On digital SLRs and compact cameras

When last summer I bought a Nikon D70, I only knew that I wanted a very good digital camera. Since all the reviews about the Nikon D70 were extremely positive, this was my final choice. But even after I bought it, I had some afterthoughts that maybe it would have been better to get an expensive (but similarly priced to a ‘cheap’ DSLR) point-and-shoot camera that has a fixed lens, like the Nikon 8700 or the Sony DSC-F828. With these, you get a lens with a wider range of zoom, without having to buy another expensive lens and then having ot change them all the time.

But since then I have been using the Nikon D70 quite often (not as often as I’d like to, but that’s another story), and I am perfectly happy with it. Ken Rockwell explains very well here why it is a no-brainer whether to buy an expensive point-and-shoot camera or a ‘cheap’ DSLR for the same price. Even the latest and greatest point-and-shoot cameras do not have the speed necessary to capture moving subjects. Here is how Ken Rockwell sums it up:

“For a small snapshot camera get a $300 point-and-shoot. I have one, love it, and take it everywhere.If you want to spend a grand for serious digital photography forget the expensive p/s cameras and go straight to any DSLR. Since you can get a far superior DSLR for what you used to have to pay for just a p/s as of 2004 I see no need for the expensive p/s digital cameras. The reason we still have expensive p/s cameras today is because camera companies still have two sets of development and marketing teams, one for each class of camera, so there are still people at these companies pushing the expensive p/s cameras even though the DSLRs made by the same company are better for the same price. Other companies, like Sony, don’t make any real DSLRs and of course they will promote their p/s cameras. Don’t waste $1,000 on a point and shoot unless you really want to trade off ease of use, speed and image quality for a little size and weight.”

Ian Anderson on Christmas

The best thing about Christmas is that you get a few free days — and I manage to spend them without worrying too much about not working. If I want to be more sympathetic, I think I can pretty much agree with Ian Anderson’s (from the good old Jethro Tull) views on the subject:

“My views on Christmas? Well, I’m not exactly a practising paid-up Christian but I have grown up and lived with a so-called Christian society for 55 years and still feel great warmth for the nostalgia, festive occasion and family togetherness, so much a part of that time of year. Maybe without Christmas we would have that much less to celebrate and enjoy in this troubled old world. But it’s really all the Winter Solstice and the re-birth of nature overlaid with the common sense and righteous teachings of Mr. C.

A Christmas in this modern world should, in my view, accommodate the leisure needs and affections of Muslims, Hindus, Buddhists, atheists and agnostics, as well as Fido the family dog and Felix the cat. Throw in a few lost cousins and that dreadful man from next door and you have it! Sip the sloe gin, pull a cracker (so long as she’s not the daughter of that dreadful man from next door), kiss and cuddle under the mistletoe, toss Vegan disciplines aside, gobble the turkey (steady on, now) and have a therapeutic respite from the rigours of daily life.”

Introverts and extroverts

An article on introverts by Jonathan Rauch — it also has been published in “The Best American Science and Nature Writing” 2004 volume (edited by Steven Pinker):

“With their endless appetite for talk and attention, extroverts also dominate social life, so they tend to set expectations. In our extrovertist society, being outgoing is considered normal and therefore desirable, a mark of happiness, confidence, leadership. Extroverts are seen as bighearted, vibrant, warm, empathic. “People person” is a compliment. Introverts are described with words like “guarded,” “loner,” “reserved,” “taciturn,” “self-contained,” “private”–narrow, ungenerous words, words that suggest emotional parsimony and smallness of personality. Female introverts, I suspect, must suffer especially. In certain circles, particularly in the Midwest, a man can still sometimes get away with being what they used to call a strong and silent type; introverted women, lacking that alternative, are even more likely than men to be perceived as timid, withdrawn, haughty.

Are introverts arrogant? Hardly. I suppose this common misconception has to do with our being more intelligent, more reflective, more independent, more level-headed, more refined, and more sensitive than extroverts. Also, it is probably due to our lack of small talk, a lack that extroverts often mistake for disdain. We tend to think before talking, whereas extroverts tend to think by talking, which is why their meetings never last less than six hours.”

U.S. science supremacy threatened by competition

Number 67 in the ‘top science stories of the year’ in Discover Magazine is entitled ‘U.S. Science Supremacy Threatened by Competition’. Some interesting facts: according to the National Science Board, an independent policy group that advises the president and the congress,

the drop in foreign applications – down 28 percent at the graduate level – is (…) certain to affect the future of science. Many who come here to study do not return to their native countries. A survey by the National Science Foundation in 2000 reported that 38 percent of U.S. scientists with doctorates were born abroad.

Also:

the number of research articles by Americans has been stagnant compared with an increasing number written by Western Europeans in the last decade.

Creationist karstology

I never knew there was a branch of science called ‘creationist karstology’. But now I know: probably the best known (and potentially the only) practitioner of it is Emil Silvestru, who was head scientist at the Speleological Institute in Cluj, Romania, before he immigrated to Canada and became a member – and apparently employee – of Answers in Genesis, a creationist organization. ‘Creation Magazine’ claims he is a ‘world authority on caves’ – OK, he probably did indeed spend some time in caves and knows something about them. But how seriously can you take someone who honestly thinks that this is reasonable and this is good science:

After becoming a Christian he quickly realized that the ‘millions of years’ interpretation, so common in geology, was not compatible with Genesis. ‘Once I became a Christian,’ Emil says, ‘I knew I had to “tune up” my scientific knowledge with the Scriptures.’

‘Although philosophically and ethically I accepted a literal Genesis from my conversion, at first I was unable to match it with my “technical” side.’

E-mail discussions with qualified creationist geologists, creationist books, Creation magazine and especially the TJ helped him realise what he calls two ‘essential things’:

  1. Given exceptional conditions (e.g. the Genesis Flood) geological processes that take an extremely long time today can be unimaginably accelerated.
  2. The Genesis Flood was global, not regional.

    ‘These factors were immensely important in my conversion and my Christian life. I am now convinced of six-day, literal, recent, Genesis creation. That doesn’t mean that there are not still some unanswered problems, but researching such issues is what being a scientist is all about.’”

According to Dr. Silvestru, radioactive dating is wrong; he is “now convinced of six-day, literal, recent, Genesis creation” and that “currently prominent creationist modeling of the post-Flood Ice Age is an important tool in understanding the karst in a young-earth framework“.

No comment.

To wrap it up, a little piece of blatant misinformation. Asked if he

experienced any ridicule or persecution because of his strong stand on Genesis creation

, I guess back in Romania, Dr. Silvestru says:

“Not really, for two main reasons. First, after so many years of almost compulsory atheism/evolutionism, most people welcome biblical creationism as a breath of fresh air. Second, God has granted me a professional status that practically bars any attempt to ridicule my creationist convictions.”

It is true that religion has gained quite some ground since the fall of communism in Eastern Europe; but I don’t think that you can make a blanket statement like “most people welcome biblical creationsim as a breath of fresh air”. In fact, most of the people I know, even those who are much more sympathetic toward religion then I am, would definitely not consider bibilical creationism a breath of fresh air.

Regarding his “professional status that practically bars any attempt to ridicule” his creationist convictions – well, here is one.

It is also true that they are ridiculous enough by themselves.

Power laws and log-log plots II.

Back again to power laws. After some more googling, I found an even more important piece of blogging by Cosma Shalizi: Speaking Truth to Power About Weblogs, or, How Not to Draw a Straight Line. The title says it all: just don’t play with power law distributions by fitting straight lines to log-log plots, because chances are that you will get a reasonably looking line and R squared will be relatively large, but that still does not mean that there is a power law distribution. Shalizi is complaining about papers in statistical physics and complexity theory that do such things — well, he should see what is going on in sedimentary geology, where somebody invented the ‘segmented power-law distributions’ and now everybody who is measuring bed thicknesses is fitting not one, but two or even more straight lines to log-log plots of cumulative distributions. It’s utter nonsense, even more so than with a single straight line, but it looks very sophisticated and regular, and people keep doing these plots and all kinds of fancy interpretations based on them (earthquakes, self-organizing criticality, confinement, erosion, etc.). If it plots as a straight line – fine, it’s a power law, we explained everything. If it does not plot as a straight line — well, just fit two straight lines and talk about two populations, and how the original power-law distribution has been modified by erosion, confinement, etc. – and we explained everything again. I know I am also guilty of some of this in my thesis, but at least I have never done the segmented power law plots.

Power laws and log-log plots I.

Did a bit of reading today on power law distributions, just to refresh my memories from three years ago when I was writing my thesis. And found some interesting papers and notes on the web, e.g., this one. I think we are still far from being able to use bed thickness distributions in a useful, predictive way, even though this has become a popular subject among turbidite experts. One of the problems is that it is easy to play with the distributions (e.g., take an initial power-law distribution and modify it by amalgamation), but things are probably a lot more complicated and cannot be explained just with amlagamation and basin topography. The other problem is that power-law distributions and their exponents cannot be assessed by fitting a straight line to an exceedence probability plot, as it is explained here. This method is bound to give erroneous estimates when dealing with a single distribution, but it is close to meaningless when people want to break out two different populations by fitting not one, but two lines to the exceedence probability plot.

Well, I guess that is enough about power laws for today.

A nice quote from “The Scientists” about Kepler and Galileo:

He was a man of his time, poised between the mysticism of the past and the logical science of the future, but whose stature as a voice for reason stands even higher in the context of a world where princes and emperors still depended on the prognostocations of astrologers, and where his own mother was tried for witchcraft. At the same time Kepler was carrying out his great work, an even more powerful voice of scientific reason was being heard further south in Italy, where although there was as mutch superstition and religious persecution as in central Europe, at least there was some measure of stability and the persecution always came from the same Church.