In Leonardo da Vinci’s phrase water is “vetturale di natura” - the vehicle of nature. He believed water to be to the world what blood is to our bodies. Indeed it is apparent to modern science that life seems to be predicated on some special properties of water - its anomalous expansion, its high thermal coefficient, it’s function as a solvent, it’s apparent ability to ‘store‘ information, its high degree of polarization, its structural complexity, and many other extraordinary characteristics. Many of these features of water are inexplicable in that they do not conform to any known physical, chemical or biological theory. Indeed some of them are the subject of heated, not to say rancorous, debate within the scientific community. What is clear however is that the mysterious properties of water are vital for such biological processes as protein folding or communication across a synapse - and thus for consciousness.
Q: Is it true that every time we take a breath of air or swallow a mouthful of water, we consume some of the atoms breathed or swallowed by Leonardo da Vinci (as I read in a children’s science book in 1960)?
A: We do indeed breathe in a considerable number of molecules that once passed through Leonardo’s lungs and, unfortunately, Adolf Hitler’s or anyone else’s for that matter. The calculation is not too difficult and is as follows:
The total mass of the Earth’s atmosphere is about 5 1021 grams. If we take air to be a mixture of about four molecules of nitrogen to one of oxygen, the mass of 1 mole of air will be about 28.8 grams. One mole of any substance contains about 6 1023 molecules. So there are about 1.04 1044 molecules in the Earth’s atmosphere.
A single mole of any gas at body temperature and atmospheric pressure has a volume of about 25.4 litres. The volume of air breathed in or out in the average human breath is about 1 litre. So we can assume that Leonardo da Vinci, in one breath, breathed out about 2.4 1022 molecules.
The average human takes, say, 25 breaths per minute, so during his 45-year lifetime (1452 to 1519) Leonardo would have breathed out about 2.1 1031 molecules. So, about 1 molecule in every 5 1012 molecules in the atmosphere was breathed out by Leonardo da Vinci.
However, as we breathe in about 2.4 1022 molecules with each breath, there is a pretty good chance we breathe in about 4.3 109 molecules that Leonardo breathed out. In fact, you can also show in a similar way that you probably breathe in about 5 molecules that he breathed out in his dying gasp.
By knowing that the number of molecules in the hydrosphere is 5.7 1046 molecules, similar calculations can be made for water. These show that a mouthful of liquid contains about 18 106 molecules that passed through Leonardo during his lifetime. So, in addition to breathing in his breath, there is also a pretty good chance of picking up some of Leonardo’s urine in every glass of water that you drink.
Source New Scientist – letters, 18th May 1996