Advertiser & Editorial Disclosure: The Bulkhead Seat earns an affiliate commission for anyone approved through the links below. This compensation may impact how and where links appear on this site. We work to provide the best publicly available offers to our readers. We frequently update them, but this site does not include all available offers. Opinions, reviews, analyses & recommendations are the author’s alone, and have not been reviewed, endorsed, or approved by any of these entities.
The Transportation Security Administration (TSA) had a sassy Tweet earlier today around peanut butter being a liquid. This has created quite a stir on X, but the agency is actually right when you look at it from a scientific perspective.
Solid foods, including peanut butter and jelly sandwiches, are allowed in carry-on bags with no quantity limitations or packing requirements.
— AskTSA (@AskTSA) March 25, 2023
Peanut butter and jelly is one of my favorite comfort sandwiches. When it’s in sandwich form, the TSA allows peanut butter through checkpoints. But, try to get through with a jar of Skippy and it will end up in the trash.
Peanut Butter is a liquid. We said what we said.
— TSA (@TSA) August 23, 2024
Sass aside, the TSA is right according to the scientific definition provided by an article from The Conversation and Encyclopedia Brittanica. Here’s what it says:
To define a liquid, we must first define a fluid. Any material that flows continuously when a shearing force is applied is a fluid. Think of a shearing force as a cutting action through a substance that causes it to flow continuously. For example, moving your arm causes the surrounding air to change shape – or deform, to use the physics term – and flow out of the way. The same thing happens to water when your arm takes a swim stroke.
There are many kinds of fluids. Some act very predictably and move smoothly, as air or water do. These are called Newtonian fluids, named after Sir Isaac Newton. Scientifically, a Newtonian fluid is one in which the shear force varies in direct proportion with the stress it puts on the material, known as the shearing strain. For a Newtonian fluid, the resistance to fluid flow – that is, its viscosity – is constant at a given temperature.
Other types of fluids do not move quite as smoothly and easily. For some, like peanut butter, a minimum shearing or cutting force may be needed to get it flowing, and it may vary nonlinearly with shearing strain. Imagine you’re stirring a jar of peanut butter. If you stir really fast, with more shearing force, the PB gets runnier, while if you stir slowly the PB remains stiff. These types of fluids are called non-Newtonian fluids.
Peanut butter may stick more than flow – maybe you could consider this movement more chunky-style. Peanut butter is actually a great example of a non-Newtonian fluid because it doesn’t flow as easily as air or water but will flow if sufficient force is applied, such as when a knife spreads it on bread. How easily it flows will also depend on temperature – you may have experienced peanut butter drips after slathering it on warm toast.”
The government agency is correct and even if it was not, you’re not going to win arguing with an agent at the airport.
Anthony’s Take: Make your sandwich in advance or leave the peanut butter at home. The Tweet above has angered lots of folks, but we’re still not at the point where liquids over 3.4 ounces can fly with you.
(Featured Image Credit: Chalabala.)
User Generated Content Disclosure: The Bulkhead Seat encourages constructive discussions, comments, and questions. Responses are not provided by or commissioned by any bank advertisers. These responses have not been reviewed, approved, or endorsed by the bank advertiser. It is not the responsibility of the bank advertiser to respond to comments.
Advertiser & Editorial Disclosure: The Bulkhead Seat earns an affiliate commission for anyone approved through the links above This compensation may impact how and where links appear on this site. We work to provide the best publicly available offers to our readers. We frequently update them, but this site does not include all available offers. Opinions, reviews, analyses & recommendations are the author’s alone, and have not been reviewed, endorsed, or approved by any of these entities.
1 comment
If I hold a can of coke upside down the coke pours to the ground. That makes it a liquid IMO. Try the same with a jar of Peter Pan. If it doesn’t flow out, it’s a solid. TSA is trying to pull a Ronald Reagan move when he tried to declare ketchup as a vegetable.