Why? Many Questions Answered

?Why Do Buses Often Come In Threes

A common complaint of people who use public transportation is that of waiting at a bus stop for ages and then three buses arrive all at once.

In fact, mathematicians have attempted to explain this everyday conundrum by means of applying complex formulae based on queuing models, correlation and renewal theories, random matrixes and bunching However, the phenomenon can be explained in fairly simply terms.

Buses leave the depot at regular intervals, but the number of people waiting at the various bus stops tends to vary considerably, and it’s these variations at the bus stops that play an important role in “bus bunching ” For example, if there’s an excessive number of passengers waiting at one bus stop, the first bus will take longer than normal to load these passengers In this time, the second bus catches up a little When this second bus arrives at the same stop, it’s likely that there won’t be as many passengers waiting, as most of them are on the first bus, so the second bus won’t stay at the bus stop for as long Also, because the first bus has taken longer at the first stop, it’s likely that more passengers will be waiting at
the next stop The process then repeats itself, with the second bus eventually catching the first until they travel in tandem, acting as one The longer the route, the more buses that are likely to join the convoy, although experiments have shown that the most common bunching number is two buses.

Despite there being such a scientific basis for bus bunching, some claim that it rarely occurs and that people forget how often single buses arrive.

Is One Dog Year Equal to 7 Human Years

| في 10:14 م

The age-old adage that one dog year equals seven human years derives from the simple mathematical division of the average human lifespan by the average canine lifespan.

It’s true that dogs do age much faster than humans because of their higher metabolic rate; generally speaking, the larger the mammal, the slower the metabolism and the longer the life However, it’s now generally accepted that the seven-to-one rule of thumb for a dog’s “realistic” age is inaccurate; for instance, it’s not uncommon for dogs to live to the age of fifteen, but few humans live to 105

It’s believed that the seven-year rule should not be applied proportionally, and that, while it might be appropriate for the middle section of a dog’s life, the beginning or final developmental phases cannot be correlated to those of
a human A dog tends to be fully sized and sexually mature at the age of one, but the same cannot be said of a human of seven A more accurate method of calculating a dog’s “realistic” age is to allocate twenty-one years for the first year.

(i e , when dog and human both reach adulthood) and then
four years for every additional year

The size and breed of a dog are also factors that impact on how fast it ages Larger dogs age the fastest, so even the above rule cannot be applied to all breeds of dogs In fact, the older the dog, the more accurate the seven-to-one ratio becomes Roughly, a large ten-year-old dog is considered to be seventy-eight, whereas a small ten-year-old dog would be fifty-six

Do you Get Wetter Walking In the Rain Than you do Running

| في 11:43 م

The question of whether people will get wetter if they walk through the rain than if they run through it has been the subject of much bar room discussion More than that, scientists have been considering the problem for many years, and have concluded that many factors can contribute to which method of progress exposes a person to more rain Some factors are the speed and intensity of the rain, the build of the person, the direction and angle of the rain, and the distance traveled

The main reason for the debate is the fact that raindrops generally hit both the head and the front of the body It has been thought that because a runner will be in the rain for a shorter period than a walker will, fewer drops will hit his or her head, and this is a generally agreed-upon hypothesis

However, some believe that a runner will be hit with more drops on the front of the body because of his or her increased velocity when running The balance of these two factors has been put to the test scientifically

A number of experiments have been performed to determine the best way of keeping dry when moving in the rain, most of which have resulted in a running person ending up less wet than a walking person While some experiments found that the number of drops per second that a runner received was the same as for a walker (because the runner was hit more on the front but less on the head), the runner was in the rain for a shorter period and so got hit with fewer drops overall A number of experiments counting the actual number of drops that hit both a runner and a walker found that the runner received far fewer head drops, but that the front drops for the runner and walker were the same, which again resulted
in the runner getting less wet

In one experiment, the runner ended up getting 40 percent less wet, while
in another this figure was reduced to 10 percent A 1997 experiment found that running in a light rain with no wind resulted in the runner getting 16 percent less wet, while leaning forward and running fast in heavy rain being driven by wind resulted in the runner getting 44 percent less
wet On the basis of these experiments, it’s possible to determine that running is always the best option, particularly in heavy rain

Does Water Travel Down the Drain In Different Directions In the Northern and Southern Hemispheres

| في 1:30 ص

Folklore states that water drains down the sink in a counterclockwise direction in the Northern Hemisphere and a clockwise direction in the Southern Hemisphere, supposedly owing to a physical phenomenon called the Coriolis effect Named after a French engineer, this effect is caused by the Earth’s rotation subjecting a twisting force to fluids flowing along its surface The force occurs over large distances and periods of time, and is reversed in the two hemispheres, which explains why macro events such as hurricanes rotate in opposite directions depending on where they are When it comes to small bodies of water, such as those contained by
a sink or bath, these are far too insignificant to be effected in any noticeable way by Coriolis forces

The direction in which water drains down sinks and bathtubs depends on the shape and surface of the bowl and drain (most aren’t completely flat), the configuration of the taps and the way in which the water is poured in Depending on these factors alone, water can drain down in either direction in either hemisphere If water is swirled into the drain in a clockwise direction, it’s likely to carry on draining in that direction

The reason for the enduring myth is most likely because it has repeatedly been quoted on television programs and in textbooks.

What is a Blue Moon

| في 3:09 ص

“Once in a blue moon” is an expression for something that rarely happens, and of course it leads people to ask, what is a blue moon?

A literal blue moon occurs when enough smoke or dustas present in the atmosphere to make the moon appear blue This occurred back in 1883, when the Indonesian volcano Krakatoa exploded, and in 1950, when masses of smoke from Canadian bush fires filled the air.

The first use of the expression was in a 1528 book, wherea blue moon referred to something that would never happen, similar to the saying “if the moon was made of green cheese ” In the 1700s, meanwhile, saying “I’ll marry you when the moon is blue” was not a marriage proposal but a statement denying that there was any chance of marriage .

The expression “once in a blue moon” came to meansomething that happened only occasionally An edition
of The Maine Farmers’ Almanac from the 1800s defined ablue moon as the third of four full moons that occurred in a season The first full moon was known as Lenten Moon, the second was known as Paschal Moon and the third—if it did appear, which was a rarity—was known as Blue Moon, and it’s from the almanac that the modern meaning of the expression is derived.

In March 1946, the author of a Sky & Telescope magazine article misinterpreted the reference to the blue moon in the 1937 edition of the almanac, interpreting the blue moon to be the second full moon in a single calendar month, and this interpretation of the term became popular and still exists today In fact, the average interval between full moons—i e , the lunar month—is twenty-nine and a half days, which is shorter than the average calendar month of thirty and a half days This makes two full moons in the one month possible but rare A blue moon generally happens forty-one times every century, which equates to once every two and a half years It can occur in any month except February (which is too short) and is most likely to happen in

either January or March, because they each contain thirty-one days and are separated by February.

.. Why Do We Yawn, and Why is it Contagious ..

| في 11:00 م

It has traditionally been thought that yawning is an involuntary

reflex that draws more oxygen into our bloodstream and removes a buildup of carbon dioxide This theory was fueled by the notion that when people are bored or tired, their breathing slows, resulting in a lack of oxygen, which causes them to yawn However,
research based on exercise suggests that this theory is incorrect In tests, it was discovered that people’s yawning rates were not altered during exercise, despite an increase in the breathing rate and levels of oxygen in the bloodstream In addition, athletes often yawn before big events, which is unlikely to be as a result of boredom or a reduced level of breathing It has also been found that fetuses yawn in the womb, even though
they don’t breathe oxygen into their lungs until after birth .

It has been suggested that people yawn to stretch the lungs, jaw and facial muscles, which increases the heart rate and makes a person feel more awake, although this suggestion is largely posited on the fact that a stifled yawn that does not stretch the jaw is unsatisfying Other theories are that yawning is used to regulate body temperature or is caused by a variation in certain chemicals, such as dopamine, in the brain It is now accepted that the exact reasons why we yawn are unknown.

It’s also not known why yawning is contagious One theory is that we have evolved to yawn when others around us do because our early ancestors used yawning to coordinate social behavior or to build rapport in a group When one person yawned to signal something, such as it being time to sleep, the rest of the group also yawned in agreement and the members’ activities were synchronized

Yawning might also have been used to bare the teeth to intimidate enemies, so that, when one member of the group yawned, the rest followed suit This has carried through to modern times, when the suggestive power of yawning is still contagious Lending weight to this theory is the fact that babies, who are unaware of social codes, don’t yawn contagiously until they’re about one year old .

What Causes Jet Lag and How Can it Be Prevented and Cured

| في 9:45 م

Jet lag, or desynchronosis, is a condition that’s caused by crossing time zones during air travel It is said to be a symptom of the disruption of the body’s circadian rhythms—i e , the day/night, light/dark cycle, which controls the timing of bodily functions such as when you sleep and eat . Other contributing factors to jet lag are the dry atmosphere of planes and the lack of fresh air; the discomfort caused by cramped conditions; swelling caused by cabin pressure; the food and drink consumed in transit; and the direction of travel North/south travel doesn’t result in jet lag because the time zone remains the same, while some suggest that flying east results in the worst jet lag, as it accelerates the passage through the time zones and that, because time is “lost,” there is less time to “absorb” (the human body is more adept at compensating for enduring longer days than shorter ones) Others maintain that jet lag is greater when traveling away from your normal time zone than toward it.

The symptoms of jet lag are irregular sleep patterns and insomnia, fatigue, confusion and disorientation, irritability, headaches, nausea, dehydration and a loss of appetite It’s estimated that one day of recovery time is needed for every one-hour time zone crossed.

The effects of jet lag can be reduced in various ways For example, before a flight you should be well rested and relaxed Plenty of exercise before a flight can help, too, and no alcohol should be consumed beforehand, though some medical professionals suggest the taking of certain drugs and hormonal supplements.

To reduce the effects of jet lag while in the air, drink plenty of water and avoid alcohol (it’s thought that the effects of alcohol are more pronounced at high altitudes) and caffeine-based drinks Get as much exercise as possible by stretching in your seat or walking about the plane Remove your shoes and get comfortable Adjusting your watch to the new time zone can also be psychologically beneficial.

Once you’re on the ground, take a shower to get your blood moving, drink plenty of water and try to adapt to the environment of the new time zone as quickly as possible Maximizing your exposure to the sun can help you to adjust to your new environment, so you shouldn’t sleep upon arrival; instead, wait until night .