SCI 8
Ring of Truth: Atoms
9/28/05
RR
The following are the important segments of the Phillip Morrison video; there are several
others that are not noted:
Gold Leaf : gold is a metallic element; it is malleable: can be rolled and beaten
into a sheet which is about 1/1000th the thickness of a piece of paper; the gold atoms
have a strong attraction for each other. He mentioned that unless the gold is purged of
its impurities, it will not be sufficiently malleable for the gold beater’s purposes
Sand at the beach: is a mixture of materials including bits of iron, grains of
quartz, bits of sea shell, etc. The parts can be separated physically because it is just a
mixture and you can see the parts.
Julia Childes burns food to show that all except salt contains carbon. The
carbon is left over when organic substances are strongly heated because it is difficult to
burn the carbon, but not the other elements that are present. Morrison’s point is that
substances can be broken down into simpler components except when we have the
elements. This is a chemical reaction.
Electrolysis of water: by passing electricity through water we can cause the
breakup of the water molecule. The resulting gases are hydrogen and oxygen. By
mixing these and setting a spark, they can be recombined into water with the release of
a great deal of energy. The proportions are always 2 parts hydrogen and 1 part oxygen.
If the mix of gases is not correct, there will be some gas left over. Both the
decomposition of water and the explosion are chemical reactions.
Geodes and crystals: show the internal structure of different substances; each
compound or element forms orderly arrangements of atoms and molecules which we
call its crystalline structure.
“Cooking a diamond”: this time Julia heats a diamond in a vacuum to show that
diamond and graphite are made of carbon, but the arrangement of the atoms is different
in each. If there had been air in the oven, the oxygen of the air would have reacted with
the carbon of the diamond to produce nothing but carbon dioxide. What would then be
visible in the oven?
Making noodles: chef Mark stretches a lump of dough to the extreme: 4096
strands after 12 doubles; the point is that we are getting closer to molecular and atomic
dimensions.
Oil slick: Morrison pollutes a lake in order to calculate the approximate thickness
of a molecule of oil; this works because the oil spreads out until it is only one molecule
thick.
Electron Microscope: shows the orderliness of gold atoms in a microscopic
sample, and their amazingly small size.