A rule that describes the fourth card sequence is that a red card is placed on
top of an even numbered card, and a black card is placed on an odd numbered card.
Again, it's a very simple rule stated in only a few words, and
it produces a surprisingly subtle pattern of cards in sequence.
When you stare at these sequences cold, without any idea of what's going on,
you can see how difficult it is to elicit the rule, or
the underlying law of nature, if you like, that describes these sequences.
So this is just a cartoon example, but
it does illustrate many of the features of the scientific method.
The Periodic Table is an excellent example of patterns in nature and
how science works.
The first notion of a Periodic Table came from the Greek philosopher,
Empedocles, almost 2500 years ago.
Empedocles came up with the idea that everything in nature,
all the material substances of the earth, and the atmosphere, and even of
human beings were made of four essential elements, earth, air, fire and water.
And the combinations of those four fundamental elements produced
the diversity of the material world.
It's an extraordinary idea, but it's the basis of modern chemistry.
Flash forward almost 2,000 years and we have Mendeleev, doing simple experiments
and drawing the skeleton of the modern periodic table where the associations and
the properties of similar elements eventually gives us the idea that
those elements have physical underpinnings.
It's not until the modern atomic theory that we truly understand the periodic
table but the patterns in nature.
The similarities between reactive elements and metals and
noble gases is a basis of understanding how the atom works.
The idea of discovery leads to a debate that's going on for many centuries.
The distinction between what is invented in science and
what is discovered is science a product of the human mind and imagination or
is it purely the discovery of things that exist in nature that we and
maybe other creatures elsewhere in the universe can understand?