Thursday, December 26, 2024

The lost worlds of 2001

Arthur C. Clarke

2001: A Space Odyssey (1968) is one of the most representative science-fiction films in the world of cinema. Its script, which took several years to develop, was elaborated jointly by Arthur C. Clarke, a renowned science-fiction writer during the golden age of this genre, and Stanley Kubrick, a famous film director. While he was working on the script, Clarke wrote a book with the same title as the film, which was published after the film’s release.

In 1972 Arthur C. Clarke published a book entitled The Lost Worlds of 2001, where he mixes reminiscences about the elaboration of the script with discarded chapters from the book. By reading this book, we can follow the process of the construction of the film by Clarke and Kubrick and the successive stages of the plot. I agree with them that the final script was much better than the intermediate versions. Reading this book has led me to the following two comments:

Thursday, December 19, 2024

Quantum mechanics or classical physics?

John Stewart Bell

The debate about which theory explains better the behavior of elementary particles, either quantum mechanics (with strange consequences such as state superposition and quantum collapse) or a still unknown classical physics-type theory that eliminates the need for such phenomena, has been going on since Bohr and Einstein started this debate almost one century ago.

The issue seemed to have been decided when John Steward Bell formulated in 1964 the famous Bell inequality, which I described in another post. However, as some physicists still raise the question, other means of distinguishing between the two types of theories are still being sought. One of them is the Leggett-Garg inequality (LGI), to which I will dedicate this post, based on a recent article in Physics World, dated August 12, 2024.

Thursday, December 12, 2024

Time travel in science fiction

H.G. Wells

A few years ago, I published in this blog a series of posts about the scientific aspect of time travel, the paradoxes it could cause if it were possible (which almost certainly it is not) and proposed solutions to these paradoxes, such as the quantum multiverse, one of the most absurd theories physicists have ever concocted. In another post I talked about the scientific errors in Michael Crichton’s sci-fi novel Timeline, which tries to avoid the paradoxes in this way, but does it poorly.

Here I am going to speak about time travel from a literary point of view, as a subgenre of science fiction. In this context, it’s irrelevant that time travel may or may not be possible. We are interested in the question, because this is one of the most frequent topics in this type of literature.

Thursday, December 5, 2024

Correlation or causality

Francis Galton, Darwin’s cousin, best known for promoting eugenics, invented the mathematical concept of correlation. Since then, many mistakes have been made relating correlation and causality, which sometimes coincide, but can also be completely different.

Two variables are said to be correlated when increases in one resemble increases in the other, and decreases in one resemble decreases in the other. But not all correlations are the same: to distinguish them, Galton devised the correlation coefficient, a number between -1 and 1.