Alex WellersteinVerified account

*cough* You don’t use instruments to measure a foot? Not a ruler? Or a laser beam?

I am saying that in addition to the measuring instruments, I have a sense of what they are measuring and can estimate from that. Or that the measurement tells me something I can feel.

I consider "judgment" and "experience" to be forms of tacit knowledge. But my main point is, if you have good/reliable instruments, you can rapidly skip over steps that previous people needed tacit knowledge to know.

Example: to identify what isotope a given radioactive source was used to take quite a bit of careful work. Today you can use "off the shelf" (though not cheap!) counters that instantly compare the gamma spectra to a database.

That means that what used to be a somewhat laborious and expert step is reduced to pushing a button. It doesn't eliminate the need for expertise at all, but it means that sort of thing is no longer a serious barrier.

In the context of proliferation, it is the difference between having to invent or fabricate a krytron from scratch and the ability to buy one from a wholesaler. It reduces the tacit knowledge needed dramatically.

The practical effect is that in many fields (not all), as "science marches on," tacit knowledge requirements will drop. Tacit knowledge requirements for a new nuclear state probably lower than they were in the 1940s, for example, because reactors no longer bleeding-edge tech.

For biothreats, the availability of new tools that let you, say, synthesize living viruses from computer code, will make the tacit knowledge requirement drop from "you need to be the very best in this field" (as when it was first done in 2002) to "you need access to the tool."