Category: Natural World

The Big Bang

Good blogging style, like good presentations, should be multi-modal. On the internet we’re limited to text, images and sound/video so we do the best we can. I tend to be text oriented so I try to add an image to each post. In an earlier post on how science works I snagged an image by cédric sorel that he contributed to Wikipedia.

Artist's impression of the Big Bang. By cédric sorel: http://commons.wikimedia.org/wiki/File:Big_bang.jpg

Each time I see this interpretation of the Big Bang I am astonished once again. The textures give the impression of a three-dimensional cut-away, and the detail in the spiral galaxies swirling away from the center just pulls my attention like a strong magnet lines up iron filings.

The image is in the public domain and a high resolution version can be found on the Wikimedia Commons page (http://commons.wikimedia.org/wiki/File:Big_bang.jpg).

How science works

Artist's impression of the Big Bang. By cédric sorel: http://commons.wikimedia.org/wiki/File:Big_bang.jpg

Science progresses from failure. When experiments don’t work, we often learn more from why they did not work than if they had given us the results we expected. Frequently, it is how scientists deal with this adversity that results in advances in science.

We build models of the world, but by definition these models are incomplete. They are only metaphors for the actual world. When our models fail, we learn, and we expand our models.

Arno Penzias and Robert Wilson won the Noble Prize for Physics for discovering the background noise left by the Big Bang. They only did so after spending a year trying to figure out why their radio telescope kept giving them too much static for them to use for their intended purpose (to map the universe’s bright stars).

Silk

How to make silk using the traditional method, by the American Museum of Natural History.

I’ve loved Barry Hughart’s novel, “Bridge of Brids” from the first time I read it a number of years ago. It is the story of a peasant boy, Number Ten Ox, who, with the assistance of the drunken sage Master Li, has to save the children of his village by unraveling the mystery of the powerful Duke of Chin. Not only is it beautifully written, with a poetic story arc and engaging characters, but it also has a wonderful description of initial stages of the silk making process, even though the book describes itself as, “A novel of an ancient China that never was.” The descriptions of Chinese traditions are accurate and detailed enough that you learn a lot about the country. Pulling apart what is historically accurate and what is fiction makes and interesting challenge but is not too difficult.


Spider silk from Madagascar.

Evolution and drug resistant bacteria

Superbugs. When the environment changes, those fortunate organisms who are better adapted to the new environment will live longer and produce more offspring than those that are poorly adapted. (The Chrysalids, is a great book that encapsulates this principle in a powerful coming-of-age story.)

When it comes to bacteria, some small fraction of any strain of bacteria infecting you are, because of random genetic mixing, more resistant to the antibiotics you may be taking. This is why your doctor often makes you to take the antibiotic for a few days after the symptoms are gone; to kill those last most resistant bacteria cells.

Unfortunately, not everyone takes the full course of antibiotics, and some bacteria cells are extremely drug resistant. Over the years since the discovery of penicillin about a century ago, bacterial cells resistant to penicillin have been surviving and reproducing, so that there are now strains of bacteria that are resistant to the drug.

Fortunately drug researchers are developing new antibiotics all the time. When your doctor prescribes one antibiotic and it doesn’t work, they can usually prescribe another that will work because a bacteria strain that has an immunity to one drug might not have an immunity to another, especially if the other is a very different type of drug.

Unfortunately, some bacterial strains have developed that are resistant to a lot of different types of drugs (according to the World Health Organization), and these bacteria are responsible for thousands of deaths in hospitals around the world each year.

Norway has come up with one promising solution; don’t use as many antibiotics. Instead of treating every, or even most colds with antibiotics, their doctors take a wait and see attitude. They prescribe other medicines that reduce the symptoms, the coughing and runny nose, and let the body’s immune system deal with the bacterial infection. And it is working. In Norway, they are able to use penicillin varieties that would not be effective in other countries.

Without the overuse of antibiotics, drug-resistant strains of bacteria are not as competitive as other strains that commonly infect people. Without antibiotic overuse the superbugs aren’t so super after all. So, using less antibiotics means fewer infections with drug-resistant strains.

It’s a bit as if, somewhere in the forests of India, one tiger was born that was much, much better at hiding from and attacking people than the ordinary tiger, but it was smaller than other tigers. Ordinarily, this “supertiger” and its genes would probably die out because it would not be able to compete with the other tigers to reproduce. However, when people start hunting tigers, the supertiger survives better and passes on its genes. Now we have alot more supertigers and a lot more people are being attacked. All because people started killing the tigers.

Evolution is a fascinating process with such a multitude of complicated interactions. I also recommend that students read the introduction to the Origin of Species. It is truly an example of beautiful science. The language is challenging but, I think, worth it.

Experiments in cooking: Testing for pectin

Ribes rubrum. From Wikipedia.

Cooking is chemistry writ large. You start by learning how to measure volumes, mass and ratios, but end up talking about polymers and stoichiometry. It can get very complicated, but it’s easy enough that anyone can do it, going into different depths.

I’m planning on jam making this fall and in testing a recipe I became curious about if I could do it without adding store-bought pectin. Red currants should have enough pectin but the question of extracting it came up.

I was curious to see if I actually get more pectin from the liquid squeezed last through the handkerchief (with much wringing) than I get from the pulp and juice of the red currants I initially squeezed through a coarse strainer. So, I tested the two batches of liquid for pectin. A simple application of science in cooking.

Date: 12/29/09.

Hypothesis: The juice (the filtrate) squeezed out of the currants through the strainer will have less pectin than the juice strained out of the seed and skin leftover of the straining (the retentate) because I think I remember reading somewhere (always dangerous) that pectin can be found in or just beneath the surface of the skin of fruits.

Procedure: Using the test from the University of Minnesota extension service: Add 1 teaspoon of juice to 1 tablespoon of rubbing alcohol and observe how well it coagulates after 2 minutes. This test is performed in two small shot glasses.

Observations: It is difficult to quantify how firm are the gels that forms at the bottom of the shot glasses. Although I could construct a simple device to test gels resistance for force, I opt to assess the gels by swirling the glasses and observing how they move. Eyeballing the results, it seems that the first extraction of pulp and juice has more pectin. An independent observer agrees with this observation.

Conclusion: My initial hypothesis is wrong. Based on this experiment I now hypothesize that the pulp of the currants has more pectin. Five minutes of internet searching seems to confirm this new hypothesis, and suggests that my initial belief that pectin can be found under the skin of fruits comes from the fact that this is true for citrus fruits.

Where does morality come from?

“Do to others as you would have them do to you”. The golden rule (in some form or the other) is almost universal. And because it is found throughout different cultures and belief systems suggests that much of what we view as morality and ethics are innate to the human mind. But what are we born with, and what do we learn from culture? Is the golden rule necessary for successful social groups, so that cultures with the golden rule are more successful that ones that don’t have it? These two questions are fundamental to how we educate, particularly in a method such as Montessori’s that has such a strong moral dimension.

Maria Montessori herself came from a strong catholic background, but the success of her approach in so many different cultures does argue that, at least for the younger kids, the innate aspects of morality and needs of the child are most important. By the time students get to the Middle School, however, the influence of the local culture has become much more important.

Morality and culture affect students’ motivations and behavior, yet much of what is considered acceptable in many cultures conflict with the core Montessori principles of respect for oneself and for others. Much of popular American culture for example, is driven by television where moral messages can be decidedly mixed. How often is it appropriate to use violence (or even torture)? Television shows give decidedly different answers from Montessori. But there are many other, more subtle differences. As Montessori educators we will be faced with the question of what to do when Montessori philosophy differs from the beliefs of the student, their family and the larger culture.

My thoughts are that the “cosmic education” that is a part of the Montessori method should be based on the “universal” aspects of morality that can be shown to make for successful individuals and societies. Some interesting work by Jonathan Haidt at the University of Virginia looks at how certain systems of morality have contributed to the success of societies. As Nicholas Wade summarizes:

… natural selection and the survival of the fittest may seem to reward only the most selfish values. But for animals that live in groups, selfishness must be strictly curbed or there will be no advantage to social living. Could the behaviors evolved by social animals to make societies work be the foundation from which human morality evolved?

Haidt suggests there are “five innate and universally available psychological systems” of ethics, and different cultures add stories, virtues and ways of policing these ethics. The Moral Foundations Theory website has a good summary of the five systems, harm/care, fairness, loyalty, authority/respect and purity/sanctity.  In a beautiful example of adding transparency and technology to scientific research, he even has a page for challenges to the theory. Each of the moral foundations these deserves separate consideration of how they evolved, how they benefit society, and how they mesh with Montessori philosophy.

Nicholas Wade has a good article on the subject and on Haidt’s work in the New York Times.

The universe … for scale

The American Natural History Museum has a YouTube channel with some interesting science-related videos. The one above, “shows the known universe as mapped through astronomical observations.”

Every satellite, moon, planet, star and galaxy is represented to scale and in its correct, measured location according to the best scientific research to-date.