Where can I send a letter through an underwater mailbox? Detailed answer

BIG ENCYCLOPEDIA FOR CHILDREN AND ADULTS
Free library / Directory / Big encyclopedia for children and adults

Where can I send a letter through an underwater mailbox? Detailed answer

Big encyclopedia for children and adults

Directory / Big encyclopedia. Questions for quiz and self-education

Did you know?

Where can I send a letter through an underwater mailbox?

On one of the islands of the Pacific state of Vanuatu, 50 meters from the coast, there is an underwater postal station. Having bought a special waterproof envelope in advance, divers can put the letter in the mailbox or give it to the postman on duty, sitting at the counter in diving equipment.

Underwater mailboxes can also be found in Japan, Malaysia, the Bahamas and other resorts.

Authors: Jimmy Wales, Larry Sanger

Random interesting fact from the Great Encyclopedia:

What is the eye made of?

The human eye is a kind of camera. It has a special hole where light rays fall (pupil), lenses that focus them, and a retina where the image appears.

There are about 130 million light-sensitive cells inside the eye. When light hits them, they immediately undergo chemical changes that are converted into a nerve impulse. Through the optic nerve, it enters the part of the brain that is responsible for vision. Here, this signal is processed, after which we see one or another object.

The eye has the shape of an apple with a slightly elongated anterior part, in the middle of which there is a hole, or pupil. It appears black because behind it is the dark interior of the eye. Light through the pupil falls on the lens, which converts the light rays into an image on the wall of the eyeball. Here, like the film of a camera, there is a layer of light-sensitive cells, or the retina.

Around the pupil is the iris. It has the shape of a donut in blue, green or brown. The iris can change its size like the aperture of a camera. In bright light, tiny muscles dilate it, and so the pupil constricts, allowing fewer rays to pass in. In the dark, on the contrary, it expands.

The entire eyeball is covered by a membrane called the sclera. The whites of the eyes are also part of this membrane. From the outside, it is transparent, this part of it is called the cornea. The space between the cornea and the iris is filled with fluid, or "chamber moisture". It acts as a lens.

The other lens of the eye, the lens, can change shape. When we look at close objects, the lens becomes thicker, when we look at distant objects, it becomes thinner.

Test your knowledge! Did you know...

▪ What is cryptography?

▪ What is glue made from?

▪ How were antibiotics discovered?

See other articles Section Big encyclopedia. Questions for quiz and self-education.

Read and write useful comments on this article.

<< Back

Latest news of science and technology, new electronics:

Machine for thinning flowers in gardens 02.05.2024

In modern agriculture, technological progress is developing aimed at increasing the efficiency of plant care processes. The innovative Florix flower thinning machine was presented in Italy, designed to optimize the harvesting stage. This tool is equipped with mobile arms, allowing it to be easily adapted to the needs of the garden. The operator can adjust the speed of the thin wires by controlling them from the tractor cab using a joystick. This approach significantly increases the efficiency of the flower thinning process, providing the possibility of individual adjustment to the specific conditions of the garden, as well as the variety and type of fruit grown in it. After testing the Florix machine for two years on various types of fruit, the results were very encouraging. Farmers such as Filiberto Montanari, who has used a Florix machine for several years, have reported a significant reduction in the time and labor required to thin flowers. ... >>

Advanced Infrared Microscope 02.05.2024

Microscopes play an important role in scientific research, allowing scientists to delve into structures and processes invisible to the eye. However, various microscopy methods have their limitations, and among them was the limitation of resolution when using the infrared range. But the latest achievements of Japanese researchers from the University of Tokyo open up new prospects for studying the microworld. Scientists from the University of Tokyo have unveiled a new microscope that will revolutionize the capabilities of infrared microscopy. This advanced instrument allows you to see the internal structures of living bacteria with amazing clarity on the nanometer scale. Typically, mid-infrared microscopes are limited by low resolution, but the latest development from Japanese researchers overcomes these limitations. According to scientists, the developed microscope allows creating images with a resolution of up to 120 nanometers, which is 30 times higher than the resolution of traditional microscopes. ... >>

Air trap for insects 01.05.2024

Agriculture is one of the key sectors of the economy, and pest control is an integral part of this process. A team of scientists from the Indian Council of Agricultural Research-Central Potato Research Institute (ICAR-CPRI), Shimla, has come up with an innovative solution to this problem - a wind-powered insect air trap. This device addresses the shortcomings of traditional pest control methods by providing real-time insect population data. The trap is powered entirely by wind energy, making it an environmentally friendly solution that requires no power. Its unique design allows monitoring of both harmful and beneficial insects, providing a complete overview of the population in any agricultural area. “By assessing target pests at the right time, we can take necessary measures to control both pests and diseases,” says Kapil ... >>

Random news from the Archive

Llamas help fight the flu 02.11.2018

Belgian scientists have found that certain llama antibodies can help fight the flu.

These antibodies are very small. Scientists noted that there is an opportunity to make them even smaller. Thus, science will receive "nano-bodies", which will give them the ability to penetrate viruses. To gain new knowledge, experts conducted an experiment. Three influenza strains and a surface protein were specially introduced into the organisms of these animals. Reacting to this situation, the body of the llamas released four antibodies. On their basis, scientists have deduced the gene. It was introduced into the virus.

The study showed that this artificial gene was able to neutralize sixty strains of the disease. They belonged to both group A and group B. Subsequently, the "new remedy" was tested on mice. First, an influenza virus was introduced into their body, and then they tracked how the "nano-body" coped with its neutralization. The experiment showed that the derived method is effective. He helped some rodents completely get rid of the virus, and in some accelerated the recovery process.

Experts plan to apply this method to people. However, first they will work on its safety for the human body.

Other interesting news:

▪ biodegradable straw made of wood

▪ Radeon RX 6600 XT graphics accelerator

▪ Earth's climate is changing

▪ The next iPhone will get the biggest changes

▪ Origins of human speech found

News feed of science and technology, new electronics

Interesting materials of the Free Technical Library:

▪ section of the Antenna website. Article selection

▪ article Models of S1B missiles. Tips for a modeler

▪ article Which Owl Screams Oo-hee, ooh-hoo? Detailed answer

▪ article Electrical heating of concrete and soil. Standard instruction on labor protection

▪ article Spicy Curry Powder. Simple recipes and tips

▪ article Semi-automatic drilling machine with laser pointer. Encyclopedia of radio electronics and electrical engineering

Leave your comment on this article:

All languages of this page

Home page | Library | Articles | Website map | Site Reviews