The dream of antigravity

Man has always wished to be able to fly. Seeing how birds do it and not being able to do it has obsessed him, to the point of causing quite a few accidents. It is a craving that even very young children know. Some mishaps caused by the viewing of the movie Superman at the end of the seventies may be proof.

At the end of the 19th century, two fundamental interactions were known: electromagnetic and gravitational. In one respect, both are quite different. Electrically charged bodies can have a positive or a negative charge. A positive and a negative charge attract each other; two positive or two negative charges repel each other. Likewise, magnetic bodies have two ends with magnetism of a different type, north and south. If we bring two magnets together, the north end of one and the south end of the other attract each other; ends of the same type repel each other.

Is there a fifth force in Nature?

The standard model of particle physics recognizes the existence of four fundamental forces (their correct name is interactions):

• Gravitation: Newton called thus the force of attraction between any two masses at a distance. For Einstein, according to General Relativity, gravitation is the curvature of space as a consequence of the presence of a mass, which affects the movement of nearby masses. This force, which is always attractive, has an infinite range, although its effect decreases in inverse ratio of the square of the distance, and is the weakest of the four, but its effect is dominant at cosmic and planetary distances, as well as on the Earth's surface.

Newton, the greatest scientist of our civilization

Isaac Newton

As I said in the previous article, in my biographical dictionary 1000 great scientists (1996) and an unpublished book, I proposed an objective quantification of the importance of different scientists, using measures such as the number of lines that various encyclopedias assign to each. Six scientists, one Greek (Aristotle), of whom we have already spoken, and five from the West (Descartes, Newton, Darwin, Freud and Einstein) were tied with the highest score in these studies. Among these five, is there one who can be considered the greatest scientist of our civilization?

In 1964 Isaac Asimov conducted another study (The Isaac Winners) on the relative importance of men of science, which resulted in a list of the 72 best scientists of all time, in his opinion. This list is simply qualitative and does not establish a relative order among the names that appear in it, although Asimov (again in his opinion) asserts that Isaac Newton, who happened to be his namesake, was the greatest scientist of all time.