Lecture 6 | Modern Physics: Quantum Mechanics (Stanford)

Lecture 6 of Leonard Susskind's Modern Physics course concentrating on Quantum Mechanics. Recorded February 18, 2008 at Stanford University.

This Stanford Continuing Studies course is the second of a six-quarter sequence of classes exploring the essential theoretical foundations of modern physics. The topics covered in this course focus on quantum mechanics. Leonard Susskind is the Felix Bloch Professor of Physics at Stanford University.

Complete playlist for the course:
http://youtube.com/view_play_list?p=189C0DCE90CB6D81

Stanford Continuing Studies: http://continuingstudies.stanford.edu/

About Leonard Susskind: http://www.stanford.edu/dept/physics/people/faculty/susskind_leonard.html

Stanford University channel on YouTube:
http://www.youtube.com/stanford

Category:

Education

Tags:

• Physics
• math
• calculus
• geometry
• algebra
• statistics
• quantum
• mechanics
• light
• waves
• uncertainty
• principle
• polarization
• photon
• system
• electric
• fields
• magnetic
• inner
• product
• wave
• function
• delta

[Taer11sho]

I admire Dr. Susskind-- His lectures are interesting and very insightful!

[quantumxd]

Absolutely grand ! I wish to thank Dr. Susskind and Stanford for suppling everyone with this series free of charge I am humbled...peace

[loopantenna]

@jamma246 He explains it in the three polarizers experiment. The photon comes out with a 45 degree polarization.

[jamma246]

@jamma246 Oh, he answers this at 1:00:00

[marcf999]

@QuaternionEM I know what a vector is, my point was does vector ALGEBRA apply. For example, Velocity is a vector but decomposing the vector doesn't have any meaning. you are NOT going in the x and y direction at the same time, you are going in one direction. With forces however you can decompose them and get meaningful results. Susskind just goes into the algebra to calculate probabilities without really explaining the principle of superposition. For a good expose I much prefer Feynman.

[QuaternionEM]

@marcf999

OK...........well......vector algebra applies because we have DIRECTIONS as well as magnitudes in the probability-space in which QM works. The first freakin line of the lecture he makes reference to THE DIRECTION in which a photon is polarized.

THAT is why vector algebra applies, but then again I think Professor Susskind gives the crowd the benefit of the doubt and assumes that the vast majority of us can make that elementary connection on our own without him spoon-feeding it to us.

[QuaternionEM]

@jamma246

I believe that at the photon's size-scale spacetime is porous...like a sponge...and the holes in the sponge are spaces "outside" of our universe. Maybe its REALLY porous like a sponge with LOTS of BIG holes.

4D spacetime in our universe is a huge huge huge giant thing...even from our human

perspective...now imagine a photon which is billions of times smaller than we are.

[QuaternionEM]

@jamma246

Now imagine this tiny photon traveling across huge expanses of this sponge. From our frame of reference (size wise) it looks like a straight path, but from the photons frame of reference it's a chaotic roller-coaster type path as it navigates the sponge while avoiding the holes. Throw in extra dimensions and you see the world the photon lives in.

It's amazing that it can move anywhere, let alone at the speed of light.

[QuaternionEM]

@jamma246

Yes, the wave function is just a probabilistic tool. WHen you deal with staggeringly large distributions you can't keep track of each element but you can get an AVERAGE for ALL of the elements. This is the basis of QM. You can never predict the behavior of a single particle because it's too small and too fast...to ethereal...but you can use differential equations to predict the average behavior for a particle.