10 responses to strange questions, if you carefully examine each

There are questions that lie somewhere on the margins of our consciousness all his life, but we don't have an answer. You can question why something is being built this way, why this thing is in this place or how your body is doing something. However, you do not find answers to these questions, although I know that they should be.

Here you will find 10 questions that people ask every day, and finally get simple answers.

1. Why planes are not allowed to smoke?

Despite the fact that Smoking is not allowed, it's hard not to notice that in the toilets of the plane has ashtrays. And not just old models, even brand new aircraft equipped with them.

The answer is that the presence of ashtrays in airplanes is a formal requirement of the Federal aviation administration to airlines. Despite the fact that Smoking is prohibited and the aircraft is equipped with a fire alarm in the FAA know that some people will still be Smoking. Giving people a place where they can safely dispose of butts, it was considered very important for security reasons.

2. Why in the books blank pages?

These net pages are not the result of deliberate waste of paper by publishers, but rather a common consequence of the printing process. Pages for books are usually printed on very large sheets of paper, not on a separate format sheet. Machines fold and cut paper on the page, but the work as a whole may not be divided exactly into eight, so after printing can be blank pages.

Sometimes these pages left for notes, as there is a corresponding label or other message to the readers thought it was a printing error.

3. Why do people sneeze when looking at bright light?

Sneezing is a response. It can be caused by a variety of reasons, but most often occurs due to irritation of the nose. However, in the case of the so-called light cauteloso reflex of a sneeze occurs when you look directly at the light source. Scientists have proposed diverse theories to explain why this is so, although none of them was widely adopted.

Now most scientists believe that Cihelny light reflex may be the result of some crossing of nerves in the brain. Optic nerve receives light is located next to the trigeminal nerve that controls sneezing. When the optic nerve sends electrical impulses to the brain, the signal affects the trigeminal nerve, causing the brain to believe that the nose was angry and urgent need to sneeze.

4. Why does hair become gray?

Hair gets its natural colour thanks to the pigment cells called melanocytes. Melanocytes produce chemicals, which transmit black, dark brown, red, and yellow melanin cells that create the main ingredient of the hair — keratin. When people age, melanocytes are destroyed, causing the keratin gets less pigment — it makes hair becoming gray. In the end, cells cease to function at all, and the hair ceases to pigment at all, becoming completely white.

5. Why when you enter the store you blown air?

6. What causes butterflies in your stomach?

7. Why does rubbing alcohol sting?

When rubbing alcohol hits the cut, it directly affects the VR1 receptors in the skin. These receptors are responsible for perception of heat. While they are activated at high temperatures, the alcohol lowers their threshold to the level at which body temperature is enough to activate them. Buds "think" that the body burns, and they transmit the pain signal to the brain, despite the fact that the skin was not damaged.

8. Why orange juice tastes horrible after brushing your teeth?

It turns out that the unpleasant taste causes the foaming agent used in most toothpastes. Sodium lauryl sulfate weakens the taste buds responsible for sweet. This means that orange juice and everything else, what you will eat or drink immediately after brushing your teeth, don't be sweet.

In addition, sodium lauryl sulfate destroys phospholipids, which is usually in the way of bitterness to be too strong. Therefore, toothpaste is not just drowns out the sweetness of the orange juice, but also enhances its bitterness. Both of these effects create terrible taste.

9. Why is the sky blue?

This effect also explains why the sky is taken for other colors. Closer to the horizon the sky becomes a much paler, because the light passes through more air and is scattered more intensively, mixing with other colors and losing its blue tinge. When the sun goes down, as at sunset, the light has to pass through more air. It scatters the blue color, allowing you to get the red and yellow.

10. Why is it so difficult to remember dreams?

Scientists have suggested several reasons why dreams are so difficult to reproduce in memory. The conditions under which is the brain during REM sleep, when most often the dream does not allow you to transfer them into long term memory. It also plays a role in the lack of the hormone norepinephrine: this hormone plays an important role in memory and is absent during sleep.

Another factor that contributes to poor memory of dreams is that during REM sleep the neurons of the hippocampus may not work as well as they do in other cases. This in turn causes a misfire in the other neurons, which help to capture the memory so that dreams disappear so quickly.