By Christopher Moore
Carlwin has the following question about energy:
I dont know if our solution is right, but here’s the problem: Compute for the energy given off by a gas doing 200 J of work and losing 1350 J of its internal energy to the environment
Normally, I don’t respond to these types of questions for two reasons: (1) I don’t do other people’s homework, and (2) no mention was given to what their solution was, so it makes it hard to comment on where their reasoning is correct or incorrect. The forums are sometimes useful for these types of questions, but usually without having shown some initial effort, most questions like this die from lack of response.
So why am I going to respond? Because the question is either a trick question or awkwardly worded, which means it is the type of question that I hate and the type that typically leads to very little learning on the part of the student. This isn’t Carlwin’s fault. This is the fault of the person that assigned this question.
Why is this question a poorly formed question? Because, I could pose this question to a room full of PhDed physicists and get 2 or 3 different answers, all of which could be justified.
The question specifically asks how much energy the system “gives off”. The answer is 1350 J.
Anytime you see the buzzwords “internal energy” and “work”, think of the 1st Law of Thermodynamics: the change in the internal energy equals the sum of the change in the heat and the change in the work, or
.
A system has a certain amount of internal energy. That is all the energy it has available to “give off”. If it looses 1350 J of energy, then it lost 1350 J of energy. Period. It doesn’t matter whether that energy was work or heat.
However, it seems like the questioner meant to ask how much heat does the gas give off. In that case, the answer would be 1150 J.
So, either the question is a “trick” question or the question is a poorly formed question. Either way, I’m not sure how you would properly assess a student’s understanding via this question.
By Christopher Moore
I’m back in Farmville after spending the weekend in College Park, MD being taught how to teach. (Technically, I’m in Richmond working on research right now, but I will be in Farmville tonight.) I didn’t get an opportunity to blog about the workshop much as it was going, because the schedule was very dense and filled 12 hours of each day. I’m very tired.
The highlights: Eric Mazur of Harvard and Edward Prather of the University of Arizona. These two could not be any more different in terms of personality and presentation. However, they both managed to completely convince me of the power of Peer Instruction. I’m sold. (I even learned a little astronomy during Ed’s workshop!)
I took notes on my fancy tablet PC, so rather than re-hash most of the meat from memory, I’ll just upload PDFs of those notes when I get back to my office tomorrow. But I will leave you with the number one technique I walked away with that will find use on day one this coming semester: Think-Pair-Share using color-coded cards.
By Christopher Moore
The San Fransisco Chronicle reports that a Quaker math teacher was fired for refusing to sign an oath of allegiance. This is not necessarily physics news, but having gone to Guilford College and having a background in the Society of Friends, this is an interesting story to me.
Marianne Kearney-Brown, a Quaker and graduate student who began teaching remedial math to undergrads Jan. 7, lost her $700-a-month part-time job after refusing to sign an 87-word Oath of Allegiance to the Constitution that the state requires of elected officials and public employees.
You see, Ms. Kearney-Brown did the following each time the oath was presented to her:
Each time, when asked to “swear (or affirm)” that she would “support and defend” the U.S. and state Constitutions “against all enemies, foreign and domestic,” Kearney-Brown inserted revisions: She wrote “nonviolently” in front of the word “support,” crossed out “swear,” and circled “affirm.” All were to conform with her Quaker beliefs, she said.
She refused to sign the statement unaltered, and she was fired.
You see, Quakers have this little hang-up on non-violence. It’s nothing big, really, it’s just sort of one of the foundations of the religion. The oath as written is like asking a Hindu to swear to defend the constitution from all enemies, including cows. Also, the statement is vague. Very vague. What constitutes an enemy of the constitution? I claim that a large majority of our Representatives in Congress are “enemies” to the constitution. Who defines “enemies”? And what constitutes “defend”.
Ms. Kearney-Brown makes the following point:
All they care about is my name on an unaltered loyalty oath. They don’t care if I meant it, and it didn’t seem connected to the spirit of the oath. Nothing else mattered. My teaching didn’t matter. Nothing.
By Christopher Moore
Epsori Space Systems announced today that its Free Seeds Experiment will be flying aboard the Up Aerospace SL-2 launch, scheduled for Saturday, April 28 th 2007 . Epsori Space Systems will distribute the experiment to 2500 classrooms in the fall of 2007. The payload contains 22 ounces of mixed vegetable seeds. Teachers in grades 3-5 will be offered a free experiment along with approved curriculum, student workbooks, and packages of seeds that have flown into space. The experiment allows students to compare the growth of seeds in a control group, to the growth of the space seeds. Students are taught classic techniques of scientific observation and record keeping during the experiment’s two week execution.
Epsori Space Systems executives believe its pioneering approach of flying experiments to space to teach fundamental science skills in the classroom provides a fun way to connect children with space science. Quoting Jerry Hilburn, founder of Epsori Space Systems:
By placing seeds which have flown into space in the hands of our children, we engage their minds, excite their hearts, and make science fun!
Teachers are encouraged to visit the site to learn more about the experiment. Epsori is now accepting applications from teachers for the free program.
Epsori Space Systems was founded in 2007 with the mission of delivering affordable space based experiments to classrooms across America . Based in the heart of the New Space industry in Southern California , Epsori plans to launch thousands of experiments onboard emerging New Space commercial spacecraft in coming years. Up Aerospace is the first “public access to space” company to provide a low cost method of placing our experiments in space. Quoting co-founder, Joshua Johnson, “We are excited to be onboard SL-2 and look forward to flying payloads with Up Aerospace for many years to come”. Epsori Space Systems will launch a new social network website for teachers and students in September, which will provide a platform for reporting experiences, research findings, classroom photography, and video content of the experiments execution. Distribution of the seeds experiment will begin September 1st , 2007 .
The Epsori Space Systems media team will attend the launch in New Mexico on Saturday, April 28th, to record videos of the event and interviews of key participants. All news, photos, and videos will be posted at www.epsori.com and ilovephysics.com will provide coverage, as well.
By Christopher Moore
Here is an interesting story about a group of teachers floating in freefall during the “Weightless Flights of Discovery” program, sponsored by the aerospace company Northrop Grumman in cooperation with Zero Gravity Corp.
On one level, the exercise gives educators a chance to demonstrate the laws of physics in an environment like nothing on Earth: Objects in motion (like those plush toys) really stay in motion rather than falling to the floor. Surface tension turns those squirts of water into floating, glistening spheres. CD players and bicycle wheels go into a stable spin like gyroscopes.
“That’s the way physics teaching is all the time,” said Jeff Klein of Cleveland’s Gilmour Academy. “We’ve got great toys.”
Great toys indeed.
Hey, Northrop Grumman — if you need a physicist blogger to float around for a few hours, then I’m your guy. 
By Christopher Moore
Physicists properly join today’s arguments involving the teaching of Darwinian evolution. There is, however, a social issue even closer to the responsibility of physicists: quantum physics is increasingly invoked to promote pseudoscience.
Such pseudoscience promotions often start correctly stating some intriguing implications of quantum mechanics, move on to legitimate hyperbole, and then go off into complete hype. Take a recent “international hit” movie as our case in point. It’s strangely titled: “What tHe #$*! Do wE (k)now!?” (It’s sometimes called “What the Bleep?”) Time magazine describes it as “an odd hybrid of science documentary and spiritual revelation featuring a Greek chorus of Ph.D.s and mystics talking about quantum physics.” Early on, the movie illustrates the uncertainty principle with a bouncing basketball being in several places at once. There’s nothing wrong with that. It’s recognized as pedagogical exaggeration. But the movie gradually blends to quantum “insights” leading a woman to toss away her anti-depressant medication, to the quantum channeling of the 35,000 year-old Atlantis god, Ramtha, and on to even greater nonsense.
A layperson cannot tell where the quantum physics ends and the quantum nonsense begins. And many are susceptible to being misguided. According to polls, well over half of Americans (and English) have significant belief in the reality of supernatural phenomena. Robert Park in his book, Voodoo Science: The Road from Foolishness to Fraud, puts the problem well. “Many people . . . seek a certainty that science cannot offer. For these people the unchanging dictates of ancient religious beliefs, or the absolute assurances of zealots, have a more powerful appeal. Paradoxically, however, their yearning for certainty is often mixed with a respect for science. They long to be told that modern science validates the teachings of some ancient scripture or New Age guru. The purveyors of pseudoscience have been quick to exploit their ambivalence.” We should not underestimate how persuasively the imprimatur of physics can be used to buttress mystical notions. We physicists bear some responsibility for the way our discipline is invoked.
The human implications of quantum mechanics that fuel popular discussion arise in the “measurement problem” and “entanglement.” That’s at least how we refer to these topics in a physics class, where we rarely go much beyond their mathematical formulation. These same issues are also legitimately discussed more broadly in terms of the nature of reality, universal connectedness, and consciousness. But we don’t distract physics students with excursions into issues that extend embarrassingly beyond the boundaries we define for our discipline. Science historian Jed Buchwald notes: “Physicists . . . have long had a special loathing for admitting questions with the slightest emotional content into their professional work.” Accordingly, unlike the biology student able to defend evolution against Intelligent Design, a physics student may be unable to convincingly confront unjustified extrapolations of quantum mechanics.
(more…)
By Christopher Moore
Robert Tai, a science education assistant professor at the University of Virginia recently published a study that claims students subjected to block scheduling in high-school science classes performed worse in college-level science. Tai along with high-school biology teacher Kirsten Dexter looked at a national sample of 8,000 introductory college science students from 31 states, many of whom went to high schools that use block scheduling.
Here is the UVA press release. From Ascribe:
Block scheduling is a way of structuring the school day so that students have fewer classes for longer periods of time. The most common type comprises classes that last for 90 minutes alternating two or three days a week, in contrast with the traditional schedule of classes that run 45-55 minutes and are held every day. Increasingly adopted over the past 15 years, the schedule remains a subject of debate. Claimed as a way to help prepare students better for college, Tai found that was not the case when students in introductory biology, chemistry and physics courses were surveyed.
“Final college course grades are a real-world measure with long-term impacts,” Tai said. “Even when students had teachers who used instruction methods specifically geared toward block scheduling, the students who had a traditional schedule had better grades in college.”
Block scheduling has been all the rage over the last few years. I have taught both block and traditional formats, and as a young teacher, I actually preferred the block scheduling. I never noticed any difference in performance or learning that I could attribute to how many days during the week a student saw me. But I also tried to be very efficient and I have very few “data points”, so my preference is just that. I preferred block scheduling mainly because it was easier for me to prepare for class.
Block scheduling has come under fire recently. Jeff Lindsay maintains a site called “The Case Against Block Scheduling” that details its problems. School administrations like it because it is cost-effective and some studies show that it helps student performance. So obviously the jury seems to still be out.
I had traditional classes in high-school. And when I got to college, my first-year physics and calculus classes were 50 minutes a day, 5 days a week as well. Today, most colleges and university classes meet longer and fewer times a week, with the exception of language classes.
Which brings up a pretty good point: foreign language teachers have successfully argued that daily exposure to the language increases retention. That’s why college Spanish classes usually meet daily. Shouldn’t the same be true for math and science?
Colleges have block-like schedules because of logistics. There is no academic reason for classes to be arranged the way they are at the university level. But it’s understandable, because it’s the only way to make it work. So high-schools are moving to what may be a poor scheduling scheme to get kids used to college schedules?! That’s the main argument for block, but that logic doesn’t make sense.
Either block scheduling helps student performance or it doesn’t. That should be administrators only concern. I don’t know the answer to this one. But Tai believes he does.
By Christopher Moore
An old post got an interesting comment yesterday, which got me thinking: was I well compensated as a high-school teacher?
The commenter, Doinkicarus, has a few things to say about Michigan’s new tougher graduation requirements that I disagree with. He’s against them. I’m trying to change the culture of education, so I like more required math and science. Stricter requirements themselves are not necessarily a bad thing (although I admittedly know nothing about the new requirements.)
But I care more right now about what he points out later in his article:
I submit that you need to increase the incentives for math & science teachers, or rather, allow the market to work it out properly. But as sure as I sit here, the teachers’ union will not hear that argument. The teachers union unfairly restricts the pay of math & science teachers, who can earn far more, in a more rewarding environment in the private sector. The teachers’ union is the one to blame for these distorted incentives, where a woodshop teacher is paid on par with a chemistry teacher.
Teachers unions do restrict pay of math and science teachers in some states. Some of Virginia’s (right-to-work state, thank God!) counties have”workarounds” such as offering extended contracts and bumps in “experience levels”. But are math and science teachers generally getting shafted when it comes to pay?
Doinkicarus again:
According to Salary.com, the median income for an entry level “scientist” in the Detroit area is about $87,900. “Chemist” indicates a median income of about $48,000, and an entry level “Physicist” can expect somewhere in the neighborhood of $53,000 annually. Now the median high-school teacher also earns about $54,000 annually. But that’s the average median, not the median for “entry level teachers.”
Now I won’t pretend to know about the cost of living in Detriot, so I’ll use Richmond, VA numbers and compare them to my entry-level salary in the Henrico County school system.
Salary.com has the median entry level “Physicist I” earning about $48,000 per year. In Richmond, the median high school teacher salary is about $49,000. Now as Doink points out, that’s not entry level.
My very first contract with Henrico was for $38,500 per year. I had a Masters degree, so it was higher than average. But the average starting salary for a teacher is somewhere around $34,000 per year. Now off the bat you might think a $14,000 difference is pretty big. But what isn’t included in these salary reports is how much time during the year are you working.
The typical high-school teacher has a 9 month contract. The typical physicist has a 12 month contract. That means the starting physicist gets paid roughly $4,000 per month of work and the new teacher gets paid about $3,800 per month. If the teacher works during the summer then s/he’d make just about as much as the physicist!
It’s not the pay that’s the problem. It’s the hurdles teacher’s unions place in the way of math and science teachers. It’s an entire culture of education geared towards humanities. It’s the fact that education classes put scientifically minded people to sleep.
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