Posts tagged as:

Science

Beatles 3000

by John on February 17, 2011

Here’s a documentary on The Beatles from 1000 years in the future:

I sometimes wonder how much history and science has about as much connection to reality as this reconstruction of The Beatles.

Related post:

Paleolithic nonsense

{ 6 comments }

How the term “scientist” came to be

by John on February 16, 2011

For most of history, scientists have been called natural philosophers. You might expect that scientist gradually and imperceptibly replaced natural philosopher over time. Surprisingly, it’s possible pinpoint exactly when and where the term scientist was born.

It was June 24, 1835 at a meeting of the British Association for the Advancement of Science. Romantic poet Samuel Taylor Coleridge was in attendance. (He had previously written about the scientific method.) Coleridge declared that although he was a true philosopher, the term philosopher should not be applied to the association’s members. William Whewell responded by coining the word scientist on the spot. He suggested

by analogy with artist, we may form scientist.

Since those who practice art are called artists, those who practice science should be called scientists.

This story is comes from the prologue of Laura Snyder’s new book The Philosophical Breakfast Club. The subtitle is “Four Remarkable Friends Who Transformed Science and Changed the World.” William Whewell was one of these four friends. The others were John Herschel, Richard Jones, and Charles Babbage.

Update 1: Will Fitzgerald created the following Google Books ngram that suggests that scientist was used occasionally before 1835 and would take another 30 years to start being widely used in books. Click on the image to visit the original ngram.

So it is with many innovations: the person credited with the innovation may not have been entirely original or immediately successful. Still, perhaps Whewell’s public confrontation with Coleridge gave scientist a push on the road to acceptance.

Update 2: Pat Ballew fills in more of the story on his blog including editorial opposition to the term scientist. Pat brings more famous people into the story, including H. L. Mencken, Michael Faraday, and William Cullen Bryant.

Update 3: Here’s an excerpt from The Philosophical Breakfast Club.

More 19th century science:

Why Mr. Scott is Scottish
Victorian method for predicting height
Grand unified theory of 19th century math

{ 12 comments }

The end of hard-edged science?

by John on February 14, 2011

Bradley Efron says that science is moving away from things like predicting sunrise times and toward predicting things like the weather. The trend is away from studying precisely predictable systems, what Efron calls “hard-edged science,” and toward studying systems “where predictability is tempered by a heavy dose of randomness.”

Hard-edged science still dominates public perceptions, but the attention of modern scientists has swung heavily toward rainfall-like subjects, the kind where random behavior plays a major role. … Deterministic Newtonian science is majestic, and the basis of modern science too, but a few hundred years of it pretty much exhausted nature’s storehouse of precisely predictable events. Subjects like biology, medicine, and economics require a more flexible scientific world view, the kind we statisticians are trained to understand.

Certainly there is increased interest in systems containing “a heavy dose of randomness” but can we really say that we have “pretty much exhausted nature’s storehouse of precisely predictable effects”?

Source: Modern Science and the Bayesian-Frequentist Controversy

Related posts:

Scientific results fading over time
Occam’s razor and Bayes’ theorem
The law of medium numbers

{ 11 comments }

Final velocity

by John on February 12, 2011

My daughter and I were going over science homework this evening. A ball falls for 10 seconds. What is its final velocity?

JC: So how fast is the ball going when it hits the ground?

RC: Zero. It stops before it bounces back up.

JC: Well, how fast is it going just before it hits the ground?

RC: They didn’t ask the almost final velocity. They asked for the final velocity.

{ 14 comments }

Acupuncture and confirmation bias

by John on January 30, 2011

Here’s another excerpt from The decline effect and the scientific method that I wrote about a couple weeks ago.

Between 1966 and 1995, there were forty-seven studies of acupuncture in China, Taiwan, and Japan, and every single trial concluded that acupuncture was an effective treatment. During the same period, there were ninety-four clinical trials of acupuncture in the United States, Sweden, and the U.K., and only fifty-six per cent of these studies found any therapeutic benefits.

Related posts:

Popular research areas produce more false results
Little malaria on the prairie

{ 10 comments }

Scientific results fading over time

by John on January 17, 2011

A recent article in The New Yorker gives numerous examples of scientific results fading over time. Effects that were large when first measured become smaller in subsequent studies. Firmly established facts become doubtful. It’s as if scientific laws are being gradually repealed. This phenomena is known as “the decline effect.” The full title of the article is The decline effect and the scientific method.

The article brings together many topics that have been discussed here: regression to the mean, publication bias, scientific fashion, etc. Here’s a little sample.

“… when I submitted these null results I had difficulty getting them published. The journals only wanted confirming data. It was too exciting an idea to disprove, at least back then.” … After a new paradigm is proposed, the peer-review process is tilted toward positive results. But then, after a few years, the academic incentives shift—the paradigm has become entrenched—so that the most notable results are now those that disprove the theory.

This excerpt happens to be talking about “fluctuating asymmetry,” the idea that animals prefer more symmetric mates because symmetry is a proxy for good genes. (I edited out references to fluctuating asymmetry from the quote to emphasize that the remarks could equally apply to any number of topics. ) Fluctuating asymmetry was initially confirmed by numerous studies, but then the tide shifted and more studies failed to find the effect.

When such a shift happens, it would be reassuring to believe that the initial studies were simply wrong and that the new studies are right. But both the positive and negative results confirmed the prevailing view at the time they were published. There’s no reason to believe the latter studies are necessarily more reliable.

Related posts:

Why microarray study conclusions are so often wrong
Popular research areas produce more false results
Five criticisms of significance testing

{ 6 comments }

Occam’s razor and Bayes’ theorem

by John on January 12, 2011

Occam’s razor says that if two models fit equally well, the simpler model is likely to be a better description of reality. Why should that be?

A paper by Jim Berger suggests a Bayesian justification of Occam’s razor: simpler hypotheses have higher posterior probabilities when they fit well.

A simple model makes sharper predictions than a more complex model. For example, consider fitting a linear model and a cubic model. The cubic model is more general and fits more data. The linear model is more restrictive and hence easier to falsify. But when the linear and cubic models both fit, Bayes’ theorem “rewards” the linear model for making a bolder prediction. See Berger’s paper for a details and examples.

From the conclusion of the paper:

Ockham’s razor, far from being merely an ad hoc principle, can under many practical situations in science be justified as a consequence of Bayesian inference. Bayesian analysis can shed new light on what the notion of “simplest” hypothesis consistent with the data actually means.

Related links:

How loud is the evidence?
Blog posts on Bayesian statistics

{ 15 comments }

The solar system in a glass of wine

by John on January 1, 2011

William Blake’s poem Auguries of Innocence opens with these famous lines:

To see a world in a grain of sand,
And a heaven in a wild flower,
Hold infinity in the palm of your hand,
And eternity in an hour.

This poem came to mind when I saw @mathematicsprof post the following on Twitter:

At your next holiday party, look straight down into your glass of wine and tilt the glass one degree. You will see the elliptic orbit of the earth.

If you tilt your glass 12 degrees you’ll see the orbit of Mercury. In general, if you tilt your glass θ degrees you’ll see an ellipse with eccentricity sin(θ).

(I’ve taken the liberty of editing the original tweets to take advantage of the extra breathing room outside of Twitter. Original tweets here and here.)

I like this for two reasons: it’s a great astronomy illustration, and it’s an example of how much information you can get into two 140-character messages.

{ 1 comment }

Earthshine

by John on December 22, 2010

The Earth appears eight times brighter from the moon than a full moon appears from the Earth.

Source: Rocket Men

Related post:

Team Moon

{ 3 comments }

Scientific opposition to the war on cancer

by John on December 21, 2010

On December 9, 1969 the Washington Post ran a full-page ad that began

Mr. Nixon: You can cure cancer.

If America could put a man on the moon, she should be able to cure cancer. And why not? Well, because cancer research isn’t rocket science. (Actually, rocket science isn’t science; it’s engineering.) The science necessary to put a man on the moon was well known; the science necessary to cure cancer was not.

President Nixon was eager to comply with the request for massive funding for cancer research. However, many scientists were opposed to the idea. Cancer researcher Sol Spiegelman, for example, believed such a push was premature.

An all-out effort at this time would be like trying to land a man on the moon without knowing Newton’s laws of gravity.

James Watson warned

… we must reject the notion that we will be lucky. … Instead we will be witnessing a massive expansion of well-intentioned mediocrity.

How many scientists today would argue against a funding increase for their area of study?

Quotes taken from Emperor of all Maladies

Related post:

Not exactly rocket science

{ 5 comments }

Rice/NASA land deal

by John on December 14, 2010

Rice University donated the land for NASA’s Johnson Space Center. However, there were strings attached. According to Rocket Men,

If NASA gives up manned space flight, however, under the terms of its lease , it will have to relinquish Houston’s Johnson Spacecraft [sic] Center back to Rice University.

I imagine NASA will always at least talk about putting people in space so they can hold on to their land.

Update: Here’s a newspaper clipping about the deal. I don’t know where it’s from or whether it’s accurate.

Related posts:

Apollo 11 wasn’t perfect
Not exactly rocket science
After two days, I’d turned into an idiot

{ 3 comments }

After two days, I’d turned into an idiot

by John on December 11, 2010

Ever wonder why astronauts schedules are crammed with activity? A simple explanation is that time in space is a very limited commodity and so they naturally want to accomplish as much as possible. While that’s undoubtedly true, there’s also another reason.

Early in the space program, a NASA psychiatrist spent two days in an isolation tank with scuba gear to experience simulated weightlessness.

I thought a little, and then I stopped thinking altogether. … incredible how idleness of body leads to idleness of mind. After two days, I’d turned into an idiot. That’s the reason why, during a flight, astronauts are always kept busy.

From Rocket Men.

Related post:

Not exactly rocket science

{ 8 comments }

Take chances, make mistakes, and get messy

by John on December 10, 2010

From Magic School Bus:

Take chances, make mistakes, and get messy.

Magic School Bus is an educational television show for children. The quote above is often repeated by the main character of the show, Ms. Frizzle.

Too many programs that supposedly teach science only teach results from science. Magic School Bus does both. It teaches specific facts, such as the names of the planets, but it also teaches that science is about taking chances, making mistakes, and getting messy.

Related post:

Preparing for innovation

{ 4 comments }

NASA did not find arsenic-based life

by John on December 2, 2010

Headlines are saying today that NASA found microbes that use arsenic the way all other known life uses phosphorous. The NASA web site says NASA-Funded Research Discovers Life Built With Toxic Chemical. Some other headlines include “NASA finds ‘alien life’ made of arsenic,” “NASA finds arsenic-based life,” and “NASA finds arsenic-loving bacterium.” These headlines are misleading.

The phrase arsenic-based life is misleading because most people would assume this is in contrast to carbon-based life. No, the discovery involves substituting arsenic for phosphorous. So this new microbe is only arsenic-based in the sense that most life is phosphorous-based. Actually, even that is not correct. This is a phosphorous-based life form that has been tricked into using arsenic.

NASA did not find a microbe that substitutes arsenic for phosphorous. They coaxed a microbe into substituting arsenic for phosphorous. Here’s the relevant paragraph from NASA’s story:

The newly discovered microbe, strain GFAJ-1, is a member of a common group of bacteria, the Gammaproteobacteria. In the laboratory, the researchers successfully grew microbes from the lake on a diet that was very lean on phosphorus, but included generous helpings of arsenic. When researchers removed the phosphorus and replaced it with arsenic the microbes continued to grow. Subsequent analyses indicated that the arsenic was being used to produce the building blocks of new GFAJ-1 cells.

So it seems that NASA found a microbe that could use arsenic, not a microbe that naturally does use arsenic. Perhaps some are inferring that because NASA was able to make this happen in a lab, it may also have happened naturally, though no one has seen that. Maybe so.

NASA goes on to say

The key issue the researchers investigated was when the microbe was grown on arsenic did the arsenic actually became incorporated into the organisms’ vital biochemical machinery, such as DNA, proteins and the cell membranes.

This is an amazing discovery, but it’s not quite the discovery that headlines imply.

Update: More detailed criticism of the NASA announcement from Nature News. Experts challenge the claim that the microbes actually incorporate arsenic in organic compounds.

{ 12 comments }

The middle size of the universe

by John on November 15, 2010

From Kevin Kelly’s book What Technology Wants:

Our body size is, weirdly, almost exactly in the middle of the size of the universe. The smallest things we know about are approximately 30 orders of magnitude smaller than we are, and the largest structures in the universe are about 30 orders of magnitude bigger.

Related posts:

There isn’t a googol of anything
Means and inequalities
Logarithms, music, and arsenic

{ 13 comments }