Photons, Entanglement, and the Quantum Eraser

Do quantum particles actually know if they're being watched like the double-slit experiment suggests? Does the delayed-choice quantum eraser finally prove this? No, but let's ask some better questions and see what's going on.
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VIDEO ANNOTATIONS/CARDS

How do we KNOW light is a wave?

What the HECK is a Photon?!

How Do Polarized Sunglasses Work?!

Three Quantum Myths:
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RELATED YOUTUBE VIDEOS

PBS Space Time on Quantum Eraser:

Vertasium on Single Photons:

Eugene Khutoryansky on Quantum Eraser:
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LINKS TO COMMENTS

Quantum Eraser:

Photoelectric Effect:

[ScienceAsylum]

To clarify: I understand the "detection" at the screen is a different kind than one that might happen at the slits or any other detectors. It was just meant as a segue/transition to the main conclusion of the video: that quantum mechanics is just a model. The way quantum mechanics works doesn't necessarily say _anything_ about the nature of matter/light. If we input some initial conditions and a few interactions, it will give us a result that matches an experiment really well... but only after we do the experiment with a _bunch_ of particles over time. That doesn't mean we can make any judgements _at all_ about what individual particles are doing at any given moment.

[danfg]

I love the “QM is not magic” mantra! Also particles being tiny waves makes a lot more sense than “they’re particle-wave magic hand-wavy particles!”. I’m so tired of being bamboozled by QM and double slits stealing my lunch money. The final part was a bit rushed for me though, I’d love to have the controversy around what’s going on addressed more meticulously maybe in another video.

[nybblesbytes]

The best explanation of the double slit experiment ever. I actually picked up quite a few new pieces of knowledge.

[ronnyvbk]

If someone says physics is ...
- boring
- for nerds
- difficult to understand
- badly explained
- needs advanced math knowledge
- or any other misconception ...
Just send them to the Science Asylum and they 'll see the 'light' in all its beauty and clarity !

[hugginskakono]

many people who try to explain the double slit experiment always do so in a very vague manner, its like they don't fully understand it .... but your explanation was very elaborate nick, you did the best way ... better than all other explanations.

[tonylikesphysics]

Whenever one of my classmates asks “so energy wasn’t conserved?” I always think of you:

CONSERVATION OF ENERGY SHALL NOT BE VIOLATED!! ⚡️

[elgaro]

Clearest quantum eraser description i have encounter.

[YawnGod]

This is a very useful and important video. The mystification of quantum mechanics is pedagogically horrific. We should always assume that everything can be understood, even if we don't fully understand it at this time.

[royrosales]

Quantum mechanics might not be magic, but you have a magical gift for explaining things. You just demystified in mere minutes all the other videos and books I have read about the double slit excitement. I do believe Albert Einstein would clap for you.

[danimateo]

Nick, I am drunk and I still understood your video, that's how good of a teacher you are. Everything so clear and still succint. Great job!

[MagnusSkiptonLLC]

I understand now!


Feynman: "If you think you understand quantum mechanics, you don't understand quantum mechanics."


Oh...

[PascalLaprade]

I am constantly amazed at how well you create highly educative yet very funny videos (I love all the twins appearances and recurring jokes like the energy conservation ^^!)! This one particularly helped me demystify a lot about my understanding of this experiment. Thanks so much for what you're doing :) !

[AL-SH]

I was having Science Asylum withdrawals, thank you for the fix 🙃

[SSMLivingPictures]

Nick just totally slam dunked the mysticism around the double slit experiment with extreme agression. This was VITAL, because as someone who have watched those vids, and been mystified, I needed this snap back to reality. Thanks!

[fishamajig]

This was a fantastic explanation. I've been trying to wrap my head around the particle/wave duality thing for ages, not to mention entanglement. This video makes things so much clearer now. Keep up the great work!

[gary_dslr]

Crazy topic, expertly delivered, and the longest vid yet😁, great animations nick, 'Waves'from UK 🙋

[ChuckTBA]

Great job Nick, after watching so many videos about this trying to figure out what kind of magic was happening here, it seems you are the only one that deserves the Nobel prize that has been put at stake! great explanation & a really conclusive model

[allannirvana]

Nick, when you say "all those videos were designed to mystify you", I knew you gonna kill it. All those videos are twisting our minds to make us and your videos makes us understand. You are literally the best science youtuber for education, the other ones are more in the show business. Exceptional.

[PeterMatisko]

Nick, this is by far the best explanation of the double slit experiment on the internet. I have watched most of them without helping me understand the deeper details. Thanks!

[regular-joe]

Thank you, Nick Lucid, for your patience in replying to a question I had in another recent video. I had lost sight of the fact that you were dealing with motion/relativity; I hadn't yet put aside my (ancient) education in classical physics, and you very kindly set me straight. That really matters when someone's doing a scary thing - physics on their own!