Among the theories about the origin of life on Earth, the hypothesis panspermia takes a special place. This concept is quite foreign. It says that life on our planet is of a global nature. Its embryo was brought to Earth by another celestial body (for example, a comet) or even by an alien ship.
Panspermia is an idea whose form is associated with the name of the ancient thinker Aristotle. One proponent of the theory was one who lived in the 17th–18th centuries. Gottfried Leibniz. However, it was only in the early 20th century that panspermia became merely a philosophical argument and acquired various scientific certifications and models.
In 1908 the Swedish scientist Svante Arrhenius put forward a concept called the theory of radiation panspermia. The physicist suggested that the first spores of bacteria appeared on Earth after migration from the far corners of the universe. The pressure of Arrhenius sunlight (or the light of another massive star) is thought to be due to this “rehabilitation”.
This hypothesis of panspermia has many supporters. Most likely ancestral life, these scientists call Venus, where heat-resistant bacteria could have gotten to Earth at a time when the two planets were at maximum short distances from each other.
Light Pressure Factor
The existence of light pressure even before Arrheniusproved experimentally by Russian physicist Pyotr Lebedev. In addition, the effect of this event on Lycopodium spores was analyzed. In this regard, in the nineteenth century, the theory of panspermia was supported by Ferdinand Kohn, Justus von Liebig, Hermann von Helmholtz, and other eminent scientists of their time.
At the same time, in the 20th century this concept was criticized by many different researchers. Among them were Joseph Shklovsky, Carl Sagan and many others. Opponents deny evidence of panspermia on the grounds that long-term space migration cannot do without receiving harmful doses of radiation for the dispute.
In a general sense, the theory of panspermia states that the vacuum, in which long-travelling bacteria can rest, should not interfere with their life, since at extremely low temperatures, the cells are frozen (suspended animation). Theoretically, such guests “wake up” immediately after their arrival on Earth, where a comfortable climate developed thanks to the coincidence of several circumstances.
The above ideas were rejected by modern scientists. Studies in laboratories have shown that the cell in a cosmic vacuum is simply exploding because of the very rapid evaporation of its water. As a result of this process, microorganisms are destroyed by excessive internal pressure. This is the main argument of experts who believe that radiation panspermia is a myth.
Another hypothesis about the existence of life on Earth, related to panspermia, is the so-called comet theory, set forth in Fred Hoyle’s book The Cloud of Life. In this publication, the author tried to prove the consistency of his hypothesis on the example of global virus epidemics (including the example of Spanish in the early twentieth century). Hoyle suggested that such a major disease (epidemic) could be explained by their causal origin. The author claimed that life can travel to Earth just like a virus.
Eternal life in the eternal universe
One of the most prominent proponents of the panspermia hypothesis today was the British scientist Fred Hoyle. Hoyle, who died in 2001, remains a dazzling figure in science to this day. His work on the creation of chemical elements through nuclear fusion inside stars, so-called stellar nucleosynthesis, paved the way in many ways.
His other ideas are more controversial: for example, Hoyle was one of the scientists who vigorously rejected the Big Bang theory. The term “Big Bang” for Big Bang goes back to Hoyle. Hoyle really wanted to ridicule the theory he had refuted with this acronym. He did not believe that the universe, or even life in it, would ever exist. Instead, the universe has always existed, he said. Life distributed throughout the universe is an equally eternal part of it.