Time Travel and Christ’s Crucifixion

Christ crucified, wood carving
by Manuel Alfonseca Santana

If time travel were possible, the greatest incentive for travelers would be to witness firsthand famous events of the past, such as the assassination of Julius Caesar and many others. The fact that we have no record of the presence of strangers in any of these cases is a significant argument against the feasibility of time travel.

There is no doubt that one of these events, perhaps the most famous of all, would be the Crucifixion of Christ. If time travel were possible, there should have been an avalanche of visitors from future times at Golgotha ​​to witness the most important event in the history of humankind.

In fact, this idea has been used in science fiction literature. In a novella titled There Will Be Time, Poul Anderson has his protagonist travel to Jerusalem on the day of the Crucifixion to witness Christ's death. Upon arriving, he discovers a large crowd, almost all of whom are time travelers.

Quantum Conscience or Conscient Quantum?

The second hard problem of modern science is the origin of consciousness or the problem of free will. This post focuses on the relation of this problem with quantum mechanics. As an example of the difficulty of the matter, I begin by including two famous quotes from renowned scientists:

·         J. B. S. Haldane, Possible Worlds (1927): The universe [of quantum theory] is, not only queerer than we suppose, but queerer than we can suppose.

·         James Jeans, The Mysterious Universe (1930): The universe begins to look more like a great thought than a great machine.

Natural and artificial intelligence

As we saw in the previous post, the book Free Agents by Kevin Mitchell deals with the origins of human consciousness and free will. In a brief epilogue, the book addresses the topic of strong artificial intelligence—the real kind, which doesn't yet exist—and formulates some hypotheses about the possibility of its becoming feasible.

It emphasizes that one of the most active branches of research in AI, especially in recent years, is the field of artificial neural networks, which has led to advances such as Large Language Models (LLMs). It compares these neural networks in our programs with those that exist in our brains and in the brains of many animals more or less similar to us. It says that we are witnessing impressive advances in fields such as image recognition, text prediction, speech recognition, and language translation, based on the use of deep learning, remotely inspired on the architecture of the cerebral cortex.

The future is not written

In several posts in this blog, I've discussed determinism, always from a critical perspective. For example, in a post entitled The debacle of determinism, I mentioned the three devastating attacks suffered by determinism during the 20th century: Heisenberg's uncertainty principle (although it would be better to use the name Heisenberg originally proposed: the indeterminacy principle); chaos theory; and the Copenhagen interpretation of quantum mechanics.

Chapter 7 of Kevin Mitchell's book Free Agents, titled, like this post, The future is not written, analyzes and refutes determinism. However, it doesn't discuss just one type of determinism, but three, refuting them one after another in successive chapters. What are these three types of determinism?

1.      Physical predeterminism: the idea that only one possible timeline exists. In other words, that the future is entirely determined by the past; that the entire history of the universe is predetermined from the beginning; that nothing that happens could have happened otherwise.

The problem of the origin of life

In a previous post titled Paul Davies, popularizer of science, I mentioned the two hard problems of modern science, so called because after several centuries trying to solve them, and although considerable progress has been made, the solution to these problems seems to recede further as we move forward, a paradigmatic case of the horizon effect, which I discussed in another post in this blog with the same title. These problems are: on the one hand, the origin of life, and on the other, the origin of free will, which is sometimes identified with the problem of consciousness, although they are not exactly the same, but are closely related. In this post, I will discuss the first problem. The next post will deal with the second.

The problem of the origin of life is not scientific. It is historical. Happened only once in the history of our planet, and is impossible to reproduce, so it is beyond the reach of experimental science. Even if we were able to create synthetic life (not to be confused with artificial life, a branch of computer science), we would not know if that method of generating life was the same as what took place shortly after the origin of the Earth.

A New Time Travel Paradox

It is well-known that time travel into the past, and sometimes also into the future, if it were possible, could give rise to destructive paradoxes. In a previous post I offered a list of five different types of these paradoxes. Here I will explain in more detail the fourth type I mentioned there: the fact that time travel into the past and human freedom are incompatible. I will do so through a short science fiction story, divided into two scenarios.

First scenario

At 3:55 PM, my friend Max said to me, “I just invented a time machine. Do you want to see it?” Of course, I agreed.

At 3:58 PM, Max and I entered the room where the machine was located. It looked like a simple metal chair. The machinery seemed to be under the seat.

The worldview of Louis Pasteur

Louis Pasteur

Louis Pasteur was, without a doubt, one of the greatest scientists of the 19th century. His scientific work was immense. Among his most notable discoveries are the following:

1.      Optical isomerism. The fact that certain substances occur in two different forms, with the same chemical composition but different physical properties, for they rotate the plane of polarization of light in opposite directions.

2.      Alcoholic, acetic, lactic, and butyric fermentations, which he showed are due to the action of bacteria or yeast.

3.      Spontaneous generation, which in his time was only defended for microorganisms, and Pasteur demonstrated it’s impossible under current conditions.