Jim Al-Khalili - Quantum Life: How Physics Can Revolutionise Biology

The speaker introduces the concept of quantum biology, acknowledging the skepticism from both biologists and quantum physicists. He emphasizes the excitement and potential of this field, which explores the intersection of quantum mechanics and biology. The speaker references his previous talk and book, highlighting the strange rules of quantum mechanics and their potential implications for understanding the natural world. He uses the example of the European robin's migration habits to illustrate the importance of investigating these quantum phenomena.

The speaker delves into the role of the Earth's magnetic field in animal navigation, particularly in birds. He discusses the historical understanding of how animals sense the Earth's magnetic field, from early experiments by Russian zoologist Alexander von Mindenhoff to the more recent discoveries about the European robin's unique method of sensing the angle of inclination of the magnetic field. The speaker explains the concept of magnetite crystals in animals and how they may contribute to navigation, but also notes the mystery surrounding the exact mechanism.

The speaker introduces the radical pair mechanism as a potential explanation for how birds sense the Earth's magnetic field. He describes the process that occurs in the photoreceptor cells of a bird's retina, involving the protein cryptochrome and its reaction to blue light. The speaker explains the quantum mechanical phenomenon of entanglement and how it might play a role in the bird's ability to navigate, despite the skepticism due to the delicate nature of quantum entanglement in a complex biological environment.

The speaker discusses the concept of quantum entanglement and its potential implications for biological systems. He highlights the strangeness of quantum mechanics and the challenges in understanding how it could function within the warm, complex environment of a living cell. The speaker also touches on the controversial idea of quantum mechanics playing a role in human consciousness, proposed by Roger Penrose and Stuart Hameroff, and how it gained traction due to the strange nature of both quantum mechanics and consciousness.

The speaker explores the role of quantum mechanics in living cells, emphasizing that all living organisms are made up of cells which are, at their heart, complex organic chemical systems subject to the rules of quantum mechanics. He discusses the possibility of quantum effects influencing the macroscopic world and the idea that a single molecule can have a significant impact on an entire organism, such as a mutation in DNA. The speaker also mentions the central mystery of quantum mechanics, known as the two-slit experiment, and its implications for understanding the quantum world.

The speaker describes the two-slit experiment with atoms, demonstrating the mysterious behavior of quantum mechanics where atoms seem to behave like waves, creating an interference pattern even when sent one at a time. He discusses the implications of observing the atoms, which changes the outcome of the experiment, and the challenges in understanding how a single atom can 'know' about both slits. The speaker also touches on the concept of superposition, where an atom can exist in multiple states or paths simultaneously, and its relevance in nuclear physics and potentially in biological processes like photosynthesis.

The speaker explains quantum entanglement, the phenomenon where particles that are far apart can have instantaneous connections, seemingly communicating with each other faster than the speed of light. He provides a thought experiment involving dice to illustrate the concept and discusses the challenges in explaining this phenomenon without resorting to abstract mathematics. The speaker also introduces Erwin Schrödinger's famous thought experiment involving a cat that is both alive and dead at the same time due to quantum superposition and entanglement, and the implications of this for understanding the quantum world.

The speaker discusses the process of quantum tunneling, where a quantum particle can pass through a barrier it has no right to cross. He explains the importance of this phenomenon in the sun's thermonuclear fusion process and suggests its potential role in biological systems. The speaker also explores the idea that quantum tunneling might cause mutations in DNA by allowing protons to jump between nucleotides, leading to changes in the DNA structure during replication. He highlights the speculative nature of quantum biology but emphasizes the potential significance if these quantum processes are proven to occur in biological systems.

The speaker concludes by acknowledging the speculative and emerging nature of quantum biology. He emphasizes the small but dedicated community of researchers in the field and the potential for significant breakthroughs if quantum processes are found to play a role in biology. The speaker expresses hope for the future of quantum biology and its potential to revolutionize our understanding of the natural world.