20190711_182714 An open air cafe by the Rąžė bridge
20190709_072113 Don't Leave It Sideways
20190710_144257 R on a stump in the Samogitian Alka
IMG_20180312_172341 Telescope tour at McDonald Observatory
Touring Harlan J. Smith telescope at McDonald Observatory with family. Left to right: dad, mom, Ray with R, and E. Our guide was an astronomer who worked at the McDonald Observatory, and he gave the most entertaining tour. I didn't know until then that you could write horror stories featuring telescopes! But his real-life tales could inspire you to write one.
The telescope sits on a round platform. Its edge is usually flush with the surrounding floor, but can be made to rise above the floor, as our guide demonstrated with a remote control. It rises as high as the top of those stairs. That's a pretty big height to fall from. There are no guardrails around the platform. It used to have posts with chains between them, but the telescope sometimes snagged on the chains when it moved. So they were removed.
And it is usually pitch-black in there, which is necessary for observing the skies. There is no light in the whole room, not even an emergency light to tell where the exit is. "Don't tell OSHA about us," the guide joked.
And that point about the telescope moving -- well, it moves. The guide made it move with the remote control, but it can also move on its own, because it is programmed to make automatic adjustments to its position. It beeps when it does so. So now you can imagine being in the pitch-black dark, on a platform a few feet above the floor, with no guardrails, no sense of where its boundary is -- and the telescope starts moving.
The most notable event when the telescope moved on its own happened about 30 years ago, and they still remember it here at the McDonald observatory. The movement got out of control and the telescope actually crashed on the floor. It did a lot of damage to the floor underneath. Luckily, there was *something* -- the guide gestured to some interior detail of the room, I wasn't sure what exactly -- that it caught on, and that kept it from crashing through the floor altogether.
The guide didn't just entertain us with his horror stories. The way he explained the science and technology behind the telescope was just as interesting. He explained how the two main types of telescope focus -- Cassegrain and Coude -- work by making sweeping motions imitating the rays bouncing back and forth between mirrors, and continuously asking the audience questions to brush off their rusty knowledge of high scool math: if we want to send a ray on a trajectory that gets close, but does not quite approach the straight line, what is it called? That's right, a hyperbola!