> then wouldn't that require a razor's edge of criticality?
Yup. From the device description in its decommissioning plan:
The CFX was a sub-critical assembly of uranium-2-35 surrounding a Cf-252 source. The function of the U-235 fuel was to multiply the neutrons coming from the Cf-252 source, which fissions spontaneously. The CFX was designed never to exceed a Keff of 0.99. The CFX assembly yielded sufficient neutron fluxes for applications such as neutron activation analysis.
Keff is the fission neutron multiplication ratio; 1 is criticality.
The hard part isn't having a telescope, but analyzing the images for objects that have moved between successive observations. Digital astrophotography and analysis software have been getting steadily cheaper and better, which leads to more amateur comet hunters each watching more sky, which has rapidly improved the odds of catching rare objects.
I'm not sure how the progress of institutional and amateur observations compare. Obviously the big guys benefit from the same technological advancement, but I don't know whether the fraction of new objects discovered by amateurs has been growing or not. I suspect the odds of the first interstellar object being found by an amateur were still pretty long.
By my back of the envelope math, burning 600000 kcal should produce couple hundred kg of CO2. You could also make that crossing in less than a third of the time under sail, with about a third of the daily calorie consumption, for maybe a tenth of the CO2 output.
> MCUs particularly from microchip had really good documentation
Oh how the mighty have fallen. I've only worked on one major project with a Microchip MCU (PIC32MK), but their documentation and support were terrible. No detailed documentation, just a driver library with vague, sketchy API docs and disgustingly bug-ridden code. Deadlocking race conditions in the CAN driver, overflow-unsafe comparisons in timers, just intern-level dumbassery that you couldn't fix without reverse engineering the undocumented hardware. Oh, and of course what documentation did exist was split into dozens of separate PDFs, individually served, many of which were 404 unless you went hunting for older versions or other chips in the product line. It certainly cured me of any desire to touch another Microchip product.
> and I was annoyed that nobody had just told me that because I would have gotten it instantly.
Right?! In my path through the physics curriculum, this whole area was presented in one of two ways. It went straight from "You don't need to worry about the details of this yet, so we'll just present a few conclusions that you will take on faith for now" to "You've already deeply and thoroughly learned the details of this, so we trust that you can trivially extend it to new problems." More time in the math department would have been awfully useful, but somehow that was never suggested by the prerequisites or advisors.
oh, my point was the opposite of that. The math department was totally useless for learning how anything made sense. I only understood linear algebra when I took quantum mechanics for instance. The math department couldn't be bothered to explain anything in any sort of useful way; you were supposed to prove pointless theorems about things you didn't understand.
I did get a lot of that in the lower level math courses, where it kinda felt like the math faculty were grudgingly letting in the unwashed masses to learn some primitive skills to apply [spit] to their various fields, and didn't really give a shit if anybody understood anything as long as the morons could repeat some rituals for moving x around on the page. I didn't really understand integrals until the intermediate classical mechanics prof took an hour or two to explain what the hell we had been doing for three semesters of calculus.
But when I did go past the required courses and into math for math majors, things got a lot better. I just didn't find that out until I was about to graduate.
The jump from spherical harmonics to eigenfunctions on a general mesh, and the specific example mesh chosen, might be the finest mathematical joke I've seen this decade.
>If you’re alarmed by the fact that the set of all real functions does not form a HILBERT SPACE, you’re probably not in the target audience of this post."
If you're wondering what a Hilbert space, know that you're in good company.
> Dr. von Neumann, ich möchte gerne wissen, was ist denn eigentlich ein Hilbertscher Raum?
(Dr. von Neumann, I'd would really like to know, just what exactly is a Hilbert space?)
Asked to John von Neumann to David Hilbert at a lecture.
I'd like to add, as a physicist by training, that anything can be a Hilbert space if you wish hard enough. You can even use results about countable vector spaces if you need them!
It's quietly reversing the traditional "We approximate the cow to be a sphere" and showing how the spherical math can, in fact, be generalized to solutions on the cow.
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