There are some things that everybody just "knows": The sky is blue, water is wet, Bono is a tw*t, etc etc etc. However, there are some truths, universally acknowledged, that actually aren't all that true nor universal. You can probably blame your school days for most of these misconceptions, as most teachers have better things to do than accurately answer children's questions, but TV, the media and that bloke at the pub who reckons that dogs can't look up, all have to take their fair share of responsibility too. It's sometimes unclear where the misunderstandings come from, but it just goes to show that a little bit of knowledge can be a dangerous thing. On the plus side, once you know the truth about a few common misconceptions, you'll probably be able to drop them smugly into conversation with almost alarming regularity and, as we all know, everybody loves a smart*rse. Anyway, let's bust some myths.
12. Deoxygenated Blood Is Blue
Nope, sorry. All blood is red (unless you happen to be a spider, in which case, congratulations on your ability to read). The myth that deoxygenated blood is blue probably comes from a combination of factors. Firstly, that diagrams of the circulatory system often have blue blood vessels on them; secondly, oxygenated blood is "more red" than deoxygenated; thirdly, your veins do appear to be blue through your skin. Deoxygenated blood is more of a brownish red colour than the bright red of oxygenated blood, but certainly not blue. Your veins just appear to be blue through your skin because of the way different wavelengths of light penetrate the skin differently. The subcutaneous fat and skin that surrounds your veins absorbs more of the low-frequency red light and allows the blue light through to be "bounced" into your eyes, making them appear blue. If you were to cut though the skin and tissue to the vein (please don't) then it would appear red.
