The mathematical calculation is very simple. The total mass of the Earth's atmosphere is 5 x 1021 grams. If we consider that air is a mixture of 4 nitrogen molecules to one oxygen molecule, the mass of one mole of air would be 22.8 grams. Since one mole of any substance contains approximately 6 x 1023 molecules, the Earth's atmosphere has 1.04 x 1044 molecules.
Let's keep going. One mole of any gas at body temperature and atmospheric pressure has a volume of 25.4 liters. If we consider that the volume of air that enters the lungs each time we inhale is 1 liter, it can be assumed that Leonardo da Vinci inhaled 2.4 x 1022 molecules with each inhalation. Humans take 25 breaths per minute. Thus, during his 45 years of life, the sage from Florence inhaled about 2.1 x 1031 molecules. In other words, 1 out of every 5 x 1012 molecules in the atmosphere have passed through Leonardo's lungs . Thus, if in each inspiration we take an average of 2.4 x 1022 molecules, there is a high probability that among them are 4.3 x 109 inhaled by Leonardo.
