Thursday, May 28, 2015

The final anthropic principle and the Antichrist

Pierre Teilhard de Chardin
In their popular science book, The Anthropic Cosmological Principle, published in 1986, cosmologists John Barrow and Frank Tipler define three different anthropic principles:
1.      The weak anthropic principle or WAP (this was offered by Brandon Carter in 1973): the simple verification that the fact that we are here imposes certain restrictions on the universe, such as having lasted long enough for intelligent life to appear.
2.      The strong anthropic principle or SAP: the claim that making possible the emergence of intelligent life was a necessary requirement for the universe.
3.      The final anthropic principle or FAP: The claim that, once intelligent life has appeared in the universe, it cannot disappear.

Thursday, May 21, 2015

Are we alone in the galaxy?

Enrico Fermi
In their famous book of hard scientific popularization, The Anthropic Cosmological Principle, published in 1986, the cosmologists John Barrow and Frank Tipler offer a proof that we are alone in the galaxy by means of a variant of the Fermi paradox (if there are any extraterrestrial intelligences in the Galaxy, why aren’t they here?) which can be summarized as follows:
1.      In 100 years we will have succeeded in creating life in the laboratory. Not just life, we will also be able to build a complete human being from its chemical components and information about the human genome, which can be stored in a digital memory.
2.      In 100 years we will have managed to build artificial intelligences as intelligent as human beings, able to replace us in any place and circumstance.
3.      Our current space technology allows us to reach a speed of 0.0003 c (where c is the speed of light). At that speed, a spaceship would take about 50,000 years to reach the nearest stars.

Thursday, May 14, 2015

How eukaryotic cells arose

Examples of eukaryotes
The discovery that there are two main types of living cells (prokaryotes and eukaryotes) gave rise to a revolution in the way of classifying living things. Although (as usual) biologists do not agree on a single classification, the following one seems very reasonable:
1.      Empire prokaryote (bacteria). DNA free in the protoplasm.
a.       Kingdom eubacteria (true bacteria). They use acyl ester lipids.
b.      Kingdom archaea. They use isoprenoidal-ether lipids. They include sulphobacteria, methanobacteria and halobacteria.
2.      Empire eukaryote (cells with nuclei). DNA inside the nucleus. They have a cytoskeleton.
c.       Kingdom archaezoa (primitive eukaryotes). They have no organelles.
d.      Kingdom protozoa (advanced unicellular eukaryotes) with symbiotic organelles.
e.       Kingdom Fungi.
f.       Kingdom metaphyta (plants).
g.      Kingdom of metazoa (animals).

Thursday, May 7, 2015

Why science can’t explain everything

The difficulty of explaining everything is not due to our mental weakness, but to the very structure of the universe. In recent centuries we have discovered that the fabric of the cosmos can be considered on several different levels. While the next level has not been discovered, what happens in the previous one cannot be explained, it can just be described. Consequently, for the last known level we can never have explanations, we can only have descriptions.

Let's look at a little history:
  1. Eighteenth-century chemists discovered many new substances. Not knowing what they were, all they could do was describe them in catalogs of properties, but they had no explanation of those properties.