The Vital Role Of Salt

This posting has nothing to do with health. The human body needs salt, but only a little bit of it.

Salt makes up several percent of the water in the world's oceans. In the posting "The Mystery Of Salt" on my physics and astronomy blog, http://www.markmeekphysics.blogspot.com/ , I explained my reasons for believing that the salt in the oceans must have originated with a meteor.

Salt is sodium chloride, chemical symbol NaCl, and virtually all of the sodium and all of the chlorine on earth is to be found united together in salt. It seems very unlikely that this thorough union could have come about unless the two were together before being scattered across the earth.

The water on earth itself was almost certainly delivered by one or more comets. A comet is basically a big chunk of ice in orbit around the sun. The tail of the comet forms as it comes close to the sun, causing some of the ice to evaporate and to trail behind the main body of the comet as water vapor (vapour), which is brilliantly illuminated by the sun.

The presence of salt in the seas appears, at least at first consideration, to be a disadvantage to humans. It makes it so that we cannot drink sea water, at least until it is distilled either artificially or naturally by the water cycle.

Salt raises the boiling point of water. The process of boiling is that when heat is applied to water (or another liquid), it increases the vapor (vapour) pressure of the liquid. When that pressure exceeds the atmospheric pressure on the liquid, evaporation begins to take place throughout the depth of the water, rather than from just it's surface. The result is the familiar bubbling of boiling water.

My reasoning is that if boiling is three-dimensional evaporation and the presence of salt in the water raises the amount of heat necessary to make water boil, it must also mean that salt in water hinders evaporation from the surface of the water when it is not boiling. This has far-reaching implications that I have never seen referred to before.

Water readily evaporates into the air, but the average relative humidity is far less than 100%. My hypothesis is that a major reason for this is the salinity of the vast majority of the water on earth. Per unit of surface area, more water must evaporate from bodies of fresh water, such as North America's Great Lakes, than from the salt waters of the sea. This must be another complicating factor which makes weather so difficult to predict more than a few days in advance.

It is easy to see the extreme weather that we get with a relatively slight increase in temperature due to global warming. This is because an increase in average global temperature of only a couple of degrees will cause a lot of ice to melt and a lot of water to evaporate, that otherwise would not have.

We can only imagine the wild weather that the world might have if evaporation were not reduced by the salt in the sea. I have even wondered if God arranged for the meteor which brought the salt to the earth, in order to make the planet more inhabitable for us.

Consider the Red Sea, a broad swath of water between two very dry areas of land. On one side of the sea is northeast Africa and on the other side is the Arabian Peninsula. It seems to me that the reason for this is that the Red Sea has a very high salinity level, thus greatly hindering the evaporation which might supply rain to the area.