Twelve More Things Your Friends Believe But You Should Not

Following the first post called Twelve Things Your Friends Might Believe But You Should Not, here are twelve more tidbits that refute what many believe is "common knowledge."

  1. The bra was not invented by a man named Titzling. Despite the delicious tempting irony that the name of an inventor should so wonderfully match his invention, this myth originated in a satirical book by Wallace Reyburn called Bust-up: The Uplifting Tale of Otto Titzling and the Development of the Bra. The true origins of the bra are a little less certain given that breast-supporting garments have been around for centuries. The first patent identified as a brassiere was granted in 1913 by Mary Phelps Jacob, though earlier versions of the idea had been around for some time.
  2. The Great Wall of China is not the only man-made structure visible from space by the naked eyeThis claim is wrong for several reasons. "Space" is largely open to interpretation, but typically means "from orbit." Astronaut Jay Apt makes clear that the Great Wall is barely visible, if at all, from an orbiting shuttle, though other objects, such as roads and airport runways, are sometimes visible. Additionally, cities and other large composite structures can easily be seen, including the Almeria greenhouse complex and the Kennecott Copper Mine.
  3. Alcohol does not kill brain cells. Despite the prevailing wisdom that drinking alcohol can destroy neurons in the brain, scientific studies have found little to support this claim. While alcohol certainly affects brain chemistry, especially under the influence of moderate to heavy amounts, the reports of the death of brain cells has been greatly exaggerated. Alcohol can affect the dendrites at the end of neurons, though, which alters the way the neurons communicate. Alcoholics can develop Wernicke-Korsakoff syndrome which can destroy neurons, but this condition is caused by a deficiency in thiamine, not the direct effects of alcohol on the brain. Speaking of brains...
  4. You do not use only 10% of your brain. This surprisingly widespread myth has its roots (perhaps) in a wide variety of explanations and has been egged on by the recent movie Lucy, but the science behind the utilization of the brain offers no evidence that this claim holds water. Brain scans show that all areas of the brain are active at some point, some more than others, and what is being utilized depends greatly on what you are doing. Evolution tends to disfavor producing organs which are significantly beyond utilization advantages, and there is no reason to suspect that 90% of our brain just sits there, waiting to be discovered as the seat of ESP, telekinesis, or any of the many other claimed 'powers' which are said to exist in the idle neurons.
  5. There are not more humans alive today than have ever died. This idea depends a lot on how you define "human" and how long you think we've been around. Assuming that modern humans have been around at least 40,000 years, estimates put the number of dead humans in the tens of billions, perhaps in the 60 billion range, an order of magnitude more than the Earth's current population. That's a lot of seeing dead people. You'd think there would be ghosts everywhere with that many departed underfoot, which leads us to...
  6. Ghosts do not cause flashlights to turn on and off. Setting aside a moment whether or not there are ghosts, the well-known "evidence" found often on ghost tours is that such spirits can communicate by turning on and off a flashlight. This feat is explained by tour guides as a way to tell if a ghost is present and wants to talk. However, the effect of a flashlight turning on and off without human intervention is a well-understood result of the physics of specific flashlight designs. Heating and cooling elements in the flashlight can cause it to cycle for long periods of time without being touched. How about one more about ghosts...
  7. There was not a ghost in the movie Three Man and a Baby. The early-Internet grapevine went nuts around 1990 when someone discovered in one scene what was claimed to be a ghost of a young boy who had died in the house sometime before. Naturally, this "proved" that ghosts existed... until skeptics pointed out that the "spirit" in the scene had a much more reasonable explanation. What looked like a ghostly boy was instead a cardboard cutout of one of the film's stars, Ted Danson. The prop was to be part of a minor plot line in the movie but was cut out at some point. 
  8. Dropping a coin from a skyscraper cannot kill someone. The basic myth goes like this: drop a penny (or, sometimes, larger coins) from the Empire State Building and the resulting fall could strike a pedestrian and kill her. This, however, defies the laws of physics, ignoring the concept of terminal velocity. In a vacuum, it might be possible to kill someone from such a drop, but coins dropped under normal conditions accelerate only to a point which is well under that needed to create enough force to do significant damage. Certainly, it might leave a welt or a bruise, and perhaps an extreme case where someone gets hit in a particularly vulnerable soft spot it might be possible to cause serious damage, but this myth fails the tests of freshman-level Physics under all but the most unusual of circumstances.
  9. Lightning can strike the same place twiceThis misunderstanding can leave someone feeling safe when darting under the cover of a recently-struck tree, but the truth is that whatever conditions led the lightning bolt to "choose" to strike a particular place could lead to a second strike as well. This is well documented on buildings and natural objects both, and the installation of lightning rods can demonstrate this multiple-strike effect quite easily. 
  10. Vikings probably did not wear horns on their helmets. We've all seen the ferocious headgear of the Viking hoards, curving, solid horns rising menacingly from the top of helms. Even the NFL's Minnesota Vikings features the display on their emblem. No evidence exists that the Norse warriors had such decoration on their skull protection. This myth may date back to Wagner's "Der Ring des Nibelungen" in 1876 where a costume designer produced horned helmets for the Viking characters. While there is some scant evidence of other cultures wearing horns or other animal decorations on their helmets, there appears to be no proof that the Vikings were one of those groups. On the subject of other things that didn't happen in history...
  11. Columbus and his contemporaries did not believe the world was flat. Despite the romantic idea that Columbus sailed over the ocean blue to find that he lived on a sphere rather than a plane, the explorer certainly was well aware of the shape of the planet when he left. As long ago as the days of Ancient Greece there were many who had already determined the size of the sphere within a reasonable margin, and navigators had known about the spherical shape of the oceans for centuries. While it is possible that uneducated folks held flat-earth beliefs, certainly no ocean-faring ship's captain had any such misconception.
  12. Napoleon Bonaparte was not particularly short for his time. This myth is so prevalent, there's even a complex named in its honor. Even during his own time, he was called the "Little Corporal" which may have contributed to the misperception, along with enemy propaganda. The French commander likely stood between 5'5 and 5'7, a perfectly normal height for a man in France during that era. Some of the confusion came from the difference between British inches and French inches. By French standards, Napoleon's height was around 5'2 which easily confused those unaware of the longer French units.