Atmospheric pressure was discovered in the 17th century by the Italian scientist Torricelli, using a mercury barometer, Torricelln collected mercury in a glass tube, clamped the open ends of the tube with his finger and immersed it in a vessel filled with mercury. Some of the mercury poured out of the tube, the remaining mercury formed a 76 cm column. The reason for this is the atmospheric pressure, which prevents mercury from pouring out of the tube.
Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.