Baer's Law - explains the causes of asymmetry of river valleys. As a result of the deflecting effect of the Earth's rotation around the axis, river channels in the northern hemisphere are shifted to the right, and in the southern hemisphere - to the left. Therefore, rivers in the northern hemisphere have steep right banks and gentle left banks, while in the southern hemisphere - vice versa.

The law is based on the principle of G. Coriolis, according to which the Coriolis force acts on a material point moving horizontally relative to the rotating Earth, causing acceleration of the point to the right in the Northern Hemisphere and to the left in the Southern Hemisphere.

According to Albert Einstein, the Baer effect is explained by the combined effect of the Coriolis force and friction force, which create a rotational motion of water masses around the axis of the channel. The resulting lateral circulation causes channel erosion of one bank and transport of insoluble sediments to the other bank, resulting in channel change and asymmetry of bank slopes.

Baer's Law applies not only to rivers, but also to sea straits and currents. Thus, according to Baer's Law, the Gulfström (main branch), heading northward after leaving the Gulf of Mexico, deviates to the right and thus washes the western shores of Europe. In the Tatar Strait, where the current runs from north to south, the right bank (mainland) is mountainous and the left bank (Sakhalin) is gentle. In the straits between the Mediterranean Sea, the Sea of Marmara and the Black Sea, also the right (European) shore is steep and the left (Asian) shore is gentle.