How Science Proved That FUTURE Changes the PAST | Retro causality Explained

 The Fascinating Concept of Retro Causality in Physics

Introduction:

In the world of physics, there are numerous mind-bending concepts that challenge our understanding of the universe. One such concept is retro causality, which suggests that future events can influence the past. While it may sound unbelievable, this idea has been explored by physicists and has the potential to change our perception of time. In this blog, we will delve into the intriguing world of retro causality and explore some groundbreaking experiments that provide evidence for this phenomenon.

The Famous Debate: Bohr vs. Einstein

In the early 20th century, two giants of physics, Neils Bohr and Albert Einstein, engaged in a famous debate on the concept of retro causality. The debate took place at the fifth Solvay Conference in 1927, where 29 of the world's best physicists gathered to discuss quantum mechanics. The conference had an iconic photo taken, featuring renowned physicists such as Max Planck, Marie Curie, and Erwin Schrödinger, alongside Bohr and Einstein.

The debate centred around the wave-particle duality of subatomic particles, a concept that was becoming clearer through experiments like the double-slit experiment. While Einstein believed in a deterministic perspective, Bohr argued for the probabilistic nature of quantum mechanics. The debate ultimately resulted in Bohr's victory, as his interpretation of quantum mechanics, known as the Copenhagen interpretation, gained widespread acceptance.

The EPR Paradox:

Despite Bohr's victory, Einstein did not let go of his deterministic viewpoint. In collaboration with his colleagues Nathan Rosen and Boris Podolsky, Einstein proposed a famous thought experiment known as the EPR paradox. This experiment aimed to demonstrate the concept of retro causality and challenge the probabilistic nature of quantum mechanics.

The EPR paradox involved entangling two particles and splitting them apart. According to the law of conservation of angular momentum, the particles' spins should be opposite and equal. However, the experiment suggested that the measurement of one particle's spin would instantaneously determine the other particle's spin, regardless of the distance between them. This implied that information could travel faster than the speed of light, which contradicted Einstein's theory of relativity.

Delayed Choice Quantum Eraser Experiment:

While the EPR paradox presented intriguing possibilities, it remained a thought experiment until physicist John Wheeler conducted the delayed choice quantum eraser experiment. This groundbreaking experiment aimed to provide practical evidence for retro causality and the ability of future events to influence the past.

In the delayed choice quantum eraser experiment, a light beam is passed through a double-slit apparatus, similar to the famous double-slit experiment. However, Wheeler introduced an additional element to the experiment. He entangled the photons that passed through the slits using a crystal called a beta barium borate crystal. The entangled photons were then split and sent to different detectors.

Here's where it gets interesting. If the information about which slit each photon passed through is known, a particle-like pattern is observed on the screen. However, if this information is erased or not obtained, an interference pattern, characteristic of a wave-like nature, is observed. The detectors that measure the slit information can be thought of as either revealing or erasing the path information.
Wheeler took the experiment one step further by introducing additional detectors that measure the particles' paths after they have passed through the slits.

Surprisingly, the pattern observed on the screen, whether particle-like or wave-like, depends on the setup of the additional detectors. If the photons' path information is revealed on these detectors, the pattern on the screen matches the particle-like pattern. If the path information is erased or not obtained on these detectors, the pattern on the screen matches the interference pattern.

What's even more fascinating is that Wheeler demonstrated that the decision to reveal or erase the path information on the additional detectors can be made after the photons have already passed through the slits. This implies that the future events, represented by the decision made on the additional detectors, can retroactively influence the past events, represented by the pattern on the screen.

Retro Causality and Its Implications:

The delayed choice quantum eraser experiment suggests the possibility of retro causality, where future events can affect the past. If retro causality truly exists, it would have significant implications for our understanding of the universe. Here are three major implications of retro causality:

1. Super Determinism: Retro causality implies that all events in the universe are predetermined. Every action and outcome would be predetermined, and free will would be an illusion. Our universe would unfold like a pre-recorded tape, playing out events in a set sequence.
2. Information Paradoxes: Retro causality raises the possibility of information traveling back in time. This could lead to paradoxes such as the grandfather paradox, where an action in the future would prevent one's own existence in the past. These paradoxes challenge the laws of causality and create logical inconsistencies.
3. Violation of the Second Law of Thermodynamics: The second law of thermodynamics states that entropy, or disorder, always increases with time. However, if information can travel back in time, it would violate this fundamental law. Entropy could decrease, and the arrow of time, which defines the direction of cause and effect, could be reversed.

The Importance of Rigorous Research and Critical Thinking:

While the delayed choice quantum eraser experiment and the concept of retro causality are intriguing, it is essential to approach these ideas with a rational mindset. Science is a field that relies on evidence, experimentation, and consensus among the scientific community. However, there have been cases of data manipulation and cherry-picking to support specific theories.

As viewers and readers, it is crucial to distinguish between credible scientific research and misinformation. Always aim to understand the fundamental principles and concepts underlying scientific theories. Seek consensus among the scientific community, which is usually supported by numerous experiments and observations. Be cautious of cherry-picked data and be skeptical of claims that go against the consensus.

By maintaining an open and rational mindset, we can navigate the complex world of science and make informed decisions. Remember, science is a pursuit of knowledge and understanding, and it is through critical thinking and rigorous research that we can uncover the wonders of the universe.

Conclusion:

Retro causality is a fascinating concept that challenges our understanding of time and causality. While the delayed choice quantum eraser experiment provides intriguing evidence for retro causality, it is essential to approach these ideas with critical thinking and a rational mindset. Science is a field that relies on evidence and consensus, and it is through rigorous research that we can uncover the truths of the universe. So, let us continue exploring the mysteries of the cosmos and expanding our knowledge of the world we live in.