Looking Glass Universe | "Many Worlds" is a simplification of quantum mechanics @LookingGlassUniverse | Uploaded 2 years ago | Updated 3 hours ago
Follow up videos answering these questions:
Why don't I experience being in two worlds? https://youtu.be/4dCrNMqvYyg

The many worlds interpretation of quantum mechanics is often criticised for being excessive. Isn't it crazy that there are an infinite number of worlds splitting all the time? In this video I give an introduction to what many worlds actually is, and why I think it's actually a simplification of standard quantum mechanics.

Book recommendations:

The best book on MW in general and the one that inspired this video is Emergent Multiverse by Wallace.

Another fantastic book is Decoherence: and the quantum-to-classical transition by Schlosshauer. It isn’t specifically about MW, and is useful to understand decoherence in general.

$I didnt believe that light slows down in water (part 1) Supported by Screen Australia and Youtube through the Skip Ahead initiative. 3Blue1Browns video: https://www.youtube.com/watch?v=KTzGBJPuJwM Part 2: https://youtu.be/uo3ds0FVpXs?si=zW8nyuZpn8NshfqC Experiment: If you’d like to try this experiment at home then you’ll need a phone with Lidar or you can get a laser meter quite cheaply. The app I found most reliable for the measurement was this one: https://apps.apple.com/us/app/lidar-measuring/id1535032210 Code: The 3D simulation is here: https://github.com/mithuna-y/speed_of_light_in_a_medium/tree/main/multiple_layers References: The Feynman lectures- “Ch 31: On the origin of refractive index” and “Ch 48: Beats” Matter and Interactions 3rd Edition - The quote is from section 24-4 on page 1001. It’s a long passage but I tried to paraphrase it accurately. Here’s the full quote: How might we measure the speed of propagation of an electromagnetic wave? One can think of two different approaches: (a) Follow a wave crest: If you watch one particular wave crest, you will see that it travels a distance λ (one wavelength) in a time T (one period). Therefore the speed of the crest is v = λ / T (b) Time the arrival of a radiative electric field: One could imagine a different way of measuring the speed of an electromagnetic wave. Suppose that you and a friend synchronize your clocks, then travel to locations that are a distance d apart. Your friend aims a laser at your location, and precisely at time t1, turns on the laser. You record the time t2 at which you first detect the radiative electric field. In the laser light, and knowing the distance between the locations and the elapsed time Δt = t2 - t1, you calculate the speed at which the laser light traveled toward you: v = d / Δt In a vacuum, these two ways of measuring the speed of a sinusoidal electromagnetic wave will give the same answer: 3 x 10^8 m/s. However, this will not necessarily be the case if part or all of the space through which the light wave travels is filled with a medium such as water, glass, or even air. In this case, method 2 (measuring the time required for information about a change in the electromagnetic field to travel a given distance) will still give 3 x 10^8 m/s. However, method 1 (timing the interval between crests in a steady state electromagnetic wave inside the medium) will give a different answer, which will almost always be less than 3 x 10^8 m/s.$

"Many Worlds" is a simplification of quantum mechanics @LookingGlassUniverse