dmwood

Photo editor of a 1970 high school yearbook here. These are accurate reflections of MY memories too. Maybe it was a Yashica Mat I used...

In my dotage I have become interested in radiation epidemiology and, of course, the issue of 'statistical power' comes up repeatedly. As noted, most physicists know only as much statistics as is absolutely necessary for their work. It would be wonderful to introduce statistics by a set of scenarios (possibly with references to relevant parts of the text itself) drawn from, say, 10 distinct fields. To my dismay, I found that chatGPT did a remarkably decent job of telling me what had been missing in my readings. So think of the project as: what value is added above what a reader could find after 30 minutes of AI delving.

C'mon, man. The use of the 'attributable fraction' (AF) in legal cases about toxin exposure is well established, if not uniformly legally applied. Careful epidemiology routinely produces the `excess relative risk' of an exposed population to a specific exposure. From this the AF can be computed as ERR/(1+ERR). For example, for uranium miners in the early days of the nuclear program the AF for lung cancer (via radon in mines) was 60% or more. Large scale epidemiology for U.S. cabin crews is already past the planning phases. Naturally not much can be said about one individual's case (except via intrusive genetic testing for predisposing factors), but the AF permits at least a rational way of proceeding.

Crashes on launch

macOS: macos-26_arm version installs (with intervention to permit running), but crashes on launch. ------------------------------------- Translated Report (Full Report Below) ------------------------------------- Process: perspec [94673] Path: /Users/USER//Perspec.app/Contents/Resources/perspec Identifier: perspec Version: ??? Code Type: ARM-64 (Native) Role: Unspecified Parent Process: Exited process [94672] Coalition: com.adriansieber.Perspec [86355] Responsible Process: Perspec [94671] User ID: 501

Date/Time: 2026-08-04 12:50:37.5848 -0600 Launch Time: 2026-08-04 12:50:37.5821 -0600 Hardware Model: Mac13,1 OS Version: macOS 26.6 (25G72) Release Type: User

Crash Reporter Key: 9FD40ACB-279F-0F79-41E1-8B4D3B663EA7 Incident Identifier: 207F9047-B786-4C8C-8263-BA9C4DB370EB

Time Awake Since Boot: 320000 seconds

System Integrity Protection: enabled

Triggered by Thread: 0

Exception Type: EXC_CRASH (SIGABRT) Exception Codes: 0x0000000000000000, 0x0000000000000000

Termination Reason: Namespace DYLD, Code 1, Library missing Library not loaded: /opt/homebrew//libwebp.7.dylib Referenced from: <47F30FA1-4AB9-310F-8988-5CABFEF76F5E> /Users/USER//Perspec.app/Contents/Resources/perspec Reason: tried: '/opt/homebrew//libwebp.7.dylib' (no such file), '/System/Volumes/Preboot/Cryptexes/OS/opt/homebrew//libwebp.7.dylib' (no such file), '/opt/homebrew//libwebp.7.dylib' (no such file) (terminated at launch; ignore backtrace)

Dyld Error Message: 1

Question from a naive macports user. To some extent brew is orthogonal to macports. Is there an easy way to link to ffmpeg installed by macports? Thanks.

Not an average software engineer--beautiful page (imperfect spelling)! Why does detection scale as the 4th root of the RCS? Nice problem for the radiation theory part of a graduate electrodynamics class.

This was the Revell 'Visible V8', first released in 1958. https://macsmotorcitygarage.com/revisiting-the-visible-v8/

Yippy! I feel like I'm 15 years younger

This appears to be prodigiously powerful, but has a --dry-run option and support for whitelists. I love the fact that it's a lightweight and verbose script.

Just a few slots down in my YC feed: the benefits of bright light

https://www.nature.com/articles/s44271-025-00373-9

Thank you for your website.

A trip to Wanamakers at Christmas (including eating in the top-floor restaurant and listening to scheduled organ concerts) was a treasured fixture of my childhood in the late 50s and early 60s. If I remember correctly, there was a monorail-like tram that ran around the periphery of the toy department too. Christmas lights festooned the facade of the organ.

Depending on the field, 3 Gy IS 'small' (with respect to doses to tissue during cancer treatment, which can be 60 Gy). Whole body doses of 1 milliGy in the environmental biz are considered worth examination. Even investigations of biomarkers for radiation exposure typically use doses in the range of 3 Gy.

Probably from one of the crazies in Dr. Strangelove (the movie)

Phenomenal. Just wish I knew if this was under a CC license.

I like this very much. BUT: What I cannot save I do not remember (quoth the Old Guy). Any way to save these images as SVG. (Screen grabs are less satisfactory.)

Shell dependencies for install? Got: bash-3.2# just package && mv dist/infat* /usr/local/bin/infat # Wildcard because output name includes platform bash: just: command not found

I welcome the new library! I have used a RadiaCode 103g for more than a month. I also have a more conventional NaI:Tl 5cmX5cm scintillator+PMT in my basement with 95 lbs of lead shielding (as lead shot). I'm painfully familiar with detector drift and recalibrations required with conventional (amateur) detectors. In my opinion the RCs are game changing: their calibration ranges from good to excellent, in that I can import a spectrum into the (exceptionally useful free Sandia National Labs) tool InterSpec, extremely quickly identify peaks and the relevant radionuclides. The RC is very compact with a well-defined detector volume (because it IS relatively small). If there is a weakness, it is that it's mostly targeted toward running on a smartphone and support for iOS vs. Android has lagged a bit, though very recently an excellent update has appeared for iOS. I have tested in on a variety of spectra (137Cs, 232Th, 60Co, 133Ba) and for long background counts and am quite happy with the resolution and stability. I have yet to use its interface to GPS data (I already have a bGeigie Nano built from a Safecast kit). Its impact is that almost everything one might like--count rates, dose rates and net dose, data logging, and GPS interface is all there in a sub pocket-size unit.

As noted, ordinary maps may suffer (for example, in epidemiology)from the impact of a very non-uniform population density. A disease cluster then MAY be a cluster, or it may be ordinary disease rates in a highly populated area. In my limited experience a cartogram is a deliberate distortion of the SHAPE of a map region in order to make some property (say, population DENSITY) constant everywhere in the new region. Then anomalies jump out. Done with care, one can do careful statistics within the cartogram and then back-transform to get statistics for the original map area.

I've used XRG (free) from gaucho.software through many changes of hardware CPU numbers and macOS versions. Light and fluffy, for me at least.

As Frank Siegert used to say (maybe still does): "Vi is the answer. Now what is the question?".

"Updated fraction of cancer attributable to lifestyle and environmental factors in Denmark in 2018", Scientific Reports | (2022) 12:549 https://doi.org/10.1038/s41598-021-04564-2 attempts to tease out causes: 38% tobacco, alcohol 7%, obesity 9%, occupational 6%, air pollution 3%, infections (like HPV) 7%.

Another data point, this time from a retired university faculty dude. I have recurring dreams of having to give a lecture (typically at a graduate physics level, which is what I taught most) but have not prepared. Worse--I'm not sure where the lecture room is. Sometimes I dream about winging it--and wake up mildly proud that I remembered as much as I did, though it was wrong in detail.

Amen. For those interested, google 'percolation theory in two dimensions' to see general results.

The INWORKS study and reports are among the best there are. What's new about this report is that error bars for low doses are much smaller, presumably due to more stringent dose quality requirements and better dosimeters, which became available only well after may nuclear processing plants came online. For high cumulative dose, there are fewer workers exposed, so error bars are of necessity large. This paper reports excess relative cancer death RATES rather than excess relative death RISKS (of course very similar) Error bars crossing reference lines are not uncommon at low doses in this biz, and have been attributed to "radiation hormesis", a BENEFICIAL or protective effect of ionizing radiation exposure at "low doses", currently believed to be somewhat more than background radiation exposures. Such hormesis naturally implies serious corrections to the "linear, no threshold" picture almost universally used in radiation dose/response.

The figure at https://www.semanticscholar.org/paper/Radiobiology-and-Radia... shows hormetic response (ERR<0).

So the new results make it more difficult to defend radiation hormesis if the ERR vs. dose is STEEPER at low doses than at larger doses.

No. The 'faceting' of a crystal is determined by a minimization of the 'Gibbs free energy' [a thermo quantity determined mostly by the relative energies of different faces of the crystal, at low temp] over all the faces. The relative energies of the facets are in turn determined by the crystal structure, and the favored crystal structure is determined by the 'electronic structure' of the material itself. Li is an alkali atom, so presumably in the metal donates its outermost 's' electron to make a relatively simple metal. Almost never does crystal shape in any way reflect directly the atomic structure

Funny how often the word recollect has come up here, without mentioning the fantastic tool recoll, updated frequently and available for many operating systems. I use it on macOS for an immense library of scientific and other documents. I think there's a standalone installer, and it's also available via macports. It may be found at

https://www.lesbonscomptes.com/recoll/pages/index-recoll.htm...

It allows me to index and find words and phrases in files of many types AND view their contents independently of external readers, or using system readers, including text, PDF, or word processing files of common sorts.

I'm surprised that ultrasonic transducers cannot be used to search for cracks or developing imperfections. Can one launch surface-localized waves at one place, pick them up relatively far away on the surface?

As a child visiting Luxor (back before mass tourism) we were able to climb fairly conventional staircases to the top of a temple near (or at) Karnak. So ordinary staircases in ancient Egypt probably predate the Romans by 1000 years or more.