Thursday, December 14, 2017

Was physics wrong in Ptolemy's cosmology?

1919 solar eclipse
A recent article in the journal Science News has this title: Eclipses show wrong physics can give right results. It claims that Ptolemy’s physics was incorrect, because he assumed that the Earth was at the center of the universe, and yet Greek science was able to predict the dates of eclipses.
According to the article, Ptolemy’s physics was less correct than the physics of Copernicus, who fourteen centuries later proposed that it was not the Earth, but the Sun, at the center of the universe.
The analysis in this article in Science News is completely wrong. Ptolemy’s physics was exactly the same as the physics of Copernicus. Copernicus did not propose a change in the physical theories that had governed classical astronomy since Hipparchus (2nd century BC). Copernicus just showed that, with a change in the coordinate system, and applying the same physics, the calculations are easier to perform. Logically, the same results are obtained.

Thursday, December 7, 2017

Automatic Learning

By popculturegeek.com
 Originally posted to Flickr as Comic-Con 2004
Terminator statue, CC BY 2.0
https://commons.wikimedia.org
As I said in a previous article, automatic learning is one of the areas of weak artificial intelligence which has been object of research for at least 40 years. Strictly speaking, rather than a field of application, automatic learning is a methodology or technique used by other fields of application, such as neural networks, expert systems or data analysis. Automatic learning is divided into two main branches:
  • Supervised automatic learning, which has been used most frequently up to now. This post is dedicated to explain it.
  • Unsupervised automatic learning, related to the field usually called Data Mining. It has lately been widely advertised by the media in relation to a program (AlphaGo Zero) that, learning by itself, has reached a level comparable to the world champion of the game called Go (at the end of this post I’ll talk more about this).

Thursday, November 30, 2017

The Turing test

Alan Turing
In 1950, in an article published in the Mind magazine, Alan Turing wrote this:
I believe that in about fifty years' time it will be possible to programme computers, with a storage capacity of about 109, to make them play the imitation game so well that an average interrogator will not have more than 70 per cent. chance of mating the right identification after five minutes of questioning.
Why precisely 70 percent? Because studies conducted, where some persons tried to deceive about their sex another person who couldn’t see them, gave that result. In seventy percent of the cases, the persons who had to guess if they were being cheated found the correct answer. In other words, what Turing said was this:
If the machine were able to deceive human beings, posing as human, with the same ease with which a human being can deceive another, it should be considered intelligent.

Thursday, November 23, 2017

When can we expect a strong artificial intelligence?

Ramón López de Mántaras
It has been said that man is the only animal that stumbles twice on the same stone. In other words, it is difficult to learn from history (especially when history is not taught) and it is difficult to learn from our own mistakes. This is happening in relation to the field of Artificial Intelligence. In the previous article I mentioned that the creators of the name of this discipline predicted that in 10 years spectacular results would be obtained. Twenty years later, something similar happened when expert systems were invented. In 1990, Ray Kurzweil predicted in his book The Age of Intelligent Machines that strong artificial intelligence would come by the year 2000. In 1999, when he saw that this prediction was not going to be fulfilled, he moved it to 2010 in his new book The age of spiritual machines. As this prediction was not fulfilled either, between 2009 and 2014 he delayed it until 2029. It seems that now he is making less optimistic predictions in this field, and more about immortality, as I mentioned in another article.
Lately the media are announcing the coming of strong artificial intelligence, the real one, in just three years, or at most ten. What do the true experts say about this, those who are doing research on Artificial Intelligence? Let us look at the opinion of Ramón López de Mántaras, director of the Institute for Research in Artificial Intelligence (IIIA, of the Spanish Higher Council for Scientific Research, CSIC). He has received the Donald E. Walker Award for Artificial Intelligence in 2017; the EurAI Distinguished Service Award in 2016; the Spanish National Computing Award in 2012; and the Robert S. Engelmore Award from the Association for the Advancement of Artificial Intelligence (AAAI) in 2011. This is what he thinks about all these announcements:

Thursday, November 16, 2017

What is artificial intelligence

Hal 9000, from the film 2001 a Space Odyssey
Terms such as smart and artificial intelligence are being abused lately. Let’s look at some recent news that have appeared in various media:
  • Smart benches with solar energy free mobile charge, and access to Wi-Fi. These public street benches, installed in London by Ford, incorporate a Wi-Fi repeater and a solar plate that gives them power to charge a mobile phone battery. Where is the intelligence in the bench? Nowhere. The intelligence belongs to the human being who invented these devices. In a similar case, we would be saying that our houses are smart because they have electricity and an Internet connection.
  • China implements smart trash cans. In this case the waste bin also incorporates a solar panel connected to a mobile phone charger. In the future they will also have a Wi-Fi repeater and a device to disinfect the garbage with ultraviolet rays. As in the previous case, the mere presence of an electrical or electronic device is confused with intelligence.
  • Goodyear tests a tire that predicts when it must be changed. The tire has a built-in wireless sensor that detects when it needs to be replaced and issues the corresponding warning. Although this case is somewhat more complex than the previous two, something is again called smart when it isn’t. To implement this, you just need a sensor and a simple electronic device, more or less equivalent to those radio devices that since decades have been incorporated to wild animals, to follow their displacements and watch their activities.
As you can see, what is now called smart is just what was formerly called automatic. But of course, the word smart is more appealing, that’s why it’s being abused. In the same way, there is a tendency to call artificial intelligence what formerly was called computer science.

Thursday, November 9, 2017

The Pascal wager and the Smith wager

Blaise Pascal
Blas Pascal (1623-1662) is known for his activity in mathematics (he devised the triangle of Pascal), physics (he proved the principle of Pascal, invented the hydraulic press and experimented with atmospheric pressure) and especially for his Pensées (Thoughts) one of which contains the first known example of the use of game theory, whose theoretical development had to wait until the twentieth century. This example is the famous Pascal wager, which he expressed thus:
Dieu est ou il n’est pas. Mais de quel côté pencherons‑nous?... Pesons le gain et la perte en prenant croix que Dieu est. Estimons ces deux cas: si vous gagnez, vous gagnez tout, si vous perdez, vous ne perdez rien. Gagez donc qu’il est sans hésiter. 
Whose English translation is:
God exists or He does not exist. Which side shall we take?... Let us weigh the gain and loss, assuming that God exists. Let us consider both cases: if you win, you win everything; if you lose, you lose nothing. So you must wager, without doubt, for His existence.

Thursday, November 2, 2017

The end of mankind

Lord Kelvin
In an earlier post in this blog I spoke about the myth of the Enlightenment, which gave rise to the theory of indefinite progress and the forecast of enormous advances for humankind that would be within our reach in the not too distant future. Although the first half of the eighteenth century was a brake on almost all the cultural activities of our civilization, including science, they were delighted with themselves. Friedrich Melchior, Baron von Grimm (1723-1807), expressed it with unequaled candor, in these words [1]:
The eighteenth century has surpassed all the others in the praises it has lavished on itself.
One of the ideas in vogue by that time was the assumption that scientific advances would let man reach immortality, not too far in time. Although the idea, as a distant possibility, goes back to Roger Bacon, it seemed much closer in the late eighteenth century. Hence the anecdote told of the octogenarian wife of marshal Villeroi, who exclaimed, while looking at Professor Charles’s ascent in a hydrogen balloon:
Yes, it is true! They’ll discover the secret of not dying, after I’ll be dead!
The optimistic ideas of the eighteenth century suffered a sudden, impressive turn in the nineteenth, when came to dominate a pessimistic vision of the future of mankind, based mainly on two scientific discoveries: