Thursday, February 15, 2018

The star of Bethlehem

Giotto - Adoration of the Magi
Chapter 2 of St. Matthew’s Gospel begins with these words:
After Jesus was born in Bethlehem in Judea, during the time of King Herod, Magi from the east came to Jerusalem and asked, “Where is the one who has been born king of the Jews? We saw his star when it rose and have come to worship him.”
First, a few considerations about this text:
  • Magi is a term with different meanings. Strictly speaking, it was applied to the priests of Mazdayasna, the religion of Zoroaster. Zoroastrian magi were frequently devoted to astrology (the name then given to the science we now call astronomy). So, in a broad sense, the word magi could be applied to anyone who worked in that science. The New Testament does not say that they were kings. That is a later tradition.
  • It will be noted that the text does not say that they were three. They must be at least two, since the term is plural, but later thinkers have discussed whether they were two, three, or even six. The three magi is also a later tradition.
  • It is explicitly stated that King Herod was alive. When did Herod die? Since Emil Schürer (1896) it has been assumed that he died in the year 750 ab Urbe condita (a.U.c., since the founding of Rome), which corresponds to year 4 b.C.e. (before the Christian era). From this, many historians deduced that Jesus Christ must have been born before that date. Therefore Dionysius Exiguus, author of the idea of ​​numbering the years since the birth of Christ, would have made a mistake in assigning the year 754 a.U.c. to his birth. But some modern historians think that Herod could have died in the year 753 a.U.c. (year 1 b.C.e.), and that his sons pushed back the beginning of their own reign, thus causing the discrepancy and leading Emil Schürer to a wrong conclusion. Consequently, the most probable date for the birth of Christ would be between the year 7 b.C.e. and the year 2 b.C.e.

Thursday, February 8, 2018

Scientific questions in Blade Runner

Philip K. Dick's sci-fi novel Do androids dream with electric sheep? was published in 1968 and quickly became a cult book, with many supporters and not a few detractors, among them myself. Fourteen years after its publication, its adaptation to the cinema with the title Blade Runner multiplied the number of its supporters.
In another post in this blog I mentioned that, in my opinion, the film is much better than the novel. When I read the latter, I did not like it. The time has come to explain why. This is the plot:
In a future world, in the year 2019, the advance of technology makes it possible to build androids (replicants in the film), beings of appearance identical to a human being, endowed with intelligence, but who have not been born in the usual way; they have been built. This future society tries to keep replicants segregated, so that they won’t mix with traditional humans. To achieve this, a new profession is invented: the killer of replicants who try to pass themselves off as humans. As soon as they detect a replicant doing this, the destroyer pursues and kills the replicant in cold blood, without a trial.
The above summary can be applied almost equally to the novel and to the film. So far, the argument is interesting, original and attractive. Why then did I say that I did not like the novel, but did like the movie?

Thursday, February 1, 2018

Chance or pseudo-chance?

Gregory Chaitin
In computer programming, certain algorithms (called pseudo-random) generate series of numbers that meet the conditions required by statistics to decide on the randomness of a sequence. These algorithms are used frequently to simulate chance.
However, these algorithms have been designed by someone (the programmer who invented them). In fact, they are not usually random, in the sense that, if they are executed several times in a row, they always give the same results.
We have a similar case with the digits of p. Ten trillion digits of p are currently known, and their number is constantly growing. So far, the digits of p have met all statistical randomization tests. However, it is evident that they cannot be truly random, that they are designed. There are simple algorithms that generate them one after another, in the correct order.
Let us go back to the mental experiment of the previous post in this blog. If intelligent beings were to emerge in an artificial life experiment,
Would these beings be able to distinguish between chance and design as the origin of their own existence?

Thursday, January 25, 2018

Chance or design?

Tree of life
In this context, we must distinguish three things:
  1. The scientific theory of evolution, which is strongly supported by data from other sciences, such as embryology, comparative anatomy, paleontology, biogeography, or molecular biology (DNA analysis).
  2. The claim that evolution is a consequence of pure chance, which is not a scientific theory, but philosophical, although its supporters claim that it is scientific.
  3. The assertion that evolution is an example of design, which is not a scientific theory either, but philosophical. The supporters of intelligent design argue that it is scientific.
To solve this dilemma we would have to answer one of the following questions:
         Is there a way to prove scientifically that evolution is a consequence of chance, rather than design?
         Is there a way to prove scientifically that evolution is a consequence of design, rather than chance?

Thursday, January 18, 2018

How the eye evolved

Let us reason about this problem by answering a few questions.
  1. Which part of the eye is most essential? The answer is obvious: the retina. If light cannot be detected, the remainder of the eye is useless.
  2. Can a retina, on its own, without the rest of the eye, play a useful role? Obviously, yes. Many groups of not too complex animals have ocelli, photo-receptor cells that just react to the presence of light, but cannot form images. Of course, perceiving the presence of light offers advantage against being totally blind. The proof of this: ocelli have appeared independently in at least 40 different animal groups.
  3. What is the next step? We also have traces among current animals. The Planaria is a Platyhelminth (flatworm) whose ocelli are located at the bottom of a concavity in its body. Thanks to this, the Planaria not only detects the presence of light, but also, to some extent, the direction it comes from. It is also obvious that being able to perceive the direction of light provides advantage to those who can, against those who cannot.

Thursday, January 11, 2018

The eye as an argument about evolution

Schematic diagram of the human eye
The vertebrate eye consists of five parts: cornea (a transparent insulating layer); aqueous humor; crystalline lens (a lens surrounded by muscles that make it possible to achieve a variable focal length); vitreous humor; and retina. The light passes through the cornea and the aqueous humor, is focused by the lens, goes through the vitreous humor and impacts on the nerve cells of the retina, which generate electric signals that the optic nerve transmits to the brain, which forms from them an image of the external world, where the light rays came from. The brain even turns the image around, as it is inverted when projected on the retina.
The complex structure of the eye has always been a problem for evolutionists, and an argument for those opposed to the theory of evolution. Darwin, in Chapter 6 of The Origin of Species, whose title is significant (Difficulties of the theory) dealt with the problem of the evolution of the eye in the following words:

Thursday, January 4, 2018

What happened to the predictions for 2017?

At the end of every year, many predictions are made about the following year. This applies especially to politics and the technological field. In this blog we are not interested in politics, so we’ll talk a little about technological predictions. What happened to those that were made for 2017 near the end of 2016? Have they been fulfilled?
This question is difficult to answer satisfactorily (with a yes or no), for those who make predictions usually do them on purpose in an ambiguous way, so the next year they’ll be able to say that they were right. For instance: