From the Collection: Velocity Model

Image collections can be an entertaining headache.  Imagine someone going through the shoebox of old photographs that your parents keep in the closet and trying to figure out each picture.  Sometimes the subject of the photo will be obvious. Other times it will be something that no one will ever be able to puzzle out without having been there.

Dudley has a modest collection* of glass plate negatives from the time of Benjamin Boss.  They seem to be part of Boss’s personal collection, so the shots of galaxies and lunar eclipses are mixed in with his wedding photographs and pictures of his children.  And there are also several pictures of whatever this thing is:

Galactic Velocity Model

The images were only labeled  “velocity model,” which isn’t very helpful.  It took a lot of digging, but eventually I stumbled across this bit from an interview with Boss:

Aided by an ordinary box which he had constructed, Dr. Boss was able to demonstrate the startling bit of news that the Milky Way actually spins or rotates.

Dr. Boss had ingenuously stretched fine lengths of thread between the top and bottom side of the box and upon which were fixed small beads. Dr. Boss pointed out that each small bead attached to the thread represented a star in the Milky Way. The entire cluster of beads suggested that they had been scattered, as a farmer scatters seed within the 180 degree angle. Dr. Boss then said that, were it possible to bring all the stars in the Milky Way into a small cluster to be held or fixed and then released for one minute and then fixed again, the stars in the Milky Way would appear in relatively the small positions he had arranged the beads. This, Dr. Boss said, proves to his satisfaction that Milky Way with its more than 30 billion stars is in reality a spinning or rotating mass.

– Albany Times-Union, Nov 24, 1935, p.2-B

Dudley’s major function during early twentieth century was creating a catalog of star positions and velocities.  This kind of work can be dismissed as boring “stamp collecting,” but it lead to some major scientific discoveries.  Here Benjamin Boss was using a simple model to show the three-dimensional position of stars within our galaxy to show how their motion leads to the realization that the whole galaxy is rotating.


(*) Bear in mind that I’m sitting next to miSci’s collection of GE photographs.  With 1.6 million photographs and negatives, it’s one of the largest image collections in the world.  In this building, anything that doesn’t fill a room will be considered “modest.”

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