Sunday, May 31, 2009

Cloud Forms Around as F-18 Approaches the Speed of Sound

I think this is a remarkable photo. 

This Navy F-18 Super Hornet forms a water vapor cone as air cools due to the pressure drop around the jet. Air cools when it expands into the lower pressure region, and that forms a cloud.  When the jet passes the speed of sound, the air flow is more turbulent and the cone is less apparent. This cone only occurs when the relative humidity is right, and at a narrow range in speed.

 The cone is also called a " shock collar" -- obviously a different kind than the "shock collar" a dog wears.

Greg is So Happy with his MacBook Memory Upgrade

I am happy with my computer memory upgrade. 

I have a 1.83 GHz Mac Book Core Duo. It is the one in the white polycarbonate case, not the cool aluminum one. It is serving me well, as it enters its third year. 

I upgraded the memory to 2GB which is the maximum for this configuration. I got the chips (two 1GB, 200-pin SODIMM) at Crucial Memory

Memory installation is easy, as you can access it by removing three screws inside the battery compartment. This youtube video makes it easy. I felt a little bit bad about buying memory at Crucial, but using the great user instructions from, but I could not figure out how to buy what I wanted at 4allmemory's site. 

Bottom line is the the computer is noticeably faster. I generally have too many applications open, and switching between them lags.  Now even Safari is opening new tabs faster. 

I had been culled into laxatude by the how the OSX Activity Monitor said that there was always free memory with my old 1 GB configuration. Now Activity Monitor has an entire 1GB in active memory, and the rest in other categories of memory. (What does "Wired" memory mean?)

Saturday, May 30, 2009

Nothing is Permanent: GM Passes Away.

"What is good for General Motors is good for America - Chairman and CEO, Charlie Wilson, 1955.

GM was an engine of industrial and financial growth, and now it is come to nought -- literally nought - financially speaking. Wilson's quote, which was outrageous in its day, was made in earnest and it reflected the importance of the auto industry and most especially General Motors to the economy and to America.  

This reminds me of how the Soviet Union was so powerful when I was little, and how it oppressed so many people, and then it was gone.  Nazi Germany and Imperial Rome are the same. So is the Republican majority in congress. 

"Creative Destruction" is an optimistic phrase used by economists to describe the failure/rebirth cycle. This is all believable.  I know that dislocation and unemployment are the best way to a more productive economy, and I accept that even I need to re-educate and move around the country to keep up. 

My mourning probably has its root in the problem of change. The earliest Greek philosophers argued that change did not happen, or if it did happen on earth, then it did not happen in Heaven. In heaven where everything is perfect -- it must also be permanent. (This was a serious argument against the Big Bang theory just 25 years ago. )

In this case however, our government will spend $40 billion to provide stability, and relaunch GM 2.0. It is possible this will be a great company that will take over the world. That probably depends on global macro economics more than auto design.

I love the above photo of the GM plant in Janesville, Wisconsin -- now slated for closing. (Photo credit to Scott Olsen.)

I don't subscribe to the silly notion of "Future Shock," where people are disoriented by all the technological change. I am know people can absorb a lot -- like refugees, disaster victims or even new Moms.

It is normal to feel wistful when something big passes away. Like someone should notice, but lots of times no one does.  Should we put up a monument or a gravestone?

Sunday, May 24, 2009

The Detroit News Electronic Edition and the Electronic Newspaper

I was unsure about the value of a digital newspaper as voiced on my previous post, however, I have come to like the electronic newspaper.

Mainly, it is a more useful, more convenient place to read the news than a source like the NY Times free site, or the USA Today free site. Secondly, it is a better place to get the local news than a TV station site like

Even though this costs some money, I think it is worth it. 

It sounds petty, but I am happy I don't need to go get the paper in the driveway every morning, nor deal with piles of old newspaper. Truthfully, I was looking for something to cover the carpet when I was painting yesterday -- so that is problem -- guess I'll need to buy a drop cloth. 

My complaint is that this version of the Detroit News is not as good as the old one was, because it is shorter. 

I would be happier if my Detroit News subscription got me viewing rights at some other regional papers. I think that would be a clever extension that would not cost anyone too much.

Saturday, May 23, 2009

Jim Cramer's conversion to Marxism fails to attract notice

CNBC's noisy, opinionated investment advisor Jim Cramer made an outrageous statement about Karl Marx, saying the following in Time.

Do you believe we will look back on the financial innovations of the last several decades with regret?

"They almost brought our country down. The only guy who really called this right was Karl Marx. Marx understood what would happen if you let the market run amok. Of course, it was done by right-wing Republicans. They brought our nation to its knees, and we're not going to end up being a great power because of what happened."

It is outrageous in that a former Wall Streeter and popular TV guy on an investment channel is talking up the insight of Karl Marx. Second, he pivoted around and dumped on the Republicans. Wow, that seems overtly political for a journalist -- even a journalist-entertainer. I would have expected calls for his head.

This lead me to consider if Karl Marx really did call this recession. Karl wrote a lot of thoughtful pieces, and most of communism was really thought up by Lenin including the anti-democratic aspects.

It seems this false quote has been posted around the internet: 

"Owners of capital will stimulate the working class to buy more and more of expensive goods, houses and technology, pushing them to take more and more expensive credits, until their debt becomes unbearable. 

The unpaid debt will lead to bankruptcy of banks, which will have to be nationalised, and the State will have to take the road which will eventually lead to communism."  (Falsely attributed to Marx)

First Cramer probably believed the false Marx quote and was reacting to that. Second, it does not sound like something written in the 19th Century. On the other hand, it does sound like some modern anti-globalization leftists.  

It seems there are real Marx quotes about a credit crisis: "In a system of production, where the entire continuity of the reproduction process rests upon credit, a crisis must obviously occur — a tremendous rush for means of payment — when credit suddenly ceases and only cash payments have validity. At first glance, therefore, the whole crisis seems to be merely a credit and money crisis. And in fact it is only a question of the convertibility of bills of exchange into money."

I was thinking of wading into this, but Marx was very wordy. There is more stuff on

Friday, May 22, 2009

Are Potato peels nutritious?

There is an urban myth or perhaps wives tale that potato peels or "skins" are the most nutritious part of the potato. I decided to look into this a bit.

First of all, the starchy center of potato is not very nutritious from a vitamin and mineral point of view -- although it has good energy value -- but most people don't see that as advantage. The peel and the cell layer just under the peel are more differentiated, and has a wider variety of compounds. Some healthy and some less healthy.

The main effect of cooking a potato in the skin is that it prevents vitamins and minerals from being leaching out. 22% of vitamin C is leached away when boiled in the skin as compared to 42% loss when boiled without the skin. One can always not eat the skin when it gets to your plate, to avoid the less healthy compounds, and the starchy flesh is more nutritious.

The skin contains some minerals like potassium and calcium at higher levels than the flesh, but it has anti-nutritional ingredients like phenolics, glycoalkaloids, and nitrosamines. By anti-nutritional I mean chemicals that can have upsetting or even toxic effects.

The greenish skin of potatoes is unhealthy, and many recommend it be cut away and discarded. It contains solanine, which is a toxic glycoalkaloid. The structure is at right. You can see like the name says, sugar residues and a big alkaloid. Typically a potato has 100 mg/kg of solanine, but green potatoes have 1000 mg/kg, and the potato peel itself is 100 times more concentrated than the potato/peel mixture.

On the other hand solanine is not the worst toxin. It causes diarrhea, fever, and cramps, but can cause coma too. It affects calcium and potassium transport in cell membranes. One population study showed a correlation with the birth defect spina bifida, but this has not been confirmed. Green tomatoes are a much more serious source, and green tomatoes should never be eaten raw. Solanine has a bad flavor, and people avoid foods high in solanine based on taste alone, unless they are starving.

A 25 mg dose has been taken as a practical threshold for nausea. This would be about 25 g, or perhaps a large tablespoon of green potato. Strangely this is only 250 g of standard potato, so this must happen fairly routinely, and or the 25 mg dose number is not that meaningful or valid.

The potato peel does not take up much of the mass of the potato, so its nutritional value is almost undetectable. This is from a New Zealand potato board study. Based on this, there is little difference if the potato is peeled or not. For example there is a two calorie difference -- more for the unpeeled.

In conclusion, people should not eat the skin. Very little advantage and why eat these potentially harmful substances?

Monday, May 18, 2009

Average Home Price in Detroit Falls to $11,533; Monthly House Payment Would Be Less Than $50

Here is a posting from Mark Perry of Detroit board of Realtor's data on Detroit housing prices. This is down about $1300 less than last month.

Now I live in Wayne County which is the same county as Detroit. I really don't like thinking about this statistic. I knew that I should have rented when I moved here. 

Perry points out that a monthly mortgage payment could be as little as $50/month.

CARPE DIEM: Average Home Price in Detroit Falls to $11,533; Monthly House Payment Would Be Less Than $50

Saturday, May 16, 2009


Wolfram|Alpha is a new search engine from the people at Mathmatica - actually called Wolfram Research. Steven Wolfram is the writer of Mathmatica, and the visionary who thinks that the computationally centered Alpha search engine will do things people don't know that they need done. 

It does things that Google does not do well. I know that Google does calculations, but put in 100 Pascal-seconds into Wolfram|Alpha and it converts it into all the different units one would want. I can never remember the Google syntax for that. 

If you put chemical names into it, then it gives the structure, the toxicity properties, the physical characticistics, even the NFPA diamond. 

This is a pretty good search engine, and I can't wait to tell people about it.   

More on DNA Origami

The previous post on the new DNA box induced me to dig further into the DNA scaffolding and folding called DNA Origami. 

In the technique, developed by young CalTech bioengineer and computer scientist Paul Rothemund,
pieces of  single stranded DNA are folded to make shapes of interest. 

This is done with single-stranded DNA "staples" that uniquely identify a piece of viral DNA and the binds to an adjoining piece with equal specificity. With detailed knowledge of the original DNA sequence and access to a machine that makes short DNA strands to your specification, one can make DNA sheets like making macramé from yarn.  DNA origami uses more fundamental DNA folding motifs developed by Ned Seeman of NYU.

This is a clever nanoengineering technique made possible by the unique specificity of the Watson-Crick base-pair bonding of DNA.

While pharmacologists are interested in studying native DNA or using it to influence biological processes, computer scientists are interested in using it as a substrate for novel information storage and computing systems. Rothemund was more interested in using DNA to make tiny maps and letters than in making structures. Obviously no one will ever read letters that are 2% the wavelength of light, at least not using their eyes. 

DNA Boxes

Jorgen Kjems and Ebbe Andersen with 12 other researchers in Denmark and Germany have made a box out of DNA as a structural material -- so-called DNA origami. 

 This is a box that is 30-40 nanometers on a side!

Plus it has a lid that opens!

This may not be worth a Nobel prize but it is a fascinating achievement. The fact that it has a latch and someone can put something inside seems secondary.

This shows how the DNA was folded. The structure self-assembles.

The DNA was from an M13MP18 bacteriophage that was folded into sheets.  The sheets were held together with "staple" strands into a cuboid shape. This is described in Paul Ruthermund's Nature paper. Then it was heat annealed to keep it from coming apart.  See my next post for more on DNA origami.

Friday, May 8, 2009

Stock Market Indexes are Highly Correlated

I have graphed several different stock market indexes including the Dow, NASDAQ, DAX, Nikkei, S&P, Wilshire 5000 and the Hang Seng. In case you don't know, these are three indexes from the US, Germany, Japan and China. This includes the time from the crash in October 2008 to today. We see that attempts to diversify geographically have not worked very well. 

Above is the correlation matrix - click on the table to enlarge. Most of these stock index are very much the same.  The correlation between the Wilshire and the S&P is 99.8% --where 100% is perfect. The least correlated pair, the Hang Seng and the Dow, have a correlation of 93.5%. You would think the Chinese market would be more distinct from the biggest US companies. 

This shows the world is a global village.

This is interesting and discouraging because the investment practice of REBALANCING, encourages us to put assets in different places, and then shift money between asset groups to get the best return. See William Bernstein's book The Intelligent Asset Allocator. If these geographic markets track each other so closely, this technique can't work very well.

Wednesday, May 6, 2009

Horseshoe Crab Blood, Hemocyanin and Blood Clots

Horseshoe crabs are primitive animals, and I found out yesterday that they have blue blood. That was going to be my post. Look at the cool blue color:

As you can see -- milky blue. The blue color is caused by the hemocyanin in their blood, rather than hemoglobin. Hemocyanin is based on copper rather than iron. It is not uncommon undersea non-vertebrates, being in mollusks and octopus too. There is lots of detail on Wikipedia.

However, it is even more interesting that horseshoe crab blood has an unusual anti-bacterial property. 

Horseshoe crab blood, as discovered by Fred Band in 1956, contains Limulus Amebocyte Lysate  a which causes clots in response to lipopolysacchrides of the kind found in bacteria. The clotting occurs quickly and isolates the bacteria from the rest of the crab. It is useful pharmaceutically to detect bacterial contamination. This can detect roughly 10E6 organisms/ml, depending on the organism and many other factors. Actually this does not sound that sensitive to me, but it seems that other methods are worse.

Recently, this has created a market in wild horseshoe crab blood. The crabs are milked and then released. It seems that it is difficult to culture the cells that produce limulus amebocyte lysate in the lab, and that the wild-caught production will continue for a while.

Friday, May 1, 2009

Talent is an Over-Rated Commodity

Thank you to daughter Michelle, for pointing out this David Brooks post.

I have for years thought that people should focus less on "talent" which is some kind of god-given attribute that pre-defines success, and a great deal more on effort and preparation. People who succeed often build on a base of previous success and high accomplishment. 

I learned this when I was teaching assistant in a college class. People that took related classes first did better, which shows simply that better preparation leads to better results. People that did not have the preparation struggled, and this was very evident in the exam grades. 

David Brooks:

Some people live in romantic ages. They tend to believe that genius is the product of a divine spark. They believe that there have been, throughout the ages, certain paragons of greatness — Dante, Mozart, Einstein — whose talents far exceeded normal comprehension, who had an other-worldly access to transcendent truth, and who are best approached with reverential awe.

We, of course, live in a scientific age, and modern research pierces hocus-pocus. In the view that is now dominant, even Mozart’s early abilities were not the product of some innate spiritual gift. His early compositions were nothing special. They were pastiches of other people’s work. Mozart was a good musician at an early age, but he would not stand out among today’s top child-performers.

What Mozart had, we now believe, was the same thing Tiger Woods had — the ability to focus for long periods of time and a father intent on improving his skills. Mozart played a lot of piano at a very young age, so he got his 10,000 hours of practice in early and then he built from there.

The latest research suggests a more prosaic, democratic, even puritanical view of the world. The key factor separating geniuses from the merely accomplished is not a divine spark. It’s not I.Q., a generally bad predictor of success, even in realms like chess. Instead, it’s deliberate practice. Top performers spend more hours (many more hours) rigorously practicing their craft.

The recent research has been conducted by people like K. Anders Ericsson, the late Benjamin Bloom and others. It’s been summarized in two enjoyable new books: “The Talent Code” by Daniel Coyle; and “Talent Is Overrated” by Geoff Colvin.

If you wanted to picture how a typical genius might develop, you’d take a girl who possessed a slightly above average verbal ability. It wouldn’t have to be a big talent, just enough so that she might gain some sense of distinction. Then you would want her to meet, say, a novelist, who coincidentally shared some similar biographical traits. Maybe the writer was from the same town, had the same ethnic background, or, shared the same birthday — anything to create a sense of affinity.

This contact would give the girl a vision of her future self. It would, Coyle emphasizes, give her a glimpse of an enchanted circle she might someday join. It would also help if one of her parents died when she was 12, infusing her with a profound sense of insecurity and fueling a desperate need for success.

Armed with this ambition, she would read novels and literary biographies without end. This would give her a core knowledge of her field. She’d be able to chunk Victorian novelists into one group, Magical Realists in another group and Renaissance poets into another. This ability to place information into patterns, or chunks, vastly improves memory skills. She’d be able to see new writing in deeper ways and quickly perceive its inner workings.

Then she would practice writing. Her practice would be slow, painstaking and error-focused. According to Colvin, Ben Franklin would take essays from The Spectator magazine and translate them into verse. Then he’d translate his verse back into prose and examine, sentence by sentence, where his essay was inferior to The Spectator’s original.

Coyle describes a tennis academy in Russia where they enact rallies without a ball. The aim is to focus meticulously on technique. (Try to slow down your golf swing so it takes 90 seconds to finish. See how many errors you detect.)

By practicing in this way, performers delay the automatizing process. The mind wants to turn deliberate, newly learned skills into unconscious, automatically performed skills. But the mind is sloppy and will settle for good enough. By practicing slowly, by breaking skills down into tiny parts and repeating, the strenuous student forces the brain to internalize a better pattern of performance.

Then our young writer would find a mentor who would provide a constant stream of feedback, viewing her performance from the outside, correcting the smallest errors, pushing her to take on tougher challenges. By now she is redoing problems — how do I get characters into a room — dozens and dozens of times. She is ingraining habits of thought she can call upon in order to understand or solve future problems.

The primary trait she possesses is not some mysterious genius. It’s the ability to develop a deliberate, strenuous and boring practice routine.

Coyle and Colvin describe dozens of experiments fleshing out this process. This research takes some of the magic out of great achievement. But it underlines a fact that is often neglected. Public discussion is smitten by genetics and what we’re “hard-wired” to do. And it’s true that genes place a leash on our capacities. But the brain is also phenomenally plastic. We construct ourselves through behavior. As Coyle observes, it’s not who you are, it’s what you do.

ipod Shuffle Gen3 - Final Chapter

I gave up on my iPod Generation 3, or Gen3, and returned it to Apple. As you may recall from previous posts, I have had a problem with the volume control on the earbud cord when it got damp. It always was damp because I wear it exercising, and it is sweaty from either my shoulder or my neck. While I am flattered that I am a rough and tough enough jock to foul a piece of electronic equipment, I did want the iPod to work. 

Apple had two work-arounds, to loop the cord to hold the control off my shoulder, and to reduce the maximum sound in iTunes. Neither of these worked well. The loop always slipped, and I simply needed the sound to be louder sometimes that others. 

I was dealing with a service rep in the engineering department since this was a problem that t
Apple was trying hard to fix. He offered me an nice iPod Nano instead. This was a Gen 4 Nano with 8GB, so that was a better deal -- about twice as expensive.

Now I have my Nano, and it seems to work well. I hope that its larger size is not going to be an issue. The Shuffle hangs from my shirt. I am going to have to buy a holder for the Nano.