The Stand-Up Physicist: Quantum Logic

Prof. Susskind gives a great description of how quantum logic is different from classic logic. Watch it several times! I point out how like a magic trick, both Susskind and the first video reply do not focus on what is vital: the coherent source. I am also able to provide a new reason why quantum logic is different from classic logic. It has to do with defining a derivative in spacetime correctly. A classic spacetime derivative can be ordered in time like a movie. A quantum derivative cannot be ordered like a movie. Instead we get all the frames from the movie, and by observing them, we know on average what happens. That is the best we can do.

Category:

Science & Technology

Tags:

• Quantum mechanics
• slits
• quaternions
• derivative

[ns2kd]

I think the two slits are used for a clearer illustration of the interference pattern and to show that a single photon goes through both slits. BTW, regarding the Dr Quantum animation which you have as a video response---it states that the single electron behaves like the marble in creating a single band...but what it really should say is that it behaves like the wave creating a single band. no? (i know its not your video but that would be in line with what you are saying with one slit.)

[sweetser]

2 slits shows an interference pattern. 1 slit shows quantum diffraction which is different from interference. Most teachers do this wrong, ignoring diffraction, claiming they are making the story simpler. In quantum diffraction, most of the signal is in the center, but there are slight bumps on the side. The interference and diffraction have the same cause: coherence of the source.

[AradynnNyzon]

Excellent as always Doug! I wish can one day be as skilled in physics and math as yourself!

Congrats on the kid!

[sweetser]

The kid sleeps through YouTube talks on quantum mechanics, just like her mom :-)

[T1meW4st3d]

GODDAMNIT!!! I hate not knowing everything!! GODDAMNIT!!! I really wish my brain spoke math!!!!!1

[Viper2026]

I don't know if I follow 100% what you're trying to explain here, but you present some interesting ideas about superposition and indeterminacy.

[krishields]

I do have an image which I really should have included in the video in which a solid interference pattern was produced... I will remake it an repost it. Looking at the images I took, it seems that the interference pattern is a matter of alignment of the two so called diffraction patterns. You can see how two slits merely provided double the number of fringes. When they are aligned perfectly, an interference pattern seems to emerge. Is it really a wave or simply a mathematical product?

[krishields]

Yea, but consider the previous post - that light is a particle moving in a waveform such as a spiral. Then its simply a matter of reflection since diffraction deals with the wave function.

[krishields]

I essentially shone the laser beam directly into the camera lens, which is why you see many copies - curved reflections off the glass.

I don't see the particle/wave duality as it is presented. It could be that the photon is moving in a wave form, such as a spiral, giving us reflection patterns - like taking two mirrors and facing them at each other. That is of course, my opinion and makes more sense to me rather than saying it doesn't require a medium like every other observed wave.

[sweetser]

Looks like quantum diffraction to me. I have found two well-respected educators describe the single slit experiment wrong: Leonard Susskind of Standford and Dr. Quantum. They both know about quantum diffraction, but in the name of simplicity, skip quantum diffraction. Too bad, because I think the fringes might be understandable if your realize they show up with one slit or two or 16 because there are places in the source that have zero particles.

[DavidAKZ]

thanks. reflection does not appear on the far side of the slit(s) does it ? Presumably you would need to use the Power Spectral Density function (PSD) to work out wither the two results were interference and/or diffraction- do you have a Charge Coupled Device (CCD) ? thanks again !

[krishields]

I just posted an experiment as a response video. It's interesting. The slits were just about the same width as the wavelength of beam - which is about 650 nm.

I'm not so sure its defraction as much as reflection, since the material I was using for the plates was graphite.