Wednesday, December 28, 2011

Followup on Chinese engineering problems

I'm a big fan of the book "To Engineer is Human", so I can't be too hard on the people involved in the investigation of a bullet train crash in China. (See my previous article and Carl's comment on it) The adults in the room took a serious look at the causes of the accident and they will clearly learn from it.

What I wonder is whether the fawning business media will also learn a lesson: It is one thing to say you have software engineers and quite another to have ones who eliminate dangerous flaws before the product goes into use in an environment where there is a major risk to innocent life. The fact that managers were also singled out for blame brings back memories of the Challenger explosion, where management ignored the pleas of engineers who knew better.

Here's to hoping the same people aren't working on their aircraft.

The article appears to blame the crash for reduced spending on their train system, but I suspect this is just cover for the severe budget problems China is facing. What has been bad for low-end retailers in the US has been really bad for China.

Read Entire Article......

Friday, August 12, 2011

A million actual engineers?

This article about the cause of the many deaths and much disruption caused by a high-speed rail crash in China contained the unsurprising conclusion that there was a design flaw in the system.

This is a reminder that it is one thing to produce a million engineers every year, as we are told they are doing in China and India, and quite another to produce highly competent licensed Professional Engineers with the guts to stand up to management. I wonder how many of those graduates in China are "engineers" in name only.

Of course, incidents like the Challenger explosion remind us that even our system can fail when the engineer can't stop management, particularly politically astute management, from doing something not based on sound science.

Read Entire Article......

Reflections on 30 years of the PC

Today is the 30th anniversary of the release announcement for the IBM PC. At the time, this was a key breakthrough in standardization of software for individuals and companies, as the platform allowed clones with the same Intel 8080 processor to have the same functionality at much lower cost.

Making the computer into a commodity changed the world, although it almost stifled innovation because money could be made on software without any vision at all. We are incredibly lucky that Apple survived the Lisa to produce the Mac with a mouse and a full GUI interface or we might still be waiting for devices like the iPad.

A long flashback digression. Although I had been programming and using computers for more than a decade at that time (my first access had been to a Honeywell system while in HS, where a teacher ran decks for us when it wasn't being used by the school system), they weren't suitable for writing. Good word processing systems that could handle special characters and equations were extremely expensive and limited to the business world. Our department got a home built using 8" floppy disks running the CP/M system with WordStar. WordStar could handle bold, italics, and greek letters along with superscripts and subscripts, which was like a dream come true when Word was still a dream and WordPerfect was not yet on the market. It still amazes me how many features of WordStar exist in HTML and the hot keys that somehow also appear in Word. (Learning basic HTML was trivial to someone who had used WordStar, since it was essentially a markup language for documents.) Later we bought a PC clone for home use, but the real revolution was when our department got a Mac and Adobe Illustrator as well as Photoshop. This was so far beyond the PC world as to boggle the mind. It is often forgotten how important the Apple consumer world was to the adoption of Adobe products like Pagemaker when PC users were still taping pictures into empty rectangles on a printout. Since our work machines ran one of the flavors of UNIX windows systems and I could use a Mac for fancier graphics, I was never as beholden to the M$ version as some. Now that I have an iPad it irritates me no end that I can't click on a link by touching the screen of a PC or laptop. For me, the iPad's only limitation is that I haven't adapted to either the glass keyboard or the nice portable keyboard for rapid touch typing. Hence the remark below. End of unnecessary digression.

As I commented over at Dean Dad's today, hand-held devices are changing the way we look at computers and what they do for us and how they hold us back.

IMHO, the most important choice today is your keyboard.

For example, M$ bloatware means even really fast hardware takes forever to boot compared to a MacBook, not to mention an iPad. This is a big deal in a classroom, where just booting up the computer can take a substantial part of the between-class time if you find it locked or off. [All of our classroom machines go into a single-user locked mode if left unattended, for security reasons. The only way out is a power-button reboot that takes several minutes.] It is truly remarkable how slow the Vista operating system is, almost as remarkable as how M$ has never admitted it was an utter failure. (I love that if you go to a Windows Vista page, it says you should buy Windows 7.)

A big change from the early days, mostly because of the internet and World Wide Web standardized interfaces, many computers are used only to "consume" information. Examples are the web sites Dean Dad was asking about, or e-mail, or various enterprise systems like our CMS, internal grading or advising systems, and college databases. Most of these involve minimal typing so they work great with a tablet like the iPad. I definitely see this as the future.

But sometimes you need a portable keyboard as nice as the one I am typing on now.

Read Entire Article......

Tuesday, August 9, 2011

CCPhysicist channels Dean Dad

I never post or comment over on College Misery, but it makes a fun read once in a while to see what a wide spectrum of faculty and adjuncts are thinking. Last week there was a real eye opener that reminded me of what a nightmare it must be to be Dean Dad or my Dean dealing with spineless snowflake faculty.

I'm talking about Candy from Casa Grande on Plagiarism. Sigh. Talk about a failure to think before you write.

When you've put your policy against plagiarism in your syllabus (namely, plagiarism = FAIL), ... (much snipped) ...
WHAT DO YOU DO...When a student STILL decides to plagiarize?
What is your process for dealing with plagiarism?

What do you do? You do what you said you were going to do!

The time to ask this question is before you put it in your syllabus. Did you seriously think that no one would ever cheat in your class? That you would never have to confront a student in something other than a passive-agressive way with just a warning about cheating?

Can you imagine that nightmare that is your Dean's life when students show up complaining that you didn't enforce your policy, or treated two students differently at different times, or violated college policy on plagiarism? Trust me, the cheaters know the rules. Many have been caught more than once and know the system inside and out. You should also.

I'm not really channeling Dean Dad. I'm channeling my own Dean. He always reminds the new adjuncts and the old faculty of the importance of having uniform grading policies in your syllabus that are uniformly enforced, ideally with a clear rubric that is built into how you grade but need not be in your syllabus in our science classes. What goes in your syllabus is what you are going to do.

If plagiarism is an important part of your grading system, you need to decide what you are going to do -- consistent with college policy -- and then put what you will do in your syllabus. Then just do it.

There was a lot of good advice and some bad advice (to me) in the comments. Some of the bad advice (to me) might simply reflect the different policies in place at a different college. For example, I don't think an F for the entire course would be enforceable at my college for plagiarizing an essay that makes up no more than 10% of the grade, but I'm not in that business so I don't pay attention to that detail. YMMV.

I rather like our system, where the first instance of cheating gets penalized however you think appropriate (pick up exam if they answer a cell phone, for example) and is final unless they appeal the penalty. In my experience, no one ever does. Second offense gets the full treatment, but my experience is that they can't pass any later test if you are standing next to them. But that is our college's system, not mine, so I won't offer it as advice.

Did I mention that you have the right to seat a student anywhere in the classroom when they are taking a test? One Silverback Snowflake at my college once complained that two cheaters sat in the back row and appeared to have swapped exams. On every test. Uh, try saving a seat for them in the front row on opposite sides of the room on the second test, if you can't catch them in the act the first time.

Oh, and before I close, don't ever hand back the actual assignment that they cheated on. Turn back a photocopy and keep the original in your records.

And if you don't know the trick of turning back a photocopy of their Scantron sheets and keeping the originals, you've never heard about one of the most common schemes for cheating. (Those who like paperwork turn back the originals and keep a copy, preferring to punish those who claim their exam was mis-graded by the machine.) I don't use those infernal things, but I still take precautions to catch anyone who changes or adds a free-response answer after the exam is returned. I can't claim to catch everything, but I think I catch most of them.

Read Entire Article......

Thursday, July 28, 2011

Vote of No Confidence

Or, should I say, No vote (on the debt ceiling) at all shows no confidence in House Speaker Boehner's leadership.

Decades after learning, theoretically, about how a vote of no confidence works to bring down the Prime Minister in a parliamentary system of government, I finally get it.

I guess it helps to have a front row seat, watching the process in slow motion, rather than just reading about it in a news story.

Of course, Boehner hasn't lost his position as Speaker, nor have fragments of his party joined with Democrats to elect a new Speaker, but his powerful voice seems muted this evening. He let an assistant announce, implicitly, that he can't get enough votes for his budget plan for him to dare bringing it to a vote.

This is a REAL mess now.

Read Entire Article......

Thursday, July 21, 2011

Special financial aid to start at a CC

Dean Dad wrote an interesting column today about a new program in Illinois that rewards a select group of students who choose to attend a community college by allowing them to carry forward the financial aid savings for use in their third and fourth years of college.

The program is described in detail here. It has a number of interesting features, one of which has the potential to be extremely effective. That feature is the tight linkage between groups of CCs and a specific university. [Note: Some CCs are linked to more than one university, but the one I looked at -- Shawnee CC -- is only linked to SIU-Carbondale.] This, along with the presence of an SIU academic advisor at Shawnee CC (as reported by the Chronicle in an illustration above the paywall) should help with one of the biggest obstacles to effective transfer.

Even at a CC where only a tiny fraction are in AS programs and where most students transfer to one of two universities that have a very strong and clear articulation agreement with us, advising is an ongoing challenge. Program requirements change, and those changes sometimes include courses that don't exist at our college. We are always the last to know, and proper articulation seems like it is usually a semester or two late. (I even know of one case where one course remains a mystery after decades. We have an articulated course, but they seem to want an additional one that is only taught at the junior level. Very annoying.) In principle, we should have two years notice because changes are supposed to affect only students who are freshmen when the change in a course catalog takes effect, but it also affects new (transfer) students immediately. In practice, the university knows about curricular changes when they are proposed, but the CC doesn't find out about them until after they go into effect.

In addition, articulation agreements don't spell out course sequencing, and what might be obvious to an historian might not be obvious to a chemist, and vice versa.

Both of these problems should be reduced by having an employee of the university assigned to the CC. There is nothing like having an expert insider nearby. I know, because I maintain irregular contact with former students who are now in engineering school -- and sometimes their faculty as well -- and this gives me insights that I would never get from the paper record.

Interesting pluses and minuses

The program in Illinois is quite limited. A student has to be admitted to a 4-year university and then choose to attend a (specific, linked) CC to be eligible. You don't qualify if you have to start at the CC for academic reasons, or if your home-town CC is not linked to the out-of-town university you want to attend.

If you have to go to an out-of-town CC, the economics shown in their example are not quite as favorable. Your tuition as an out-of-district student is higher, and the allowance for room and board might not be adequate. However, you will still do better in the long run, just not as well as that example shows.

One might be tempted to assume that students who were admitted to a university will be guaranteed to succeed at a CC, but I would warn against that assumption. The risks of partying or Facebooking your way to an F are still there. They might be higher if the student thinks they are stepping down to a glorified high school. Orientation becomes even more important, as are professors and fellow students who notice who is in class each day. Professors might find new problems to deal with. I know that I have had to make adjustments to deal with kids who come in thinking that an AP class was taught at a college level and pace.

IMHO, setting a professional tone on the first day of class is always important in helping students transition from being childish learners to adult learners.

Cost to the CC?

Dean Dad argues that a program that gives needy (Pell-Grant) students almost a full ride [*] at the CC will "squeeze quality" because it directs the money to "students instead of institutions". The problem, he says, results because "community colleges charge students far less than what it costs to educate them". I couldn't disagree more, and I base this on experience at my CC as well as the even more favorable situation at Shawnee CC in Illinois.

I already made some terse comments about this on his blog, so I will give the promised details here.

First, my experience is that a policy that slightly increases some state scholarships if they are used at a CC (where they go much further) has made us much more attractive to students at the margin -- ones who could get into nearby Wannabe Flagship (or a similarly ranked university in the state) but would be in the bottom half of the incoming class. They follow the money, but find the small classes to be an unexpected bonus and that word seems to slowly leak back into the high schools. (Many don't appreciate what they had until after they transfer. Advertising sometimes has to help make that point.) Similarly, the faculty find that having a broader mix of students, in terms of entering SAT scores, helps everyone in the class. There aren't enough great students to improve success rates all by themselves, but the pool of student tutors gets deeper when you have sophomores who have finished calc 3, and those students learn and help others learn at the same time.

Second, our economics are similar to those in Illinois even if our pay rates for adjuncts and faculty are somewhat higher. Adding students is a net plus at the margin. Shawnee tuition is $92 per credit hour (apparently with no additional fees). Note that there is an extra fee for "out of district" students because local property taxes help support the college.

The state of Illinois maintains a central portal where you can find the FY10 salary report (pdf) for all of the state's community colleges. Detailed tables toward the end show that adjuncts earn $450 per credit hour and regular faculty on overload earn $600 per credit hour (Table 5) for individual classes at Shawnee CC. Those define part of the marginal cost of adding a class, with the rest coming from incremental printing costs (exams and quizzes). You might double the salary cost to get a conservative estimate of the total, based on the rough fraction of our total budget that goes to faculty salaries. However, some major budgeted costs are fixed (we heat and cool classrooms whether they are in use or not) and we have to grow a lot before we need to hire more permanent office staff.

On this basis, a 25 or 30 student class staffed by an adjunct or as a faculty overload will turn a "profit" of well over $1000. More if they use an adjunct. Even more if the students are "out of district", which I consider to be more likely under this financial aid scenario.

Long term is a different issue, because it depends on whether the larger student population is going to stay that way. What if Shawnee has to add another full time professor? Table 2 suggests their starting salary is around $42,000 (lowest) to $47,000 (25th percentile) for the regular 2-semester year that teaches 15 credit hours per semester. According to Table 20, their fringe benefits were under $6,000 (compared to a state average of $11,600 in Table 18). CHEAP! So the regular load of a new full-time professor works out to be about (45k + 6k)/30 = $1700 per credit hour. With only $2300 to $2760 coming in from a class of 25 to 30 students, this does not break even when other staffing costs are included ... but you might be able to cut it close for five lean years.

However, once you are talking about long-term budgets, other intangibles come into play. For example, our state funding formula takes enrollment into account. If we grow relative to other CCs, our base budget will grow. Or, I should say, it will grow if the depression ends.

Other costs:

Dean Dad also referred to this article on financial aid regulations as an example of unfunded mandates. However, as I read the Illinois description, it looks like the state system will keep track of what is owed to the student. I think the new GI Bill and other things are a bigger deal for our college than the basic tracking of student credit hours for a state scholarship, and eligibility is determined by a state office, not us.

Side remark

I've always, both as a HS student and a professor, been around a CC where most students are interested in transfer rather than career programs. I gather from DD's comments that this is rare in the community college world. Perhaps the anomaly is because both places have (or had) a significant vocational program run within the public school system, although there are some other similarities that play a role. Nonetheless, my views here about transfer reflect a situation where the vast majority of our graduates get an AA degree and transfer to a university.

[*] Full ride comment

The example student appears to be one whose FAFSA form leads to a particular maximum state grant along with a Pell Grant. Under the assumption that the student is living at home when at a community college (often a poor assumption), the room and board number is realistic and the remaining $600 can be earned doing work study or with limited work hours that will allow plenty of time for studying. Not quite a full ride scholarship, but close.

Read Entire Article......

Tuesday, May 17, 2011

Mom scientists in the news

Although the story itself (concerning possible carcinogens in unnamed baby products) is interesting -- albeit the usual promotion of a university of its status as a major research center -- what suddenly caught my eye was what was in the the background as the director of the National Institute of Environmental Health Sciences was interviewed about the results of this study.

Photos of her children (and a grandchild?) next to her two computer screens. [Guess confirmed via a bio turned up by Google.]

I thought "that was a hidden positive part of the story".

Then came the punch line, as we saw a second interview with the lead researcher. At home -- rather than in the classic p.r. laboratory shot used to lead the story -- with her new baby as she explained how she had made the decision to remove foam pads that she no longer trusted from her kid's room. Best of all, she discussed the trade off between fire safety and the risk of known carcinogens (in California, at least), suspected carcinogens, and other chemicals whose risk might not have been assessed because you don't have to prove something is safe vis-a-vis asthma or autism before using it in a product.

The sub text, successful women scientists with families, was there for some to see on the CBS Evening News. You can see the video here for yourself.

The safety issue remains an open one, as this was one of those classic preliminary studies. However, my comment would be that flame retardants are of greatest value if you have lit cigarettes, candles, or an open flame from a gas burner or fireplace near the child's bedding or car carrier. What are the odds of a fire starting in a crib if the parents and the baby don't smoke?

Read Entire Article......

Saturday, March 26, 2011

Don't believe what the press is telling you!

Consider this news story (and accompanying video) from the BBC about radioactivity in the sea within 300 m of the Fukushima nuclear plant:

Levels of radioactive iodine in the sea near the tsunami-stricken Fukushima nuclear plant are 1,250 times higher than the safety limit, officials say.

The readings were taken about 300m (984ft) offshore. It is feared the radiation could be seeping into groundwater from one of the reactors.

But the radiation will no longer be a risk after eight days, officials say. [Emphasis added]

There is no explicit by-line on this article, but the video contains an interview with BBC reporter Chris Hogg in Tokyo that repeats that a half life of 8 days means "that after 8 days the risk will have dissipated".

The reporter is WRONG. Twice, because that is also not what the officials said. His ignorance of basic physics, in this case a topic I always teach in a college general education class, led him to misinterpret what was actually said by a government spokesman and hence mislead the public.

The risk will not dissipate after 8 days.

First, what did the official say? The article reports that
"Generally speaking," spokesman Hidehiko Nishiyama told a news conference, "radioactive material released into the sea will spread due to tides, so you need much more for seaweed and sea life to absorb it." He continued: "And, since [the iodine] has a half-life of eight days, by the time people eat the sea products its amount is likely to have diminished significantly."

This (emphasis added) is correct.

The most significant effect is dilution. Levels will be very high near the source, but get reduced significantly as the source gets mixed into a larger volume of water. (Like smoke when you are a long way from a fire.) It also matters what the ratio is of radioactive iodine to the iodine that is naturally in the water, since the seaweed can't tell the difference.

It is also correct because in 8 days the radiation level in the seawater will be half what it is today. Half. Not "dissipated", half. The radiation level of the iodine in that bay will only fall to 625 times the safe level, not zero, in those 8 days. The risk is reduced, but not gone.

But there are other factors. For example, I have no idea how long it takes from the time seaweed is harvested and when it shows up on shelves all nicely dried and packaged, but it is unlikely to be a few days. Only fresh items like milk and vegetables appear "just in time" in supermarkets. Radiation drops every day it sits in a warehouse. It falls to half after 8 days, one quarter after 16 days, one eighth after 24 days, and one sixteenth after about a month.

The obvious fact (pull out your calculator) is that what remains after a month is still 1250/16 = 78 times the safety limit if all of the iodine stayed in the ocean near the plant. This shows why dilution is so important.

Side comment 1:

The other contaminant in seafood, mercury, does not go away with time and is not as easy to detect and monitor as radiation from I-131. I-131 emits a gamma ray which can be detected through the usual plastic packaging used for seaweed, right on the shelf. Mercury requires a careful (and destructive) chemical test.

Side comment 2:

The reporter quite correctly puts attention on cesium, which has a 30 year half life. Isotopes with very short half lives are "hotter" but go away quickly, so you just have to keep your distance for a month or two. Gram for gram, cesium isn't as hot but you have to avoid it for a longer time. That can be hard to do.

However, this ignores the other significant factor, which is biological activity. Our body needs a regular supply of iodine, so it will go looking for it in anything you eat. (Naturally iodine deficient diets in the Ukraine contributed to the uptake of I-131 after Chernobyl.) Further, it gets concentrated in one place, the thyroid.

Cesium (Cs) is in the same chemical family as sodium (Na), in table salt, and potassium (K), in sports drinks and bananas, which are both essential to the operation of our body. However, since it is much heavier, I doubt if it can substitute for the many ionic processes the body uses Na and K for. Any biologist or chemist know if Cs is concentrated by the body?

By the way, one reason I knew this was a major incident was that Cs-137 could be detected above background in California. You see, it takes a significant release to see it above the Cs-137 that still remains from atmospheric nuclear testing. As big as Chernobyl was, its Cs-137 was barely detectable over the stuff left from weapons tests done decades earlier once it got diluted by one trip around the globe.

Side comment 3:

There has been no new I-131 made since fission was stopped on March 11, fifteen days ago. That means only one quarter of the original I-131 remains in the fuel rods inside the three reactors that had been operating at the time of the quake.

The most important thing in this article might be that the levels in sea water had increased by a factor of 8 in the past week. That means I-131 from inside fuel rods inside the reactor vessel is not only finding its way into the water, but a larger fraction of it has been released from the fuel rods. (There is less I-131 available to leak out, but more of what remains is getting out. Did I say that clearly enough?) This is further indication that the fuel rods have been damaged significantly, which we already knew, but might just result from the iodine -- already vented from the reactor vessel -- being washed out of the containment building as they can now pour more water onto and into the containment building.

Side comment 4:

That observation in the quotation at the top of this article, that radiation "might" be seeping into ground water, struck me as strange. There is I-131 in Tokyo drinking water. This is because Tokyo's water supply comes from surface water (mostly behind dams based on a city water department document I found), which will be contaminated by radioactive rain carrying I-131. But everyone should know that rain also soaks into the ground. Apart from geochemical processes that would capture iodine, it will go into the ground water.

Read Entire Article......

Wednesday, March 16, 2011

Measuring "pi"

Rhett Allain had an interesting post for "Pi Day" concerning the use of a simple harmonic oscillator consisting of a mass on a spring to measure pi. Clever!

However, he neglected the effect of the spring mass. The correct formula for this problem requires the addition of 1/3 of the mass of the spring to the mass hanging on the spring, which appears inside the square root used to calculate the value that goes on the x axis of his fit. Although it is really hard to tell what his fit looked like or what the mass of the spring might be, including this necessary effect should increase the slope and make his result worse.

Nice idea, however. I'll have to give this a try when we have the lab setup.

That said, I have special praise for his OUTSTANDING blog about how to build you own energy balance thing. I did the human demo in one class before spring break, and might have saved some students some money if the showmen are out on the beaches this week. The plastic version looks like it might make a good demo all on its own ... even without the cute crown with its cell phone re-receiver energy recycling thingy.

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Tuesday, March 15, 2011

From ridiculous to sublime

Time to weigh in, quickly, on the nuclear crisis in Japan.

As I commented on a link dump at Uncertain Principles that points to a half decent article that has since been moved and corrected to some degree, the news reporting about the reactor problems was truly awful for the first day or two. What an abomination.

It has, however, improved a LOT. Tonight I was stunned at how well MSNBC covered the subject. And not just with the experts, who no longer need scare quotes around their titles, but also in a lengthy intro by Rachel Maddow on her show. Yeah, she was still a bit confused by the fact that rust is oxidation (of iron) but the oxidation of zircalloy is not rust, but the presentation was not wrong and well pitched to a (scientifically illiterate) audience.

It is worth watching on Hulu or wherever they archive it.

The real key, however, is that they have real experts. I missed the name of the guy from Sandia who was on an earlier show, but they had Frank von Hippel from Princeton on the Maddow show along with some others of similar quality but whose work is not personally known to me. Clearly a whole bunch of people were as horrified as I was by the junk that was being broadcast and had the pull to get the attention of the networks and change what is out there. It probably also helped the DOE Sec Chu can teach as well as do physics, and did a good teaching job in front of Congress.

The changes are dramatic.

The comparisons to Chernobyl are now rational, rather than nonsensical.

No idiot is out there saying that a scrammed boiling water reactor will go prompt critical if it melts down. The "expert" that didn't seem to know that the heat in the shut down plant comes from internal radioactive decay of fission products is long gone, replaced by one that knows spent fuel rods are also hot -- and "hot" with radioactive elements that live just long enough to be very dangerous if they were to be released.

OK, one Congressman (who as a physicist should know better) was out confusing a civilian nuclear power program that only uses fuel under IAEA supervision with a rogue state operating a clandestine enrichment program probably designed with help from North Korea and Pakistan, but let's ignore that one.

Actual facts, like the location of the spent fuel storage pools 40 feet in the air !! ????? !! above the containment structure in an earthquake zone, are now clearly featured in the stories. Ditto for giving radiation levels in Sv rather than in "chest x-rays" (which deliver much less radiation than they used to). Even Livermore managed to get out the fact that they have a nuclear weather forecasting program for this, and other purposes.

And I am particularly impressed that we are sending some of our specialized monitoring equipment (I'd guess it is the stuff developed to look for weapons or the result of a "dirty bomb" or an event just like this one) to Japan. I hope it works as well as advertised.

That is about all that I have time for tonight, but I will try to blog about some specific details when I get a chance.

I'll close with the most important point that hasn't been emphasized in the reporting so far, and might have confused people about the extent of the radioactive plume. Radiation detection is EXTREMELY sensitive. I heard of a case where the detectors outside of a nuclear plant were set off by the alpha radiation from the Thorium and Uranium in the smoke from a coal plant that had been pushed down to the ground by an inversion layer. A nuclear carrier would have similarly sensitive monitors on the ship, so we would need to be told the level that was detected -- not just the fact that radiation was detected -- to get a sense of what our carrier picked up off the coast of Japan. Further, it can be far more discriminating that a simple Geiger counter. You can tell what radioactive isotope is out there as well as how much, and the specific isotopes tell you where they came from. That is how people know fuel elements have been damaged without being able to see inside the plant.

Read Entire Article......

Beware the Ides of March!

A belated "Happy Pi Day" and "Happy Einstein's birthday" ...

... as well as my fourth blogiversary (the day before).

Read Entire Article......

Tuesday, February 15, 2011

Reaction Time

"Watson" didn't have to push a button, a huge advantage when everyone knows the answer well before the question ends on "Jeopardy".

You could see it in real time, but I'd like to see data equivalent to what was used to determine the lock-out time for a false start in track when they shifted to electronic timing. I'd guess that "Watson" rung in at the same instant every time as it didn't have to worry about moving a finger or the delay as flesh meets button. After all, it could devote a processor to that task without any distractions from the main task at hand.

Indeed, this raises two questions about how "Jeopardy" determines when the board is open to ring in with an answer.

1) Does a human press a button, or is the end determined by an electronic sensor listening to the host's microphone? If the latter, a machine with a non-mechanical reaction time can learn to anticipate when the lights will come on.

2) Does the system lock out for a reasonable reaction time after the lights come on, the way they do for false starts in track? In track, extensive tests with world class sprinters showed that none had a reaction time less than 0.1 s, with the best around 0.12 s. Since visual responses are, reportedly, slower, does Jeopardy have a 0.2 s lockout for a valid response?

If it doesn't, "Watson" had a huge advantage.

Read Entire Article......

Saturday, February 5, 2011

Unacceptable humor?

Comments complaining about Rudbeckia Hirta's snark about psychology and biology at her university sound like they also don't appreciate where she is on the "Purity" continuum! (And it appears that Psychology and Sociology are reversed at her university.)

They also reminded me of the kerfuffle created by the Top Gear guys being their usual selves. Complaints that their remarks were "offensive, xenophobic and humiliating" led me to say "and this is news?". Ever notice what they think of the US, particularly the southern parts of the US, and our giant cars designed to hold our giant bellies? Or what they think of France?

But back to the academic question of easy majors that drew the ire of RH's commentariot: You don't have to do much advising at my CC before you encounter students who wish there was a tool to help them select a major at Wannabe Flagship based entirely on a list of classes they don't want to take. Each time you click on the radio button next to a class, the possible majors would change. The opposite of the way we usually do advising, which is to pull up the major and tell them what they need to take next.

Their exclusion list usually starts with any math above about what I characterize as the 9th grade level (basic algebra with some inequalities, the occasional exponent but no exponential or trig functions,a few fractions, and the rules of probability), but can also include "too much reading" or "science".

The people who teach the HS-level science classes perceived as the easier choices among those that meet our liberal arts requirement have my greatest sympathy. Imagine students complaining about exponents being used to give the size or age of the universe, because there isn't supposed to be any math in the class, and you get the general idea.

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Saturday, January 22, 2011

Forcing the horse to drink

You can lead a horse to water ... but you can't make hir drink.

Did you know I was talking about "Academically Adrift"? (IHE articles here and here point to the main story lines.) That's right, I'm talking about the folks who don't realize that you can send a kid to school ... but you can't make hir learn.

I've commented about this book twice, and was ready to comment again when I decided it was time to put those comments here in my blog.

Just for background, it first came to my attention in a January 18 comment on Dean Dad's blog that pointed to a column by someone from “The Hechinger Report” in the Sacramento Bee. That led to the following observation:

That article about Critical Thinking was interesting until we got to the inevitable “decline of civilization” comments from various experts. How can you compare the results of an Unprecedented One-of-the-First Study with guesses about college life 30 or 50 years ago? You can’t. I’m pretty sure we spent 50% of our time socializing in the dorms back in the good old days.

I’m impressed that almost two thirds !! of the study group made significant gains in critical thinking, even if the journalist chose to emphasize the negative side of the same results.

And I was stunned to learn that students in “business, education, social work and communications” showed the least gains, not to mention that “students learned more when asked to do more”. Who would ever have imagined such a result.

When Sherman Dorn questioned the reliability of the assessment tool used to generate data for the book (and later decried the over generalized conclusions drawn from it, I ventured the opinion (on the former article, slightly rewritten here) that:

Commentary based on perceiving a single data point as if it were a century long time series does not show any critical thinking on the part of the commentator.

I would also add that I think I would not have shown any significant improvement in my critical thinking skills after 4 years of college because I entered college with spectacularly good ones due to my high school experiences. I’m sure I improved, but not within the uncertainties of an instrument like they used.

The best article, however, is the one Chad wrote in Friday's Uncertain Principles. What makes it the best is, of course, is that he agrees with me that it is no surprise that 1/3 of all students in college are coasting. Well, that and he links to reports on the actual study the book is based on.

I'll add to his comments that the headline findings are based on an evaluation instrument that Sherman Dorn, a professor of the history of education and an expert on assessment in K-12, thinks is not suitable as an accountability measure.

Further, I'd guess that his students at Union and his fellow students at Williams are and were, like me, likely to have scored pretty high on the "critical thinking" essay they were given and thus less likely to improve. You have to push such students REALLY hard if you want them to improve their already high-level skills.

And I'll also add that I use a very good textbook (Wolfson's "Essentials" for calc-based physics) that runs about 22 pages of reading per week for the first semester (Mechanics and Thermodynamics) and 18 pages for the second semester (Electricity and Magnetism and Optics) -- a total that includes the textbook problems. Yet few students in any random sample at any university would trade that (not to mention homework assignments that are thick with critical thinking challenges) for 40 pages of a history book.

The worst article, however, is the NYTimes interview with one of the authors. There we discover that he actually thinks surveys and a single essay test -- likely taken without any academic (grade) or monetary (continued employment) motivation -- actually measures learning, for example, marketable engineering skills. What a load of narrow minded crap. As if the only job in the world is writing a sociology book.

And I take any claim that grades have been inflated to a Gentleman's B in my classes as a personal insult. My students know better.

But I will agree with the conclusion that challenging students makes them better. What bothers me is that someone who is a professor Emeritus at NYU thinks this is news. This has been known for centuries and obvious to me since elementary school.

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Saturday, January 15, 2011

Teaching Majors

Dr. Crazy is back from sabbatical with shorter hair and fully energized to teach the class that introduces students to the real subject matter of the discipline they are going to major in. Now English is not exactly Physics or Engineering, but I've found plenty of common ground with her in the past and this topic is no exception.

I'll start with the comment I posted on her blog:

I never really thought of my Physics for Engineers class as an intro to the major until reading how you described your course, but maybe I should. It has many of the characteristics of yours (mini-PhD curriculum, viewed as a service course, foundation for everything that follows).

Technically, there is another course that physics majors take that is actually the start of the major program, but students won't take it if they don't like the view of physics they get in the class I teach! Once physics departments figured out that they were losing future majors to engineering (where you can also make a living), they put more emphasis on having their best teachers in the intro class and trying to make it more engaging and hands-on ... within the limits of a 200 student lecture hall.

Continuing here, so as to avoid thread hogging "man splaining" behavior ...

And within the limits that the room is not big because there are 200 physics majors in the university. No, most of those students are wannabe engineers and that fact is why calc-based physics devolved into a service course that often discouraged potential physics majors along with potential engineering majors.

Now my classes are not that big. Not even close. Furthermore, I rarely saw a self-identified physics major until recently so I view most of my students as engineering majors and teach the class with that in mind. The result is that I might actually be teaching an into to engineering course! I need to think about that this weekend to get ready for next week.

[Side remark: Some, but not all, engineering majors at nearby Wannabe Flagship have an actual "intro to the major" course with that name, but many have a course that inculcates a particular way of doing things into their majors and require that they take it during their first semester by making it a pre-req for just about everything else. Others appear to trust that someone will teach that new way of looking at the world in a core course for the major.]

And maybe that is why my better students often turn into stars after transfer. Even people who get the concept of prerequisites don't always pick up key basic skills the first time. Learning is hard. But if you fight the battle in my class at least once, your chances of picking it up for good in the actual "Intro to Whatever" class probably gets close enough to 100% to make me happy. Or at least Not Unhappy.

So what do I do? In addition to using the "This week in lab" method of making connections between lecture and lab, I use the "Next year in ..." method of making connections to the next level of application of skills that might blend both physics and, say, third semester (vector) calculus. I use the latter to put an explicit emphasis on skills I know their profs will want them to employ in their major, whether it is physics or engineering. (The computer science majors get hung out to dry here, although the term "algorithm" has been known to cross my lips.) Dare I say the "O" word - Outcomes - in this context?

I shall. (I'll worry about the "A" word - Assessment - to a lesser extent for the time being.) For a course like this it is really all about aligning Outcomes with the most basic needs of the classes that will come along later. And that isn't easy.

So that is my advice to Dr. Crazy. It is GREAT that her department has settled on a common book for the course while developing it collaboratively. As a result, it will be more likely that students will come out with the experiences they expect. Along the way, keep talking about what those expectations actually are.

I've changed my physics class a lot after discovering what engineering faculty were expecting based on their vague recollection of when they first picked up a certain basic skill. We "covered" it, but only in a way that a future PhD in Engineering would be likely to pick it up right away. The Engineering Way is to expose, as much as possible, the inner workings of your analysis of a problem by making certain procedures mandatory. Physicists tend to not do that, using those processes on an as-needed basis, so I have to be even more conscious of each problem solving step when we do problems in class. However, that way and The Physics Way share an emphasis on analysis. Is there also an English Way? Probably, although I'd guess it is more like the let-a-thousand-flowers-bloom physics approach given my past experiences.

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