When I was in college (pre-Google), this was one of our favorite “pick an argument” questions. That is, a straight-forward question that someone (reasonably knowledgeable) is convinced they know the answer to, but are in fact objectively wrong.
Other fun argument starters:
Does nuking something in a microwave irradiate it?
No, it’s microwave radiation, “nuking” is purely a figure of speech.
Does peanut butter have milkfat (or cholesterol)?
No, “butter” refers to the texture, not the ingredients. No animal fats involved.
Technically, isn’t putting food over a fire subjecting it to thermal/infrared radiation? (Or being anywhere that has a temperature above 0 degrees Kelvin.) We’re basically being irradiated all the time from multiple sources, no matter where you are.
I remember walking past a table manned by some nurses at a street fair. They were showing off their brand-new MRI machine (which was very new technology at the time). I nudged my friend and classmate, and said “Huh, look at that, it uses Nuclear Magnetic Resonance.” We had just been studying that in my Physics class, and had done some simple experiments with it. The Nurses looked horrified, and said “No, no - there’s no radiation involved!” I agreed, but said that the machine worked on the NMR principle, but it was clear there was no explaining that to them.
I don’t mix meat and dairy. I’ve learned that many (possibly most) people think mayonnaise is a dairy product. Not only is it not a dairy product, it was invented as an alternative to dairy products.
I had read that it was indeed originally a butter substitute. A quick read of the Wikipedia article on mayonnaise, makes it look like I was wrong about that bit. Sigh.
Eggs are often (well, maybe only “sometimes” these days, but I feel like it used to be “often”) grouped into “dairy,” for whatever reason, so that could also be part of it.
When I was writing on lactose intolerance, I had to put up lists of non-dairy items that sounded like they had dairy in them. Peanut butter was on the list, and apple butter, and cocoa butter. So were all the imitation milks, like soy, almond, and coconut. I even put milk of magnesia and cream of tartar and shea butter on it. Never, ever underestimate the power of assumption.
I once had a person seriously ask me if chicken contained lactose.
Yeah, ‘wet ingredients you might put into baked goods’ is enough for some people to class them as ‘dairy’. I encounter this misconception a fair bit (and the peanut butter one) as a concern people voice when I make something that is dairy free.
‘Complete protein’ is a thing a lot of people are convinced they understand, but are wrong. There’s a very common misconception that you have to have all of the essential amino acids together in the same meal, or else they are completely worthless and your body ignores them.
It just isn’t true. It’s not like your body is looking at a list and saying “where the hell is methionine? I’m not accepting any of this unless methionine shows up!”
Of course you need all of the essential amino acids - that’s what ‘essential’ means. You don’t need them all in the same simultaneous mouthful.
What shape is the Earth? It is not “round” and it’s not really even a proper sphere. It’s an oblate spheroid. But we’re getting into pedantic territory here.
That’s not really fair, because ‘oblate spheroid’ is just a made-up term to describe the shape of the earth. By any reasonable human-scale observation it’s correct to say it’s round.
When I make a pancake or a tortilla it’s correct to describe them as “round” even though they have little blobby bits sticking out here and there.