Edward Teller - Schrödinger's cat: I don't need to look (28/147)

To listen to more of Edward Teller’s stories, go to the playlist: • Edward Teller (Scientist)
Hungarian-American physicist, Edward Teller (1908-2003), helped to develop the atomic bomb and provided the theoretical framework for the hydrogen bomb. He remained a staunch advocate of nuclear power, calling for the development of advanced thermonuclear weapons. [Listener: John H. Nuckolls]
TRANSCRIPT: So, to summarize: if you look at the past, we find nowhere any contradiction with causality, with cause and effect relation. But - here comes Heisenberg's contribution - in regard to the future, it's different. We never can know enough about the present to predict the future, in every case, except for predicting probabilities. Let me repeat the usual form in which this is set. I have a particle, I know it's here now. I want to know where it will be in a second. For that purpose, I have to know the place of the particle and the position of the particle. And Heisenberg points out that in the formalism of quantum mechanics, because of the particle's behavior, in some cases as a wave, you cannot do- know both the position and the momentum or the velocity, at the same time. Now, I want to talk about this in a little detail. Because the idea has not been as generally accepted. I already mentioned that Einstein was not happy about it. Two of my Hungarian friends have not been either. Wigner objects to Heisenberg's reasoning, because Heisenberg says- In order to have enough knowledge about the future, I have an observer, the observer disturbs the state, and that gives rise to difficulties of quantum mechanics. Wigner says- That is no explanation, because I don't know what an observer is. An observer, I am an observer. I don't know myself. Having explained something you don't understand by something else that you don't understand, is not a great feat. I had the same discussion - Eugene would not listen to my answer - I had the same discussion with Johnny von Neumann. And he listened to my answer, and I am glad to say, he agreed with me. And to explain this, I'd better tell you the sharpest objection that has been made to the uncertainty principle, that is connected with the name of the physicist who made the first good Wave Function, good description of the hydrogen atom, Schrödinger. And the story is famous and known as the story of Schröding- Schrödinger's cat. We have the following arrangement. Here we have a radioactive substance that emits, on the average, a particle - an alpha particle - once every second on the average. Now, here I have a counter, and I close that counter, so it won't count, except that I open it for half a second. If, in that half a second, a particle arrives - the probability is one half - then the same apparatus that I have already used can be coupled into other apparatus that will open a horrible door, which will let out some poison, which will kill the cat. So, the quantum mechanical description is, a velo- a probability distribution, after an hour, with the cat, the probability of cat being alive, one half, being dead, one half. And the correct description is that I don't know. Now, here comes our observer, and looks. And his looking will either result in killing the cat for good, or for reviving it. And this finishes, Schrödinger, I can't believe. This is an ob- an objection published, generally quoted, my scientific listeners will know that this is age old and not forgotten, very well known. I have no objection to any of this except that I say- I don't need to look.

[@RoverT65536]

The next video in the playlist tells why he doesn’t have to look.

[@NisseOhlsen]

0:59 he meant: 'The position of the particle and it's derivative', or r(t) and dr(t)/dt

[@MrFujinko]

its derivative in respect of time, just for the sake of completness

[@-danR]

That took me by surprise. I guess he was getting a little older. At 1:20 he fixes it.

[@ray.shoesmith]

Teller was the cat

[@HyperFocusMarshmallow]

In the asymptotic future I hope we’ll all just learn the Everett interpretation in kinder garden…

[@richinoable]

Sensitive dependence on initial conditions?

[@morpher44]

i don't need to look : ah. the cat is the observer

[@Q.Mechanic]

What's does he mean to say" I don't need to look"?

[@rhomaioscomrade]

He means that an observer is not defined as a sentient being actively making an observation. The act of observation is technically defined as any physical system or process that interacts with the quantum system at hand and provides observables like energy or momentum. The counter and the cat are classical systems that interact with the alpha particles and cause the wave function to collapse regardless of our own observation. There is no reviving or killing the cat by looking - the cat's own "observation" determined its fate. Then we can simply interpret the uncertainty as just a regular case of odds for or against something; in this case the cat dying.

[@Joe-uc9kf]

@@rhomaioscomrade Any physical system, which interacts with the cat, will get into the same superposition. All systems are quantum systems. Classical systems just exist as approximations. For a collapse to occur, you need the observer, which observes what has happened and then updates the wave function. Yes, quantum amplitudes gradually turn into classical probabilities which is callled decoherence. But yes, maybe he wants to say, that the obsever is only needed to check the probabilities and it is hard to imagine, how you can formulate a fundamentally probabilistic theory without referring to observers.

[@davidwilkie9551]

Nuclei and line-of-sight superposition Fluxions correspond in logarithmic condensation wave-packaging formation, e-Pi-i orbital-orbits interference, holography. Therefore "The Observer" is this Universal Holographic 1-0-infinity Entanglement Resonance, a sum-of-all-histories, Eternity-now omnidirectional-dimensional self-defining coherence-cohesion objective.

[@RK-fr4qf]

Subtitles would be great

[@frun]

There's a transcript in description.

[@ray.shoesmith]

English is hard to understand

[@ghostmanscores1666]

A tree falling in the forest makes a noise. It doesn't need me.

[@dougr.2398]

Am I?

[@dougg1075]

Doug R. Yes

[@Sharperthanu1]

The cat is a consciousness that collapses it's own wave function.That's why the speaker in this video doesn't have to "look."

[@urosuros2072]

Im not sure why do people keep using the term conscious, if you put unconscious camera inside and leave it to film it , system will behave excatly like concious being was observer Implying that consciousnesses dosnt mater Interactions are what matters

[@bill_lumbergh]

No the human outside the box is part of the same system. The box isn’t a closed system. it’s already collapsed

[@TheLuminousOne]

zis is ze fahzher of ze atomik bömp...alzouh i vish he wud fahzher an odinary schild

[@ray.shoesmith]

Truly living up to your username..

[@TheLuminousOne]

@@ray.shoesmith 😄

[@EiziEizz]

Of course one doesn't need to look, it is the interaction of the quantum state with any force or field that flips the uncertainty, so the cat is of course never in two states. I am surprised a man as smart as Schroedinger came up with this ridiculously dumb and false thought experiment.