PBS Space Time Season 2018 Episode 43 Quantum Physics in a Mirror Universe

In episode 43 of PBS Space Time season 2018, titled "Quantum Physics in a Mirror Universe", the team dives deep into the fascinating world of quantum physics. This episode explores the concept of a mirror universe and how the laws of physics could behave differently than in our reality.

The episode starts by introducing the idea of a mirror universe, which is a hypothetical alternate universe where everything is flipped or mirrored. This means that particles and their corresponding anti-particles would swap roles, as well as left and right-handedness. The team explores what this would mean for the laws of physics, specifically in the realm of quantum mechanics.

The focus then turns to the double-slit experiment, which is a classic quantum mechanics experiment that demonstrates the wave-particle duality of matter. In this experiment, a beam of particles, such as electrons, is fired at a screen with two parallel slits. On the other side of the slits, a detector measures where the particles land on a second screen. The results of this experiment can be explained by the wave-like behavior of particles, which interferes with itself as it passes through the slits.

The team then considers what would happen in a mirror universe. Would the results be the same, or would the laws of physics behave differently? The team breaks down the experiment and concludes that in a mirror universe, the interference pattern would be flipped horizontally, but still the same otherwise. This is because the wave nature of particles would still be present, and so interference would still occur.

Next, the team delves into the concept of chirality, which refers to the distinct and asymmetrical left and right-handedness of molecules. In our universe, amino acids are left-handed, while sugars are right-handed. This is called homochirality and is a mystery in itself. In a mirror universe, however, the opposite would be true, and this would have huge implications for our biology. The team explores what this would mean and discusses the possibility of a universe with a different form of life, where homochirality is not a requirement for biology.

Finally, the team discusses the concept of time-reversal symmetry, which is the idea that the laws of physics remain the same if time is reversed. This is a fundamental concept in physics, but the team proposes that the mirror universe could break this symmetry. They examine the decay of particles and suggest that if the laws of physics were mirrored, this would result in certain particles that are stable in our universe becoming unstable in a mirror universe, and vice versa.

In conclusion, the team explores the fascinating concept of a mirror universe and how quantum mechanics would behave if the laws of physics were mirrored. From the double-slit experiment to the concept of chirality and time-reversal symmetry, the team provides a thought-provoking and accessible exploration of a complex subject. This episode is a must-watch for anyone interested in quantum mechanics or the possibilities of alternate universes.