Posted in Education, Philosophy, Physical Chemistry, Spectroscopy

Why Do I Love Pchem?

abstract-concrete

Pchem, how do I love thee?
Let me count the ways

1. Pchem connects abstract concepts to concrete reality.

The concept of the wave nature of light and matter is very abstract. It is not directly measurable. But the mathematics of interacting waves allows us to predict the interactions of light and matter. This is called spectroscopy.

Your eyes are pigment-based spectrometers detecting light at different wavelengths giving you the ability to perceive what we call color.

From these abstract wave equations we get concrete products like laser pointers and digital cameras. And I love it!

2. Pchem simulates natural phenomena well.

Some of the spectroscopic simulations I have seen in pchem have been truly amazing. To appreciate this, one may need a micro-course in statistics.

The R² value can be thought of as “how much scatter in the data is explained by your model”.

A decent calibration curve in an environmental lab or water quality lab will have a 99.95% R² value, meaning that the calibration model captures 99.95% of the scatter in the data.

The R² value for modeling the rotational-vibrational spectroscopic transitions in carbon monoxide is often 99.9996% or better. This means our pchem model for molecular vibration and rotation is capable of capturing over 99.999% of the variation in the data.  That’s crazy-good! In fact, this model is so detailed, we can tell how much the CO bond length stretches as it spins faster and faster. I love that!

3. Pchem transforms your imagination.

OK. So the wave function concept allows us to simulate nature and to produce exciting gadgets. But what IS the wave function, ontologically?

This is perhaps the most exciting thing about pchem. It transforms your imagination. I am drawn to think deeply about the wave nature of matter, the balance of Coulombic attraction and repulsion, the coupling of intrinsic angular momentum.

What IS the angular momentum of a WAVE?

Where IS the mass in a WAVE?

What (or WHO) sustains these never-decaying ground state wave functions?

Amazing questions for an amazing life of the mind, which is another reason I love pchem.

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Posted in Education, Physical Chemistry, reading science, Science Education, working problems

How to Teach Yourself

How do you teach yourself a new skill? How do you learn a tough subject? (like pchem?) I’m glad you asked. Here are my tips and tricks specifically focused on pchem survival (but applicable to life in general).

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1. Don’t be afraid! (and that’s an order!)

Thousands have been down this road and they were in your shoes back then. You may have to shore up some mathematical deficiencies and look up some vocabulary, but these tasks are obvious to you as you go along. None of this affects your value as a person. But do you have the drive to re-learn what you have forgotten and dig into what you don’t know yet? Decide now! This is not a technical question. It is a heart question. Your answer to this question will determine your future as a productive team member after graduation.

2. Do the tutorials.

Every book has example problems in the text. Every coding site has tutorials. Even Excel has example data sets in its help files to show you “how it is done”. Do the tutorials.

3. Read the text with a pencil NOT a highlighter.

Write in your book margins. Rework math proofs in your problems notebook. Unless the material goes in your eyes, rattles around in your brain, filters down your arm, and out through your pencil, then you haven’t comprehended the material. Highlighting is nothing but self-deceptive Arts and Crafts.

4. Keep a problems notebook.

Do all your problems in a composition book. It is bound and sturdy. It will last much longer than a spiral notebook. Thirty years from now, you can be amazed at how bad-a$$ you were in college when you look at the math problems you did!

AND you can use it to shame your college-aged kids when they complain that their college prof won’t just upload the homework concepts directly into their brain-chip.

5. UNITS!

If you would just use UNITS on your numbers you would catch 99% of your errors. I can’t scream this loudly enough! Units, units, UNITS! Use them, or fail. It’s on you.

“But they take up space. They take time. Whaa Whaa Whaaaa” Look at the photo uploaded with this post. There is NO way to catch all the powers of 10 that jump around in that problem without using units.

6. Pro-tip: Be Disciplined

“The scheduled task gets done”, said my father.

If your homework time is not scheduled, then it will not get done. If you are not using the phrase, “I can’t, I have PHCEM homework to do.” Then you are not learning pchem.

If you want to learn piano or guitar and you don’t schedule practice time, then I don’t want to hear you play. It is the same with sports. If you don’t schedule practices, then I’m not buying a ticket to your game.

Put LEARNING on the calendar, not just TESTING.

—Here endeth the lesson.

Posted in D L Williams, Education, Physical Chemistry

Brainstorm Session on 3D Printer Waste

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Friends, Romans, Countrymen, lend me your ideas. Look at the picture of the dual extruder tip cleaning fences and give me your thoughts on what they could be used for.

Background: I have recently added a 3D printer to my lab to prototype chemical laboratory accessories.

I purchased a dual extrusion Makerbot and I love it. I will blog a review of its performance sometime soon.

Technical Details: Aside from the waste produced from being a noob at 3D printing, there is also a lot of built in waste from raft and tip cleaning fence material. Turning off rafts and supports does not save filament because these help ensure a successful print. If the print fails without rafts and supports, then you have still wasted a lot of filament.

So get those creative juices flowing, and comment on what you would use these tiny little fences for. Toys? Rear view mirror bling? Let me know.

Posted in Education, Physical Chemistry, Science Education

Same Behavior, Same Results

T-minus one week and counting…

first class day

We start up the semester at Sam Houston State University one week from today. So I thought I would address the students at SHSU in general and the Physical Chemistry students in particular.

What are YOU going to do differently this year to ensure you improve performance, retain knowledge, and cultivate character?

Even the 4.0 student can improve in these areas. Begin by writing out your goal. It might look like:

  1. Make straight A’s this semester.
  2. Not get behind in my classes, job, club officer position, and family commitments.
  3. REALLY learn the material so that I can draw on my knowledge in future classes and jobs.

Whatever the goal is, do not forget to do this next important step.

Think back to last year. Identify what kept you from achieving this goal last year. Be specific. Was it a habit? a video game? a TV show? a friend who dominated your time? a student organization?

Now, change it. If this activity, person, or situation pulled you off your path to success, then either change it or change your path. You cannot follow two paths.

You cannot do everything.

Now, is the time to plan. If you are a chemistry major, especially, now is the time to commit yourself to hard work, problem sets, reading the text, and a smaller social agenda.

In the future, you will be hired based upon your chemistry abilities, not how many activities you were in. Be the best, most knowledgeable graduate you can be, no matter what your major.

It starts today.

Posted in Education, Physical Chemistry, Science Education, Spectroscopy

What is pchem?

Pchem is short for Physical Chemistry. It is hated by all. It is SO bad (the audience asks, “How bad is it?”), that it has it’s own bumper sticker!
p-chem
Why is pchem so mistreated?
Like a scientific tax accountant, a P-chemist worries about the energetic balance sheet, the gains and losses of energy, the ratio of usable to unusable energy. We pull the thread through all states of matter – liquid, solid, gas, plasma, elastic, plastic, glass, etc.
My favorite subsection of pchem is symmetry and spectroscopy. Spectroscopy is the study of light interacting with matter. And symmetry is used to decipher these interactions. There is no better example of the mathematical beauty of our universe than the unexpected explanatory power of group theory as it applies to absorption and emission of light.
Fireworks, hair dye, crayons, ink, glow sticks, lightning bugs, and all the rest can be understood through pchem – specifically my field of spectroscopy.
There is much more to pchem. If you have made it this far, then you are truly curious. Therefore, I give you the table of contents to a typical pchem textbook. (You will have to “Look Inside” at the Amazon site to view the TOC.)
And, I ask you to share and subscribe to this blog. Comment below with suggestions for posts.
Posted in Education, Spectroscopy, UV-VIS-NIR

What makes a rainbow?

All of us love a rainbow, and a double rainbow is even more exciting. This is pchem* in action!

350px-Double-Rainbow
A double rainbow photographed in Karlsruhe on July 22, 2011. Leonardo Weiss http://commons.wikimedia.org/wiki/File:Double-Rainbow.jpg

You may have noticed that rainbows only appear with the sun at your back. Why?

Rainbows are angle-dependent. The light coming from behind you hits water drops of a particular size and at a particular angle so that they are diffracted (bent) inside the drop. This can occur in a clockwise or counter clockwise manner. The clockwise path through the drop to your eye and the counter-clockwise path occur at slightly different angles. This creates the two rainbows.

The different wavelengths of light from red to blue also travel at slightly different angles (just like through a prism), and this creates the spread of colors in each rainbow.

Have you ever seen a triple or higher-numbered set of rainbows?

Some will brag and say they have. But this is extremely improbable. If their eyes were sensitive enough to see this higher-order diffraction, then they would be blinded by the bright sunlight needed to produce the rainbow in the first place. The probability of light traveling multiple circles within the water drops to create second- (and higher-) order diffraction effects is very slim compared to the single pass rainbows that we are all familiar with.

Post links to your favorite rainbow images in the comment section.

Subscribe to this blog for more Pchem* topics.

*Pchem (Physical Chemistry) is the study of the physical properties of the universe.

Posted in Education

The #WAR on Cramming

Homework serves several purposes in academic pursuits.  It guides the students through a subset of material the professor deems important. It forshadows the examination. It serves as a scaffold for the student to assist the building of their body of knowledge in the topic.

It should not be “busy work” because this wastes valuable student time.  It should not create a protracted grading burden on the professor, because immediate feedback is best for the student when learning new material.

Therefore, I am exploring the following with positive initial results.  I use multiple choice homework problems, because these are automatically graded online by the Blackboard learning system.  These assignments fullfil the purposes of forshadowing the exam, and guide the student through the appropriate material.

The negative aspect of this is the natural focus of the student on “which letter is the correct answer”.  I do NOT care about which letter they check.  I want them struggling with the problems, building their body of knowledge, and internalizing the concepts and theories.

Therefore, I have changed the grading rubric to punish simply getting the correct letters in one setting.  The only way to achieve a perfect score on the homework is to do the following:

1. Take the homework exam multiple times over several days showing improvement towards the eventual score of 100%.

One can EASILY fake this, which is why it will only be 5 to 10% of the weighted average of a given course.  But instead of faking this apparent activity, consider actively using the process that I am encouraging.

So to my students, I give the following advice:

  • As soon as the homework test is made available, log in and take it cold.  Give your best guess on the vocabulary.  Estimate the numerical answers.  Do your best to ace the test “cold” without knowing the material.
  • Then, download the pdf version of the homework test. Over the next few days, work the problems in your “problems composition book” (hint, make one of these).  Work similar problems from the back of the text.  Work similar problems from the Internet.  Evaluate why the right answers are right.
  • Log back into Blackboard.  Take the homework test again.  If you do not make 100%, then work the ones that confuse you.  Ask about them in class.  Get with your study group.  If you are convinced your answers are right, perhaps there is an error in the homework test.  Ask about it in class.
  • Finally, you should be able to achieve a 100% on the homework test, AND THE RECORD OF YOUR MULTIPLE TESTS ON BLACKBOARD will be evidence that you deserve a 100% for PARTICIPATING in the homework assignment.

I welcome your constructive input.