Infinite Wishes: ♾️🧞‍♀️✨

Is a weblog by Emma Humphries

29 Sep 2021 » Ions for peace

SF writer Charlie Stross on the state of ion engines for space propulsion

Ion thruster in operation
Credit: NASA/JPL-Caltech/ASU

Charlie Stross on ion engines for space propulsion:

“Silently, and without anyone outside the industry paying any attention, ion rockets have gone from being SF in the 1980s to being a ubiquitous enabling technology today, propelling deep space missions as well as significantly extending the working lifespan of satellites that previously relied on chemical fuels for maneuvering/orientation.”

The spacecraft which visit asteroids and comets such as Dawn, Hayabusa I and II, Rosetta, and Lucy, as well as SpaceX’s constellation of Starlink satellites all use ion engines. The thrust generated by an ion engine is small, but unlike a kerosene/LO2 or H2/LO2 engine, it can run for weeks or months at a time.

Bonus: Learn how ion thrusters work and how to build your own (safety warning for high voltage, and now I need a Wimshurst generator.) And if you just want to buy one, talk to Busek, who offer a variety of solutions depending on your mission requirements.

26 Sep 2021 » What does God need with a meteorite?

In which the worst Star Trek movie has a commentary on the meteorite-destroyed-Sodom matter.

Kirk asks God a question
Credit: Paramount Pictures with added text

When I was still in graduate school, one of my housemates and I decided to take a Friday afternoon and a bus to a theater off-campus to see a matinee of the fifth Star Trek movie on opening day.

My housemate and I stumbled into the cloud-covered daylight afterwards and questioned why William Shatner was allowed to direct a Star Trek movie.

The movie is about Spock’s brother trying to commandeer the Enterprise on behalf of God.

Reader, it was horrible.

Kirk, at some point in this disaster of a movie, where the bridge crew sings “Row, Row, Row Your Boat” at Yosemite, Uhura does a fan dance, and that’s about the only other bits I remember from it, asks the obvious question: What does God need with a starship?

And this is the question I have for the authors of the Tall el-Hammam paper purporting to establish the cause of the destruction of Biblical Sodom as a meteorite airburst’s plasma spike. If one believes that God destroyed Sodom isn’t faith that God did it enough, considering other experts are questioning the paper’s conclusions.

What does God need with a meteorite?

25 Sep 2021 » Dad jokes of Biblical proportions

Theodicy is when God lets a meteorite destroy a city, comedy is when your physics experiment triggers a vacuum catastrophe

There was a recent off-Broadway production of stories from the Bible.

It was done without understudies.

Last week one of the leads was in a freak accident and the show had to go dark.

The show’s producer stormed in on the casting director and exclaimed, You only had one Job?

20 Sep 2021 » High powered abstractions

Progressing through high powered model rocketry certifications is about filling in abstractions

If you’ve flown a model rocket, most likely the first one was something with a pre-fabricated fin can, that you built in a few minutes and flew right away. Mine was an Estes Alpha III my brother gave me as a gift.

The kit got you flying rockets, and if you were excited by launching that first rocket, you’d be willing to fill in the gaps in knowledge that kit abstracted away such as stability, center of gravity, aerodynamic drag, and recovery systems. I got a copy of G. Harry Stine’s Handbook of Model Rocketry (still have it, thank you) and started reading, filling in the gaps in my knowledge, designing, and flying my own rockets.

Julia Evans describes the same process around learning programming. You may have started writing HTML by hand and viewing it in a browser, or wrote a simple app and deployed it using Heroku or Glitch, and from there you learned about HTTP, threads, queues, and caches.

But getting a result right away, whether it’s Hello World or the rocket you built a few minutes ago landing safely under an orange and white parachute, is a foundation to build from.

Even the path through the levels of High Powered Model Rocketry certifications works through a similar plan.

The level one certification, which I completed in Summer of 2021, let me ignore fine details. I had to demonstrate the basic skills I had from building rockets, applied to bigger motors, using epoxy instead of wood glue, through the wall fins, and flying and recovering a rocket in view of an examiner.

For level two, not only do I have to build and successfully launch and recover a rocket, I have to demonstrate knowledge of aerodynamics and safety in an exam. I have to demonstrate I know why I’m using a technique, not just that I can fiberglass a fin or use a dual deployment altimeter.

Level three is, in many ways, a thesis project. You’re building a rocket with redundant systems. You submit the design to a committee for review and approval. Here the role of abstractions is project management: the recovery system is a block, but you know the details of everything in it, as you do with the motor, the the airframe, and the tracking and telemetry.

A level one rocket is Hello World, a level three rocket is a web application running at scale.

I’m flying some more ‘H’ and ‘I’ motors before starting on my level two rocket. It’s not just about leveling up, but enjoying what I can do with my knowledge now.

08 Sep 2021 » Founding Failsons

W.E.B. DuBois on the South's Aristocracy

Today the State of Virginia, at long last, and not without the sacrifice and efforts of people of good will, removed the mounted statue of Confederate General Robert E. Lee from its plinth in the state’s capital of Richmond.

Reginald Braithwaite linked to a scan of DuBois’ short, biographical entry on the slave states’ war leader on Twitter, and I find it describes too many of our Governors and Senators today.

“It is the punishment of the South that its Robert Lees and Jefferson Davises will always be tall, handsome and well born. That their courage will be physical and not moral. That their leadership will be weak compliance with public opinion and never costly and unswerving revolt for justice and right.” — W.E.B. DuBois

Keep punching fascists, folks.