explanation

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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Use that camera! . . . but why?

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Kodak 1918 camera and iPhoneOur photography correspondent writes: We’ve just gone live with our Use that camera! service, showing people how to use their film cameras.  But why would anyone want to do that?

Well, it’s not that film is better than digital.  That’s been settled.  With possible very tiny, specialized exceptions, digital photography can do everything film can do, and plenty that it can’t.  Digital pictures are available immediately, can be sent from your phone, can be adjusted to match your imaging vision in amazing detail; you think up your own virtues.

I still shoot film, for reasons that aren’t relevant here.  The question is why you would want to.  I can think up a few possibilities:

  • It’s different. You want to distinguish yourself from the crowd, or maybe just want some variety.
  • It’s difficult.  You like challenges.  There’s also the fun of bragging about how you overcame them.
  • Operating a fine old machine.  There is a pleasure in using a well-crafted device, even apart from any results you get.
  • It’s there, so it should be used.  It’s a shame that any well-made machine should rust away uselessly.
  • There’s a special connection.  Your great-uncle used it to take those pictures in the old album, and when you look through the viewfinder you realize you’re doing just what he did.  (Our working title for the service was Your Grandfather’s Camera.)
  • You’re writing an historical novel.  You’re aware that a 1940 Leica does not work like an iPhone, but you’re fuzzy on the details and it’s important to the plot.

The most important reason is the one that motivates you.  It may not be possible to put it into words, and it doesn’t need to be noble and serious.  Simple curiousity is a wonderful thing.

So: why would you use that camera?

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