I found this wiki page and its p addictive.
If you know of any common misconceptions that aren't on there feel free to post them.
Going to start posting interesting ones that I think people still subscribe to.
The word "crap" did not originate as a back-formation of British plumber Thomas Crapper's surname, nor does his name originate from the word "crap", although the surname may have helped popularize the wordContrary to popular belief, dogs do not sweat by salivating. It is not true that dogs do not have sweat glands or have sweat glands only on their tongues. They do sweat, mainly through the footpads. However, dogs do primarily regulate their body temperature through panting.The idea that lightning never strikes the same place twice is one of the oldest and most well-known superstitions about lightning. There is no reason that lightning would not be able to strike the same place twice; if there is a thunderstorm in a given area, then objects and places which are more prominent or conductive (and therefore minimize distance) are more likely to be struck. For instance, lightning strikes the Empire State Building in New York City about 100 times per year.People do not use only ten percent of their brains.
Normally only really stupid people bring up the 'ten percent of their brains' thing. The best reply is 'maybe you do'.
Originally Posted by Fenn
Depressing.There is no evidence that Vikings wore horns on their helmets. In fact, the image of the horned helmet stems from the scenography of an 1876 production of the Der Ring des Nibelungen opera cycle by Richard Wagner. The actual Viking helmets were practical battle gear, and had a rather plain appearance.
What.Contrary to a widespread perception, the real number 0.999...—where the decimal point is followed by an infinite sequence of nines—is exactly equal to 1. They are two different ways of writing the same real number. A 2009 study by Weller et al. states that "Tall and Schwarzenberger (1978) asked first year university mathematics students whether 0.999... is equal to 1. The majority of the students thought that 0.999... is less than 1." Weller et al. go on to describe their own controlled experiment, performed "during the 2005 fall semester at a major research university in the southern United States. Pre-service elementary and middle school teachers from all five sections of a sophomore-level mathematics content course on number and operation participated in the study. [...] On the question of whether .999...=1, 72% of the control group and 83% of the experimental group expressed their view that .999... is not equal to 1."
There's an easy way of proving that 0.999... = 1.
1/3 = 0.333...
0.333... * 3 = 0.999...
1/3 * 3 = 1
Therefore 0.999... = 1
EDIT: It's not mathematically rigorous as it doesn't prove it from first principles but it's good enough. Anyone with a degree in symbolic logic or maths to give a better proof?
Last edited by Delphinus; 12-28-2011 at 02:48 PM.
Originally Posted by Fenn
James if you like this sort of thing you would love a show called QI.
Delphinus that doesn't prove it considering .333 is merely a numerical representation of the fact that an exact third cannot exist.