...
Special Forces Call Signs: Why are they needed and which are

Why do we need special call signs? Who invented them? We will answer these and many other questions in the article. The call sign (PSO, call sign recognition) in radio communication is the identifier that identifies the radio transmitter. As a rule, this is a set of numbers, letters, a musical phrase or a meaningful word sent at the beginning of a communication session and necessary to identify the radio station with the receiving object.

2019-12-08 11:45

...
Shanhaiguan Pass: history and modernity

The article tells about the history of the construction and development of one of the most important fortifications in the Great Wall of China. You will also find out what condition the fortress is in today.

2019-12-08 11:45

...
Daylight hours in Moscow and St. Petersburg

Why are there white nights? What is daylight hours? Why are summer days in Moscow longer than winter, and white nights in St. Petersburg?

2019-12-08 11:45

...
A geomagnetic storm is ... The effect of magnetic storms on people. Solar flares of 1859

A geomagnetic storm is a sudden disturbance of the Earth's geomagnetic field, which can last from several hours to several days. It arises as a result of the interaction of solar wind flows and the planet's magnetosphere.

2019-12-08 11:45

...
Herbaceous plants

Grassy plants in the forests of our country are much more common than shrubs and trees combined. The length of their stem, as a rule, is small, although there are also quite high ones - banana, reed, corn, etc.

2019-12-08 11:45