Thursday, December 22, 2016

Why polls and surveys fail

Polls and opinion surveys often predict results that never happen. Is there a scientific reason that can explain it? I think so. The problem could be that the mathematical theories behind the polls are misapplied.
A branch of statistics is called sample theory. It was invented to solve the problem of estimating whether the products of a factory are well made or defective, without having to analyze them one by one, which would be too costly.
Let us say, for example, that a factory produces one million screws a day. In theory they should be checked one by one, but since that is impossible, only one part is analyzed. Which part? This is what sample theory tries to solve.
Suppose we analyze just 2000 screws, and find that one of them is defective (0.05%). Can we extend this result to the million screws and assert that in that population there will be approximately 500 defective screws?

Thursday, December 15, 2016

What is immortality

Pieter van Lint - Allegory of immortality
Immortality is in fashion. Every few weeks, the media publish news or interviews related to this matter. In addition to the one I mentioned in an earlier article, let's look at two others, quite recent:
         We will live 1000 years (Aubrey de Gray, May 1, 2016).
         Man is about to attain immortality and artificial intelligence, which will turn him into Homo Deus (Yuval Harari, September 11, 2016).
But first we must define what we mean by immortality; otherwise, we will hardly know what we are talking about. As one reader pointed out in my previous article, living 1000 years is not the same as being immortal. If you live 1000 years and then die, you are not immortal, you have just lived longer. This applies, whatever the duration of life. Living 1000 million years and then dying would not be the same as being immortal.
Those who believe that someday we will be immortal do not put all the eggs in the same basket. In recent years, three different ways have been proposed to achieve immortality:

Thursday, December 8, 2016

The three trunks of the tree of life

The tree of life
As time goes by and more and more genomes of living beings of very different types are sequenced, we are learning a lot about the tree of life. This is a summary of what we know:
  • From the fact that all current living things use the same genetic code (with very minor variations) it follows that all the living beings we know, current or extinct (including viruses), descend from a single ancestor, unknown, of course, because there is no trace of in the fossil record, and if we found it, we would not recognize it. This hypothetical common ancestor has received the curious name LUCA, the acronym of Last Universal Common Ancestor. The first living creature should be placed at the very origin of the tree of life (in the root). Many biologist also think that this common ancestor appeared over 3000 million years ago, near the hydrothermal vents found on the mid-ocean ridges that separate the plates of the earth’s crust, where the magma in the mantle tends to rise to the surface.

Thursday, December 1, 2016

A global conspiracy?

Isaac Asimov
In 1976, at the peak of the pessimistic forecasts about the catastrophic rise in global population, foreseen by the first report of the Club of Rome (1972), Isaac Asimov published a science fiction short story (The winnowing), which suggested a (highly unethical) way to stop this catastrophic increase in population. This is the summary of the story:
In 2005, the unstoppable population growth causes famine in the third world countries. To contain it, the world authorities (the UN), controlled by the developed world, decide to apply a triage to the world population. To do this, a scientist (who does not want to do it, but is threatened with reprisals against his family) is ordered to develop a protein, poisonous for 70% of the population, but harmless for the remainder, depending on each individual DNA, so that its effects will be dramatic, but random. The protein will be introduced in the food sent to alleviate famines, so as to bring the world population down to more manageable levels. The project is not applied exactly as planned, because the biologist who must develop the protein gives it to eat to the world leaders without their knowing, so that 70% of them will die. As the protein has been adapted to the scientist’s DNA, by eating it he commits suicide, thus escaping the consequences of what he has done.