10 Five Senses  
The error: We have five body senses – sight, hearing, touch, smell, taste.
These  are the traditional five senses, but there are in fact many more – some  say up to 21. Obvious additions to the list are balance, pain, and  temperature. Furthermore, we have internal senses which traditionally  number four: imagination, memory, common sense (not to be confused with  commonsense which many people lack!), and the estimative power.  Wikipedia has a very interesting article which covers the large number  of senses seldom mentioned. 
9 The Rainbow Lie  
The error: A rainbow has seven colors
We  are, no doubt, all familiar with the old phrase “Roy G. Biv” used to  remember the colors of the rainbow: red, orange, yellow, green, blue,  indigo, violet. This series of colors was coined by Newton who initially  excluded indigo and violet. While a rainbow does appear to have seven  colors, it is, in fact, one continuous spectrum of color and it is  merely an artifact of human color perception that makes it appear to be a  series of bands. There are also things called supernumerary rainbows  which have more than 7 bands visible to the human eye (pictured above –  note the extra green and purple bands at the bottom of the rainbow).
8 Cold Comfort  
The error: Drinking alcohol warms you up
This  is entirely untrue – yet it is still commonly seen as an antidote to  coldness in movies, and people still believe the myth about the St  Bernard dogs with casks of liquor around their necks! In fact, when you  drink alcohol, your body temperature drops! This is because alcohol  allows more blood to reach the surface of the body, and more heat is  radiated or conducted away. Any feeling of warmth experienced after  drinking alcohol is explained by the fact that this flow of blood to the  surface warms the skin and the ends of the sensory nerves in the skin,  and these convey to the brain a sensation of warmth. The fact that  alcohol actually lowers the temperature of the body was first announced  by Sir B. Ward Richardson in 1866 to the British Association. 
7 Quake with Fear  
The error: Small earthquakes can reduce the chance of a big one
There  is a common myth (particularly in New Zealand where earthquakes are  common) that if you have a lot of small earthquakes, it helps to  alleviate the pressures building up that can cause a big one. But this  is not true. Seismologists have observed that for every magnitude 6  earthquake there are 10 of magnitude 5, 100 of magnitude 4, 1,000 of  magnitude 3, and so forth as the events get smaller and smaller. This  sounds like a lot of small earthquakes, but there are never enough small  ones to eliminate the occasional large event. It would take 32  magnitude 5’s, 1000 magnitude 4’s, 32,000 magnitude 3’s to equal the  energy of one magnitude 6 event. So, even though we always record many  more small events than large ones, there are never enough to eliminate  the need for the occasional large earthquake. 
6 Don’t Swim  
The error: You must wait 30 minutes after eating before swimming
While  there is a theoretical concern based on the fact that the body diverts  the circulation of blood to the gut and away from the muscles that this  might possibly cause a cramp, no one has ever drowned because they went  swimming with a full tummy. Going swimming after eating a big meal might  make you uncomfortable, but it won’t cause you to drown. And even if  you did get a cramp, in most cases you could easily exit the water  before any real damage is done.
5 Population Explosion  
The error: The earth is dangerously overpopulated or is getting close to being so
This  is a myth which has been around for quite some time – from the Anglican  minister Malthus in the 18th century who said: “The power of population  is indefinitely greater than the power in the earth to produce  subsistence for man” to environmentalists who see humans as evil in  comparison to the rest of nature. But, in truth, the world is a big  place with plenty of space. So, how much land does it take to hold 6  billion people? To give you an idea, consider the small nation of Japan.  It has about 143,000 square miles of area. One square mile has 5280 *  5280 = 27.9 million square feet. Japan has a total of about 4 trillion  square feet, enough to give each person of the earth 670 square feet. If  we housed people in families of four in simple two-level buildings (8  people per building, one family of four per level), each building could  be on a lot of over 5300 square feet. If we used the American average of  8,000 square feet to four people, the entire population of the planet  would fit into a space as big as Texas and Nevada combined – leaving the  rest of the land for food production and entertainment venues. I should  also mention that many countries in the west are now in a period of  population implosion as families are getting smaller.
4 Cellphone Plane Crash  
The error: Using a cellphone on a plane can cause interference and, consequently, a crash.
The  FAA has tested all sorts of electronic devices for 25 years, at 100  times the RF interference levels—and nothing happened. The FAA simply  states that no link between operating the devices has been proved. It’s  been left up to the airlines to determine their own policy—and that  policy is to put away your Blackberry. By using your cellphone during  flight, you risk interfering with a flight crew—but the plane won’t  crash. Consequently, some airlines are now allowing the use of  cellphones during flights. 
3 Grumpy Old Men  
The error: When you get older, you become bad tempered
A  recent study found that our personalities don’t change much after age  30. So, if you’re cheerful and gregarious in your 40s, you can expect to  be the same in your 80s. Marked personality changes some seniors  experience are due not to normal aging but to some related disease like  dementia or stroke. This is something worth considering when you are  planning to marry in your thirties – your future spouse probably behaves  now the same way he or she will for the rest of his or her life. 
2 Raw Fish  
The error: Sushi is raw fish
Sushi  does not mean raw fish, and not all sushi includes raw fish. The usual  Japanese term for raw fish is sashimi. The term sushi actually refers to  the way the rice is prepared with a vinegary dressing. Toppings for the  rice may traditionally include raw fish—but also cooked seafood, fish  roe, egg, or vegetables such as cucumber, daikon radish, or ume plum.  The dish constituting sushi and other fillings wrapped in a seaweed is  referred to as makizushi, not sushi.
1 Are you a Cop?  
The error: In the United States, a policeman must answer truthfully when asked if he is a cop
Entrapment  law in the United States does not forbid police officers from denying  that they are police. It is more concerned with enticing people to  commit crimes they would not, in the normal course of events, have  considered. This is an error that is frequently seen in movies – or  perhaps it is just that films are realistically depicting people who  believe the myth – though I doubt it.
Read More Other Unsolved Mysteries article!