A paradox in physics is a contradiction or inconsistency in our understanding of the natural world. These paradoxes can often be resolved by further study or by adapting our understanding of reality to fit the new evidence. However, some physical paradoxes may remain unresolved and could potentially reveal flaws in current theories. It is generally believed that reality is consistent, and any apparent contradictions are due to incomplete or incorrect information. In cases where the assumptions we have about reality are challenged, such as in the fields of quantum physics and relativity, we may need to revise our understanding of reality to incorporate new evidence in a self-consistent manner.
Paradoxes are common in the field of physics, appearing in all areas of the subject. While there are various ways to classify paradoxes in general, there is currently no specific system for categorising paradoxes in physics. In modern physics, which is a highly formalised and fundamental science, paradoxes can be seen as a sign of incorrect or flawed theories. This work aims to group paradoxes in physics based on shared characteristics, with the goal of better understanding the causes of paradox formation. Now, let’s dive into three weird paradoxes in physics.
Grandfather Paradox
The grandfather paradox is a paradox that arises in the concept of time travel. It is based on the idea that a person may travel back in time and prevent their own grandfather from having children, including the time traveller’s own parent. If this were to happen, the time traveller would not have been born and, therefore, would not have been able to go back in time to prevent their grandfather from having children. This creates a paradox because it means the time traveller, both does and does not exist, which is a contradiction. The paradox is often described using the example of a time traveller going back in time and killing their own grandfather before he can have children, which would prevent the time traveller from being born and, therefore, from being able to travel back in time.
The grandfather paradox has been a popular theme in science fiction, appearing in literature and media such as movies like “The Terminator”, “Tenet”, “Back to the Future”, and “Hot Tub Time Machine”. However, the grandfather paradox is not just a fictional concept. It has been the subject of serious consideration by philosophers and physicists, particularly in light of Albert Einstein’s theories of special and general relativity, which suggest that time travel could potentially be possible.
Fermi Paradox
In 1950, physicist Enrico Fermi famously asked his colleagues at Los Alamos National Laboratory a question that has since become known as the “Fermi Paradox.” Fermi observed that, in a universe that is billions of years old and contains billions of trillions of stars, it seems likely that there would be other intelligent civilisations. However, there is little evidence of this. Fermi asked, “Where is everybody?” referring to the lack of evidence for extraterrestrial life. The question has since become a paradox, as the apparent likelihood of other intelligent life existing in the universe contrasts with the lack of concrete evidence for it.
Despite much progress in our understanding of the universe, the question about the existence of intelligent alien beings still needs to be solved. The Fermi Paradox refers to the apparent contradiction between the likelihood of other intelligent life existing in the universe, given its vast size and age and the lack of concrete evidence for it. Since the 1950s, humanity has made great strides in space exploration and technology, including landing on the moon and sending probes beyond our solar system. If we have been able to achieve these feats in just a few hundred thousand years, it seems likely that other civilisations in the 13.8 billion-year-old universe would have had similar or even greater advancements. One would expect to see some evidence of their existence, such as radio signals or visual clues, but this has yet to be observed. The Fermi Paradox continues to puzzle scientists and thinkers.
Schrödinger’s Cat
Schrödinger’s cat is a hypothetical scenario used to demonstrate the strange behaviour of quantum particles. In the thought experiment designed by physicist Erwin Schrödinger, a cat is placed in a sealed box with a hammer, a radioactive material, a bottle of poison and the Geiger counter. If the radioactive material decays, the Geiger counter will detect it and stimulate the hammer, which will shatter the bottle of poison and kills the cat. On the other hand, because the decay of the radioactive material is a random process, it is impossible to assume when it will happen. This case is used to explain the concept of quantum superposition, which suggests that particles can exist in multiple states at the same point in time.
Quantum mechanics suggests that an atom can exist in a state of superposition, where it is both decayed and not decayed simultaneously. This means that the state of the atom is linked to the fate of the cat inside the box. Until the box is opened and the state of the atom is observed, the cat’s state is uncertain and can be considered to be both alive and dead simultaneously.