it makes sense now with this examples

what cortex ... you need to more specific

It's a medieval measurement, still in popular use. Nowadays it means approximately 2.54 centimeters. Historically, it's the height of the ash pile a "witch" would leave behind, and the word has morphed only slightly from "witches" into "inches."

Actually nowadays it means exactly 2.54 cm as that’s how it is defined. Which also means all distance measured in US Customary units is ultimately metric too

Inches from the source. Inverse square law applies

Fast electrons through air mostly have elastic scattering making their long distance path a 3D random walk with exponential dropoff which dominates the inverse square geometric dropoff.

Sr90 beta decays emitting an electron becoming daughter decay product Yttrium-90. Yttrium-90 then beta decays (after a half-life of a few days) emitting more energetic electrons than Sr90, and those electrons travel a mean distance through STP air of maybe meters and effectively don't travel further than say 10m.

At long distance through air the Bremsstrahlung xray radiation dominates? It is generated by the fast electrons curving when passing close to nuclei. Xrays through air are inverse square? I guess it depends on the absorbtion characteristics of air.

AFAIK the above is mostly correct but I haven't checked anything properly sorry.

Basically anything to do with radiation is usually deeply complex and you need to look at all the different factors before making assumptions.

Presumably the measure of distance from the source to receive dosages under those conditions.

is this project still going or this is dead for now

what do you trying to say with your first para .

can you give me example

You are very important research subject, pls share more about your experience to the world , or try to be part of some research/project.

I dont have Aphantasia ,but there is something weird I noticed ,

when I am trying to visualize something I dont know about or know very little about I have to draw it in my mind instead of instantly visualize it .

example - like pretzel , I saw this for the first or second time in my life, so I have to draw it out. not like a house or horse or..

I think they should worth much much more than this

as a naive , it is non-intuitive for me how the lower bound is 0 kelvin, is this the temp where things truly stops oscillating (quantum level) or we just dont care .

All fields have a zero point energy/ground state energy they cannot go below. So, no they won't stop. The Heidelberg uncertainty principle also disallowes zero momentum and a fixed position.

I am here to just appreciate the article how clear it is .