Nights I spent puzzling over where they went

I am very, very tired. In the general way, I am not doing well at all. I think I had a good day. As a result of accompanying schreibergasse and Peter to the Cambridge Science Festival's Carnival of the Sciences and Robot Zoo this afternoon, I—

Watched my ungodson stream the air with enormous soap bubbles and fire off compressed air rockets courtesy of the Inventor Mentor in a very windy field, meaning that I took very few photographs and dodged a lot. He seemed to be having a wonderful time. I think he spent more of the afternoon with the soap-bubble frames than with anything else except maybe the football, on which more in a minute. Two festival volunteers were using compressed air to fire other items into the air, namely a stuffed animal monkey and handfuls of marshmallows, which were being caught with plastic-lined landing nets. They may have taken special requests from the audience: at one point I saw a stuffed Elmo ragdolling thirty feet above the ground. I was delighted.

Admired a student-built horn antenna from the Harvard-Smithsonian Center for Astrophysics. It was being used to detect the hydrogen line, also known as the 21-centimeter line—the spectral line of electromagnetic radiation at a frequency of 1.42 GHz created when electrons in the vast cold clouds of neutral hydrogen that swirl throughout our galaxy spontaneously flip from a higher-energy state to a lower-energy one, emitting the difference in the form of a radio photon with a wavelength of 21 centimeters. It's called the spin-flip transition because the electron reverts to spinning in the opposite direction from its proton where previously it had been slightly excited enough to align their spins, not unlike a pair of bar magnets that naturally configure themselves north-to-south and only stick north-to-north if external force is applied. Because we live in a spiral galaxy, neutral hydrogen rotates with the rest of the disk around the galactic core; it is distributed evenly enough that it delineates the structure of the galaxy. Which does absolutely jack for us in the visible spectrum, but since the radial velocities of hydrogen clouds at varying distances from the core can be determined by the Doppler shifts of their emission lines, by taking measurements of the hydrogen line from different points along the galactic plane and then comparing the observed wavelengths against the 21-centimeter standard it is nonetheless possible to calculate the rotation curve of our galaxy and from there the distances of the hydrogen clouds in question, leading to a map of the Milky Way, which was the project I did in high school with the homebuilt radio telescope that I have sometimes mentioned. I had a dish, not a horn. (It had been used for satellite TV. I gave it something more interesting to look at.) I got a very small slice of deep sky out of it, because 42° 26' 50" N is not a terrific latitude for this particular foray into radio astronomy, but since I had done the experiment partly to find out whether it would work at all given my resources and location, I still consider it a success. I mentioned it to the professor whose students had built the antenna and he wanted to know all about the technical and programming details that in nearly twenty years I have mostly forgotten (which makes me feel like a moron, by the way), so I promised to get him a copy of my two-year high school science project and now I have to deliver. He is very interested in amateur astronomy. I could at least tell him I definitely didn't have a USB receiver.

Realized my childhood dream of eating a grasshopper, thanks to the sustainable protein efforts of the students at the British International School of Boston. Also a queen weaver ant and a brownie made with locust flour. The insects themselves tasted toasty and crispy, with a texture unsurprisingly like chewing shrimp tails; if I had been handed it without comment, I would have said that the brownie was made with an alternative flour like spelt or rye, but I wouldn't have guessed anything as protein-stocked as locust. While I was eating the weaver ant, a young man came up and remarked dismissively on the size of the insects on offer, asking if the students had anything really substantial. He was offered a tarantula. He went away.

Was still hungry and got a lamb wrap from the food truck for Couscous Kitchen, I believe. It was the one that had run out of falafel and wasn't from Bon Me. There was also a truck specializing entirely in whoopie pies, but we would not patronize it until there had first been some tree climbing and more soap bubbles and stomp rockets and general running around. I ate it sitting on a bench in front of the Cambridge Public Library, remembering how it looked before the expansion in 2009. I knew where to find everything in the old building by kinesthesia. The children's room was around the back, at the basement level; at the top of the stairs was a mural with a diversity poem that did not rhyme (and might not have been meant to, but it bothered me when I was small; I kept trying to make it and it wouldn't). The stacks had black metal grilles underfoot and fluorescent bar lights overhead; they rattled when you went looking for books and hummed when you curled up to read them. The wooden climbing structure on the lawn smelled like a shipwreck after rain.

Got distracted by the hypnotic three-dimensional screen rendering of sound waves courtesy of the audio engineers at iZotope, who had set up two exhibits in a room off Cambridge Rindge and Latin's Field House: one to provide a visual translation of the frequencies of the human voice and the other to mess around with them electronically. "Who wants to sound like a monster?" one group of incoming children was asked by the guy at the sound board. A small girl shouted instantly, "I want to sound like a monster!" He asked her to record a line; she was so happy when he gave it a reverb-heavy bass snarl. There was an oscilloscope on the table next to the monitor screen. It was not identical to the one we had in the house when I was growing up, but it looked about the same vintage to me. Apparently I find that sort of thing comforting.

Shivered in the bright cold wind for about an hour after the festival ended and did not regret it, watching Peter and a total stranger about his own age learn to throw a football from two young men tossing and catching on the lawn. I never learned any of their names. The older ones looked like students, late high school or early college, the age that my brain mostly processes as "nascent adult" and "younger than me"; they incorporated Peter and then his playmate effortlessly into their game, even when the eight-year-olds decided that the best way to deal with the disadvantage of being literally half their opponents' size was to throw themselves at the older kids' legs in a massively inefficient but compensatingly tenacious semi-tackle, meaning that the student nearer us was intermittently running to make a play with a small child trailing doggedly from his ankle. From time to time there was a spaniel on the field, but no one stepped on it. I think it may have belonged to the stranger kid's family. I invited a third kid to join when I saw him leaning wistfully on the rail, but he had to ask permission from his parents first and apparently they said it was time to leave instead. Eventually we pulled Peter away because I was starting to be unable to feel my fingers, having not realized from the quality of the sunlight that I needed to carry gloves when I left the house, and also dinner needed to happen on a reasonable timeline. The whole thing was adorable, which may be the first time in my life I've been able to say that about football.

Discovered a copy of Ernest Tidyman's Shaft (1970) in the basement of the Harvard Book Store while Schreiber' was racing his son around Harvard's campus in hopes of burning enough energy off Peter that he could actually sit still for dinner. Of course I took it home. I have no idea how it compares to the film, but by the end of the first chapter it's fascinating. Stylistically, it is perfect hardboiled noir, but its protagonist is a black private eye in 1970 New York and that is such a specific viewpoint that it makes the generic elements of the story pop suddenly into new perspective.

Had dinner with Schreiber' and Peter at Christopher's because Peter desperately wanted a hamburger. My favorite burger went off their menu sometime last year, so I have been coping by ordering a partial reconstruction of it every time I eat at the restaurant. English muffin, pepper jack cheese, avocado, chipotle mayo, it falls apart as soon as you pick it up, but it tastes great. Extra chipotle mayo on the side for the fries. I can't tell if I am recognizable to the kitchen yet.

Then I came home and gaudior asked me circumspectly if I knew anything about the carving knife hidden under a pile of bookmarks on the shelf nearest the kitchen. I didn't. That made three of us. Either one of the cleaners in March had unique ideas about filing cutlery or we have a really scary domovoi.

Maybe tonight I can get more than two hours of sleep.