a laser excites a single Strontium Atom, and it gives enough light off to be visible, with a long exposure, in this picture. it's the tiny blue dot dead center.
This model is from a SpanAm war era periodical. I up scaled and cleaned it up a bit, as it was closer to N than HO scale, and I wanted it for background with my Civil War figures.
pics from my Muskturtle Bend and Hidebehind Creek railroad. wonder if I still have the stuff in storage... the Walmart Battery train is great, but won't handle lionel points... Marx and old Hornby switches work fine.
One of my favorite things in the world are Vovelles. Vovelles are a sort of primitive computer that were integrated into old manuscripts. The Greeks certainly used the mathematics and principles behind them (see the Antikythera Mechanism). and may possibly have made them, but scrolls of that period haven't preserved. The ones we know mostly date from the 15th century. Most of them involve calculations relating the lunar and solar calculators; either for navigation or for medicine. Keeping in mind the medicine was hard to distinguish from Astrology.
Here's a pic from Billy Hill in NC of that Starlux Castle and the custom mounted knights I made, enjoying the weather in their new home. I sent them to him when I downsized, back when we were planning to move back to Washington.