Is The Wave Function The Building Block of Reality?

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Objective Collapse Theories offer a explanation of quantum mechanics that is at once brand new and based in classical mechanics. In the world of quantum mechanics, it’s no big deal for particles to be in multiple different states at the same time, or to teleport between locations, or to influence each other faster than light. But somehow, none of this strangeness makes its way to the familiar scale of human beings - even though our world is made entirely of quantum-weird building blocks. The explanations of this transition range from the mystical influence of the conscious mind to the grandiose proposition of multiple realities. But Objective Collapse Theories feels as down to earth as the classical world that we’re trying to explain. Let’s see if it makes any sense.

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Hosted by Matt O'Dowd
Written by Katie McCormick & Matt O'Dowd
Post Production by Leonardo Scholzer, Yago Ballarini, Pedro Osinski, Adriano Leal & Stephanie Faria
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[IAmNumber]

The internet has me locked in a superposition of wondering _“How could humans be so unbelievably stupid?”_ and _“How could humans figure out something so brilliant?”_ at the same time

[PADARM]

Wow! Diósi–Penrose model makes a lot of sense! The fact that the more particles implies the greater the curvature of space-time in a specific point in space it "forces" the wavefunction to collapse and to define a position. It explains why gravity cannot be quantized because gravity is curvature of space-time.

[theglobalwarming]

I like how this theory explains why gravity can't be quantized like the other three forces because it isn't quantum. And, it makes sense since gravity isn't supposed to be a force when following General relativity.

[apollon]

I always get a deep appreciation for Matt as he breaks down these ideas for everyone. Truly one of the great resources for curious minds in the world.

[evoov]

I like how Roger Penrose uses a ceramic cat and a hammer attached to a detector. Instead of a living cat and a vile of poison attached to a detector. So as to avoid the absurd spectacle of the thought experiment.

[carlkatzenberger]

Thanks to PBS for continuing to produce a high-quality stream of content that will inspire the generations to come to seek out truth and understanding

[Hi_Im_Akward]

I don't always fully understand everything in the videos, but I'm happy you make them in a way to bring it down to laymen terms. I find this stuff absolutely fascinating and have been binge watching your quantum videos.

[deep.space.]

Penrose's idea sounds so elegant that it feels like it must be close to the underlying truth...

[lunasophia]

10:32 "Unlike the interpretations that we've discussed, for example Bohmian mechanics or many worlds, OCMs can actually be tested." FINALLY. This is the most exciting part of this video, for me. I was thinking, from the very beginning of the video, "Yeah, new theories are great, but... do they agree with the data?" and it took 'til halfway through for that discussion to start. That was a super long ten minutes. :P

[Nethershaw]

I really wish I had had a professor like Doctor O'Dowd back when I was in school and thinking about what I wanted to do with my life.

[duckspeaker]

His shirt is both buttoned and unbuttoned until someone watches the video

[unfairleyc]

Wait, wait, wait. So if I have this right. The Higgs field gives particles mass, that mass causes particles to warp space time, that warping of space time gives the appearance of an attractive force, that attractive force cause the density in an area to increase, that increased density causes a higher chance of particles to collapse, and that gives us a solid non-superposition reality?

[jelmerl]

These are my personal favorite "interpretations" of quantum mechanics! I just recently brought this up in our university journal club and nobody had head of these before. So glad to see a spacetime episode on this!

[sebastienpaquin]

I wonder if in the future, once we've finally figured it all out, people will remember all the different yet fascinating theories that were competing to explain the weirdness of quantum theory. It also makes you wonder how many amazing ideas that were later proven wrong have been lost to the sands of scientific time. All these quantum theories are in agreement with all the experiments we've ran, and yet only one of them can be true. I mean it must be so, they can't all exist at the same time, in a sort of theoretical superposition of explanation... right?

[sethlawson]

I'd love it if there was an episode going deeper into the experiments that can be done to probe and constrain objective collapse models, e.g. getting deep into literature on things like dual slit experiments with ever larger molecules, the experimental set up and connecting it to theoretical work. Love PBS Spacetime!

[henk-]

I have no background in physics nor do I understand half of what you're saying. But it is fascinating trying to wrap my mind around physical theories and the nature of reality they are trying to describe.

[ThatCrazyKid]

Great episode, I especially loved the breakdown of the experiment on the ball emitting radiation. That was nuts how they were able to isolate it so much, they managed to detect single photons at a time. As necessary and fun theoretical physics is, experiments are the true heart and soul of physics and are the ones that bring us a step closer to understanding the reality we reside in. Just wanted to show some appreciation for the breakdown of an actual experiment and its results.

[JackCox]

I’ve always been frustrated by the “mystical consciousness” reason for collapse and was delighted to learn more about other testable theories! After all, why should a wave or a particle care about our cognitive processes? Kind of implies consciousness is made of the same “fabric” as the quantum field, and when we observe, it’s like giving that fabric a shake. Neat to think about, but this is way more exciting! Best video yet!

[xepher]

This is the best channel on YouTube. Full Stop. You approach the impossible, and not only make it real, but make it understood!

[jamesi]

Such wonderful content, thank you! Gravitational Decoherence makes a lot of sense to a layman like myself, but as always this video has raised several questions that I'll be pondering all weekend :)