Last week on Independence Day, July 4th, it was 100° F (38° C) where I live, as it was for most of the week, and it seemed you could fry an egg. Is that really possible?
Here, Bill Nye suggested that you might try it: So Hot, You Could Fry an Egg
From my cursory reading, it seems he found that a constant temperature of 130° F (55° C) can cook an egg. Having a bit of time to kill, why not do some science? (Truth be told, I was partly just passing the time until the beautiful girl that suggested we try frying an egg, on the sidewalk, was done working.)
To perform this “eggsperiment,” I used one of my black cast iron pans and placed it in the sunshine around midday. Fairly quickly, a thermometer indicated that the pan’s surface temperature exceeded 140° F and it was too hot to handle comfortably.
This looked promising, so I put a bit of olive oil and an egg into the pan. A portion of the egg white, at the edge, immediately cooked to opaque.
Shortly after though, the action stopped; in part, I think, this was because the egg (which began at approximately room temperature, actually ~90° F) cooled the pan and decreased the pan’s ability to absorb the sun’s energy (by decreasing the non-reflective, black surface area).
After about 1/2 hour in this state, shadows encroached on my wooden deck, so I moved the pan to the sidewalk.
However, despite continuous sunlight on the hot sidewalk, the egg didn’t cook much more. I believe this was because the sidewalk acted as a heat sink, pulling heat from the pan, resulting in a lower cooking surface temperature than when the pan was on the (insulating) wooden deck.
After perhaps 1/2 hour again, I returned the pan to the sunlit deck.
So, after about 1 1/2 hours total sunshine-cooking time, I ended up with this half-cooked, partially dried-out unappetizing fried egg.
My conclusion is that it is possible to cook an egg this way under some conditions, but maintaining the pan temperature, despite the egg being introduced and despite possible heat-sapping surfaces, is imperative.
Anyway, I hope you all stayed cool and likewise had a pleasant Independence Day!