Skip to content
Modern WisdomModern Wisdom

SEAN CARROLL | The Problem With Quantum Mechanics | Modern Wisdom Podcast 126

Sean Carroll is a theoretical physicist, podcaster and author. Quantum physics is complicated. The quantum world does not operate like the one we see around us, yet our human experience of life emerges from this strange universe. Today we learn how it can be the case that something so alien can give rise to something so familiar. Extra Stuff: Buy Sean's Book Something Deeply Hidden - https://amzn.to/2rsRcL2 Follow Sean on Twitter - https://twitter.com/seanmcarroll Check out everything I recommend from books to products - https://www.amazon.co.uk/shop/modernwisdom - Listen to all episodes online. Search "Modern Wisdom" on any Podcast App or click here: iTunes: https://apple.co/2MNqIgw Spotify: https://spoti.fi/2LSimPn Stitcher: https://www.stitcher.com/podcast/modern-wisdom - Get in touch in the comments below or head to... Instagram: https://www.instagram.com/chriswillx Twitter: https://www.twitter.com/chriswillx Email: modernwisdompodcast@gmail.com

Sean CarrollguestChris Williamsonhost
Dec 11, 20191h 1mWatch on YouTube ↗

At a glance

WHAT IT’S REALLY ABOUT

Sean Carroll Explains Quantum Mechanics, Many Worlds, And Misused Mysticism

  1. Sean Carroll discusses why quantum mechanics, despite its success, remains conceptually unfinished, focusing on the long‑ignored measurement problem and the split between quantum and classical descriptions of reality.
  2. He explains entanglement, Bell’s theorem, and Hugh Everett’s Many Worlds formulation as a clean way to remove ad‑hoc 'measurement' rules and treat observers as fully quantum systems.
  3. Carroll also describes how historical events, personalities, and academic incentives sidelined foundational work for decades, and how this vacuum helped enable pseudoscientific uses of 'quantum' in spirituality and self‑help.
  4. He outlines his current research goal: starting from a fully quantum description and deriving space, time, gravity, and the classical world, rather than 'quantizing' classical theories after the fact.

IDEAS WORTH REMEMBERING

5 ideas

The measurement problem exposes a fundamental split in quantum theory.

Standard quantum mechanics uses one rule for how systems evolve when unobserved and another rule (collapse) when 'measured,' without clearly defining what counts as a measurement. This unresolved split is the core of the measurement problem.

Entanglement and Bell’s theorem force us to accept genuine nonlocality.

Entangled particles share a single joint quantum state such that measuring one instantaneously fixes correlations with the other, even light‑years away. Bell’s theorem shows you cannot explain these correlations with pre‑existing hidden values that respect strict locality.

Many Worlds removes collapse by treating observers as quantum systems.

Everett’s formulation applies the Schrödinger equation to everything, including observers. Measurements create branches of the universal wavefunction—effectively multiple non‑interacting 'worlds'—instead of invoking a special, ill‑defined collapse process.

The classical world should be derived from quantum theory, not assumed.

Physicists usually start from classical models and then 'quantize' them, smuggling in classical notions like definite positions and trajectories. Carroll argues we should instead begin with a purely quantum description and explain how tables, cats, and planets emerge via decoherence and entanglement.

Human observers are not special to quantum mechanics.

Modern, serious approaches treat 'observers' as ordinary quantum systems; no consciousness or human presence is required for quantum processes. The old observer‑centric language helped fuel misconceptions about 'manifesting reality' and quantum mysticism.

WORDS WORTH SAVING

5 quotes

Physicists are extremely good at using quantum mechanics without understanding it.

Sean Carroll

What quantum mechanics needs is getting rid of all these dumb rules about measurement and probability and collapse.

Sean Carroll (describing Hugh Everett’s move)

If they don't make you uncomfortable, you're not doing it right.

Sean Carroll, quoting philosopher of physics David Albert on deep physical theories

Quantum mechanics is true at all scales. You and I are perfectly quantum mechanical.

Sean Carroll

It was just the bad old days when the idea of observers or experiences were thought to be in any way related to quantum mechanics.

Sean Carroll

History and politics of quantum mechanics and its foundationsThe measurement problem and the quantum/classical divideQuantum entanglement, Bell’s theorem, and nonlocalityEverett’s Many Worlds formulation of quantum mechanicsMisuse of quantum ideas in spirituality and pop cultureDifficulties unifying quantum mechanics with general relativityCarroll’s research on deriving classical spacetime and gravity from quantum theory

High quality AI-generated summary created from speaker-labeled transcript.

Get more out of YouTube videos.

High quality summaries for YouTube videos. Accurate transcripts to search & find moments. Powered by ChatGPT & Claude AI.

Add to Chrome