Menu English Ukrainian russian Home

Free technical library for hobbyists and professionals Free technical library


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

Which goods are the most dangerous? Detailed answer

Big encyclopedia for children and adults

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

Comments on the article Comments on the article

Did you know?

Which goods are the most dangerous?

Excluding medicines, food and medical devices, the most dangerous for consumers are toys (24%), mainly Chinese, electrical appliances (19%), cars (14%), lighting devices (11%) and cosmetics ( 9%).

Author: Mendeleev V.A.

 Random interesting fact from the Great Encyclopedia:

Why do clock hands move the way they do?

Before the invention of mechanical clocks, the main device with which people determined time was the sundial. They consist of a dial and a rod, the shadow of which, moving along the dial due to the movement of the Sun across the sky, shows the true solar time.

In the Northern Hemisphere, shadows move in a direction we call "clockwise" throughout the day. According to the quite logical idea of ​​the inventors of the first mechanical clocks, the hands of mechanical clocks had to imitate the movement of the shadow in a sundial.

If mechanical watches were invented in the Southern Hemisphere, the "clockwise" direction would most likely be the opposite.

 Test your knowledge! Did you know...

▪ What was the first movie?

▪ Which subway is the longest?

▪ Can a person drown in quicksand?

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:

A New Way to Control and Manipulate Optical Signals 05.05.2024

The modern world of science and technology is developing rapidly, and every day new methods and technologies appear that open up new prospects for us in various fields. One such innovation is the development by German scientists of a new way to control optical signals, which could lead to significant progress in the field of photonics. Recent research has allowed German scientists to create a tunable waveplate inside a fused silica waveguide. This method, based on the use of a liquid crystal layer, allows one to effectively change the polarization of light passing through a waveguide. This technological breakthrough opens up new prospects for the development of compact and efficient photonic devices capable of processing large volumes of data. The electro-optical control of polarization provided by the new method could provide the basis for a new class of integrated photonic devices. This opens up great opportunities for ... >>

Primium Seneca keyboard 05.05.2024

Keyboards are an integral part of our daily computer work. However, one of the main problems that users face is noise, especially in the case of premium models. But with the new Seneca keyboard from Norbauer & Co, that may change. Seneca is not just a keyboard, it is the result of five years of development work to create the ideal device. Every aspect of this keyboard, from acoustic properties to mechanical characteristics, has been carefully considered and balanced. One of the key features of Seneca is its silent stabilizers, which solve the noise problem common to many keyboards. In addition, the keyboard supports various key widths, making it convenient for any user. Although Seneca is not yet available for purchase, it is scheduled for release in late summer. Norbauer & Co's Seneca represents new standards in keyboard design. Her ... >>

The world's tallest astronomical observatory opened 04.05.2024

Exploring space and its mysteries is a task that attracts the attention of astronomers from all over the world. In the fresh air of the high mountains, far from city light pollution, the stars and planets reveal their secrets with greater clarity. A new page is opening in the history of astronomy with the opening of the world's highest astronomical observatory - the Atacama Observatory of the University of Tokyo. The Atacama Observatory, located at an altitude of 5640 meters above sea level, opens up new opportunities for astronomers in the study of space. This site has become the highest location for a ground-based telescope, providing researchers with a unique tool for studying infrared waves in the Universe. Although the high altitude location provides clearer skies and less interference from the atmosphere, building an observatory on a high mountain poses enormous difficulties and challenges. However, despite the difficulties, the new observatory opens up broad research prospects for astronomers. ... >>

Random news from the Archive

Genetics have found the cause of female happiness 10.09.2012

Researchers from the University of South Florida, the US National Institutes of Health, Columbia University and the New York State Institute of Psychiatry have found that a low-profile form of the monoamine oxidase A (MAOA) gene in women is associated with increased feelings of happiness. Curiously, men did not find such a connection.

"I was surprised by the results, as a milder form of MAOA has been associated with some negative outcomes such as alcoholism, aggressiveness and antisocial behavior," said Henyang Chen, lead author of the study. "Some scientists even call it the 'warrior gene.' side of this gene: at least for women."

Although women are more prone to bad mood, anxiety and excitement, they are also more likely than men to feel happy. Chen says the discovery will help explain gender differences in perception and shed light on the link between specific genes and human happiness.

The researchers analyzed data from a representative sample of 345 people: 193 women and 152 men. Study participants' DNA was analyzed for MAOA gene variations, and their happiness was measured using a widely used and well-tested scale. After checking for factors ranging from age and education to income level, the researchers found that women with a mild form of the MAOA gene were significantly happier than the rest. At the same time, two copies of the gene increased the feeling of happiness. At the same time, for almost all men who had the "happiness gene", the results were the same as for the representatives of the "strong half" who did not have it.

Researchers believe this difference can be partly explained by low testosterone levels in women compared to men. Chen and his co-authors suggest that testosterone may reverse the positive effects of MAOA on men. The potential benefits of MAOA in boys may wane as testosterone rises as they grow older, Chen says, "Maybe men are happier before puberty because their testosterone levels are lower at that time."

At the same time, according to Chen, happiness is hardly determined by a single gene - rather, there is a set of genes that affects the individual level of happiness at every moment of our life experience. According to the scientist, now is just the right time for more genetic research related to happiness and well-being.

Other interesting news:

▪ Renewable energy sources will become more popular than natural gas

▪ Digital wallet instead of paper and plastic documents

▪ Electronic cigarettes are not better than regular ones

▪ The coldest cubic meter in the universe

▪ Corsair M75 Air Wireless Mouse

News feed of science and technology, new electronics

 

Interesting materials of the Free Technical Library:

▪ section of the site Audio Art. Article selection

▪ article Civil defense at an industrial facility. Basics of safe life

▪ article What famous slogan was created on the basis of the last words of a condemned man? Detailed answer

▪ article Wild lettuce. Legends, cultivation, methods of application

▪ article Light telephone based on a laser pointer. Encyclopedia of radio electronics and electrical engineering

▪ article Active load regulator for low currents, 2,5-4,5 volts 20-200 milliamps. Encyclopedia of radio electronics and electrical engineering

Leave your comment on this article:

Name:


Email (optional):


A comment:





All languages ​​of this page

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

www.diagram.com.ua

www.diagram.com.ua
2000-2024