PH253: server issues

UPDATE 2: with the server being down, Moodle is also down until further notice. Hopefully it will come back up some time today. Also, a draft of the formula sheet for the final.

UPDATE: HW and Exams mirrored here. The additional notes as well (well, most of them, until I hit my quota on bama.edu. Lame.)

For what I hope to be a short while, old HW/exams/etc are unavailable, owing to some script kiddie messing with the server I'm using:

I just got word that the machine that runs the faculty websites has been hax0red, so we have to take it offline till we can figure out what happened.

I will try to get a mirror up later this morning.

Make your own spectrometer / misc

This is awesome. Cell phone spectrometer ...

In other news: I've been unavoidably detained by advising issues the last day or so, but I will be updating Moodle grades, putting out HW6 solutions, and posting HW7 over the weekend. HW7 will not be due until ~Friday next week since I'm delayed in posting it.

Tuesday, we will look at the angular parts of the hydrogen atom solution we ignored so far, and figure out what p, d, and f orbitals are all about. That will run in to Thursday, but by the end of the week we'll have a good understanding of atomic orbitals, ideally.

PH253: Public talk

Dr. Orzel has been nice enough to post his slides, so if you were not able to make the lecture, you can complete the extra credit assignment by reading his slides and sample book material. Write a page on what you learned.

PH253: HW6 is out

Due next Wednesday ...

Also, a nice applet for visualizing wave functions.

PH253: Wave functions

Hyperphysics is good stuff. Good example calculations/solutions and explanations of Schrodinger's equation.

Everyday life is basically understood

Interesting couple of posts.

One.
Two.

The basic argument is that while everyday phenomena can be hideously complex (turbulence, for example), the basic laws governing them are completely understood. There is no everyday example of something that violates quantum mechanics or relativity, you have to go well beyond the everyday to find situations where we don't even know the basic rules that apply.

Of course, knowing the basic laws (i.e., equations) is one thing. Solving them is completely another, plenty to keep scientists gainfully employed for some time to come.

PH253: HW5, misc

Here is the exam you took yesterday. Your HW5 is to solve the two problems you didn't choose on the exam, due Monday before midnight. My suspicion is that a few of you get together in a group, you've probably solved them all amongst you ...

Also, I'll have your exams back on Tuesday at the start of class.

A recent tour-de-force experiment by NIST managed to demonstrate gravitational time dilation on ordinary length scales. Neat stuff. (We didn't really cover gravitational time dilation, part of general relativity, but there is a small bit on it in your textbook.)

Interference & diffraction

http://www.flickr.com/photos/animal-mafia/161879717/lightbox/

Black body radiation & climate change

Interesting interview/discussion on how black body radiation provides feedback for earth's climate.

Double slit applet

A nice applet to illustrate the crazy double slit stuff we talked about today.  You can use photons, electrons, neutrons, and helium atoms, and even use multiple sources or vary the incident wavelength. Note the different modes - high intensity, single particles, and lasers. If you like, add a detector on one or both of the slits and watch the interference go away ... neat stuff.

Also, the actual experiment with single electrons!

How to read science papers without reading every word

Nice read. Applies equally well to sections of a textbook, I think.

PH253: HW 2.1

For problem 1 on HW2,  you'll find this interesting. (Note the 'dot' notation to signify derivatives with respect to time.)

PH253 facebook group

Find each other and commiserate. ;-)

PH253: applet for tomorrow's lecture

http://webphysics.davidson.edu/applets/retard/Retard_FEL.html

Lets you visualize the field from moving & accelerating charges. Drag the velocity slider to start & stop a charge in an inertial frame (what we'll start with) or set it in simple harmonic motion (SHO, what we'll end with).

PH253: what is the speed of gravity?

Related to the material for the next couple of lectures, in a way.

Just neat.

By the end of PH253, you should have a good idea of how this works. I hope.

Alkali metals

Remember how I told you alkali metals were desperately reactive?



Direct link, in case embedding fails ...

Right around "let's try cesium" one knows things are about to get interesting.

(h/t, and more fun with chemistry)

PH253: Cool laser simulation / Reading

Based on what we talked about today, you should be able to figure out how to make this simulation work ...

Also, today's lectures were based mostly on material from the Feynman lectures:
Volume III, Ch. 4 (Ch. 3 as a reminder)
Volume I, Ch. 42 (Ch. 40, 41 as a reminder)

I also made use of Solymar & Walsh (Ch. 12) for specific examples of laser systems. Again, note the (now 10 part) series on cool laser applications over here.

Amazing laser applications

A (so-far) 9-part series of amazing laser applications.

Coincidentally, we'll figure out how lasers work in Tuesday's lecture. We'll start from where we left of with particle statistics, and figure out the 'stimulated emission' part of the acronym first. Once we have the key bits in place, I'll talk briefly about how one goes about constructing a laser,  and why they are not just fancy flashlights.

Well, they are fancy flashlights, but they do other things too ...

PH253: molecular orbitals

Here's a nice introduction to the variational method and the linear combination of atomic orbitals (LCAO) we were talking about last time. It describes some further approximations that one can use to do calculations on molecular systems, and the level is about the same as our last class (modulo a bit of linear algebra). Those of you in chemistry classes should be able to follow it pretty easily I guess.