10 familiar things, the true purpose of which we did not know

We are surrounded by thousands of little things that we see so often that we are already used to them and do not notice them. But have you ever thought about the true purpose of these things?

Here are some interesting examples that reveal the secrets of invisible devices for us.

Buttonhole on the back of the shirt

There are three possible use cases. The first and most obvious is to hang up the shirt. The second, perhaps, comes from an era when removable and starched collars and ties were worn, which were more like scarves, and they had to be fixed somehow. Perhaps this loop was made just for this purpose.

The third option is unexpectedly romantic — in an American university, a student who is in a relationship with a girl cut this loop as a sign that he is busy. And the girl, in turn, wore a scarf with the emblem of the university of her lover.

Cylinder on the charger wire

You probably noticed this small cylinder on the laptop charging cord. This very important detail is the ferrite filter. It suppresses high-frequency interference in electrical circuits.

Hole in the plane windows

For the porthole in airplanes, several layers of strong transparent plastic are used, which form a kind of"double-glazed window". Windows can withstand huge loads and have recently been made of high-strength acrylic plastic. The inner glass is not as strong and is made of cheaper Plexiglass. They serve for better noise and heat insulation of the interior, creating an air layer between themselves and the outer window. 

Therefore, there is a risk that in the case of a large pressure difference in the gap between the windows and in the cabin, the inner "glass" may not withstand and burst. A small hole allows you to normalize the pressure, removing excess air from the inter-glass space, or vice versa.

Blue half of the eraser

Ask anyone why you need the blue half of the eraser, and they will probably answer you: to erase the ink of the pen. This is not entirely true. Initially, this half was intended for removing a pencil from thick paper. The pink part usually leaves traces, erasing the pencil not completely, but the blue elastic band removes everything.

The creators of this eraser soon realized that people did not think to use the blue half for its intended purpose, and decided that it was better to adapt and advertise the eraser in a new way.

Horizontal button loops

Another shirt mystery. Have you ever noticed that the loops for the top and bottom buttons are horizontal, and the rest are vertical? This is due to the fact that these two buttons are more likely to unfasten. And the horizontal loops will prevent them.

Extra holes on the sneakers

You've probably seen the extra holes in your sneakers, wondering why you'd have to thread your shoelaces so high. In fact, these holes are designed to lock the shoes on the foot and prevent slipping and chafing when you exercise.

Hole in the spaghetti spoon

Using the hole in the spaghetti spoon, you can measure the amount of pasta for a standard serving.

Small pocket on jeans

The most common answer to the question of why they make this small pocket on jeans is to carry contraceptives there. Of course, in addition to condoms, this pocket will fit a lot of small things, but initially it had a very specific purpose. In 1873, Levi's jeans were produced with a dedicated space for a pocket watch.

A hole in the cap of a ballpoint pen

Many people suffer from the habit of chewing on a pen or cap. The hole in the cap is made in case a person accidentally swallows the cap and it gets stuck in the throat — then you can breathe through the hole until the foreign object is removed.

Samples of material on new clothes

In fact, these pieces are not intended to plug a hole in new clothes. It turns out that they need to try how the material of your new shirt will react to washing powder or bleach.