explanation

It’s about time

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Not about saving daylight

watchWe’ve just gone through the annual ritual of Falling Back, shifting our clocks by an hour to conform to Standard Time. It’s the regular opportunity for scientists to point out, with either smugness or exasperation, that all summer we haven’t really been Saving Daylight; that there is exactly the same amount of daylight regardless of what our clocks read. Sometimes they wander off into explanations of Local Solar Time, Standard Time Zones and, if not quickly stopped, bring up atomic clocks.

Here we will avoid that sort of thing. In the interests of understanding other people, or at least building character, we’ll look at time from the standpoint of non-scientists. It’s not the same time as we understand, and translation is in order.

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In the eye’s mind

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What you see depends on what you’re looking for

catalog1Our photographic consultant is fond of pointing out to us, with the help of books and magazines, the different styles of great photographers. Clearly part of the variation in the final image is in the subjects they choose: Ansel Adams is famous for mountains and landscapes of the Southwest, quite a different thing from a New York City street photographer catching an instant among people. “But,” he says, “put in exactly the same place, facing exactly the same subject, they’d still come up with different pictures. They just see differently.” Which is true, and much more widely applicable than he meant. Even the same person looking at the same scene can see something entirely different at a different time.  A simple exercise can show this.

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“I was, like, you know. . .”

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A different kind of communication

Our astronomer has often found himself traveling on public transport and occasionally eating alone at crowded restaurants. This means he has overheard many a conversation, unintentionally to be sure (he lacks the gossip gene, or alternatively the instincts of the spy). Many of them have been very irritating to him, and at least he sat down to work out why.

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What were the odds against that?

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Concidence, probability and asking the right question

Our chief consultant writes:

diceWe’ve all had it happen: some unexpected, unusual occurrence, and someone asks: “What were the odds against that happening?” As an exclamation, an alternative to the pedestrian, “That’s unusual,” this is fine. Language should have flexibility and the freedom of metaphor. This becomes a problem, however, when the unusual event is taken to imply unknown laws of physics or perhaps sinister forces at work.

Actually working out probabilities in any but the simplest cases can be pretty tedious, and we’re not about to get into that here. But it’s easy to make basic mistakes in setting up this kind of question (respected scientists have done so); we present two rules to help keep you out of trouble, even if you’re not going to punch any numbers into your computer.

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How do you set out to learn something?

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Taking charge of your own education

rolls of filmThis week our photography consultant had the opportunity to watch as two young people developed their first rolls of film. Of course he enjoyed their excitement at actually using this unfamiliar old technology, and was reminded that his own first roll was a long time ago. (It’s still available in the archives, but is—understandably—not brought out for printing very often.) More important, though, are his observations on learning things, which is not the same as being taught.

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Mythology and cosmology

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bbcc1Our chief consultant writes:

Science is a part of our culture. It’s not just that the products of science are all around us, in our hands and in our lives; no less, the discoveries of scientists are covered in the mainstream news media (not always well) and the concepts widely known (not always accurately). It’s clear enough by comparing our world with that of other cultures, say in the particular case of astronomy. We have cosmology (the Big Bang and all that); the ancient Greeks, a series of stories about gods and Titans.

Studying humans, even as amateurs, one seeks out similarities across cultures, and so we see cosmology equated to cosmic mythology. This leads to assertions like, “Cosmology is only our way of explaining the universe to ourselves, exactly the same way other cultures use other explanations.” This is just true enough to be seriously misleading.

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Are selfies selfish?

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A subtle social effect of technology

lensOur photographic consultant was somewhat bemused by the rise of the “selfie,” that picture of one’s self possibly including others, possibly including a situation or location, taken normally with a smart-phone camera and distributed immediately and electronically. Self-portraits are as old as art and pictures of the family in front of the Grand Canyon as old as Kodak Brownies, but the enormous flood of “selfie” shots seems to be a new phenomenon. An older generation is inclined to blame the self-centered Millenials, using the newest of technology mostly in an adolescent game of self-promotion.

We think, however, that the “selfie” instead demonstrates an interesting example of how a simple technological change can result in a social phenomenon. This is not to say that technology is a cause, but it enables unexpected things—when people are included.

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How can you tell, if you’re not an expert?(3)

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Dueling PhDs

Our chief consultant writes:

gas-tube spectrumWe come to the hardest problem to set a layman: suppose there are two (or more) experts, that is, people who disagree strongly about some scientific or technical question, each of which has some claim to expertise. Call this “dueling PhDs.” You, as a layman, are called upon to decide between them. What do you do?

We assume that the matter is advanced or esoteric enough that there’s no question of you actually checking the math yourself. Also, that it’s not a matter of current research, where the answer really isn’t known. (That excludes, for instance, Stephen Hawking and Roger Penrose disagreeing about the Nature of Space and Time.)

You could try to evaluate the credentials of either side, working out whose PhD is stronger; or take of vote of scientists working on the matter; or, perhaps, decide on the basis of motivation, asking who is funded by whom. Slightly more useful is analyzing the rhetoric, on the assumption that someone with a poor scientific case is more likely to try to cover it with noise. All of these techniques leave us uneasy, and though we have some suggestions on how to use them we prefer a harder, more time-consuming method as a more reliable way of getting at something like the truth.

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A Textbook Case

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textbook and calculationsOur astronomer writes:

Now and then I come across an interview of some Nobel prize-winning (or otherwise distinguished) scientist with the inevitable question, “What got you started on your path to fame?” Almost always it was an inspiring teacher or mentor, a person who imparted a love of or excitement in doing science. Somewhere in the years between High School and Grad School, between the time when our differences were mostly potential and the time we’re on our way in a particular direction, someone lit a fire. Often there’s a quote something like, “He/She showed me that [insert science here] is more than just a set of results in a dusty textbook, but something that I really enjoyed doing.”

Similarly, in accounts of some part of the history of science it’s almost inevitable that I encounter a sentence like, “so science proceeds in sometimes a roundabout and uncertain fashion, not at all as the textbooks tell you.” Textbooks are not often held up as good examples.

The message, sometimes explicit but often implied, is that our job as teachers and scientists is to inspire and excite. Trying to impart “textbook results” is deprecated. Well, this time I am standing up for the textbook and the type of learning it represents. There is a time when it is just what we should be teaching. We need to ask the question: what are we trying to do? What is the outcome we want in our students?

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Big numbers in science communication

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table of astronomical numbersOur astronomer writes: In his book Wind, Sand and Stars, Antoine de Saint Exupéry tells the story of a group of Bedouin from the Sahara brought to metropolitan France. This was in the days of the French colonies in North Africa, and the intent was to impress them with the greatness of the civilization of Europe (or at least its power) so they would stop fighting against it. On their return, they said Paris, iron bridges, locomotives, everything was “very big.” They’d learned that Frenchmen seemed to be satisfied by the phrase and used it to buy some peace. In fact they did not comprehend what their guides had tried to show them.

I find that, in explaining astronomy to the public (including students in introductory classes) there is a temptation to play to the “ooh and ahh factor,” to try to impress one’s audience with big numbers to show how different it is from normal experience. (Sometimes there is the unspoken subtext: “Look at me, how good I am to be able to work with huge numbers!”) But if we are not very careful we may, in the end, only leave the vague impression that astronomy is “very big.”

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