Thursday, January 6, 2011

We learn something new everyday

Thanks to a army friend who posted this on Facebook, I learnt a few interesting stuff today. First of all, no matter the source, we should always keep an open mind and be skeptical, just like how we should have been when we heard of the misconcepton and believed in it, if applicable.

Here are my favourites from the wiki page:
-There is no evidence that Vikings wore horns on their helmets.

 -A belief that decades/centuries/millennia begin not on the year ending in 0, but rather on the subsequent year ending in 1 (e.g., "The current millennium didn't really begin on January 1, 2000, but rather on January 1, 2001") -- based on an assumption that there was no year 0 -- are founded in an incomplete understanding of historical calculation. The currently dominant system of numbering years, known as the "Anno Domini" or "Common Era" system, was proposed by Dionysius Exiguus in 525 for application to the Julian Calendar (and later was applied to the Gregorian Calendar). For this reason, all year numbers prior to 525 are the result of calculation rather than historical record. Two systems of calculation exist in parallel: The Historical System, which holds that 1 AD/CE was preceded by 1 BC/BCE, and the Astronomical System, which incorporates a year 0, and thus has 1 AD/CE preceded by 0. With scholarly works in which precision is important in BC/BCE years, it is necessary for the researcher to identify which system of calculation is being used. The Astronomical System (with a year 0) is actually more common[citation needed], and is endorsed in ISO 8601, which deals with representation of dates and times.

-Searing meat does not "seal in" moisture, and in fact may actually cause meat to lose moisture. Generally, meat is seared to create a brown crust with a rich flavor via the Maillard reaction.

-Mussels that do not open when cooked may still be fully cooked and safe to eat.

-Sushi does not mean "raw fish", and not all sushi includes raw fish. The term sushi actually comes from the rice used, sumeshi, which is gently folded with rice vinegar, salt, and sugar dressing. The rice is traditionally topped by raw fish, cooked seafood, fish roe, egg, and/or vegetables such as cucumber, daikon radish, and avocado. The related Japanese term, sashimi, is closer in definition to "raw fish", but still not quite accurate: Sashimi can also refer to any uncooked meat or vegetable, and usually refers more to the dish's presentation than to its ingredients. The dish comprised of sushi rice and other fillings wrapped in seaweed is called makizushi, and includes both "long rolls" and "hand rolls".

-It is commonly claimed that the Great Wall of China is the only man-made object visible from the Moon. This is false. None of the Apollo astronauts reported seeing any man-made object from the Moon, and even earth-orbiting astronauts can barely see it. The misconception is believed to have been popularized by Richard Halliburton decades before the first moon landing. Shuttle astronaut Jay Apt has been quoted as saying "...the Great Wall is almost invisible from only 180 miles up."

(I learnt this in PC1322 Understanding The Universe last semester too)
-Black holes, unlike their common image, do not act as "cosmic vacuum cleaners" any more than other stars. The collapse of a star into a black hole is an explosive process, which means, according to mass-energy equivalence, that the resulting black hole would be of lower mass than its parent object, and actually have a weaker gravitational pull. The source of the confusion comes from the fact that a black hole is much smaller and orders of magnitude more dense than a star, causing its gravitational pull to be much stronger closer to its surface. But, as an example, were the Sun to be replaced by a black hole of the same mass, the orbits of all the planets surrounding it would be unaffected.

(I learnt this in GEK1506 Heavenly Mathematics & Cultural Astronomy in my first semester too)
-It is a common misconception that seasons are caused by the Earth being closer to the Sun in the summer than in the winter. In fact, the Earth is actually farther from the Sun when it is summer in the Northern Hemisphere. Seasons are the result of the Earth being tilted on its axis by 23.5 degrees. As the Earth orbits the Sun, different parts of the world receive different amounts of direct sunlight. When an area of the Earth's surface is oriented perpendicular to the incoming sunlight, it will receive more radiation than it will when it is oriented at an angle to the incoming sunlight. In July, the Northern Hemisphere is tilted towards the Sun giving longer days and more direct sunlight; in January, it is tilted away. The seasons are reversed in the Southern Hemisphere, which is tilted towards the Sun in January and away from the Sun in July. In tropical areas of the world, there is no noticeable change in the amount of sunlight. See also effect of sun angle on climate.
-There is no single theory that satisfactorily explains myopia—in particular, studies show that so-called eyestrain from close reading and computer games can lead to myopia, but the underlying physiologic mechanism is poorly understood. There is also no evidence that reading in dim light or sitting close to a television causes vision to deteriorate.
 
-Shaving does not cause hair to grow back thicker or coarser or darker. This belief is due to the fact that hair that has never been cut has a tapered end, whereas, after cutting, there is no taper. Thus, it appears thicker, and feels coarser due to the sharper, unworn edges. The fact that shorter hairs are "harder" (less flexible) than longer hairs also contributes to this effect. Hair can also appear darker after it grows back because hair that has never been cut is often lighter due to sun exposure.
 
-Sugar does not cause hyperactivity in children. Double-blind trials have shown no difference in behavior between children given sugar-full or sugar-free diets, even in studies specifically looking at children with attention-deficit/hyperactivity disorder or those considered "sensitive" to sugar. The difference in behaviour proved to be psychological.
 
-Prolonged exposure to cold weather such as rain or winter conditions does not increase the likelihood of catching a cold. Although common colds are seasonal, with more occurring during winter, experiments so far have failed to produce evidence that short-term exposure to cold weather or direct chilling increases susceptibility to infection, implying that the seasonal variation is instead due to a change in behaviours such as increased time spent indoors close to others. Viruses spread more easily when humidity is low which is the case during wintertime. A lowering of body temperature can, however, reduce the body's resistance to an infection that is already present, and cause temporary sneezing and runny nose.
 
-Humans have more than five senses. Although definitions vary, the actual number ranges from 9 to more than 20. In addition to sight, smell, taste, touch, and hearing, which were the senses identified by Aristotle, humans can sense balance and acceleration (equilibrioception), pain (nociception), body and limb position (proprioception or kinesthetic sense), and relative temperature (thermoception). Other senses sometimes identified are the sense of time, itching, pressure, hunger, thirst, fullness of the stomach, need to urinate, need to defecate, and blood carbon dioxide levels.
 
-The notion that goldfish have a memory of only three seconds is false.
 
-Bats are not blind. While most bat species do use echolocation to augment their vision, all bats have eyes and are capable of sight.
 
(for laughs)
-It is a common misconception, even among adults, that humans and dinosaurs (in the ordinary sense of the term) coexisted. According to the California Academy of Sciences, around 41% of U.S. adults mistakenly believe they co-existed. The last of the dinosaurs died around 65 million years ago, after the Cretaceous–Tertiary extinction event, whereas the earliest Homo genus (humans) evolved between 2.3 and 2.4 million years ago.
 
-Bulls are not enraged by the color red, used in capes by professional matadors. Cattle are red-green color-blind. It is not the color of the cape that angers the bull, but rather the movement of the fabric that irritates the bull and incites it to charge.

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