May 30, 2010

"Even should you shake more arms than the giant Briareus himself, you'll still have to deal with me!"

Just one sentence (from Volume 1, chapter 8) from Burton Raffel's translation of Don Quijote by Miguel de Cervantes:
"As he said this, he entrusted himself with all his heart to his lady Dulcinea, imploring her to help and sustain him at such a critical moment, and then, with his shield held high and his spear braced in its socket, and Rocinante at a full gallop, he charged directly at the first windmill he came to, just as a sudden swift gust of wind sent its sail swinging hard around, smashing the spear to bits and sweeping up the knight and his horse, tumbling them all battered and bruised to the ground."

May 28, 2010

This one just keeps coming up!

Failure to prove that two quantities are significantly different is not proof that they are equal.


My favorite chapter title, in any book by a physicist, is "You mean you just ask them?", which was, we are told, Richard Feynman's response when he learned from an older, more experienced friend, how to, ahem, get women to go to bed with him.

May 22, 2010

"Bond. James Bond."

Some people can be funny. Some people can be wise. Some people can be funny sometimes, and wise at other times.

Adam Gopnik is often funny and wise at the same time. From this week's New Yorker, here is his resonant analogy for the "Arian heresy," the question at the core of the fourth-century battles between Homoiousians & Homoousians:
"Was Jesus one with God in the sense that, say, Sean Connery is one with Daniel Craig, different faces of a single role, or in the sense that James Bond is one with Ian Fleming, each so dependent on the other that one cannot talk about the creation apart from its author?"

May 21, 2010

Euclid & Maxwell (per Millay & Einstein, respectively)

Euclid alone has looked on Beauty bare.
Let all who prate of Beauty hold their peace,
And lay them prone upon the earth and cease
To ponder on themselves, the while they stare
At nothing, intricately drawn nowhere
In shapes of shifting lineage; let geese
Gabble and hiss, but heroes seek release
From dusty bondage into luminous air.
O blinding hour, O holy, terrible day,
When first the shaft into his vision shone
Of light anatomized! Euclid alone
Has looked on Beauty bare. Fortunate they
Who, though once only and then but far away,
Have heard her massive sandal set on stone.
- Edna St. Vincent Millay, 1923

Imagine [Maxwell]'s feelings when the differential equations he had formulated proved to him that electromagnetic fields spread in the form of polarised waves, and at the speed of light! To few men in the world has such an experience been vouchsafed...
- Albert Einstein, 1940

May 20, 2010

Birds do it, differently.

People, like dogs and ginko trees, do it using the XY sex-determination system: The sperm determines the sex; individuals with a pair of the same sex chromosomes (XX), or "homogametes," are female, while individuals with a pair of different sex chromosomes (XY), or "heterogametes," are male.

Birds (& some fish, insects, & reptiles) do it differently: They use the ZW sex-determination system, in which the ovum determines the sex, males are homogametic (ZZ), and females are heterogametic (ZW).

May 19, 2010

SASI, a Semi-supervised Algorithm for Sarcasm Identification

From POPSCI (um, Popular Science), Computer Algorithm Can Recognize Sarcasm (Which is Just Soooo Cool)
SASI...can recognize sarcastic sentences in product reviews online with pretty astounding 77 percent precision. To create such an algorithm, the team scanned 66,000 product reviews, with three different human annotators tagging sentences for sarcasm. ...

This isn’t all just so your Roomba gets the joke when you tell it it sucks. Computer programs that can recognize sarcastic statements could generate better personalized content and make better recommendations to human users by not mistaking a product review titled “keep your receipt” with a sound piece of online shopping advice. It could also benefit opinion-mining systems that troll the Web trying to measure public sentiment about a product or idea.

May 18, 2010

The name of the sign.

Sometimes, a sign has a name.

There is a minus sign in the Maxwell-Faraday equation:

x E = - ∂B/∂t

That minus sign has a name, which is Lenz's Law.

Heinrich Lenz (1804-1865) wrote in 1833 that "An induced current is always in such a direction as to oppose the motion or change causing it."

The sign might be negative, but I look upon the Law as being positive. That is, in my opinion, Lenz's Law is a Good Thing. Because, otherwise, the electromagnetic universe would be profoundly unstable, with any perturbation resulting in positive feedback, amplification, and, ultimately, explosion!

May 17, 2010

I confess.

I confess that, in my darkest moments, this thing we call doing science reminds me of the famous description of driving due to George Carlin, who said that everyone else on the road is either a maniac or a moron.

[The maniacs, of course, are those going faster than you, while the morons are those who go slower.]

But then I get over it, drink some coffee, and get back to work.

May 16, 2010

"Practice, man, practice."

How do you get good at something? Eddy Merckx, the greatest professional bicyclist of the twentieth century, when asked for "the secret" to winning bicycle races, replied: "Ride lots."

May 15, 2010

art & life

William Moulton Marston (1893-1947) invented Wonder Woman, whose magic lasso would force villains to tell the truth, and pioneered the use of systolic blood pressure to detect deception, which is the basis of the modern polygraph.

Photo-blogging Spring's arrival, part III.

While we aspire to drink moderately, we admit to photographing immoderately. Especially peonies. Here's a shot from yesterday morning:

May 14, 2010

Are legs the new fish?

We've written here about the presentation at last year's Brain Mapping meeting on functional brain imaging in a dead fish.

And we've written about imaging functional connectivity during rest, based on the observation that the "noise" in functional MRI data ain't just noise, because spatially-correlated low-frequency fluctuations reveal intrinsic functional brain networks.

Well, last week, at the annual meeting of the International Society for Magnetic Resonance in Medicine, Duke University's Drs. T.B. Harshbarger & A.W. Song presented a paper entitled "Connectivity patterns produced without neuronal activity," showing that "... basic vascular fluctuations ... are sufficient to produce 'connectivity' patterns' in ..." a (living) person's calves.

May 13, 2010

May 12, 2010

not just reading, but seeing

I recently heard about the Slingshot Fund's use of video to share knowledge, and I reached out to Will Schneider, Slingshot's Executive Director, to ask about why and how Slingshot chose video as a story sharing tool.

The Slingshot Fund
describes itself as "a collective giving community for next generation philanthropists," providing unrestricted grants to "innovative Jewish organizations." Will told me he realized grantees were taking a lot of time to prepare the requested three- to five-page mid-grant reports, and that although he himself read all the reports, donors did not read each and every one. The Slingshot community wanted to more effectively share their stories about impact.

So, last year, in addition to the grant itself, the Slingshot Fund gave each grantee a Flip video camera “to document their programs and projects” and asked “grantees to submit a mid-year video so that we could share their good works with the Slingshot community.” Will admitted, “We fund innovation, and it’s pretty clear we had to be innovative ourselves.”

He elicited compelling stories by telling grantees, “We just want to see what your work looks like,” and asking them, “What do you wish a donor could see?”
“The cameras went to Jackson, Mississippi to document Jewish life in the South, they taught us how Hebrew schools can use visual aid strategies to engage children with special needs, they showed us the side of the West Bank Security Fence we have never gotten to see, and provided dozens of other moments that a written report could never have conveyed.”
Will points out that the videos are "not a replacement evaluation technique", but rather, "an effective way to share information we were excited about." As a result of the videos, he told me, “Our donors are not reading a brochure about great the program is, they are seeing it.”

It’s not just the donors who now, as Will says, “get it, because they saw it,” it’s also board and staff members – and the grantees themselves, who are now able to more easily learn of each other’s work.

And you, reader: several of the videos are posted to YouTube, and you can view them at <>

"Respiratory sinus arrhythmia."


Following up on our tale of shooting an iris through a pinhole, we wanted to ask a question: How much smaller?

As we mentioned, we used an aperture ("aperture" is a pretentious word for "hole") that was small - a little less than one square millimeter. But, as Dad would say, "Compared to what?" How much smaller was that "pinhole" than the usual photographer's hole, or the biggest possible photographer's hole?

The formula for hole size is area = π (f/2N)2 (where f is the focal length, and N is the f-number). So, using a 60 mm lens at f/57, the hole was 0.87 mm2; but with that lens fully open at f/2.8, the hole would be 361 mm2 (a bit more than half a square inch), which is about 414 times bigger.

So, you could say, that to get that shot, we shrunk the hole by about a factor of 414.

Comment: (57/2.8)2 = 414.413...

May 11, 2010

intimacy + immediacy = enthusiasm

The physical and technological intimacy, coupled with the immediacy of social media, makes it an ideal platform for expressing enthusiasm.

When I am positively excited about something, I want to share that thing. Whether it be an idea, the sighting of the season's first hummingbird (2:04 PM yesterday!), or a professional epiphany, I want to share it with people on
Twitter and friends on Facebook who may also find it exciting.

And, I enjoy being surrounded by people who are also open to and excited by new ideas,
images, and knowledge. That's my social media meme.

May 10, 2010

Story Knows No Gender

My latest post at PhilanTopic, the Philanthropy News Digest blog, exploring the question, "Should you tell a story differently based on whether your listener is a woman or man?"

How we shot an iris through a pinhole. (Flashing helped.)

In a dog-related incident, an iris flower was snapped off in the kitchen garden.

So, we brought the flower inside, set it on the kitchen counter, and lay down, right beside it, on either side, an SB600 speedlight (off-camera flash-unit), to provide lots & lots of light. And shot it with the 60 mm f/2.8 lens, as close as possible, with a very small aperture.

Why small? Because without a small aperture, shooting way-up-close with that lens yields a remarkably shallow depth-of-field, such that that very little of the scene is actually in focus.

How small? The aperture was set at f/57, which, in case you were wondering, works out to be an opening of a little less than one square millimeter, which is biggish, for a pinhole.

May 9, 2010

Let Your Listener Be!

Asking too many questions can actually distance you from your listener. Think of how you react to people who ask a lot of questions, versus how you respond to individuals who demonstrate a sincere interest in you. A lot of this is in how the questions are asked: are they directive, or open-ended story elicitations?

Ask for a story, and allow your listener to think about him or herself – not about you, why you are asking the question, and what your preferred response might be. Allow your listener to be the hero.

May 8, 2010

All numbers are interesting.

This is one of the 101 things - say, 101 is an interesting number, like 1729 - I learned about doin' science 'n' stuff.

Claim: Every number is interesting.

Stronger claim: There is a proof that every number is interesting.

Consider the numbers:
  • 0 is the unique identity operator for addition, which is interesting.
  • 1 is the unique identity operator for multiplication, which is interesting.
  • 2 is the only even prime, which is interesting.
  • 3 is the first odd prime, which is interesting.
  • 4 is the first square, which is interesting.
  • 5 is the first Pythagorean hypoteneuse (22 + 32 = 52), which is interesting.
  • 6 is the first perfect number, which is interesting.
  • etc.
  • ...
Suppose we go on inspecting numbers, and we do eventually find a number that is not interesting. Why, that number would be the first non-interesting number, which is interesting.

Therefore, by induction, all numbers are interesting. Q.E.D.
Observations: 1. This is a (humorous & paradoxical) proof, or (what mathematicians call) an argument, but it is not a story. 2. Wikipedia says it is related to the Berry paradox.

May 6, 2010



Photo-blogging Spring's arrival, part II.

"Just move along; nothing to see here."

[60 mm f/2.8 lens & D700 camera. f/40, 1/13 s, ISO 6400. full-res at < > ]

May 3, 2010

Photo-blogging Spring's arrival!

Just last week, we had light frost two mornings in a row. But the weekend saw record high temperatures (90 degrees at National Airport on Saturday, May 1st) and our first iris:

[60 mm f/2.8 lens & D700 camera. f/16, 1/15 s, ISO 1600. full-res at < > ]

May 1, 2010

detection versus estimation

When designing experiments, it is helpful to know what you are designing them for.

What is the best task design for functional MRI?

That is, the best experiment for detecting responses (i.e., to answer the question "where in the brain does the MRI signal resemble my task timing?") is different from the best experiment for estimating the timing of the brain responses (i.e., to answer the question "what is the time course of brain responses to task events?").


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