Paradoxes of Time Travel

In several previous posts, I have discussed various paradoxes that time travel could cause if it were possible. Travels to the future controlled from the past do not cause paradoxes. That they are possible is obvious, since we all travel to the future at a rate of twenty-four hours each day.

It is also possible to travel to the future if one is in a coma and later awakens; or through hibernation, if it were possible, which it is not at the moment, but it may become so someday; or by traveling through space at relativistic speeds, which would result in a time dilation that, upon returning to the starting point, translates into a journey to the future. This last procedure is not possible right now, but it could become so someday, apart from the technical difficulties of achieving it.

Units of Length

It was natural for humans to use their own dimensions as a basis to measure distances. Thus arose the inch, the width of a thumb; the span, the width of the palm of the hand with spread fingers; the foot, the length of a human foot; the cubit, the distance from the elbow to the tip of the middle finger; the fathom, the distance between the two hands with outstretched arms; the pace, the distance between the two feet while walking; and so on.

This system of measurement has two problems. The first: that these lengths depend on each person. The second: that they are not simple multiples of one another. To solve the first problem, standard values ​​were introduced. To solve the second problem, some of the measurements were slightly modified. Thus, in England, the inch was approximated by one-twelfth of a foot. This introduced a third problem, because each country chose different standard values ​​and made approximations in its own way.

A new Goldilocks zone

We are familiar with the Goldilocks zone, considered necessary for the emergence of life in a planetary system. It is the region where the surface temperature of the planet allows for the existence of liquid water, which is generally considered essential for life as we know it, although in science fiction literature (remember Fred Hoyle's The Black Cloud) there are life forms that might not require this condition.

Planets very close to their star would have a temperature too high for the existence of liquid water; all the water would vaporize, and in some cases escape the planet's gravitational pull. On very distant planets, the temperature would be too low, and all the water would be in a solid state (ice). In both cases, it is thought that the emergence of life would not be possible.

The Death of Words

C.S. Lewis

In an article published on September 22, 1944, in The Spectator with the same title as this post, later included in the collection Of This and Other Worlds, C.S. Lewis pointed out that the meaning of many words evolves until they become mere synonyms for “good” or “bad,” and when this happens, the word is dead, because its original meaning is eventually forgotten, while the new one is useless, since the number of synonyms for “good” or “bad” continues to grow.

Lewis notes that many words, throughout history, have undergone this evolution, which transforms them from descriptive terms into insults or praises (synonyms for bad or good). He gives as examples villain, which from inhabitant of a village came to mean  a mean, evil, or unprincipled person (synonyms for bad); bastard, which from illegitimate child came to mean a person, especially one who is mean or unpleasant (another synonym for bad); or to say that someone is a gentleman, which initially referred to a profession or social category, and came to mean a man of good breeding, education, and polite manners (that is, a synonym for good).

About the Encyclical Magnifica Humanitas. Can it be called Luddism?

The publication of Pope Leo XIV's Encyclical Magnifica Humanitas has prompted some people to accuse it of being an exercise in Luddism and a return to the Middle Ages (many of these people know little about the medieval period), sometimes accompanied by gruesome images of robots being burned at the stake, undoubtedly generated using AI tools. The speed of their responses is so surprising that one may wonder if they are judging the text without having read it. Are they right? Can the encyclical be accused of Luddism?

Let's begin by defining the word Luddism, as it appears in the Merriam-Webster dictionary:

The beliefs or practices of the Luddites: one of a group of early 19th century English workmen destroying laborsaving machinery as a protest. Broadly : one who is opposed to technological change.

It is, therefore, a term primarily applied to the use of violence against technological advancements. Violence is certainly difficult to justify, although in Ned Lud's case it is understandable, considering what happened at the time as a consequence of the introduction of machinery (looms) in textile factories. Some employers took advantage of this to dismiss their workers, telling them something like this:

Craig Venter, rest in peace.

Craig Venter

Craig Venter died on April 29, less than six months shy of his 80th birthday. This biologist revolutionized genomics research with two major achievements:

·         Deciphering the human genome. The Human Genome Project, whose scientific director was Francis Collins, was launched in 1990 by a multinational consortium with huge funding and the support of several governments. Its goal was to decipher in 15 years all the genes in human DNA. In 1998, eight years later, Craig Venter founded Celera Corporation and decided to apply the shotgun sequencing method, which he had developed, to decipher the human genome in parallel with the Human Genome Project, but much faster and with far less funding. His efforts culminated successfully, as in 2000 Venter and Collins jointly announced the success of both projects, several years ahead of schedule, and presented partial results, which were completed in 2003.

The future of science

Friedrich Nietzsche

With the loss of the impetus of Christianity, cyclical conceptions of history have resurfaced in the West. Let us see how Nietzsche expresses this in Thus Spoke Zarathustra (Part III, 2.2), at the same time as predicting the replacement of man by the Superman, so he should have been immune to it:

And that spider creeping slowly in the moonlight, and that same moonlight, and you and I, standing before this door chatting about eternal things—must we not all have existed once before? And must we not come again and travel that path that stretches before us, that long and dreadful path? Won't we have to return eternally?

Twentieth-century atheist cosmologists often expressed a preference for a cyclic cosmology, which in their view would make God unnecessary to explain the existence of the universe. Although some of those theories (steady-state cosmology and the alternation of the Big Bang and the Big Crunch) are no longer in vogue, thanks to the data we now have about the origin and future of the universe, new theories continually emerge to replace them.