my only credential is a bio-eng degree, but i read a lot and hope to put together a novel or something to get ppl thinking about it, until we can find a way to test the hypothesis
wouldnt the average refund come out to basically a free year of membership? the easiest thing for them to do might be just check who was a member during the tariffs, and credit their membership fee for the 'tier' they were buying
people using costco as basically a small-business depot would be lifetime non-transferable free members, and typical family/consumer gets some extra years, which they'll turn around and spend in the store anyway
win/win? costco members are sticky, and refunding cash is hard
i made a small 3x3 proof of concept using more expensive geiger tubes, and their really long 'z-axis' lengths made 'traces' happen very often, like a persistent cloud chamber
trying to find a reliable semiconductor (read:cheaper) method i can scale to an arbitrary number of pixels, but something seems to happen in between the bench and the wall :(
* scanning a linear array of BPW34 photodiodes, in a similar spirit to a scanner to cover a plane, each photodiode going to its own "MCA circuit" (TIA->cheap audio codec like those from Everest Semi). Either direct measurement of generated charge pulses or covering the photodiode with phosphor on aluminum foil or so
* cloud or bubble chamber (cloud chamber is less dense and will generate fewer events, so probably bubble chamber): instead of needing a large 2D or 1D array of parallel circuits, we image and track generated charged particles and use the trajectory starting end (less curved) to determine the source direction!
* consider X-ray crystallography, an incoming straight beam can diffract in many directions on a monocrystal. rotating say a silicon wafer, and measuring the incoming photon energies with one or more photodiode/MCA circuits we can assign a source likelihood distribution by keeping track of the orientation of the monocrystal. akin to sparse sampling but instead of masks its diffraction patterns.
If you have better ideas or variations in mind, let me know!
for resolution, i'm only limited by whatever the bus company is throwing away that day ;) but i'd love to come up with an easy-to-produce design that can work per-pixel for arbitrary spacing
yup after seeing #2 at a museum and learning about the chemistry needing to keep it running, i started looking for something like #1, but i'm not able to get any PIN diode circuit properly reporting events with consistency compared to my GM tubes :(
#3 sounds fun! i'd like to turn this into something i can open-source and hang on a wall, emitting x-rays might make it a hard sell :P
For your PIN diodes, what was the depletion region width/thickness of the Intrinsic layer?
Do you have access to a high bandwidth oscilloscope? do you observe the expected exponentially decaying pulses? Sound like you could debug your circuit to find out what is happening.
For higher energies on would want to use a thicker intrinsic region, one approach I have considered would be to use a distant aperture, so that the direction of incoming rays is known, and then tilt the photodiode so that the rays can experience a much longer path in the intrinsic region (so that when a photon generates a high energy electron, the stopping length can be attained without clipping / aliasing the energy resolution as much). Basically tilt the photodiode so that its plane is closer to parallel (or exactly so). There is a trade off between cross section (fewer events) and maximum energy measurable, one can compensate for the lower cross section by having more photodiodes.
all 3 proposals would be passive, including #3, so it wouldn't emit X-rays, just detect them and build up a self-consistent picture that explains the observation statistics for each event (with that energy and time/orientation of the silicon wafer).
i was just using BPW34s :) i have a batch of different photodiodes that i was planning on swapping and comparing but i can't even make these work reliably...
currently limited by my 20MHz scope (and free time...), but i saw the expected pulses after they were drawn out long enough by the amplification circuit to validate it was working on my desk (https://physicsopenlab.org/2020/06/15/cern-diy-particle-dete...), but i think my issue is shielding the diodes without introducing noise?
The reality of most multi-generational households is that the wife is eventually coerced into becoming an unpaid caregiver for elderly parents (who often constantly criticize how the household is managed). This sort of "worked" in traditional societies when women didn't have other options but when they're educated and have their own careers it usually doesn't seem like such an attractive choice anymore.
I'm not opposed to multi-generational households and I have friends who have made it work well. Let's just not assume that it can be a scalable solution.
It was never an attractive choice- people simply did not have options. In my country it was not until the 1950s that retirement homes were invented and the elderly finally got their social security (remember pensions did not exist).
for incredibly simple parts that i can describe using measurements, i've had a lot of fun pointing a high-power ai at openscad and letting it iterate through making the design for me
it's still tough to turn it into something i can then keep fiddling with in freecad though
put on "tron: ares" in the background to fully appreciate the model designing something that will be 3d-printed :)
You can get even more vague and just generally describe the design of something, making sure it leaves exact measurements to parameters, and end up with something usable. ("Make me an openSCAD file for an pointed star with curved points and an inward taper. The number of points, thickness, and angle of taper should be configurable")
putting together a theory on how bacteria organized multicellular life to exploit our macro-movements and proliferate between damp spots
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