The Oxford Museum of the History of Science is full of beautiful brass and glass

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As part of my tour of Europe I visited Oxford in southern England. A personal favorite was the Museum of the History of Science.

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When Albert Einstein came to Oxford to give a seminar in 1931, someone saved the chalkboard and now it is in a museum. Never erase chalkboards after seminar?

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They had an ample collection of vintage microscopes, including these of the single lens variety.

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The Leeuwenhoek microscope replicas are museum pieces in their own right: 1800s recreations of 1600/1700s technology. You can see that the simple objective is stopped down substantially, limited by a small hole in the brass. Simple microscopes had better resolution than their early compound counterparts, which suffered from the aberrations brought on by all the extra optical elements. Single lens microscopes, essentially ball lenses, mainly suffered from spherical aberration, which can be decreased by limiting the aperture diameter as seen above.

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I am fairly certain the objective on the above simple microscope is mounted upside down, but that gives us a good view of the Lieberk├╝hn reflector. The reflector, a concave mirror around the objective lens, was used to illuminate a specimen with epi-fill light across a wide range of angles.

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The Oxford Natural History Museum was down for maintenance, but I walked through on the way to the Pitt Rivers Museum. The Pitt Rivers Museum includes shrunken heads (the trick is to take all the head parts out first) among many, many other specimens. Even a modicum of interest in anthropology will keep you in the museum for hours.

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The Radcliffe Camera may be my favorite building in Oxford. It is much larger than it appears in pictures. Compare the view through a not so wide-angle lens (above) and wide-angle lens (below).

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I tried to capture the schlieren effect created by the heat rising from this juggler’s clubs, which you can make out on the right edge of the tall building in the background.

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Johannes Kepler’s Boarding School

theScinder is currently doing a world tour of sorts. Normally bound to North America, I am now in Europe and will be visiting several points of interest to science history and future. Last weekend theScinder toured the Kloster at Maulbronn, Germany. A historic monastery, UNESCO world heritage site, and the location of Johannes Kepler’s seminary school.

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You have heard of Kepler’s laws of planetary motion if you have taken an introductory physics course, but his education here was steeped in religion, and religion played a prominent role in his scientific work.

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Impressive lighting effects in the church.

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I brought a manual perspective control lens on the tour, and found an opportunity to demo parallel-line correction. There is an interesting trade-off between correcting your earth-bound perspective by shifting the lens and introducing off-axis aberrations. The lower photo of this stained glass window is more corrected for perspective (notice the lines of the framing) but blurry. The optimal conditions for a maximum degree of perspective shift may be a good question for Ernst Abbe’s column.
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Maulbronn sunset over the Kloster.

Next week theScinder visits the University of Glasgow, alma mater of William Thomson, namesake of the most sensical units for temperature.