommend eating it after you’re done.
We decided to test it out ourselves in the Kansas heat. Waiting for the hottest day in July, we set out certain to fry an egg with a scorching temperature of 95 degrees Fahrenheit and a heat index of 107 degrees. To get the best results, we attempted to cook the egg on blacktop pavement; however, we were also fighting a humidity of 57 percent and strong winds – welcome to Kansas.
We created three different trials of frying the egg: one using only the pavement, one with tinfoil around the egg, and one cracked onto tinfoil. For each one, we waited more than 10 minutes to let the egg cook, but we realized we didn’t have the patience for it and were starting to feel sunburned, so we eventually gave up. With all the different factors that came into play, our eggs couldn’t reach the required temperature to start the cooking process.
Even though this might seem like a hard project to tackle, it’s possible! This project is a great way for you and others to get together to create your hands-on project using an egg, solar power, and your imagination.
We want to see you fry an egg on the sidewalk this summer. Comment below or share your ideas and inventions on social media!
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