Where to start with Quantum Theory?

[9white5]

Hey guys, I've recently become more interested in science (The double slit experiment cartoon on youtube completely blew my mind) and am starting to wish i paid more attention to it in school instead of screwing around. Does anyone have any books\documentaries\websites they'd recommend to someone with very little prior knowledge?

[studiot]

Well since you didn't pay much attention to quantum theory in school. did you pay any attention to the basic stuff that comes before it?

 

Without an appreciation of this quantum theory is indistinguishable from magic.

 

Do you have at least a feel for what energy is and what shapes and forms it comes in, because quantum theory is largely about energy.

[9white5]

We werent even taught quantum theory in school, but no i didnt pay much attention to the basic stuff. Isnt energy just everything?

[Nicholas Kang]

Quantum theory/Quantum mechanics is a theory first based on the Planck Light Hypothesis. Max Planck proposed that light comes in discrete packets of energy known as quanta. This idea is further extended by Werner Heisenberg in 1937 in his Heisenberg`s Uncertainty Principle. Basic formula is as follows:

 

Uncertainty of position times/multiplies uncertainty of speed times mass is greater than or equal to planck constant divides by 2

 

whereas planck constant is greater than 0. This is basic knowledge. Another famous equation is E=hv whereas E is energy, h is planck constant and v is an object`s frequency.

 

This equation links an object`s, usually a particle, energy to its frequency. Thus, particle-wave duality exist. This means you can treat an object as both particle and wave. But for macroscopic objects like human, the wave is too small. A cat, for instance, if drawn to a size of a solar system, it`s wavelength would be no longer than an atom in it.

 

You should have known wave-particle duality from the double-slit experiment.

 

Here are some basic links and videos to be shared:(one of them includes an explanation about the double slit experiment)

These links are from Dr. Tom Swanson`s blogs and other members in this forum.

 

Here`s That Cat Again by swansont- Animation that is informative and suitable for newcomers

http://ed.ted.com/lessons/schrodinger-s-cat-a-thought-experiment-in-quantum-mechanics-chad-orzel

 

http://ed.ted.com/lessons/einstein-s-brilliant-mistake-entangled-states-chad-orzel

http://ed.ted.com/lessons/what-is-the-heisenberg-uncertainty-principle-chad-orzel

 

Try volume 1 in Feynman`s Lecture of Physics

http://www.feynmanlectures.info/

http://www.feynmanlectures.caltech.edu/

 

How old are you? Quantum mechanics isn`t being taught in secondary school. Only classical physics is being taught in secondary school.

Edited November 4, 2014 by Nicholas Kang

[ajb]

How old are you? Quantum mechanics isn`t being taught in secondary school. Only classical physics is being taught in secondary school.

In the UK some very very basic quantum mechanics is taught at high school. They don't see the Schroedinger wave equation, operators or anything like that. They meet wave particle duality, electron diffraction, the photoelectric effect, Planck's law and atomic spectra. There you are, if one is looking for a place to start one could google these terms.

[elfmotat]

In the UK some very very basic quantum mechanics is taught at high school. They don't see the Schroedinger wave equation, operators or anything like that. They meet wave particle duality, electron diffraction, the photoelectric effect, Planck's law and atomic spectra. There you are, if one is looking for a place to start one could google these terms.

 

Yeah, my high school in New Jersey taught basically the same stuff to the upperclassmen.

[Mordred]

Pick up differential geometry

 

A good text on QM is Griffiths "Introductory in Quantum Mechanics"

 

However a strong math skill is needed in QM along with the other recommendations

[elfmotat]

Pick up differential geometry

 

Why would he need differential geometry for intro QM? I mean, more math knowledge can only help, but that seems like a strange recommendation.

[9white5]

Quantum theory/Quantum mechanics is a theory first based on the Planck Light Hypothesis. Max Planck proposed that light comes in discrete packets of energy known as quanta. This idea is further extended by Werner Heisenberg in 1937 in his Heisenberg`s Uncertainty Principle. Basic formula is as follows:

 

Uncertainty of position times/multiplies uncertainty of speed times mass is greater than or equal to planck constant divides by 2

 

whereas planck constant is greater than 0. This is basic knowledge. Another famous equation is E=hv whereas E is energy, h is planck constant and v is an object`s frequency.

 

This equation links an object`s, usually a particle, energy to its frequency. Thus, particle-wave duality exist. This means you can treat an object as both particle and wave. But for macroscopic objects like human, the wave is too small. A cat, for instance, if drawn to a size of a solar system, it`s wavelength would be no longer than an atom in it.

 

You should have known wave-particle duality from the double-slit experiment.

 

Here are some basic links and videos to be shared:(one of them includes an explanation about the double slit experiment)

These links are from Dr. Tom Swanson`s blogs and other members in this forum.

 

Here`s That Cat Again by swansont- Animation that is informative and suitable for newcomers

http://ed.ted.com/lessons/schrodinger-s-cat-a-thought-experiment-in-quantum-mechanics-chad-orzel

 

http://ed.ted.com/lessons/einstein-s-brilliant-mistake-entangled-states-chad-orzel

http://ed.ted.com/lessons/what-is-the-heisenberg-uncertainty-principle-chad-orzel

 

Try volume 1 in Feynman`s Lecture of Physics

http://www.feynmanlectures.info/

http://www.feynmanlectures.caltech.edu/

 

How old are you? Quantum mechanics isn`t being taught in secondary school. Only classical physics is being taught in secondary school.

Thanks for the links, didnt really understand the majority of what you said but o well

19, and yeah like i said we werent taught quantum at school

[ajb]

Why would he need differential geometry for intro QM? I mean, more math knowledge can only help, but that seems like a strange recommendation.

A little symplectic and Poisson geometry in relation to the Hamiltonian description of classical mechanics would be useful for canonical quantisation. Connections, geometric phase, gauge transformations etc come later and not as an introduction I would say.

[Delta1212]

 

Yeah, my high school in New Jersey taught basically the same stuff to the upperclassmen.

My high school in New Jersey did not.

[studiot]

studiot

Do you have at least a feel for what energy is and what shapes and forms it comes in, because quantum theory is largely about energy.

 

9white5

 

Isnt energy just everything?

 

 

Well there several forms of energy, but energy there are also other quantities / properties that can be considered.

 

However you have to start somewhere and energy is a good starting point because most people have a reasonable intuitive feel for it, that just needs sharpening up to scientific standard.

 

Energy is a property possessed by material things (matter) and some non materieal things (sunlight, radio waves..).

 

There are several forms of energy and there is a fundamental law (the law of conservation of energy) which states

 

Energy is neither created nor destroyed, it is merely transferred from one object to another and/or changed from one form to another, in some process/interaction of interest.

 

At this stage is is not wise to be diverted by subjects like zero point energy, many worlds, quantum chromodynamics (and many others) which are extensions of the basic idea.

 

In physics we like to consider one process at a time and when we do the energy change(s) associated with that process may occur over a whole continuous range of values. (for example any value between 1 and 10 units, including fractional ones)

 

Changes of this sort are considered by what is called classical physics.

 

Alternatively the energy changes may only occur in certain specified values (eg 5 units and 10 units exactly and only)

 

Changes of this sort are considered by quantum physics, the discretisation of a continuous range of available values into only a few specific values is the main idea behind quantum physics.

 

To return to my original question, we can easily explore the above in relation to two forms of energy - viz kinetic energy and potential energy - once you know what these are.

 

So please tell me what you think they are if you wish to continue.

 

[elfmotat]

A little symplectic and Poisson geometry in relation to the Hamiltonian description of classical mechanics would be useful for canonical quantisation. Connections, geometric phase, gauge transformations etc come later and not as an introduction I would say.

 

That's true, but it's probably not something the OP should devote a massive amount of time to if he just wants to get a good feel for QM. Though I'd say it's definitely worth spending the time on once he gets into relativistic QM and QFT.

 

My high school in New Jersey did not.

 

Haha, where in NJ? Monmouth county reporting.

Edited November 5, 2014 by elfmotat

[Sensei]

Hey guys, I've recently become more interested in science (The double slit experiment cartoon on youtube completely blew my mind) and am starting to wish i paid more attention to it in school instead of screwing around. Does anyone have any books\documentaries\websites they'd recommend to someone with very little prior knowledge?

 

IMHO you should start from buying lasers. Red, green and blue at least.

 

https://www.youtube.com/watch?v=HOPyo0T2sRU

 

There are setups for diffraction granting (couple different models 1000 slits/mm, 500 slits/mm at least),

http://www.eduvis.pl/oferta/fizyka-pomoce-dydaktyczne/optyka/siatka-dyfrakcyjna-z-1000-szczelin-mm-detail (2 usd for each)

polarization filters (typically two are needed),

http://www.eduvis.pl/oferta/fizyka-pomoce-dydaktyczne/optyka/zestaw-nr-2-do-badania-zjawiska-polaryzacji-swiatla-polaryzatory-liniowe-detail (4.24 usd per each, 2 in package)

single slit (different widths of slit) and double slit (different distance between slits and width of slit).

http://www.eduvis.pl/oferta/fizyka-pomoce-dydaktyczne/optyka/zestaw-nr-9-do-badania-interferencji-swiatla-doswiadczenie-younga-detail (3 usd per each, 2 in package)

 

You can even build particle detector at home for 50 usd or so. Here is example instruction (in half hour or less):

http://www.ultimate-theory.com/en/2014/6/8/how-to-build-cloud-chamber-particle-detector

 

Enter "Cloud Chamber" in YouTube, and you will see many examples how it works:

 

It's showing traces leaved by radioactive isotopes that are decaying, or primary and secondary cosmic rays that're decaying or flying through medium all the time (but we don't see it).

Edited November 5, 2014 by Sensei

[Delta1212]

Haha, where in NJ? Monmouth county reporting.

Bergen here. I'm actually going to be in Monmouth this weekend.

[elfmotat]

You can even build particle detector at home for 50 usd or so. Here is example instruction (in half hour or less):

 

That's pretty cool.

 

 

Bergen here. I'm actually going to be in Monmouth this weekend.

 

I won't be . I'm at school until Thanksgiving.

[JohnSSM]

Hey guys, I've recently become more interested in science (The double slit experiment cartoon on youtube completely blew my mind) and am starting to wish i paid more attention to it in school instead of screwing around. Does anyone have any books\documentaries\websites they'd recommend to someone with very little prior knowledge?

You can learn a lot from youtube videos...dont stop watching...

[ydoaPs]

Hey guys, I've recently become more interested in science (The double slit experiment cartoon on youtube completely blew my mind) and am starting to wish i paid more attention to it in school instead of screwing around. Does anyone have any books\documentaries\websites they'd recommend to someone with very little prior knowledge?

Well, you need to start with classical physics. Luckily for you, there's been a slew of somewhat rigorous popsci books recently. I'd start with Susskind's "The Theoretical Minimum" along with its companion YouTube series. After that, continue Susskind's series with "Quantum Mechanics: The Theoretical Minimum" and its companion video series.

 

After you've got the basics of QM, and a bit of background knowledge of SR, you can take a look at "Quantum Field Theory for the Gifted Amateur" and Susskind's QFT video series.

 

If you want to get into cosmology, you'll also need to get a basic grip on GR. For that (and, to get the background on SR if you don't have it already), I suggest "A Most Incomprehensible Thing: Notes Towards a Very Gentile Introduction to the Mathematics of Relativity".

 

After getting the basics of QM, you could also go the philosophy route and check out Maudlin's book, "Quantum Nonlocality". Maudlin's also got a great book on spacetime, so after "A Most Incomprehensible Thing", check out "Philosophy of Physics: Space and Time".