Thursday, December 25, 2014

Science, ethics and democracy

John Boyne’s novel, The boy in the striped pajamas (2007) is about the slaughter in the gas chamber in the Nazi concentration camps. The book ends thus:
Of course all this happened a long time ago and nothing like that could ever happen again.
Not in this day and age.
Is this true? Those things can never happen again?
I think this ending is not right. First, it’s not true that it all happened a long time ago. Seventy years is not a long time for historic events. Second, it’s not true that those things could never happen again. Have we forgotten the Ruanda massacres in the nineties?
But perhaps the author meant that those things can never happen again in Europe. Have we forgotten the Srebrenica massacre and the Sarajevo tragedy, also in the nineties?
Or perhaps he means that these things cannot happen in a democratic country. Has he forgotten that Hitler reached power after a democratic election? Has he forgotten that the Athenian democracy was discredited for millennia by their death sentence against Socrates, the result of a secret vote that took place just after the restoration of democracy, which followed the oligarchy imposed by Sparta after the Peloponnesian war?

Thursday, December 18, 2014

Classifying living beings: Cladistics or complexity levels

The tree of life
Since Aristotle, living beings have been classified in kingdoms. At first there were two: plants, practically unmoving, and animals, capable of active movement.
When Antony van Leeuwenhoek discovered microorganisms, biologists tried to maintain this two-fold division, integrating some with animals (amoebas and Paramecium), others with plants (bacteria and microscopic algae and fungi). But at that level, the separation between animals and plants is blurry, and in the mid twentieth century a third kingdom was added to the other two: protists, unicellular living beings.
A little later, biologists came to the conclusion that the kingdom of plants should be divided into two: fungi at one side, all the other plats (metaphyta) at the other. By 1975, therefore, there were four different kingdoms.

Thursday, December 11, 2014

Artificial life is not here

Saccharomyces cerevisiae (yeast)
Last spring, the media published the news that a scientific team had replaced the smallest chromosome of a yeast cell by a synthetic chromosome, built from the nucleic acid sequence of the replaced chromosome with a few changes, such as the elimination of a section. Once added to the yeast genome, the synthetic chromosome seemed to work correctly.
The headline of the article linked above is meaningful: Scientists Move Closer to Inventing Artificial Life. As it is worded, it seems to imply that we are close to building artificial life. But is this true? Or is this one of those typical overstatements of the media?
In the scientific parlance, artificial life may have two very different meanings:

Thursday, December 4, 2014

The fine tuning problem

In two previous posts I dealt with the relation between the multiverse theories and the problem of fine tuning, noting that those theories do not solve the problem. This third post describes briefly what is the fine tuning problem.
Brandon Carter
In 1973 Brandon Carter formulated the anthropic principle, a name later deplored by its author, because it may be prone to misunderstandings. This principle is simply the verification that the universe must fulfill all the conditions necessary for our existence, since we are here.
Over a decade later, John Barrow and Frank Tipler published a book entitled The anthropic cosmological principle, which offered a stronger version of the anthropic principle, posing that the values of many of the universal constants are critical and minor variations would make life impossible. This finding raises the fine tuning problem, based on the analysis of the possible effects of changing the values of those constants. In other words, the universe seems designed to make life possible. Let’s look at a few examples: