Pater Familias » Science

WEBCAMS AND BIRD NESTS.

Philip — Wed, 23 May 2012 21:33:26 +0000

WEBCAMS AND BIRD NESTS. Dick Weisfelder kindly sent me links to three sites which are following baby birds in nests:

Herons: link

Red Tail Hawks: link

Bluebirds: link

I am posting this immediately because birds grow rapidly.

SOME THINGS I LEARNED ABOUT BIRD NESTS.

Philip — Tue, 22 May 2012 20:47:34 +0000

SOME THINGS I LEARNED ABOUT BIRD NESTS. I haven’t seen a lot of bird nests—a few under eaves. Sometimes small birds can be seen visiting nests under the roof at the Darien train station. Jack Sanders had an article about bird nests in our local Darien Times a while ago. I had thought that birds got the nest built in a day or two, but it turns out that construction often takes a long time. For example, a robin takes one to three weeks to make one. Birds get better and faster in making nests with practice. And most nests are hidden. The ones that we see tend to be built by by big birds who have no fear, which is why night herons can build nests that are easy to see. Night herons seem to show up overnight in a nest because they do show up overnight. They are simply moving back to last year’s nest.

NIGHT HERON NESTS.

Philip — Tue, 22 May 2012 02:16:56 +0000

NIGHT HERON NESTS. On our walks down to Long Island Sound, we look for birds—seagulls, of course, sometimes an egret or a swan, occasionally a cormorant. Now the night herons are back. They are big birds, about waist high. They look more menacing than the egrets as they stalk the edges of Farm Creek, even though the egrets are about the same size. (My imagination is influenced by the dark colors of the herons compared to the brilliant white of an egret). When I say the herons are back, I mean they are back in their nests, which are in the same locations from year to year, very high up in certain trees. The nests seem small for such large birds. The nests are conspicuous and so are the birds, either in the nest or standing guard outside the nest. Annalisa was the first to notice a nest some years ago. She said that the white markings on the ground gave notice that there was a nest above.

A CHART OF ATROCITIES.

Philip — Sat, 19 May 2012 00:22:54 +0000

A CHART OF ATROCITIES. In connection with my posts on Steven Pinker’s theory that human violence has declined over time, Dick Weisfelder sent me a hard copy of a graphical display of the 100 greatest atrocities in history. This link is from the New York Times, but the Times gives credit to Matthew White’s THE GREAT BIG BOOK OF HORRIBLE THINGS. World War II still accounts for the most deaths (66 million). The Atlantic slave trade is 10th with 16 million deaths and the Mideast slave trade is 8th with 18.5 million deaths. Despite Mary Beard’s suggestion that gladiatorial contests were rigged, deaths of gladiators rank 26th with 3.5 million deaths, and these deaths occurred one at a time. There are surprises because we don’t know about a lot of horrors. The Bengali genocide ranked 5th in deaths per year with 1.5 million deaths in the single year of 1971. In 1971! I remember no mention of it in the news. Six of the ten events with the largest percentage of the world population that was killed took place in China. I know nothing about them. It’s a fascinating and appalling timeline.

5% TO 20%—THE GOOD NEWS ABOUT “OBSERVATIONAL STUDIES”.

Philip — Fri, 18 May 2012 00:22:12 +0000

5% TO 20%—THE GOOD NEWS ABOUT “OBSERVATIONAL STUDIES”. I am encouraged by the estimates of the percentage of findings from statistical studies that can be replicated. The estimates of 5% to 20% for multiple regression studies are higher than I would have expected, and the figure of 80% for randomized controlled experiments is heartening as well. Observational studies are much cheaper than controlled trials (tens of thousands of dollars for a study versus millions of dollars for a randomized controlled trial.) Observational studies generally serve a different purpose—formulating hypotheses and checking leads rather than testing whether a proposition is true.

The “bad news” about both kinds of statistical studies comes about because the scientific process is slower and less accurate than people think. Problems develop because results of trials are almost always reported without a caveat. If people were aware that in general only 80% of controlled studies and 5% to 20% of observational studies can be replicated, finding these facts out would not be considered bad news.

5% TO 20%—THE BAD NEWS ABOUT “OBSERVATIONAL STUDIES”.

Philip — Thu, 17 May 2012 00:21:37 +0000

5% TO 20%—THE BAD NEWS ABOUT “OBSERVATIONAL STUDIES”. Gautam Naik had an article in the Wall Street Journal (May 3) headlined “Analytical Trend Troubles Scientists”. The troubling trend is that “observational studies often use different methodologies and arrive at different conclusions.” (“Observational studies” are one ones in which “scientists often use fast computers, statistical software and large medical data sets to analyze information previously collected by others”. I think of them as multiple regression studies.) Estimates are that there were almost 80,000 observational studies published across all scientific fields from 1990 to 2000 and over 260,000 published from 2001 to 2011. The article cites Dr. John Ioannidis as estimating that observational studies in general can be replicated only 20% of the time versus 80% of the time for controlled random trials. Another expert estimates the replication rate for observational studies at 5% to 10%.

AMERICANS AS AN INVASIVE SPECIES (COMMENT).

Philip — Thu, 26 Apr 2012 16:12:09 +0000

AMERICANS AS AN INVASIVE SPECIES (COMMENT). Lee Bryant posted a wonderfully apt comment on my post about Matt Ridley’s argument that gray squirrels, which have been displacing the native red squirrels in Britain, are better suited to the English environment and constitute an example of an invasive species enriching an ecosystem. Lee linked to a passage from HITCH-22 in which Christopher Hitchens used the invasion of Britain by the gray squirrel— “riffraff, once imported from America by some kind of regrettable accident”—as a metaphor for the threat that Americanism posed to the British way of life after the war. The passage begins: “Americanism in all its forms seemed to be trashy and wasteful and crude, even brutal.” It concludes that the replacement of the red squirrel by the gray squirrel “…seemed to be emblematic, for the anxious lower middle class, of a more general massification and de-gentrification and, well, Americanization of everything.”

MAKING A GEARBOX WITH A 3D PRINTER.

Philip — Sun, 22 Apr 2012 15:55:25 +0000

MAKING A GEARBOX WITH A 3D PRINTER. The Economist (April 21) has an article on the revolutionary possibilities of 3D printing. To give an idea of the importance of 3D printing, it seems that it will considered for use in the manufacturing of any solid object. It is already being used in making products ranging from jewelry to car dashboards. The technology is well-suited to customized products: “Millions of dental crowns and shells for hearing aids are already being made individually with 3D printers.” The article describes a gearbox that was printed for a racing car. The gearbox had smoother internal pathways than if they had been drilled with right-angle bends, and it was 30% lighter. One potential use of 3D printing is to “teleport” spare parts to remote areas. The “blueprints” for the part can be sent digitally to the remote area, where it can be printed.

You can buy your own personal 3D printer. A chart with the article shows that over 20,000 personal 3D printers were sold in 2011.

EJECTING TONS OF ROCK INTO SPACE.

Philip — Mon, 16 Apr 2012 22:54:02 +0000

EJECTING TONS OF ROCKS INTO SPACE. Instapundit posted on this article in MIT’s Technology Review blog which describes a new study on the impact of the asteroid weighing over one trillion tons which struck the earth some 65 million years ago. Among the consequences of the collision with the asteroid was: “the mass extinction of land-based life on Earth.” The new study deals with another consequence: “the ejection of billions of tons of life-bearing rocks and water into space.” Where did it all go? The study estimates that as much of it wound up on one of the moons of Jupiter as on our own moon because of the large gravitational pull of Jupiter. And as much would have gone into interstellar space as to all the other planets and moons in our solar system.

A DEFENSE OF INVASIVE SPECIES.

Philip — Sat, 07 Apr 2012 00:09:29 +0000

A DEFENSE OF INVASIVE SPECIES. I have conflicting feelings about invasive species. Matt Ridley argues that they are sometimes good things: “Some ecosystems are enriched and made more productive by invasive species.” He supports this with examples of invasive species that provide improved “ecosystem services” such as creation of soil and the prevention of erosion. He gives the example of gray squirrels in the United Kingdom, who are displacing the red squirrels that have been there since the ice age. He says: “ecologically,…the gray is better at filling the squirrel niche in [the UK] broadleaf woodland’ because red squirrels are a “pine-adapted species”. Of course, there is a weakness in his argument. A successful invasive species will be successful because it is better adapted to an environment. The question of whether invasive species are bad in themselves is a different one—and, I think, an aesthetic question.

IS THERE A BALANCE OF NATURE?

Philip — Fri, 06 Apr 2012 00:17:09 +0000

IS THERE A BALANCE OF NATURE? Matt Ridley had a review in the Wall Street Journal (March 23) of THE RAMBUNCTIOUS GARDEN by Emma Marris, which summarized her challenge to the idea of a balance in nature. Ridley begins by stating “a paradox that is increasingly vexing the science of ecology, namely that the only way to have a pristine wilderness is to manage it intensively.” Until recently ecologists have believed in a tendency of nature to reach a stable equilibrium (economists have had a similar belief in economic systems tending to reach a stable equilibrium.) Ridley points out examples of equilibrium states that are unstable. In African forests, elephants sometimes have to be controlled to prevent deforestation. Oak forests are unstable because oak seedlings don’t do well under mature oaks. The mature oaks rain caterpillars on the seedlings. Without management, some species become dominant. “To let aspen, willow and beaver return to Yellowstone, it was necessary to reintroduce the wolf, which reduced elk numbers.”

SOME ADVANTAGES OF AUTISM.

Philip — Mon, 02 Apr 2012 20:54:39 +0000

SOME ADVANTAGES OF AUTISM. Jonathan Lehrer had an article in the Wall Street Journal (March 31) about a recent experiment in which autistics surpassed nonautistics in dealing with difficult perceptual challenges. The autistics were able to process more information in a short period of time. Lehrer quotes Professor Nilli Lavie, who conducted the study: “Our research suggests autism does not involve a distractibility deficit but rather an information-processing advantage.” Lehrer then points to research that shows that people with attention-deficit disorders are more creative (fiction, prizes at science fairs) and that people with dyslexia are often better at visual tasks (peripheral perception, “quickly grasping the gist of a scene”). What Lehrer says about autism can be said about attention deficit disorder and dyslexia as well: “…it represents an alternate way of making sense of the world, a cognitive difference that, in many instances, comes with unexpected benefits.”