Classical and quantum physics.

[Dorilian]

What could be a good example or textbook problem which could be solved using quantum physics and classical physics in order to see the difference?

If you wan to explain the differences to a non-physics student, what would you do? (Don´t use the blackbody radiation problem).

 

[niklaus]

How about the fact that atoms are stable?

 

[Dorilian]

How about the fact that atoms are stable?

Good, are there any more examples?

 

[A. Neumaier]

What could be a good example or textbook problem which could be solved using quantum physics and classical physics in order to see the difference?

If you wan to explain the differences to a non-physics student, what would you do? (Don´t use the blackbody radiation problem).

The standard example is an experiment for testing the Bell inequalities.

 

[A. Neumaier]

What could be a good example or textbook problem which could be solved using quantum physics and classical physics in order to see the difference?

If you wan to explain the differences to a non-physics student, what would you do? (Don´t use the blackbody radiation problem).

The standard example is an experiment for testing the Bell inequalities.

Much more difficult to calculate but much more interesting is the spectrum of an electron surrounding a proton.

 

[unusualname]

Quantum tunnelling is a common example given in introductory texts, it's apparently required to explain usb flash memory erasure, so relates directly to everyday technology:

http://www.tech-faq.com/how-a-usb-flash-drive-works.html

 

[eaglelake]

What could be a good example or textbook problem which could be solved using quantum physics and classical physics in order to see the difference?

If you wan to explain the differences to a non-physics student, what would you do? (Don´t use the blackbody radiation problem).

Consider an object moving through a slit in a wall.

Assuming no forces acting anywhere, a classical object, like a bullet, say, passes straight on through in a straight line. This is Newton’s first law at work. If we repeat the experiment many times we always get the same result – the bullet always goes straight ahead. It is never deflected away from straight line motion. This classical behavior has been observed in many experiments.

But a quantum object does get deflected as it passes through a slit, even when there are no forces acting. And if we repeat the experiment we do not always get the same result. The particle can be scattered in many different directions. This quantum behavior has been observed in many experiments. There is no classical explanation for this. We only know that Newton’s laws do not work at the quantum level.

The classical calculation is trivial. The quantum calculation is not trivial, but doable.
Best wishes

 

[martinbn]

The equation for the harmonic oscillator can be solved in classical mechanics and the Schrodinger equations for the quantum harmonic oscillator can be solved. Many comparisons can be made. In the classical case the motion is oscillatory in the quantum mechanical there are stationary states, those with exact value of energy.