Wednesday, February 27, 2008

Paradoxical Cat

Time Travel Cat ...
Humorous Pictures
... Almost Cause Paradox.

Thoughts follow below the fold.

Original 27 February comment:
I should add some physics content here, but it is too late at night.

Finally got my Round Tuit on 11 March

The real question is, which time travel paradox are you worried about? The cat is clearly unconcerned because there is no paradox if the time travel event is a part of history as it took place the "first" time. The model for that is Harry Potter and the Prisoner of Azkeban, where Harry would not have been alive to save himself if he had not gone back in time to save himself. That circle closed perfectly. He even had the advantage of knowing that he could actually do it.

There are too many different Star Trek variants of the grandfather paradox to explore here, but see below.

When I went to IMDB to pull up the Harry Potter link, I noticed a trailer on their front page. A trailer for Star Trek, that was uploaded on 23 January giving a Christmas 2008 release date rather than the less optimistic May 2009 date on the IMDB page. It would appear to be an entirely new invention, the seqprequel, since it is a prequel to the original TV series but a sequel to the Enterprise TV series and caught in the center of the time loop of Star Trek: First Contact. That used an entire movie to establish the same result as Hermione and Harry did when they had to go back in time because that is what history required.

They are breaking new ground, bringing a young Kirk and Spock to the screen while all of us who saw the original series (made when they were both a spry 35 years old) are still around. The "young" actor playing Kirk is 28 and the one playing Spock is 31. I suppose the premise is that Shatner and Nimoy were playing people who were quite a bit more experienced than their age at the time would indicate. It may work. The casting for Captain Pike (someone, at 52, who is old enough to have seen the pilot!) looks pretty good.

It will remain to be seen which working title will apply: Will it be typical of the odd numbered films (it is Star Trek XI), or the even ones (they used "Star Trek: Zero" as another working title). Yes, I know that zero is not an even number, even though it can be divided by two.

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Monday, February 25, 2008

NASCAR Cocktail Party Physics

Check out the two articles (part 1 and part 2) by Jennifer Ouellette featuring an interview with Diandra Leslie-Pelecky, the author of "The Physics of NASCAR".

Great discussion of some of the physics of motorsports as well as the interesting dynamics of gender in racing ... and physics. Also some excellent points on using racing to better engage students in the enterprise of learning, although I have noticed in my experience that it tends to engage mostly the guys if the emphasis is on the dramatic side of the sport.

However, I find the entire class gets engaged with the specific role of momentum and impulse in whether you survive a collision. (I never cease to be amazed at the number of my gen ed students who have been in a serious crash or are close to someone who has, and my sample is not a large one.) One is also likely to engage the entire class when the real world of engines is tied to more widely held concerns such as energy efficiency of internal combustion engines and the tradeoff between efficiency and high performance.

I was quite amused by the mention of using fuel limits in auto racing as a way to drive innovation. That was actually done back during the 70s fuel crunch. It had little effect on racing. Corporate interest in fuel economy seems driven by larger factors, such as the real cost of gasoline (by that I mean the price in real dollars) driving a change in consumer demand.

Before I stop, I want to single out parts of a specific quotation from part 2 of the interview with Prof. Leslie-Pelecky of Nebraska:

I've been working with teachers from elementary to high school for more than 10 years and frankly, I'm frightened by much of what I see there. Even the best teachers are paralyzed by the implementation of the idea that we can prove that students are competent at science by giving them multiple choice vocabulary tests. We are teaching kids that learning is nothing more than rote memorization of unrelated facts they will never use again. They get to college or the workforce and are shocked to find that your results and not your intentions are what matters. They can't write persuasively. They can't read a chapter from a book and pull out the main ideas. The best of our students will be the best in the world, but I fear that the distribution is getting broader and broader. We are not doing well by the majority of the students we educate and, in the end, it is going to come back and hurt us as a country.

As I have written elsewhere, this emphasis on a particular kind of testing in K-12 is (IMHO) leading to a decline in the analytical and critical thinking skills of the students entering college, and this requires some significant changes in the way we approach teaching physics (and probably other subjects as well). They come to us as 10-minute crammers, not life-long learners.

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Sunday, February 24, 2008

Thoughts on Political Plagiarism

I have been entertained no end by the charges of plagiarism between the Democratic Candidates seeking four years of free lodging in the White House.

What strikes me as odd is the very idea that any politician (beyond one running for county dog catcher) is speaking words originally created by himself or herself that purely reflect his or her view of the world. Have we learned nothing from watching talk show comedians working without writers? Most of their clever words come from someone else.

My perspective on this is rather unusual. My Russian professor in college wrote jokes for Phyllis Diller. My teacher would not tell us what jokes she had sold; her contract would not allow her to do so. Once the joke was sold, Phyllis Diller owned it just as if she had thought it up herself. It was abundantly clear to us, however, that my teacher had plenty of wry humor to draw from if needed. (There is even no way to know if the "quote" given in the Wikipedia article was invented by Phyllis Diller or by one of her writers. All we know for sure is that she said it.)

The best moment so far had to be the matched clips of Bill and Hillary speaking the exact same line 16 years apart (shown on one of the Sunday talk shows) after a comparison of Obama and Patrick giving a similar speech. So? What makes anyone think that Bill wrote the line he spoke? It is not out of the question that he said something Hillary wrote 16 years ago, and now she is using it herself. Or that the same speech writer wrote it for both of them. Ditto for Obama and Patrick.

And don't even begin to look at the "as told to" books, or the ones that were entirely or mostly ghostwritten by someone being paid to produce words for someone who was too busy to produce more than an outline. "Profiles in Courage" comes immediately to mind on the political side, along with books where a ghostwriter is actually thanked in the book (including one by Tim Russert, a journalist).

Much the same applies in politics, with the complication that good ideas have many parents while bad ones have none. Effective phrases become part of the national dialog, whether they are completely true and accurate or not. When Kerry said "I actually did vote for the $87 billion before I voted against it.", it was widely overlooked that Bush had opposed the $87 billion before supporting it. Bush was opposed to paying for the war with current taxes, while Kerry voted against doing it on credit. He lost because he was too inarticulate to point out the Bush flip flop and the media played along with the Rovian spin without bothering to point out the true difference between those two votes. Now we are stuck with politicians who are afraid to ask the American people to actually support the war with, you know, actual money because to do so would be "raising taxes" or "voting against the troops".

Clinton and Obama are playing a similar game today with half truths, which are the same thing as half lies, about each other's position on various issues.

Last week's New Yorker reminded me of the wild mismatch between what people were told to say to get elected and what they actually did after being elected. Roosevelt ran on a balanced budget platform against the spendthrift Hoover, who was running up a deficit to fight the Depression. I don't think that position even lasted until inauguration day. GW Bush ran as an isolationist against the foreign activist Gore (Clinton), who had supported overseas intervention against terrorists in Africa (Blackhawk down) and elsewhere, following the line taken by the Republicans in Congress. That lasted just long enough to let the Cole bombing go unpunished and August warnings be ignored. Was Bush "borrowing" someone else's words before the election, or after? I don't think we know today which of those was the real Bush, or the real Roosevelt.

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Free the Energy!

I was amused by last week's What's New by Bob Park where he wrote about seeing 5 perpetual motion machines in an average year.

I got got visited by a Free Energy crank a few weeks ago. This one wanted to use motors to drive flywheels that would drive generators that would do some work while driving motors that drove flywheels ...

I'd guess that even a professor of English could spot the flaw in that one, but it took some doing to convince him that the first law of thermodynamics was not going to let him get more energy out than he put in.

Despite the obvious fact that even a tiny bit of friction or resistance anywhere in the system would result in a loss of energy, the magic of the word "theorem" (referring to unrelated proofs by Carnot, et al.) seemed to do the trick. You see, he was convinced that the losses were only a problem if there was one motor and generator. Ten of them would make those losses go away rather than get worse. Classic.

I didn't ask him if he wanted to buy mail order device a friend told me about, a device that alters the quantum mechanical phase of gasoline to increase the mileage you get on your car.

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Thursday, February 21, 2008

Lunar Eclipse

This picture of the moon during the total lunar eclipse on Wednesday was taken about 6 minutes after totality.

I love how lightly colored this eclipse was, and how well the craters showed up as a result. A blood red one some decades ago was spectacular, but ones that take place with a relatively clear atmosphere and close to the edge of the umbra (like this one) have really nice shades of color.

Additional comments and some pictures that include Saturn are below the fold.

This photo was taken with a Nikon D70 and 300 mm lens from a tripod (3 sec at f/5.6 using a 250 ISO setting) by Mrs. Pion. [I would have preferred 400 ISO to more closely match a speed that worked well when I shot slides of past eclipses, but that's life. It's her camera!] Both this one and the next one had the long exposure noise reduction feature turned on. The image above has been cropped from the jpeg and was not saved at max quality. I haven't done anything from the raw files.

Saturn was next to the moon, clearly seen in the lower left of this frame taken about 18 minutes into totality. The finite size of the planet is obvious in comparison to the star visible above the moon. [This picture has been cropped and resized and was saved at fairly low quality settings.]

We got some great looks at Saturn and its rings with a spotting scope, but the lens we have on the camera is not big enough to to resolve much more than the oblong shape due to the rings.

This picture was taken about 25 minutes into totality.

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Thursday, February 14, 2008

Happy Valentine's Day

A sampling from our Pink Perfection camellia for Valentine's Day

The old deco-style vase was "gifted" to us as my parents decluttered their house ... and cluttered ours. It seems perfect for these branches from the bush. (An individual bloom is normally floated in a special holder.)

Another photo is below the fold.

This year the bush came into full bloom late last week and is peaking right now.

Only part of it is shown in this picture, which was taken yesterday. The bush itself is almost 10 feet tall, and has not bloomed like this since we planted it as a tiny sprig of a plant. Normally it puts out a half-dozen or so blooms every week over a period of months, sometimes dropping all of its buds if we get a really severe freeze.

I have no idea if I randomly fertilized it at the right time this fall, ignored it more than usual (I am not a diligent gardener), or if we got just the right combination of cold snap, warm weather, and rain this winter. Comparison with others around the office suggests it is the latter, as others of this variety are also in unusually full bloom this year.

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Tuesday, February 12, 2008

Thank You Bill Simpson

That is what Tony Pedregon said in a live interview with ESPN between walking away from the wreck of his car (and some assistance for his second degree burns from the first-response team at Pomona) and getting a hug and kiss on the forehead from (fellow driver) John Force on his way to the ambulance.

If you have not seen the fireball on the news (it has been on everything from NBC Today on Monday through the evening news, a pair of YouTube links are below the fold.

Tony Pedregon repeated that thought in a CNN interview Tuesday morning (80% of the way down), when he said "But I've got to shake the hand of the guy that makes the fire equipment because it did its job." The guy who invented the Nomex firesuit is Bill Simpson.

If you don't know about Bill Simpson and fire safety in auto racing, keep reading. Last year was the 40th anniversary of this innovation.

In the old days, when I was a kid, people died or were horribly scarred for life after an incident like this one. The only fire protection was from cotton clothing that had been soaked with fire retardant chemicals.

In one of those strange coincidences, Nomex, a fire resistant fabric invented by DuPont, and Bill Simpson, inventor of the drag chute used to reduce the need for braking when you may only have a quarter mile or two to slow down from 200 or 300 mph, came together through the US space program. You can read about it in his Wikipedia biography linked above. He learned about Nomex and figured out how to use it to make a fire suit.

One of his more legendary marketing ploys was to make a movie where he tested it himself by soaking it in gasoline and lighting it. The famous (infamous) video of Bill testing a fire suit can be found on his new company's web site.

A key thing to remember is that safety is not a static thing. Just this year, NHRA increased the level of protection required in nitro cars. As performance improves and speeds increase, the intensity of a fire will increase. Surviving a fireball of gallons of nitromethane mixed with oil fed by oxygen flowing in at 270 mph does not happen by accident.

Video of the Explosion:

The video embedded here consists of the replays of the event shown by ESPN to sort out what happened.

There is also a YouTube video (ESPN copyright violation) called "Tony Pedregon on Fire" that shows the live-to-tape broadcast of the incident as it happened. You can see, around the 1:06 mark, Tony shaking his burned right hand after he gets out of the car as well as the burned knees of his fire suit.

[Still incomplete ???]

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Sunday, February 10, 2008

Drag Racing Data

A new season has started for NHRA drag racing, which brings a new set of data from the Winternationals out in Pomona.

A run from Friday qualifying showed an average acceleration of over 5.0 g's over the first 60 feet, which makes the 3.0 g launch of the Space Shuttle look lame. A run on Saturday was even quicker at the start, over 5.1 g's, but two thousandths of a second slower for the full quarter mile. It looks like it will be quite a season if Sunday's elimination runs match what was done in qualifying, with six cars running over 330 mph at the top end.

Data first, then calculations and an explanation of terms like "Top Fuel".

What do the data show?

Friday: Right Lane: Antron Brown runs 4.495/330.07
Antron Brown's incremental times:
60ft-0.862 sec., 330ft-2.152, 660ft-3.059/278.40mph, 1,000ft-3.824

A time of 0.862 seconds for 60 feet (18.288 m) corresponds to a constant acceleration of 49.2 m/s2 or 5.02 g (5.02 times the acceleration of gravity).

Antron Brown has moved from winning drag races on a motorcycle to Top Fuel. IMHO, the driver matters more on a motorcycle. Top Fuel is more about setup by the crew. The driver 'just' has to keep calm and the car straight at 300 mph while fighting the forces produced by such high acceleration.

Saturday: Right Lane: Larry Dixon runs 4.497/325.14
Larry Dixon's incremental times:
60ft-0.850 sec., 330ft-2.152, 660ft-3.053/278.98mph, 1,000ft-3.822

A time of 0.850 seconds over the first 60 feet corresponds to a constant acceleration of 50.6 m/s2 or 5.16 g.

Note that these accelerations mean that there is a force of over 800 pounds pushing a 160 pound person back into the seat. Five times the force of gravity is trying to pull your arms back and your hands off the wheel. That is why the Beach Boys sing about "being pushed out of shape" so it is "hard to steer" in one of their 60s ballads about racing cars, only they were talking about 1 g acceleration, max.


Assuming constant acceleration, the formula is a = 2*x/t2. You can do this yourself without doing any conversions by taking the 60' time T and evaluating 3.73/T2 to get the acceleration in units of "g", the acceleration of gravity. The number comes from 2*60/32.17 where 32.17 is approximately g in ft/s2.


Drag racing is about acceleration, not top speed. Quick at the start means you are at a higher speed sooner, so you cover the quarter mile in less time. The fastest run did not have the highest speed (which was over 334 mph).

You might wonder how it is possible for a car to accelerate at over 5 g's. If I told you that the car is going almost 100 mph after traveling just 60 feet from a standing start (roughly zero to 60 in just over 0.5 seconds), you would think I was making this up. One key is having an engine that makes about 1000 horsepower in each of its 8 cylinders, while another is having tires with really soft rubber that has a coefficient of friction (when in contact with a carefully prepared concrete surface) in excess of 5.

It helps that "Top Fuel" refers to the use of a mixture of 90% nitromethane and 10% methanol as fuel. (I think they are back to using 90% nitro.) Like in high explosives such as nitroglycerine, the nitrogen in nitromethane acts as an oxidizer. This fuel needs very little air to burn, so you can stuff more fuel into the engine than with gasoline (less air means more fuel, so they can burn several gallons per second) and it detonates almost like dynamite. Seriously, these cars literally explode off the line. You have to feel it (the shock wave hitting your body when the throttle opens) to appreciate it.

The real trick, however, is in the clutch. They simply drop the clutch with the engine at full rpm. The engine runs at a constant rpm corresponding to 330 mph, and the clutch slips at a rate that keeps the tires stuck to the pavement. This is done with a very complicated, yet entirely mechanical (no electronic computers here!) multi-stage clutch system. They first drop a tiny disk that slips a lot, then more, then more, until it goes to full lockup at the top end.

[Correction: See comment posted today. I was given misinformation somewhere along the line ... You can get a fair description of the centrifugal clutch described in the comment by looking at the lines about "racing karts" in the Wikipedia entry linked here.]

By the way, sometimes they literally explode, but safety rules and good engineering keep that to a minimum and kevlar blankets and straps help confine any debris. Nevertheless, they do have to rebuild the engine completely, including replacing all of the head bolts, after each 5 second run even when all goes correctly. During eliminations, this engine rebuild has to be completed and the car ready to run in 90 minutes. That alone is something you have to see to believe.

Other details:

Top Fuel cars must weigh at least 2300 pounds after the race, should you want to work out the forces involved.

I am using the standard acceleration of gravity of 9.80665 m/s2.

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Saturday, February 9, 2008

Why I Enjoy Teaching Physics

This article is motivated by Dr. Crazy's follow-up article where she explains that she enjoys teaching literature for reasons that are a bit different than the reason she thinks it is important to teach it.

Although my enjoyment when teaching was clearly part of my explanation for why I teach, there are some things that deserve separate mention here.

Yes, I enjoy helping them change their lives. I wasn't really aware of what a big deal that could be when I was teaching as an undergrad or in grad school, even when I knew someone was hoping to be an engineer, or go from being a nurse to a physician. I think I took it all too much for granted back then. The vast majority of the kids I started college with did not drop out and seemed to find their way to a goal even if it was not the one they started with. (I doubt if one of them planned to be a Provost!) I now know that is far from the norm.

I now know the difference between a suburbanite son of a doctor or engineer and the daughter of a logger. I know the difference between the kid who has no motivation other than going to grade 13 and the kid who was lucky to survive inner city life in Baltimore (making 6 years as a Marine look pretty comfy by comparison). It is no surprise that motivation beats background most of the time, but there are lots of kids in the middle who aren't fully motivated because they don't really believe that a kid like them can do it. I love every success story because I can use it as a seed to grow some more.

That is probably the very best thing about teaching physics at a community college, followed closely by the smaller class sizes and my ability to control the synchronization of lecture and lab. I really enjoy having a class where the lecture section is half the size of a recitation section at a university; where I know the name (not to mention strengths and weaknesses) of every student in the class.

I also enjoy making them think. Think hard. Work on a problem that might take several tries, where the answer is far from obvious. Help them realize that careful reading of a question is as important as algebra if you want to get the right answer. Make them see a familiar phenomenon, like a roller coaster or a flag hanging on the wall, in an entirely different light.

I enjoy making them really think hard when they read a problem. Forcing them to pay attention to detail. This was not a challenge when I was first teaching, either because my students had higher verbal SAT scores on average or because they had been taught critical reading skills in high school. (I have many reasons to suspect the latter, the biggest one being that I see this problem in students who I know have first rate verbal and math SAT scores.) I share Dr. Crazy's interest in this kind of problem, and sometimes have them see if they can write a precis' of a physics problem rather than of a story or article.

I enjoy opening their eyes to what is behind the curtain. Showing them what is inside a switch, or a TV set, or a microwave. Pointing out that size of the antenna on a cell phone is related to the frequency it transmits. Seeing the wave guide on a satellite truck, not just the antenna. Seeing the forces in a bridge, or in a grocery cart, or holding up a bookshelf.

I enjoy teaching calculus (and algebra and trig) indirectly, while teaching physics. I get to teach some things they don't cover in calculus class, like the real skill of applying math to the real world, and I get to reinforce the skills that will really get used. The skills they will need to be fluent in when they get to their junior-year classes in engineering or other science areas.

I love it when I get good questions, and love it even more when they appear perfectly timed to what needs to be discussed next. That is always a clear indicator that at least some of the students are engaged and thinking along with what I am doing.

I even enjoy taking roll in my head, so I can compare regular attendance with grades on exams. Its not all in the homework ...

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Why I Teach (Physics) - The Meme

I put Physics in parentheses because I was teaching long before I taught physics, but teaching physics is my current career and the topic of this post.

This article is a response to a suggestion at Free Exchange on Campus last month that was triggered by yet another of Dr. Crazy's interesting articles on teaching: why she teaches literature. I've been a bit slow joining all of the other responses, including Dr. Crazy's own addition to the meme, an early response from Sherman Dorn that was what first brought my attention to it, and Profgrrrrl's comments this past week that reminded me I still hadn't written about it. Too busy getting rolling through the first exam block of the semester and all the other little things of life.

It is also a very challenging topic to write about.

I probably put it off at first because it is very hard to articulate an answer. It is easier to say why I enjoy teaching physics at a community college, which I will take up separately. Nonetheless, the fact is that I enjoy teaching and have always enjoyed teaching, but there is more to it than that. I'll follow Profgrrrrl's lead for two reasons: I think her approach of starting with history will make it easier to work my way into the topic, and I owe her an answer elaborating on the similarity in the way our stories start.


I also started teaching before I had any idea that is what I was doing. For me, teaching started in elementary school. I was part of a "pull out" program for gifted students, and we spent part of one year on algebra. That came naturally to me (I worked my way through the first 3 or 4 chapters of my Dad's College Algebra book in fourth grade) and I worked with some of the other kids in the very open classroom environment used in that program. We also team-wrote a play, by the way. That continued into high school, but I never considered myself a teacher. In particular, unlike a friend who wanted to be a teacher (but never did), I never took any opportunities to do a pseudo-student-teaching gig.

Except I did. I just didn't see it that way at the time. I taught one day of my physics class, introducing special relativity. It was actually meant as a learning experience for me, which it was on many levels. One lesson I learned right there was that it was much easier to understand (or think you understand) a subject yourself than it was to explain it to others.

I was a math major as an undergraduate, and got asked to be an undergrad TA in the residential college I was in. (Talk about leading edge; we had a learning community embedded within an Enormous State University before the people pushing them today were even in school.) Now I knew I was really teaching, or at least playing at being a math professor. I think I was still more effective at 1-on-1 assistance at that time, but I got excellent training before, and mentoring during, that experience that helped me transfer individual teaching methods to the classroom. That also was the only training I ever got in teaching! It was also the first time I taught an undergrad who went on to graduate school in physics.

I also participated in a really novel training program on interpersonal communication via my best friend, a dorm Resident Assistant. I still use those skills, when I remember that I have them.

Thanks to burnout in math, a recession in the sector that otherwise could have used a really clever programmer and applied mathematician, and well-timed recruiting by a physics professor, I went to grad school in physics. As I commented in some thread over at Dean Dad's, I was "lucky" enough to be in a research group that had more students than money for research stipends. Someone figured I had enough of a clue to teach recitations, and I got pretty good at it. (Really good according to the University, which gave me a teaching award, but I was still a hack by my present standards.) No training there at all, but some really excellent mentoring from another best friend, a fellow physics grad student who continues to be an award winning teacher at his university.

Best advice ever: Be yourself in the classroom.

I then spent a long time (almost two decades) as a post-doc or research faculty member, teaching a class or two or subbing here or there along the way. I even turned down a t-t job in a small department at a university (one with an engineering school at that) along the way. No, I was more interesting in doing research than teaching at that particular time. And, although doing a good job at research most definitely requires the skills of a teacher, when you try to communicate some really new result to people who are learning it for the first time, its not at all the same.

I was quite lucky to stumble on my current job as the contracts that my research position depended on led to a "change in emphasis" where I was working. In all modesty, they were lucky that I was there. I am back doing what I have always loved, if you haven't figured that out already.

Why Physics teaching is important to me

Lives depend on it. Physics is one of the basic skills, along with critical thinking and mathematics, upon which engineering is based. The vast majority of my students want to be engineers, so a bridge might fall down if someone does not do a good job teaching basic physics to them. (If you missed that memo, the I-35 bridge in Minnesota did not fall down because of poor maintenance. It fell down because of a design error made 40 years ago by someone figuring out whether the net force at a joint could be resisted by a particular piece of metal, and got it wrong.) There are some key skills that my students need to learn, and I mean learn for life (not just the next test), if society is going to survive after they graduate.

I take this pretty seriously. I first learned it in grad school when someone told me he decided on final grades in a pre-med course based on whether he wanted to find himself in an emergency room with that student standing over him. Same goes for driving across a bridge built from plans signed by a former student.

The original blog asked about academic freedom. You might think it odd that a well-established subject like physics would have that concern, but it does. There are preachers out there who would want a bogus version of thermodynamics taught so they could use it to justify their anti-evolution preaching. There are people who reject relativity because they think it leads to free love and abortions and would not like to see it taught. We all must stand for the right to teach the truth as we see it.

Why I teach

I teach because it changes lives, for the better.

I teach because my impact on society is magnified by every student I teach that goes out there and does an important job as well (or better) than I could if I had gone into the corporate world right out of college as I had planned to do.

I mentioned teaching someone in an undergrad calculus class who went on to graduate school. It was quite a surprise when he told me he had learned calculus from me, and a bit of an eye-opener. As an undergrad, I enjoyed teaching because I was helping my fellow students figure things out. It was fun to put my knowledge to use, and always rewarding to show off that I could do the hardest nastiest problem someone decided to assign that semester, but it was more than that. I'd help kids who were not in my class. Or some friend's girlfriend who was having trouble with chemistry. That old scouting "do a good turn every day" thing, perhaps. But it never quite crossed my mind that I could help someone get into grad school.

Then there was the day that I saw a picture of a former student in Time. A kid who was in my physics recitation had made a big splash in medical research as a resident. (He now runs an entire building at Stanford Medical.) OK. If someone learns like he did, and has the initiative he did, anything is possible. And I could help make it possible. How many lives has he saved, or enriched. It boggles the mind.

More recently, I saw that one of my better students had earned an MS in Engineering. (This would be one of those non-traditional students, who literally came out of the woods to attend our CC before entering a big university. She did not have any confidence at all when she came in here. Did telling her that she was as good as that guy 20 years ago, the guy now at Stanford, help her see herself differently? I sure hope so, because she is good enough to change the world, too.)

I get some students who are straight out of high school and could go to a university as their first step, but most of the really good ones are returning students. The group of Iraq vet Marines (you are never an ex-Marine) who formed the most interesting cross-cultural cross-ethnic study group I've ever seen. Really smart kids who, for one reason or another, never went to college. The cosmetologist who was brilliant at mathematics and is going to be a chemical engineer. Or the kid who earned a scholarship as a now-honest graduate of a "residential" school for delinquents. We see the great cross-section that the CC was created to serve, and some of them use everything we have to offer and more.

A big part of my job is the same as it is at a university teaching calc-based physics. We all are trying to give them an entirely different way of looking at the world and (simultaneously) the tools to enter a highly technical profession. Few students enter physics with the unique perspective the subject requires. Few normal people see vectors of forces when they look at a bridge, or think about the coefficient of friction and terminal velocity when watching automobile racing, but most engineers and physicists do. When Dr. Crazy writes about how going to college changed her in a way that makes it difficult to fit into her parent's world, I know what she is talking about. My students face that same challenge, in a more technical than philosophical sense, and I am here to help them with it.

I teach to help my students achieve their goals, if they are willing to work at it.

I don't teach to "help" students pass if their bridge would fall down without extra credit or a retry at an exam.

And I teach because I seem to have a talent when it comes to simplifying the complex and clarifying the opaque for kids who are willing to work at it. I've never understood how I make those connections for them, but part of it must be the same talent that helped me make some connections that changed how physics is done in a few narrow fields of little interest to hardly anyone.

And finally, I think I teach because it is in my genes along with building and designing things. My grandmother was a teacher, and one grandfather actually taught physics labs while studying engineering as an undergraduate. And my father taught me all sorts of things almost every day when I was growing up. Things like this week's factoid/ homework example: The average person puts out the same amount of heat as a 100 Watt incandescent light bulb.

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Sunday, February 3, 2008

Watching History Not Being Made

I've seen a lot of football games, and every Super Bowl (IIRC), and I can't remember a Super Bowl that was nearly as good as this one: closely played right down to the end with every yard fought for as if the game depended on it.

Thank God, because the ads during the first half of the game were awful.

I imagine that lots of commentators will not like it because it was a defensive masterpiece on the part of the Giants, and defense just does not get appreciated by the folks who want NFL scores to look like NBA scores. At least the TV coverage showed some replays of the blitz packages that NY used to neutralize the totally superior offensive line of NE.

The one game it reminded me of, early on, was the 10-10 tie between Michigan State and Notre Dame that I saw in person in 1966. Every inch was contested, even on a 2 yard run. Exceptional plays were needed to evade the defense, like Manning's move that might have won the game. Every hit was solid with no cheap shots. The only difference is that holding is totally legal now, so the only way to beat your man around the end was what Strahan did: get far enough away that he could not grab on.

And hearty congrats to Chad over at Uncertain Principles whose New York Football Giants won the game. He even got it almost right, saying it would be decided by a field goal in his anti-woofing pick of the Patriots. But one of my co-workers, from Rhode Island, is going to be very unhappy tomorrow morning.

Note added: She was very unhappy this morning. She even wore black.

For the record, my prediction was that it would be won by the last team to score, although I made that at halftime when it was clear this was going to be a defensive struggle with every score a challenge.

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Friday, February 1, 2008

Improving Student Success

My brother e-mailed me an article featuring a rather novel (in my experience) method of improving student success in science classes. It does seem that this method would increase retention rates for introductory biology, but there were some indications in the article that it does not increase student learning.

The headline to the story, teacher could face firing over giving test answers, suggests why this might be the case. The method itself, however, was novel enough that The Thomas commented "You just can't make things (like this) up" and I felt compelled to share it with my few readers below the fold.

You see, the teacher did not actually "give" the test answers to his students. He allegedly italicized (or bold faced or increased the font size) of the correct options on 29 of 34 questions on a multiple choice test. For those of you keeping score at home, that would amount to a grade of 85% or 87 (if he gave 3 points per answer for a max of 102) before trying the remaining questions.

A student quoted in the article said ""I think everybody was passing, unless they had attendance issues, but we weren't learning very much. At least I felt unprepared when I got to chemistry." Perceptive student!

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