Thermal Contraction for Dummies - The Freelance Files MMMCLXXXVI

We'll never know for sure, of course, but it seems logical that the self-proclaimed "professional freelancers" who tilled those many long rows of posts at content farms like ehow.com and HubPages.com were in such a hurry to get their product online that they didn't have the time to perform due diligence. To put it another way, they didn't run the content past someone more knowledgeable on the topic... heck, sometimes they didn't run the content past a better writer. Take, for instance, returning nominee Kimberley McGee, who is responsible for the Hunker.com article titled "A Pan Lid Is Stuck to My Granite Countertop."

We're not saying that McGee didn't explain how to loosen the counter's hold on the lid; no, we're saying that despite finding at least one video that explained exactly why this happens, Kimberley still botched her explanation. Here's how she explained the phenomenon:

"Negative pressure creates suction. The smooth surface of a granite kitchen countertop creates a perfect surface for the concaved shape of a hot pan lid to get sucked down to. The hot pan lid creates a hot spot on the counter and the air is trapped between the lid and the counter. Air condenses as it cools and occupies less space under the dome of the lid... This creates a vacuum between the cooling pot lid and the room temperature countertop."

Our comments and corrections?

1. Not only does one not describe a lid as "concaved," in reality a pan lid is a convex surface.
2. No, Kimberley, a volume of air contracts as it cools. If present, water vapor "condenses" as the air cools.
3. The space under the lid remains the same; so according to the ideal gas law (PV = nRT), the pressure decreases. In this particular case, V, n, and R remain constant; so a decrease in T (temperature) must be mirrored by a decrease in P (pressure). Think of it: you just said that "Negative pressure creates suction"... which would be more accurate if you'd included the word "differential"...
4. No, there is not a "vacuum between the... lid and... countertop." It's a volume where the air pressure has been reduced to below the ambient pressure.

McGee explained later that,

"To release the pan lid, air needs to be introduced into the pocket between the two objects."

Someone with a more scientific bent might sat that the pressure under the lid and the ambient pressure must be equalized. But we suppose that introducing air will do that. You might also raise the temperature of the trapped air with a hot towel on the lid, which would do the same thing. We argue against, however, McGee's suggestion to remove the handle on the lid; since that would be of no use on most lids.

Based on her educational background (B.A. in Journalism) and areas of focus (interior design, business, home improvement) it's a safe bet that McGee was outside her comfort zone with this post; being decades removed from any science classes that covered the physics involved. Writing about science without knowing it is like asking us to give you the Dumbass of the Day award. Well, here you go (again).

SI - PHYSICS