Sean Carroll is a theoretical physicist at Caltech and Santa Fe Institute specializing in quantum mechanics, arrow of time, cosmology, and gravitation. He is the author of Something Deeply Hidden and several popular books and he is the host of a great podcast called Mindscape. This is the second time Sean has been on the podcast. You can watch the first time on YouTube or listen to the first time on its episode page. This conversation is part of the Artificial Intelligence podcast. If you would like to get more information about this podcast go to https://lexfridman.com/ai or connect with @lexfridman on Twitter, LinkedIn, Facebook, Medium, or YouTube where you can watch the video versions of these conversations. If you enjoy the podcast, please rate it 5 stars on Apple Podcasts or support it on Patreon. Here's the outline with timestamps for this episode (on some players you can click on the timestamp to jump to that point in the episode): 00:00 - Introduction 01:23 - Capacity of human mind to understand physics 10:49 - Perception vs reality 12:29 - Conservation of momentum 17:20 - Difference between math and physics 20:10 - Why is our world so compressable 22:53 - What would Newton think of quantum mechanics 25:44 - What is quantum mechanics? 27:54 - What is an atom? 30:34 - What is the wave function? 32:30 - What is quantum entanglement? 35:19 - What is Hilbert space? 37:32 - What is entropy? 39:31 - Infinity 42:43 - Many-worlds interpretation of quantum mechanics 1:01:13 - Quantum gravity and the emergence of spacetime 1:08:34 - Our branch of reality in many-worlds interpretation 1:10:40 - Time travel 1:12:54 - Arrow of time 1:16:18 - What is fundamental in physics 1:16:58 - Quantum computers 1:17:42 - Experimental validation of many-worlds and emergent spacetime 1:19:53 - Quantum mechanics and the human mind 1:21:51 - Mindscape podcast
The author explains the basics of quantum mechanics and the many worlds interpretation in his new book titled "Something Deeply Hidden". He also touches upon the difficulties posed by classical mechanics and cites Isaac Newton's perplexity on the concept of gravity.
The speaker claims to have a good understanding of fields in space-time, including the gravitational and electromagnetic fields, but acknowledges that intuition fades as we delve into quantum field theory. The speaker believes that those who believe in cells should also be able to believe in quantum mechanics.
The most beautiful idea in physics is the idea that objects in motion tend to stay in motion and objects at rest tend to stay at rest unless acted upon by an external force, which shifts us from a view of natures and teleology to a view of patterns in the world.
The relationship between math and physics is complex, as physics often uses the tools of mathematics to understand the world beyond the limits of current understanding. However, the fundamental facts of our world seem to be unexplainable and rock bottom.
Quantum mechanics, unlike classical mechanics, gives a fundamental role to the act of measurement, which is something unique in the world of physics. The act of measurement or observation is considered to be profoundly fundamental in the way quantum mechanics is taught.
The wave function of an electron determines the probability of observing the system at a certain location, but it is small outside the atom and large inside the atom. This suggests that electrons have both particle-like and wave-like properties.
The Hilbert space in quantum mechanics is an abstract mathematical space that contains all possible wave functions for a given system, and corresponds to a space of possibilities for momentum, position, and other dimensions.
The separation of what is observed and what is real in the textbook definition of quantum mechanics is one of the most interesting philosophical points. Despite measurement and observers playing an important role in quantum mechanics, they may not play a fundamental role in the ultimate laws of physics.
Sean Carroll, author of Something Deeply Hidden, explains how the multiple worlds interpretation of quantum mechanics can help us better understand the behavior of particles at the subatomic level.
The concept of quantum mechanics in the Many Worlds Interpretation is explained, including why quantum systems can be both wave-like and particle-like, and how the universe splits rather than generates new copies.
The Many Worlds Interpretation of Quantum Mechanics suggests starting from the most quantum theory possible, which brings along classical baggage like perceived locations in space, in order to understand phenomena like gravity and space time.
The idea of locality, which is built into every field theory including general relativity, may not be fundamental to the nature of our existence. This presents challenges for unifying general relativity and quantum mechanics as the quantum theory of gravity is not a field theory.
This podcast episode explores the ideas of holography and complementarity, and how they relate to the strange behavior of quantum mechanics inside a black hole.
The concept of time in the many worlds interpretation of quantum mechanics differs from the traditional notion of time as a fundamental aspect of reality. It is possible, however, to observe the past state of the universe without actually traveling back in time.
The speaker reflects on their diverse podcast guests, mentioning interviews with Wynton Marsalis about jazz, a master sommelier about wine, and psychologists like Carol Tavras about cognitive dissonance.
Sean Carroll discusses how to differentiate between scientific edge cases and individuals who are fundamentally unscientific.