Wiregrass Seniors Magazine January 2019 JANUARY ISSUE | Page 5

WiregrassSeniorsMagazine.com Page 5 Despite the fact that smoking is forbidden, it is hard the brain. The optic nerve that senses light is located not to notice that toilets on airplanes have ashtrays right next to the trigeminal nerve that controls sneez- in them. It is not just older plane models, either; brand ing. When the optic nerve sends electrical impulses new commercial aircraft also come fitted with ash- to the brain, the signal triggers the trigeminal nerve, confusing the brain into thinking the nose is irritated trays. and a sneeze is necessary. The answer is that the Federal Aviation Administra- tion requires airlines to have ashtrays on their air- Why Is The Sky Blue? planes. Even though smoking is banned and airplanes Barring cloudy days (along with both sunsets and are fitted with smoke alarms, the FAA knew that sunrises), the sky will usually appear to be blue. This some people would still smoke. Providing a place happens because of the way certain things can ma- for people to safely dispose of their cigarettes was nipulate light. Just as prisms can bend light to create a rainbow and a mirror can reflect light back to where deemed too important for safety reasons. it came from, some objects can scatter light. The Why Do Books Have Intentionally Blank Pages? white light from the Sun hits oxygen and nitrogen A huge portion of all published books come with at molecules that make up most of the Earth’s atmo- least one or two blank pages. Some books have sphere and is scattered to produce all the colors. even more empty pages, and they may carry a However, since the color blue has a shorter wave- message saying “This page has been intentionally length than the rest, it is scattered more. left blank.” This effect also explains the other colors that can These blank pages are not the result of publishers appear in the sky. Closer to the horizon, the sky will purposefully wasting paper but rather a consequence look much paler. Here, the light has traveled through of the printing process most commonly used. Pages more air and has been scattered more intensively, for books are usually printed on very large sheets of mixing in with the other colors and losing its blue tinge. paper—called “signatures”—rather than on individual With the Sun lower in the sky, as with sunsets, the pieces, allowing groups of 8, 16, or 32 pages to be light has to travel through even more air. This scat- printed together. Machines then fold and cut the ters the blue light further, allowing the red and yellow pages into book form, but most written work will not light to travel through. divide exactly into eight, so there will be spare pages Why Are Dreams So Hard To Remember? from the process. Everyone has experienced waking up after an amaz- ing dream and struggling to remember it only mo- Why Do People Sneeze When Looking At ments later. It can be infuriating, and even with self- A Bright Light? Around a third of all people will uncontrollably sneeze help techniques, dreams can usually only be fully re- when they enter a brightly lit environment, such as membered for a matter of minutes. when they go outdoors from a dim building. It’s a phenomenon that has baffled scientists for thousands Scientists have suggested several reasons for why dreams are so hard to recall. The conditions in the of years. brain during REM sleep, where most dreaming takes Sneezes are a reactionary response. They can be place, are not suited to putting experiences into long- caused by a number of different stimuli but usually term memory. Lack of the hormone norepinephrine happen due to nasal irritation. However, in the case also plays a part. The hormone plays an important of the so-called “photic sneeze reflex,” the sneeze is role in memory and is absent during REM sleep. triggered by looking directly at a source of light. Re- searchers have proposed various theories to explain Another factor that contributes to the poor recall of exactly why this happens, although none have ever dreams is that during REM sleep, neurons from the hippocampus may not fire as they do at other times. been widely accepted. This causes them to misfire with other neurons that Most scientists now believe that the photic sneeze help to record memory, which is why the dream quickly reflex may be the result of some crossed wires in fades.