### Advance assignments

We start the course by studying wave motion. In order to prepare you for that, watch the video (26 minutes) and answer the following questions before the first lecture.

**https://archive.org/details/SimpleWaves**Were you surprised about something in the video? Did it present something that you would like to understand better?

The video presented two types of waves: transverse waves and twist waves. Explain briefly the difference, and identify where is the potential energy and the kinetic energy in both types of waves. For twist waves, how are potential and kinetic energy affected by changing the cross arm length (at constant twist angle amplitude)?

I suppose you have observed waves somewhere before. Tell me shortly some observation you have made. Concerning your observation, is there something that you would like to know more about it.

As an introduction to second lecture (on Wednesday), watch the video "introduction to optics" (22 minutes)

https://archive.org/details/IntrotoOptics .

There is no question about physics, but respond by telling whether you found something interesting or new, or not.

- Watch the video "Group and phase velocity"

What is the velocity of the rapids oscillation called? What is the velocity of the envelope called. What is claimed to be more physical and why?

This movie Photons (18 min) clarifies the point 2 made in connection of the photoelectric effect in the lectures.

https://archive.org/details/Photons

Explain in your own word: why is that the first experiment, which showed electron spikes, is not necessarily a proof of the photon concept, but the latter experiment including the shutter and the calculation, is.

This movie "Interference of Photons" (12 min) describes the particle-wave duality of photons.

https://archive.org/details/InterferenceOfPhotons

This was already discussed at the end of lecture 4. Comment does this sound understandable to you? Are there things that remain puzzling you? Feel free also to comment anything about the advance assignments, lectures, lecture notes or exercises.

This iime we have a mathematical exercise, see the attached file.

Here is short presentation of the Schrödinger equation including the interpretation of the wave function (10 min).

Unfortunately, the drawings are not very precise. Did you find problem in sine wave wave function psi(x) and its absolute square |psi(x)|^2 ?

As a second case the video present spin of electron, which will be discussed later in the course. What are the numerical values of coefficients of the two spin states?

In lecture 8 we learn about quantum tunneling. One important physical process where quantum tunneling is essential is alpha decay. That is explained in the following video (11 min)

Would there be alpha decay in classical physics, and how fast would it take place?

Warning: at the end of the video the tunneling is explained saying that energy is not conserved for a short time. In the lectures tunneling is explained using Schrödinger equation, where energy is strictly conserved. This just reflects that there can be different ways of explaining the same physical phenomenon.

Second time we have a mathematical exercise, see the attached file. A hint has been added in the second version.

This video (6 min) tells about electron spin

Why silver atoms instead of electrons were used in Stern-Gerlach experiment?

In the video Nick says that when the z component of the angular momentum is known, there are two values for x component and 2 values for y component (4 arrows total). How does this differ from the one we discussed angular momentum in the lecture? Why the difference is not essential for the video?

This movie "The map of quantum physics" (21 min) presents a collection of topics in quantum physics

Below are some categories uses in the video.

- pre-quantum mysteries

- quantum foundations

- quantum phenomena

- quantum technology

- quantum information

- quantum biology

- quantum chemistry

- nuclear physics

- particle physics

- quantum theory

- interpretation of quantum mechanics

Pick out one topic in each category and comment, for example: I think understood this / I have heard this before /I would like to learn more about this / I rather would skip this topic and concentrate on others.

This assignment has double points, and can be returned also after the lecture.