Showing posts with label knowledge sharing. Show all posts
Showing posts with label knowledge sharing. Show all posts

September 12, 2014

"...close to music..."


"The true content of a photograph is invisible, for it derives from a play, not with form, but with time. One might argue that photography is as close to music as to painting."

- John Berger, from "Understanding a Photograph" (1968).

Bucky, December 2010. (Click image for full-screen.)

January 19, 2014

Under the influence.


Heraclitus said that you can't step into the same river twice, but sometimes I wondered whether I was photographing the same dog twice, thrice, and more.

I like to photograph Bucky. Sometimes, though, I found that I would take a photograph of him, and it would look very familiar:

(July)
(October)
(November)

(Click any image for full-screen.)

Old dog, new photo. If you photograph the same dog, repeatedly, how different can any new photo be...?

Last weekend, I visited the Yousuf Karsh exhibition at the National Portrait Gallery (USA). In spite of my familiarity with some of Karsh's truly iconic images (his portraits of Churchill & Hemingway, for instance), looking at his prints moved me. Wow. What exquisite compositions! What use of light - and darkness - to frame, and to highlight!

After visiting the exhibition, I took these two photos (click any image for full-screen), indoors, by available window-light; I think they are different from all my earlier photos of Bucky:



Thank you, Mr. Karsh!

And thank you, Bucky.


November 5, 2013

Triangle vs. Circle!


If you're going to drive (or even walk) in Germany, you really should know the difference between these two signs:


Do you know the difference? For the answer, click here.

October 29, 2013

Brains are different like bikes are different.


The dominant analogy for the brain has tracked the leading technology of the day.

The human brain was like a clockwork, then a hydraulic system, then an electronic circuit, then a digital computer, then a computer network, – until the present day, when, according to Stephen Kosslyn & Wayne Miller, writing in the Wall Street Journal, the brain is like a bicycle:
Our brains are not engaged in some sort of constant cerebral tug of war, with one part seeking dominance over another. (What a poor evolutionary strategy that would have been!) Rather, they can be likened roughly to the parts of a bicycle: the frame, seat, wheels, handlebars, pedals, gears, brakes and chain that work together to provide transportation.
The distinguished scientist and journalist continue:
Although the ... parts of the brain are always used during all of our waking lives, people do not rely on them to an equal degree. To extend the bicycle analogy, not everyone rides a bike the same way. Some may meander, others may race.
To be sure, Kosslyn &  Miller are right: Brains are like bikes.

But Kosslyn &  Miller are wrong, in that brains are not different like bikers are different; brains are different like bikes are different.

The apt bike analogy for inter-individual differences in brain function is not inter-individual differences in how people ride bikes, but rather inter-individual differences in bikes. Road bikes, mountain bikes, cyclocross bikes, touring bikes, BMX bikes, commuters, recumbents, etc. – bikes are different.

Brains are like bikes, and brains are different from one another like bikes are different from one another – not like how cyclists ride differently from one another, okay?

Because otherwise, you're just putting Descartes in the saddle.

October 17, 2013

O Lucky Man!


(self-strangling morning glory; 
no cameras or photographers were harmed making this photograph)

I am very fortunate. 

I recently came upon a Serious Warning in my camera's user's manual: 

"Sunlight focused into the camera when the sun
is in or close to the frame could cause a fire."

And another: 

"When operating the viewfinder diopter adjustment control with your eye to the viewfinder, care should be taken not to put your finger in your eye accidentally."

I am very fortunate! Taking photographs – many photographs – without having heretofore consulted these Serious Warnings, I never set the camera on fire, nor stuck a finger in my eye. I shall give thanks for my good fortune, next month on Thanksgiving, once I get my finger out of my ear.

August 14, 2013

Proposed: Understanding the brain doesn't suck.

"... recall the famous quip from Jeff Hammerbacher, a former Facebook engineer, who said, 'The best minds of my generation are thinking about how to make people click ads. That sucks.' We contend that working in biostatistics using complex neuroimaging data to solve the biggest puzzle of them all – understanding the human brain – is a worthy alternative."
-from "WANTED: Neuro-quants" by Brian Caffo, Martin Lindquist, and Ciprian Crainiceanu, which appears in the the Huffington Post.

April 4, 2013

Magnetic fields: Threat, or menace? [repost]


I have worked with magnets for over thirty years, yet I admit that I'm not sure if magnetic fields are real.

Now, they tell you that the magnetic field is real, real like the river's undertow that pulls you past the eddies beneath the sharp rocks and beats you down, but it's not. Not really. You feel magnetic forces, to be sure, but the magnetic field is not the fundamental truth. The truth is the magnetic vector potential. And this is not just my opinion; this has been known for over sixty years.

The magnetic field (what you hear about) is written as B; the magnetic vector potential (what you perhaps never heard about before today) is written as A. They are related by:

B =  x A

("The magnetic field is the curl of the magnetic vector potential.")

The truth is revealed by the Aharonov–Bohm effect, in which particle traveling past a long thin solenoid experiences a phase shift, even though the magnetic field is confined to the interior of the solenoid, which the particle never enters! Why does this happen? It happens because the particle sees the magnetic vector potential outside the solenoid. (A cool animation is available.)

So, A (the magnetic vector potential) is what's true and real and actually felt by the particle, while B (the magnetic field) is sort of an emanation, or a mathematical device, that almost always gives you the right answer (except in clever made-up configurations designed to demonstrate the Aharonov–Bohm effect, that is), and is handy. I suppose an attorney might say that while the magnetic field is (usually) a truth, it is not the whole truth.

Perhaps it's like your car's engine, where horsepower is what you read about, but torque is what you feel. The magnetic field is what you read about, but the magnetic vector potential is what you feel.

[Please note: Persons seeking legal advice should consult a member of their state Bar Association; we may in the future discuss an alternative approach to interpreting the Aharonov-Bohm effect, which does not appear to to rob the magnetic field of so much of her charm; post title refers to this.]

[reposted from June, 2010]

March 28, 2013

Headline of the Week!


The article "Dairy Finds a Way to Let Cows Power Trucks" appears in today's New York Times.

January 11, 2013

"Teaching to see."


May I suggest that you find a big screen and a comfy chair before clicking through to watch this amazing 38-minute video produced by Edward Tufte?


December 9, 2012

No kidding.


We like much of what the folks at the Flying Dog Brewery come up with, but we cannot recommend their Double Dog "Double Pale Ale," because 11.5 % alcohol by volume is just too high for us.

November 4, 2012

Is abuse of the null hypothesis a felony or a misdemeanor?


Just one sentence from "Activity Metabolism Measurements Made Easy in Metabolic Phenotyping" by Dr. J.R.B. Lighton:
"Thus the null hypothesis is not only falsified, it is smashed into smithereens that daintily and prettily drift down to the floor like dandelion seeds, except that they sparkle in the moonlight."

September 13, 2012

Title of the week!


"'Doctor' or 'darling'? Decoding the communication partner from ECoG* of the anterior temporal lobe during non-experimental, real-life social interaction" appears in Frontiers in Human Neuroscience.

________
*"ECoG" (pronounced "ee-cog" = Electrocorticography or intracranial EEG)

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