Science or pseudoscience?

Martin Gardner

The word pseudoscience is defined as follows in the Cambridge Dictionary:

a system of thought or a theory that is not formed in a scientific way

As for Wikipedia, it is defined like this:

statements, beliefs, or practices that claim to be both scientific and factual but are incompatible with the scientific method

We can deduce that pseudoscience is a theory or discipline presented as scientific, but not really scientific. The distinction between science and pseudoscience is important, because there are many pseudosciences, almost more than sciences, although sometimes it is difficult to distinguish them, because throughout history, ideas about what is scientific and what is not, have changed.

Five years in PopulScience

Albert Einstein

This week we celebrate a small anniversary: five years since this blog was created. In this time, 245 posts have been published. The Spanish version of the blog is a little older: it was created 30 weeks before, in January 2014, and has published 257 posts.

To mark the date by some kind of celebration, I have decided to compute the list of people most mentioned in the blog in these five years. The following table shows the names of the ten people most quoted and the number of times their name has been quoted:

Name	Times quoted in PopulScience
Albert Einstein	42
Isaac Newton	33
Stephen Hawking	20
C.S. Lewis	20
Aristotle	17
Charles Darwin	14
Isaac Asimov	14
Richard Dawkins	12
Plato	10
Ptolemy	9

The symbol of death

Azrael, the angel of death
Evelyn De Morgan (1855-1919)

For an educated classical Greek, the number 8 represented death. Why? Let’s see what this funeral assignment was based on.

1. Multiply by 8 the first 8 natural numbers.
2. Add the digits for each result.
3. If the total obtained has more than one digit, we add those digits again.

Multiply	Add digits	2nd addition
1×8=8	8	8
2×8=16	1+6=7	7
3×8=24	2+4=6	6
4×8=32	3+2=5	5
5×8=40	4+0=4	4
6×8=48	4+8=12	1+2=3
7×8=56	5+6=11	1+1=2
8×8=64	6+4=10	1+0=1

Observe that we obtain the sequence 8,7,6,5,4,3,2,1. For the Greeks, this succession starts at 8 and descends to die at 1. That is why number 8 represented death.

Are the digits of Pi real?

Martin Gardner

In an article published in Discover magazine in 1985, Martin Gardner wrote this:

As it happens, the thousandth decimal of pi is 9... The question: Was [this assertion] true before the 1949 calculation? To those of the realist school, the sentence expresses a timeless truth whether anyone knows it or not... [Others] prefer to think of mathematical objects as having no reality independent of the human mind.

This problem is quite old, as we have been discussing it for over two thousand years. The question about whether mathematical objects really exist or are a pure creation of our mind is a particular case of another problem, much more general, that debates whether ideas and concepts (like the dog species) really exist, or just this dog and that dog exist. This is the problem of universals, famous in the Middle Ages, which has not yet been solved to everyone’s satisfaction. In fact, at present, this debate is more virulent than ever.

What’s a scientific theory

Karl Popper

Although it is fashionable to assert that Karl Popper’s theories about the evolution of science are outdated, his definition of what is a scientific theory is unassailable:

A theory is scientific if and only if it is possible to design an experiment that proves that this theory is false.

A paradigmatic case is the Copenhagen Interpretation of Quantum Mechanics. In 1935, Einstein, Podolsky and Rosen designed an experiment that could prove this theory false. A few months later, Niels Bohr published another article in the same magazine, in answer to the previous article. Almost 30 years later, as I explained in another post in this blog, the EPR experiment, which up to that point had been mental, could be carried out and confirmed Bohr’s predictions, rather than Einstein’s. As this theory was able to resist an attempt to prove it false, it must be considered a scientific theory.

Of course, this success of the theory does not imply that it should automatically be considered correct or true. Scientific theories (always according to Popper) never become so. This theory has successfully withstood an attempt to prove it false, but the next attempt could do it.

What really happened in the history of cosmology

To complete last week’s post, I will offer here a summary of the history of Cosmology, from the Greeks to the paradigm shift that took place in the sixteenth and seventeenth centuries.

The basic elements of Ptolemaic astronomy, showing a planet on an epicycle (smaller dashed circle), a deferent (larger dashed circle), the eccentric (×) and the equant (•).

• Greek cosmology (with the exception of Aristarchus of Samos) put the Earth at the center of the universe. Plato and, above all, Aristotle established the idea that, since the sky is perfect, the orbits of the planets must be exactly circular, because, for them, the circumference is the most perfect curve of all.
• The Greek model explained well the movements of the sun and moon, and therefore made it possible to predict eclipses, but had a problem with the retrograde movements of the planets then known (Mercury, Venus, Mars, Jupiter and Saturn). Three centuries before Christ, Apollonius of Pergamum proposed that the orbits of these planets are epicycles, circumferences centered on another circumference (the deferent), which in turn revolves around a point located near the Earth, but apart from its center (the eccentric).

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.

Plato's Timaeus, the philosophical basis of the medieval cosmological model

Plato, according to Raphael Sanzio

Among Plato’s dialogues, Timaeus has always captured the attention of scholars, for it represents the first description in Greek philosophy of a coherent cosmological model, which reached great resonance by becoming part of the medieval model through the partial translation into Latin of this dialogue by the mysterious Roman philosopher Calcidius.

Very little is known about Calcidius. Although he lived in the fourth century, we do not know his date of birth or death, nor the place where he lived. It is not even known whether he was a Christian or a pagan (a Neo-Platonist). His book is dedicated to a certain Hosius, who may or may not be the bishop of Cordoba who participated in the Council of Nicaea.

It is often said that medieval philosophy in Western Europe was based initially on Plato, and from the twelfth century on Aristotle. This happened because, in the realm of the Western Roman Empire, the knowledge of the Greek language had been lost, therefore the Greek classics could no longer be read in their original language. There were no Latin translations, for the illustrated Romans of the imperial period could read the Greek language perfectly, so did not need them. What is not usually mentioned is that Plato’s works had also become inaccessible, with the sole exception of the Timaeus, which in the partial translation by Calcidius knew an unexpected boom during the Middle Ages, even stronger than Calcidius’s work during his life.

Is there a universe?

The Spanish Wikipedia defines the universe thus:

The universe is the totality of space and time, all forms of matter, energy and momentum, plus the laws and physical constants that govern them. However, this term is also used in slightly different contextual senses and refers to concepts such as cosmos, world or nature. Its study, at the highest scales, is the object of cosmology, a discipline based on astronomy and physics, which describes all the aspects of this universe, together with its phenomena.

Before applying to the universe, the Greek word cosmos meant order and beauty. Notice that this sense is maintained in one of its derivatives, the word cosmetic. The Latin word mundus also has the two meanings: as a noun, it means the world, the totality. As an adjective, clean, neat, elegant. Presumably the first sense was copied from Greece, and to translate the world cosmos they adopted the same word that represented in Latin its other meaning. Finally the word nature (physis in Greek) has phenomenal connotations (rather than to the universe, it refers to what happens in it). From this word come physics (the study of nature) and metaphysics (beyond physics).