Tracing the history of medieval astronomy
One of the long term goals of this project is to collect enough data to derive the orbit of Mars. However, because Kepler didn’t know the orbit of Earth, he couldn’t use the observation on any given night. Instead, he only used observations from when Mars was at opposition1. This happened to be last night, so we packed up the quadrant and headed out.
Continue reading “Data: Stellar Quadrant Observations – 7/27/18 (Mars Opposition)”
Having finished the quadrant this past weekend, I was finally able to take it out for it’s first light2. A special thanks to Her Excellency Slaine for helping me transport parts that wouldn’t fit in my car as well as Padrig for being my chief observer.
So how’d it go? Continue reading “Data: Stellar Quadrant Observations – 7/20/18 (First Light)”
The great quadrant is finished.
Continue reading “Instrumentation – The Great Quadrant: Day 12”
Today’s project: Finish the scale.
The process on this was very straightforward albeit tedious. At the edge of each line for a degree, I made a slight notch with a razor knife. For each of the 810 transversal dots, I took a small nail and hammered it lightly.
Continue reading “Instrumentation – The Great Quadrant: Day 11”
Today was a much shorter day in part because I’d lost track of time causing a late start and in part because we’re running low on things to do on pieces that don’t currently have paint drying on them.
In particular, getting the scale transferred was one of the larger things remaining. So we started the night by masking off the scale:
Continue reading “Instrumentation – The Great Quadrant: Day 10”
We’re getting very close to the end of construction, so it’s the point where it’s down to a lot of small details. To start, here’s a better picture of the axle assembly:
I’d shown a picture last time, but today, we added a brass fitting to help tighten the portion that goes through the central column, and using a pipe wrench, tightened the portion that will go through the arm so it cannot rotate, forcing the quadrant arm to rotate on it whereas during the test assembly last time, the arm caused the axle itself to turn. The cap on the end still goes on finger tight so it can easily be removed to disassemble the instrument for transport. Continue reading “Instrumentation – The Great Quadrant: Day 9”
It’s said that a project involves blood, sweat, and tears. Today was two of the three. Somehow have managed not to get splinters till today, but got a pretty good one. It was also hot in the workshop:
Continue reading “Instrumentation – The Great Quadrant: Day 8”
With the upper portion of the base ready to hold the center column, today’s focus was on getting a socket for the center column to rest in. To start, we created a set of cross beams.
Continue reading “Instrumentation – The Great Quadrant: Day 7”
Today’s focus was on starting to build the discs that would allow the central column to rotate.
The central column is 4.75″ square (a roughly 6.75″ diagonal), so we decided to cut an 8″ disc as well as a 9″ disc which would lay over it.
Continue reading “Instrumentation – The Great Quadrant: Day 6”
With the quadrant itself pretty much complete (aside from the scale), it was time to start working on something to mount it on. So today we started with the central column which was assembled from plywood to make a 5″ box that was 8′ tall.
Continue reading “Instrumentation – The Great Quadrant: Day 5”