Cellular automata and the game of life

John Horton Conway

On April 11, the mathematician John Horton Conway, age 82, died of the coronavirus disease (COVID-19). Conway became famous during the 1970s for inventing a very special cellular automaton, the Game of Life, which turned out to possess peculiar properties.

Contrary to what is done with most scientific discoveries, Conway did not publish his invention of the Game of Life in a typical scientific journal. It was first published in the Mathematical Games section of the Scientific American magazine, written by Martin Gardner. The article, titled The Fantastic Combinations of John Conway's New Solitaire Game 'Life', appeared in the October 1970 issue.

The evolution of the pandemic in Spain

Logistic curve

Using the data provided every day by the Spanish Ministry of Health, about the number of new cases affected by the pandemic each day, and the number of deaths, we have carried out the following analysis:

1. We have manipulated slightly the real data to take into account the weekend effect, pointed out by the minister, which consists in the fact that the figures for new cases for March 28, 29 and 30 are not faithful to the reality, because fewer cases are declared on the weekend (we are used to waiting until Monday to do it), and then, on Monday, all the missing cases get accumulated. As by then the curve had flattened, what we’ve done is replacing the data about new cases for those three days by the average of the three, thus redistributing the Monday excess between Saturday and Sunday. The following weekend, April 4, 5 and 6, we made the same correction. The attached figure represents the number of new cases for each day (red curve) and the number of deaths (green curve). The numbers in the abscissa of the figure represent days counted from the beginning of the data. Day 1 corresponds to March 3. Day 36 is April 7, the last day about which there were data when this post was published.

Behavior versus Behaviorism: Tabula Rasa and Gender Ideology

Konrad Lorenz
Nobel Foundation Archive

The theory that holds that we are a blank slate, on which someone (perhaps ourselves) should write our character and our behavior is quite old. It could go back at least to Aristotle’s theory of potentiality and actuality, according to which the human soul is born in a state of potentiality, like an unwritten tablet, and must become an actuality:

What [the intellect] thinks must be in it just as characters may be said to be on a writing tablet on which as yet nothing actually stands written: this is exactly what happens with mind. (On the Soul).

This idea was recovered by medieval philosophers such as Avicenna and Saint Thomas Aquinas, and later in the 17th century by John Locke in his An Essay Concerning Human Understanding, where he replaced the term Tabula Rasa by White Paper:

For such who are careful... to principle children well... instill into the unwary, and as yet unprejudiced understanding, (for white paper receives any characters) those doctrines they would have them retain and profess.

And later he adds:

Suppose the mind to be, as we say, a white paper, void of all characters, without any ideas: How comes it to be furnished?

Quantum supremacy?

A Wafer of the D-Wave Quantum Computer.
By Steve Jurvetson from Menlo Park, USA

We have been speaking about quantum computers for a few decades. These computers would work with qubits (quantum bits) instead of bits, and would perform certain operations much faster than ordinary computers.

It has been known since the thirties that quantum computers cannot solve problems that cannot be solved by ordinary computers. Those problems are called non-computable. What they would do, in principle, is solve certain problems (not all) much faster than ordinary computers. That higher speed, which in some cases should be enormous, is called quantum supremacy.

Let's give an example: we know that the decomposition of a composite number into its prime factors can be difficult. It’s trivial if the factors are small, but if the composite number is the result of multiplying two prime numbers of 100 digits each (for example) it is almost impossible to break it down, if we don’t know ay least one of the prime numbers.

The heralded pandemic

SARS-CoV-2

The November 2005 issue of Scientific American published an article signed by W. Wayt Gibbs and Christine Soares titled Preparing for a Pandemic. The article had the following subtitle-summary:

One day a highly contagious and lethal strain of influenza will sweep across all humanity, claiming millions of lives. It may arrive in months or not for years--but the next pandemic is inevitable. Are we ready?

Fourteen years later, the pandemic is here, although the authors were mistaken in one detail: they thought it would be caused by the influenza virus, but it was actually a coronavirus. These viruses belong to two different families:

Scientific models: adjustment or validation?

Leonard Nimoy
as Mr. Spock

One of the ways in which science advances is by building models, which are often made up of more or less complex sets of mathematical equations, and trying to verify whether or not these models adapt to the functioning of the real world, as described by our senses and our instruments.

When building and using a model we must consider two distinct phases:

• Model adjustment: it consists of assigning values ​​to the parameters of the model to ensure that it fits the data we already have about the real world. A model not adjusted to such prior knowledge would be totally useless.
• Model validation: it consists of using the model to make surprising predictions that nobody could have foreseen without the help of the model. If these predictions are confirmed, they become surprising accurate predictions, validating the model. However, the validation is never final, for a new surprising inaccurate prediction could invalidate it in the future.

Let's look at a few examples:

Is there energy in the cosmos?

Georges Lemaître

During the 1950s two cosmological theories entered in competition: the Big Bang, proposed by Georges Lemaître, and the steady state, proposed by Hermann Bondi and Thomas Gold. Although the second had to renounce the principle of the conservation of energy, the most sacred of physics, atheist cosmologists preferred it to the Big Bang, as it seemed to them that this theory required to accept God's creation. In the words of the English astronomer Raymond Littleton, in his popularization book The Modern Universe (1956):

A theory such as this [the Big Bang] that puts back creation to a singular instant in the remote past... to some minds it is an objection that it would imply the removal of the question of the origin of the material of the universe from the realm of science... This consideration does not of course mean that the explosion theory is necessarily wrong, but it puts the act of creation, as we might name it, beyond the reach of science.

In other words: Raymond Littleton objects to the Big Bang theory because it could force us to recognize the existence of a creative God. It cannot be said more clearly.