The Heisenberg Uncertainty Principle Part 1: Position/Momentum and Schrödinger's Cat

What do you think, that Breaking Bad made up the name Heisenberg? Think again! He was an awesome physicist. He has a few things to say about what we can and can't know about the quantum world. Then we will wrap things up with the most famous cat in the world after Garfield, Schrödinger's cat.

Check out "Is This Wi-Fi Organic?", my book on disarming pseudoscience!

[dalenassar]

Schrodinger overlooked that the fact that there must be NINE decays--He should have used a dog!

[HumbertoRamosCosta]

2:50 Congratulations, FINALLY a video on youtube that explains that the 'observer' in the experiment is not a 'soul' or a 'consciousness', etc...

[colorx]

Man, I've been familiar with the Schrodinger's cat for a a long time now (like 2-4 years since I saw it being mentioned in a show I watched) but this is the first time I actually understood the proper context for that thought experiment. I did not expect it to be a means of discrediting an interpretation lol. The more you know.

[aydenh.]

I've never taken a physics class (yet), and the fact i almost understood what he was talking about goes to show how good of a teacher Dave is
Also i thought heisenberg was a chemist

[danielholta]

Well after a year of keeping this stuff in my mind i think i'm finally making sense of it. I love these aha moments! :D

[godzilla]

Does the cat not act as an observer?...

[arbboxing]

U r the best youtuber of science I've ever seen..

[martinstubs]

What a roundabout way to explain the Heisenberg uncertainty principle! It follows from Planck's constant of action. Any two values that form this constant cannot fall below this constant between them, that's all. No need for particles, waves, probabilities etc. etc.

[nachannachle]

Pitch perfect!
Great transition and extrapolation from the Maths to the interpretations!
Too often I see these topics treated separately, when, just like you showed, they are all under the same continuum of calculus => experiments => interpretations => peer-review.

[krishnaswamy]

Wow! 👏You explained this so well and clearly. Once students get to know your videos, you will really become a popular channel. Probably, they look at your picture and they don’t know that you are really a great prof. Also some people don’t like the fact that you look like you are reading the script. May be you can think about it. I am only suggesting because I feel that not many students know that you have good information. I am sorry if I offended you. Good luck!

[mrnerd]

Heisenberg: You're goddamn right!

[wombatlover]

I have just watched Schrodinger's equation (no mention of time dependent or time independent) however, it was simply wonderful, as was this Heisenberg's paradox, as a consequence, I have subbed you




Thank you, Professor Dave !!!


Love from bloody Australia

[fgnmghdshd]

Heisenberg is pulled over on a highway. The cop gets out of the car and asks Heisenberg "do you know how fast you were going?!" and Heisenberg replies "no, but i know exactly where I am."

[yarodi]

I have a doubt. The photons will be interacting with the system whether or not we are looking right? Our eyes just happens to be in the way of some of the photons, so the system must have already collapsed into a reality whether we look at it or not.

[bilimbilin]

Hey Dave! Doing an episode on the uncertainty principle in Turkish and man - got a little confused. Watched a decent amount on it, and read some articles. Wanted to know your input.

Here's what I got out of it - since everything is both wave and particle (de Broglie), this imposes the superposition principle - they can be in multiple places at once (or a probability) and their location is the sum of all the possibilities - until we measure or observe it; then the state collapses (like you mentioned and from what I understand).

So the uncertainty principle is when you limit the superposition of location lets say (or decrease the possibility of the particle being in more places), then you increase the superposition of the momentum (when you get close to the heisenberg uncertainty limit). When it is said that the uncertainty principle is when you measure one, the other goes crazy is wrong I feel like - since the principle does not depend on an observer being there. But it is caused by you decreasing the possibility of superpositions? I saw the episode that Veritasium did, and he had a light passing through a slit, and as he made the slit smaller - at one point the light that was projected on the wall started expanding - where you are limiting position, so the uncertainty in momentum has to increase. So the act of knowing where the particle is doesn't cause the uncertainty, but limiting the places it can be (so the position is more certain) does? Does that sound right?

Quantum dude.. Would appreciate your thoughts!

[PabloPerroPerro]

1:56 When it's gotcha, it's gotcha!

[masterofmuppets]

Is it possible to have a probabilistic view of Quantum Mechanics while also agreeing with Schrodinger that the cat being both dead and alive is absurd?

[lakemcgreevy]

Absolutely fascinating content!! Does this imply that everything is inherently a wave and particle until observed? How does quantum understanding apply to the observation of the self? Does this imply that we are superimposed in a physical/wave state simultaneously? If so, is death a release of this observational constriction of our selves as ‘particles’?

[marvinsimukonda]

Is the cat dead or alive?

Schrodinger: YES

[loganfong]

you're making me want to become a physicist