Thursday, December 31, 2020

Mesozoic marine reptiles

Jules Verne

In 1867, Jules Verne published his famous novel Journey to the Center of the Earth, whose protagonists discover an underground ocean at great depth, which they baptize as the Liddenbrock Sea, and witness the fight to the death of two great marine animals: a plesiosaur and an ichthyosaur, supposed descendants of ancestors that sank with the Liddenbrock Sea a hundred million years before and survived down there, protected by the Earth's crust, while their surface congeners became extinct as a result of the impact of the meteorite or comet that put an end to most dinosaurs, although that was not known in Verne’s time. But what were those plesiosaurs and those ichthyosaurs that populated the seas during the Mesozoic, formerly called the Secondary Era?

At the dawn of the age of dinosaurs, the oceans of the Earth were joined in a single sea, Panthalassa, which surrounded the supercontinent Pangaea. In that global ocean, at the beginning of the Triassic period, ichthyosaurs appeared. Since the Jurassic, and during the rest of the Mesozoic, Pangaea gradually fragmented, giving rise to new seas.

Thursday, December 24, 2020

The Clock in Strasbourg Cathedral

Clock of Strasbourg Cathedral
One of the most surprising instruments used to measure time is the clock of Strasbourg Cathedral, which contains a mechanical computer, a marvel made up of gears and cogwheels, a pinnacle of the instrumentation of that time, which could be considered comparable to Charles Babbage's Analytical Engine, except that it is not a programmable computing device, but a computing machine built for the specific purpose of calculating time. More details can be found in this article in the journal The Sciences of the New York Academy of Sciences.

The clock is inside the building, rather than at a tower, like those of many other cathedrals. It has a long history, as it dates back since the 14th century, although it was completely rebuilt in the 16th. By the end of the 18th century it stopped working. Legend says that, at the beginning of the 19th century, an orderly who was showing the cathedral to a group of visitors mentioned that the clock had not been working for a long time. Then a boy who was part of the group exclaimed: I will fix it! Forty years later, he did. That child would have been Jean-Baptiste Schwilgué, who remodeled the clock around 1840.

Thursday, December 17, 2020

The enigma of the natural order

In 2019 a book I wrote was published and distributed with the Spanish newspaper El País in a collection dedicated to the popularization of mathematics. The translation into English of my book title is Everything is Number: Is Reality Mathematical?

I addressed the problem of whether mathematical ideas correspond to an external reality, or if on the contrary they are arbitrary and vary with our current mentality. In other words, the question is whether mathematics is discovered, or invented. In one of the posts in this blog I dealt with this issue in relation to the real existence (or not) of the digits of number π (pi).

In the last chapter of that book I addressed a related issue: whether scientific theories, especially those proposed by physicists, are true (in the sense that they represent an underlying reality independent of us), or if are they mental or social constructs unrelated to a reality that could be unknowable (such as Kant's noumena) or even non-existent. I suppose my readers won't be surprised if I say that my personal position is clearly realistic, as is that of many physicists, while supporters of the anti-realist hypothesis tend to be predominantly philosophers.

Wednesday, December 9, 2020

Striking Errors in Scientific Research

Venus. Image taken
by Mariner 10

Errors are not rare in scientific research. Since man is doing science (i.e. since man is man), errors have been made. Science often progresses by trial and error, which means that something is tried, found to be wrong, and then something else is tried. From that point of view, making mistakes and verifying that they are errors is one of the typical procedures of the scientific method, so no one should be criticized for using it.

The problem is, in late times the way to publish the results of an observation or an experiment has changed. Up to now, a well-founded article was written, criticized by a number of scientists in the field, and published in a magazine, which disseminated the finding. This is still being done today, but mass media are often used, before or after the article is published, to spread the "discovery" much more quickly and to many more people. If we take into account that the knowledge about science in mass media is usually ridiculously small, the news is often accompanied by misleading headlines (and sometimes misleading texts), as I have denounced in previous posts in this blog.

Since the dissemination of scientific discoveries is done in this way, the general public frequently finds out about the supposed "discovery", but not about its refutation, because this has not the same appeal and the media don't usually publish it. For this reason, the supposed "discoveries" can be engraved in the people's mind, and it's very difficult to eradicate them.

Let's look at a few examples of striking mistakes made in scientific research:

         The discovery of polywater: in the late 1960s, some Soviet chemists claimed to have discovered a new form of polymerized liquid water, which would arise spontaneously when normal water passes through very narrow capillaries. At that time, the media did not spread it much. For example, the Spanish major newspaper La Vanguardia just published an article on October 21, 1969, saying this:

The surprise has now come from water, as it seems that there exists a polywater. That such a simple liquid, so familiar to us, which has been studied a lot, can still give us surprises, will seem strange to some.

Another piece of news, published on March 26, 1972, is a review of a lecture given by Luis Miravitlles, where he was already suspicious about the existence of polywater:

Despite the many results obtained to date... it is still impossible to decide whether polywater is a true polymer or an artifact produced by conditions in the preparation.

The second alternative turned out to be true. Experiments carried out around the world showed that the properties of polywater were a consequence of the presence of impurities in ordinary water. But La Vanguardia did not publish another article on the subject, so the final refutation did not receive the same diffusion as the original news.

         The discovery of cold fusion: 20 years after polywater, this new "discovery" received much more attention by the media. In the archive of La Vanguardia, for instance, there are dozens of news items related to this, the first of which was published on April 13, 1989. This was due to the fact that, for the first time in the history of science, a "scientific discovery" was disseminated through a press conference before being published in a scientific magazine. And since, from the beginning, most physicists considered the "discovery" impossible, the media echoed them, so just a year later it was considered a failure by almost everyone.

Thalidomide molecule.
A scientific mistake
with awful consequences

Let's look at a few recent cases, which not so long ago made big headlines and then faded away:

         A bacterium uses arsenic rather than phosphorous in its DNA: Announced with fanfare by NASA in December 2010, this "discovery" was removed from the scientific heritage less than two years later.

         Neutrinos faster than light. The news came out in 2011, but it was soon refuted by the discoverers themselves, who found a loose cable that had broken synchronism between the starting point and the arrival point of the neutrinos.

   Gravitational waves in the cosmic background radiation. Announced in 2014, the "discovery" of those waves was supposed to confirm the inflationary theory of the early universe. (Some media incorrectly spoke of a confirmation of the existence of the multiverse). In less than a month it was found that the effect detected had been produced by the dust of our own galaxy. It is still unobserved in the background radiation.

         Presence of phosphane in the atmosphere of Venus, news of 2020, which could be considered as an indication of the possible existence of microscopic life. Subsequent analyzes have not confirmed the presence of phosphane.

The same post in Spanish

Thematic Thread about Science in General: Previous Next

Manuel Alfonseca

Thursday, December 3, 2020

Is there a tree of life?

Tree of life

Many biologists would not hesitate to answer this question in the affirmative. However, in these lines I am going to raise the possibility that the answer should be negative. Let us see why.

First of all, what is a tree? When we use this term, talking about the tree of life, we don’t mean a biological tree, i.e. a plant with a woody trunk that grows to a height of several (or many) meters. We mean a mathematical tree. But what is that?