Thursday, September 20, 2018

Conan Doyle’s mistake

Sir Arthur Conan Doyle
Sir Arthur Conan Doyle is famous as the author of the character Sherlock Holmes, the detective who relies on logic to solve the most abstruse cases, as in the famous quote from the story The adventure of the blanched soldier, included in the collection The Case-Book of Sherlock Holmes:
When you have eliminated all that is impossible, then whatever remains, however improbable, must be the truth.
Apart from his mystery books, one of his science fiction novels is also very well known: The Lost World, published in 1912, whose protagonist is Professor Challenger, an unbearable scientist, who also appears in other stories by Doyle. This is the plot of The Lost World:
A group of explorers manages to reach an almost inaccessible mesa, lost in the Amazon rainforest, so isolated that dinosaurs and other extinct animals survive there, as well as two races of humans or primitive pre-humans (Pithecanthropus and Homo sapiens). After they manage to escape and return to England, Challenger gives a lecture about his findings, which nobody takes seriously until he exhibits a specimen of Pterosaur that he managed to take from the mesa in the form of an egg, later incubated.

Thursday, September 13, 2018

Irreversible time: illusion, or simplification?

Ilya Prigogine
We know Einstein believed that the passage of time is an illusion. In a letter of condolence he wrote in 1955 he said: ...the distinction between past, present and future is only a stubbornly persistent illusion. To assert this, he relied on the fact that Newton’s equations of gravitation, his own equations of General Relativity, Maxwell’s equations (which apply to electromagnetic waves) and Schrödinger’s equation (which gives the wave function of a particle in quantum mechanics) are all symmetric with respect to time.
How then can we explain the fact that it seems so obvious that time goes from the past to the future? Usually, physicists who believe that time is an illusion explain it by saying that, at the microscopic level, time is actually reversible, but when we move to the macroscopic level, new, emerging phenomena appear, one of which is the irreversibility of time. Let's give an example:
According to the usual theories, the movement of the molecules of a gas is perfectly reversible. If we reverse the direction of time, all the particles behave exactly the same and continue colliding with each other, only they would move in the opposite direction. However, when we consider all the trillions of particles that make up a gas, we see irreversible phenomena arising, such as the fact that the gas always tends to occupy as much space as possible, while its accumulation in a corner of the container is much less likely.
The problem is that our physical theories are based on approximations. Mathematics is a very important tool for physics, but in mathematics there are several kinds of very different problems, which differ in their difficulty to be solved. Let us look at a few:

Thursday, September 6, 2018

Freedom and prior censorship

Wikipedia Logo
On July 5, 2018 the European Parliament rejected, by 318 votes against 278, the proposal for the Copyright Directive in the European Single Market. In the days leading up to this vote, there were many public and private activities in favor and against the proposal, which after this defeat will have to be debated again in committee, probably with amendments. The most controversial points of the proposal, those that gathered most rejection, were incorporated in two articles of the regulation:
  • Article 11: Establishes what has been popularly called the Google tax. It makes it compulsory, for those responsible for web pages, to request permission, and if the copyright owners wish, to pay a fee, for including a link to a news or copyright owner that has appeared in any of the media. The most favored by this article are not individual authors, but mass media (especially the press on the Internet), the main defenders of this measure.
The MEPs who defended this article argue that it does not affect individuals or the Wikipedia, although the latter felt so threatened, that it declared a strike for the first time in its history, so that access to the Spanish, Italian and French versions of the Wikipedia was closed during the day before the vote. The problem is, this article may be expressed so ambiguously that, although just now may not apply to individuals or to Wikipedia, there are no guarantees that in the future this cannot be done.

Thursday, August 30, 2018

Zero risk does not exist

No entry: radiation risk
We would like to live in a world where we run no risks, but that is impossible. Whenever we get into a car, cross the street, turn on the gas, or play sports, we run a risk. The most elementary acts of our life entail a risk: breathing polluted air; getting exposed to the natural radioactivity in buildings; passing under a roof just when a tile is falling down... We have always known that life is synonymous with danger, and we have adapted to that. In our time, however, it seems that the threshold of risk we are willing to tolerate has fallen down. In other words: we are now more cowardly.
The media are largely to blame. Trying to attract readers and increase their profits, they often encourage states of opinion close to panic. We can see it in the way many news are presented, especially those affecting health (mad cow syndrome, bird flu, SARS, type A influenza, whatever...); the viability of human life on Earth (global warming, collision with an asteroid); or the economy (times of crisis). Many of these threats are real, but they are systematically exaggerated.

Thursday, August 23, 2018

Exaggeration of scientific news: superconductivity

Levitation of a superconducting sheet
In 1986, a team from the IBM research center in Zurich discovered high-temperature superconductivity. Until then, this phenomenon, well known since it was discovered by Heike Kamerlingh Onnes in 1911, only occurred at temperatures close to absolute zero. Thanks to the use of ceramic materials made with copper and rare earths, the critical temperature rose first to 35K, and soon after to 92K (Kelvin, or degrees above absolute zero). As a comparison, take into account that the fusion of ice into water takes place at about 273K.
Immediately the media announced this discovery as the door to a new technological revolution. Among the revolutionary applications announced were nuclear fusion, high-speed trains and ships that would move in levitation, the lossless transmission of electrical energy over long distances, supercomputers, and many more. The “fever” of the media grew even more when Bednorz and Müller, members of the team that made the discovery, were awarded the Nobel Prize in just one year, in 1987.

Thursday, August 16, 2018

Has research on the human genome stopped?

We all know the Human Genome project, officially launched in 1990, although it had been working partially since 5 years earlier. Its purpose was to identify and decipher all the genes in human DNA in 15 years. The project was completed in 2003, within the foreseen term, although in the year 2000 partial results were published. From the scientific point of view, the project was a success, but perhaps for a part of the public it can look like a failure, as the exaggerated expectations aroused by some media have not been fulfilled.
The media hailed the project as the door to a new medical revolution. Among the revolutionary applications announced were: gene therapy to prevent or correct genetic diseases; premature diagnosis of actual or potential diseases, even from the embryonic stage; or personalized medicine, which would adapt treatments of diseases to the ailing person. Possible dangers were also discussed, such as the manipulation of human embryos to adapt their genes to the wishes of parents or dictatorial governments; or the use of genetic data to select personnel, or to grant or deny insurance and credit...

Thursday, July 12, 2018

Extraterrestrials in literature

Extraterrestrials can only appear in two types of literary works: in essays, or in novels, and in the latter only in the genre of science fiction. If an extraterrestrial appears in any novel, the novel automatically becomes science fiction.
Science fiction literature shows very many types of extraterrestrials:
  • Fully humanoid, such as the red men in the Mars series by Edgar Rice Burroughs, who are so humanoid that they are even fertile when mating with terrestrials, as shown by the two sons of John Carter and Dejah Thoris, despite the fact that Martian women are oviparous (!!!) To this group also belong the aliens of The People series by Zenna Henderson, who are only different from us by their mental abilities, and those of Perelandra by C.S.Lewis, also titled Voyage to Venus.
  • Partially humanoid, such as those in Star Ways by Poul Anderson, whose women are also capable of falling in love with terrestrials. This novel develops a typical Anderson argument: extraterrestrials who differ culturally from us in their ecological view of the world, but who are fated to be defeated when confronting terrestrials, who are much more active and aggressive than they are.