Thread by @sfiscience

Queuing up for tonight's sold out (but streaming) Community Lecture by Fractal Faculty Professor @seanmcarroll!

🧵 Follow this thread as we look into Schröedinger's Box with @seanmcarroll (newly appointed to Chair of #NaturalPhilosphy at @johnshopkins) and learn about the #ManyWorlds hypothesis of #QuantumMechanics:

"Even if we're wrong, it's not magic, it's #physics, it's #science, and it can be understood."

"When we look at the world, we don't see the entirety of reality. What reality is, is the #superposition of the many different ways..."

"#Space is one of the many things in #reality."

This is not what the #atom looks like. The Rutherford atom is dramatically unstable and would immediately collapse.

"#QuantumMechanics says the world is made of waves. But when you do the #math, the #waves take shape."

"When you look at #electrons, you don't see #waves. You see #particles."

On a crisis of understanding in #physics:

"They bit the bullet." AND "They all objected to this."

"To #Einstein, quantum mechanics was a step in the right direction, but it wasn't finished yet."

"Uniquely in the history of #physics, we have two sets of rules: one for when you're looking at it, and one when you're not. The textbook picture is clearly unacceptable."

"You can see how a whole INDUSTRY of #quantum healing [etc.] could spring up around this...it's almost as if we're bringing #reality into #existence, like a spooky TV show."

"The problem is that there's no consensus."

On the #DoubleSlitExperiment:

"Even though you're sending the electrons through one by one, they interfere. It's hard for *representations* of reality to interfere. The #WaveFunction is a real thing."

"What you will see if you look for particle number 1 is that it's moving in a certain direction...if you see one particle moving in a certain direction, the other must be moving in the other direction, b/c of the conservation of #momentum. You would instantly know." #Entanglement

"What the wave function is doing is assigning a number to the location that any possible configuration the particles could be in. There's only one wave function, and so it's not like a wave propagating through 3-d space. It's an assignment of possibility..."

(Stray electron got into that Schrödinger up there... 😏)

"Hugh Everett said...all the wave function ever does is behave the Schrödinger interpretation. This is his legacy."

"For some reason, observers were supposed to be treated classically. No questions are permitted at this time."

"Everett called his theory the Theory of the Universal Wave Function: Everything is quantum, so there's a wave function that describes both the cat & the observer."

BUT "You always perceive a definite measurement outcome."

Enter #Decoherence: entangle the quantum system with its environment.

"You might think, 'I'm not sure how this helps things.' At no point did you think, 'You know what would be awesome? If there were a million worlds."

"The possibility of a superposition of many, #ManyWorlds was always there as long as you know there was a wave function. The question was whether you let them be real. Every other interpretation was the Getting Rid of #Worlds Interpretation."

"Arguably, the Everett interpretation is the ONLY one in which #energy is being conserved, because the universe is getting thinner. But you don't notice, b/c—and here's the good news—you are getting thinner."

"There is really no ethical, moral, or philosophical impact...the fact that there are many copies of you gives you the same utility function."

"Everett in particular faces a challenge that other interpretations don't. But every other attempt to make sense of quantum mechanics smuggles in some classical mechanics. In Everett there's no room for space, or fields, or particles..."

"Maybe the mistake that we've been making is trying to quantize #gravity. We should be trying to find gravity *within* #QuantumMechanics."

"We want to know, can you find #spacetime being curved under the influence of #energy just from #QuantumMechanics?"

"In #QuantumFieldTheory, empty #space is not empty [and] distance is a measure of #entanglement."

"We can imagine an alternate history of #physics in which #GeneralRelativity was not discovered until after all of this."

"It is time to climb out of the box."

Moving into the Q&A:

Join us one week from tonight, 7:30 pm MDT, for our next Community Lecture with Miller Scholar @andrea_wulf on legendary explorer #AlexanderVonHumboldt's restless life packed with #adventure and #discovery, and The Invention of #Nature:
santafe.edu/events/inventi…