Four Things Science Doesn’t Know (Apr, 1932)

Four Things Science Doesn’t Know

FOUR processes which industry has used for generations without really understanding any of them were listed by Sir Frank Smith, British scientist.

The oldest of these is the use of oil or grease for lubrication, an invention made even before the development of any machines except very simple ones like mere wheels or rollers. Yet modern physical chemists admit that they do not really understand why films of oil act as lubricants.

Another ancient invention is that of making different kinds of iron or steel by leaving definite quantities of impurities such as carbon in the metal. Modern metallurgists are just beginning to discover what happens in these instances; making the difference, for example, between cast iron and steel.

Coal has been heated to make gas for more than a century, yet this process, too, is not well understood. British coal interests now are trying strenuously to improve it by scientific research.

The vulcanization of rubber by heating it with sulphur was the fourth example of an industrial process still not understood.

  1. Stephen says: June 18, 201010:03 am

    There isn’t anything very mysterious about the production of gas from coal: it just has other chemicals mixed in with it besides solid carbon, in the same way that crude oil is a mixture of different kinds of oil that can be separated by distillation. The solid leftover from heating coal in this way is coke; see the Wikipedia article to which I have linked. As for vulcanisation, this is fairly common knowledge nowadays – it was in the Science Encyclopaedia I had when I was eight or so – and is due to sulphur linking the long rubber molecules together, producing a stiffer, more elastic product. Carbon dissolved in steel produces crystals of different types of steel, and the properties of the steel are affected by what proportion of it is this or that type of crystal, how the crystals are arranged, and so on. This is an immensely complicated field which you can read about in, for instance, a book on materials science. As for lubrication, that one I don’t know.

  2. Jari says: June 20, 201012:16 pm

    Stephen: Lubricants generally just create a film between moving surfaces, preventing those surfaces “roughness” to grinding each other.

  3. Fred S says: June 21, 201011:15 pm

    Jari is right. Picture 2 surfaces, let’s say made of metal. They may look smooth, but on a microscopic level, there are pits & nooks covering the surface. Slide them together & the pits & nooks catch each other, causing friction (and a squeaking sound). Place oil on one surface & the oil fills in the nooks & pits & creates a completely flat film, making the surface of the metal flat. Thus the friction is reduced & the pieces move much smoother & quietly. And with less friction, there is less heat build up too.

  4. LS says: July 5, 20104:42 am

    Actually, at the molecular level there is a little more going on in lubrication than just making things “less rough”. Most lubricants have an atomic configuration that orients particular non-bonding electron orbitals against an adjacent orbitals of another lubricant molecule. The net result is separation of two surfaces (including the surfaces of the lubricant molecule) by way of electrostatic repulsion.
    You can have items that are “smooth” at the microscopic level, but do not glide. Conversely, you can, in theory, have items that are “rough” at the macroscopic level, but glide over each other freely with proper manipulation of the free orbitals surrounding the molecules of the surfaces.

  5. Jari says: July 5, 20108:48 am

    Emphasis on little. Fluid dynamics play much bigger role, unless the films thickness is less than micrometer, when intermolecular forces gets significant. Typically in eg. car’s crankshaft has a clearance about 20 microns.

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