Frying an egg directly on bitumen or a dark tin roof in Penrith during summer is possible, but it depends on a few factors:
Peak Summer Temperatures: Penrith's average maximum temperature in summer (December - February) is around 28°C (82°F). However, heatwaves can push temperatures well above that, sometimes exceeding 40°C (104°F).
Heat Absorption of the Surface: Bitumen and dark tin roofs absorb heat readily, and their surface temperature can be significantly higher than the ambient air temperature on a hot day. Studies have shown that road surface temperatures can reach up to 60°C (140°F) under extreme conditions. Dark tin roofs can also become very hot, potentially exceeding 50°C (122°F).
Cooking Time and Sunny Conditions:
Egg Yolk Coagulation: Egg yolks begin to thicken and solidify at around 62°C (144°F).
Egg White Coagulation: Egg whites begin to set around 63°C (145°F).. If the surface temperature of the bitumen or roof is hot enough and you crack the egg directly onto it during the hottest part of the day with sustained sunshine, it could cook. However, it would likely take longer than on a conventional pan because the heat wouldn't be as evenly distributed.
Here's why it might not be a guaranteed success:
Short Contact Time: If you place the egg on the hot surface for a brief moment, it might only get warm or the whites might partially set before the heat source loses contact.
Heat Loss to Air: The bitumen or roof will also be losing heat to the surrounding air, which can slow down the cooking process.
Uneven Cooking: The heat wouldn't be as evenly distributed as on a cooking pan, potentially resulting in a partially cooked or unevenly cooked egg.
So, frying an egg on a hot bitumen road or dark tin roof in Penrith
during summer is technically possible.