Ep 7. The Fabric of the Cosmos: Quantum Leap

The NOVA season 39, Episode 7 titled "The Fabric of the Cosmos: Quantum Leap" takes on the extensive and fascinating world of physics beyond the tangible "classical physics" that we know so well. What lies in store is a striking insight into the world of quantum mechanics, filled with perplexing ideas and mind-bending experiments that astound even the brightest of minds.

Our host, Brian Greene, begins by delving into the conundrum of how a cat in a box could be both alive and dead at the same time? This fascinating scenario comes from one of the most significant thought experiments in the quantum world -- Schrödinger's cat. Greene explains how this paradoxical situation expands to the entire quantum universe, where particles are said to exist in multiple locations and multiple states simultaneously until observed and measured.

But, how can this be possible? Using imaginative examples and first-hand experiments, Greene takes us on a journey through the mysterious quantum world, explaining how the laws of physics, as we know them, do not apply to this other dimension. Instead, in the quantum universe, particles act like waves, appearing to be in multiple places at once.

The main focal point of the episode is the exploration of "entanglement," which is a phenomenon where particles become linked, acting as one entity, no matter the distance between them. Greene explains that the idea is so absurd that even Einstein called it "spooky action at a distance." Entanglement has real-world application, and the most notable is quantum computing.

The concept of quantum computing is so unique and abstract that at first, we may not be able to comprehend the gravity of its potential. Still, with Greene's help, we can grasp the immense power that this technology holds. Being able to use the principle of entanglement in computing allows for data to be processed almost instantaneously, far beyond the capabilities of current computing tech.

Greene also steps back in time to the "double-slit" experiment, which has become the archetypal quantum mechanics experiment. Two slots are created, side by side, with a screen behind them to capture whatever passes through the slots. The most unexpected result comes when a stream of particles passes through the slots, instead of showing two clear lines on the screen, we see an "interference pattern" that shows up as a wave.

The fact that particles moving as waves instead of individuals doesn't make sense in the classical world, and it's this experiment that made physicists question what was happening in the quantum world. The experiment has since become the origin of the "uncertainty principle," coined by Werner Heisenberg.

Another example presented is the "quantum tunneling" phenomenon, where particles can pass through walls, leading to possible innovations in energy, space travel and medical technology.

As Greene walks us through the world of quantum mechanics, we are introduced to the many physicists who had significant breakthroughs that helped shape our undemanding of the quantum world. A few of these highlighted individuals includes Neils Bohr and Werner Heisenberg, who created the famous "Copenhagen Interpretation," Richard Feynman and his award-winning "Feynman diagram," and the duo of Bell and Aspect, who showed through their Bell tests that the entangled particles could communicate with one another instantly, no matter how far apart they are.

Throughout the episode, Greene explores all other possible variations of quantum mechanics theories, and instead of favoring one interpretation over another, he states that quantum mechanics is inherently strange, and we should embrace those unsureties as it helps us get closer to understanding how our universe works.

In conclusion, "The Fabric of the Cosmos: Quantum Leap" is an incredible journey into the boundless world of quantum mechanics. The episode, although challenging in some areas, is made interesting and engaging thanks to Greene's excellent storytelling skills, as he interweaves educative and entertaining analogies with scientific explanations that flow perfectly. The show serves as a great introduction to quantum mechanics for the average person and is sure to entice and fascinate science enthusiasts.