My 6th grade science teacher taught us that blood is red but that some people think it is blue until it touches air because our veins look blue under our skin. He explained how the different wavelengths of light are absorbed differently and they was why it looks that way. Two years later my 8th grade science teacher taught us that blood is blue until it touches air. She was not happy when I told her she was wrong. I even explained it and told her to go talk to the other teacher if she still did not understand. She still would not listen to me. Over half the class was in the same sixth grade class as me but I was the only one that either remembered or was willing to stand up to the teacher. I finished losing faith in the education system on that day.
Airplanes even had ashtrays with little flip up lids in the armrests.