Tech Tuesday for 11/20


Oscar Gordon

A Navy Turbine Tech who learned to spin wrenches on old cars, Oscar has since been trained as an Engineer & Software Developer & now writes tools for other engineers. When not in his shop or at work, he can be found spending time with his family, gardening, hiking, kayaking, gaming, or whatever strikes his fancy & fits in the budget.

Related Post Roulette

10 Responses

  1. Avatar Michael Cain says:

    TT2: Russia has many functional nuclear power reactors. You should replace the word “functional” with “floating”.Report

  2. TT4: I’ve come to the belief that these mass shootings are at least partially a result of social contagion. We’re seeing that they’re increasingly studying each other’s methods, improving on them, becoming obsessed with being the next Columbine. I’m not sure what you do about that. We had a similar thing with hijackings in the 70s and it sort of burned itself out.Report

  3. TT1:

    That was a fascinating article on a topic that should be familiar to every elementary school student.

    “It’s a credible criticism, then, to say that this dependence on technology removes units of measurement from public ownership just as much as the use of the king’s foot did.”

    Indeed, I’m skeptical that the new definition of kilogram isn’t just as arbitrary as some prototype object, considering that the Planck constant is a proportionality constant. A skeptic or a Marxist might say that this change is more symbolic of the paradigm shift to technocracy than real improvement.Report

    • Avatar James K says:

      But it’s more accessible than the single canonical Kilgogram we had before. Precise measurement is always going to be exclusive because precision is hard, but at least this way our whole system of measurement won’t collapse if some disaster strikes Paris.Report

    • Avatar Oscar Gordon says:

      All units of measurement are arbitrary. There is nothing universal about the meter or kilogram, it’s just an agreement that this length, or that mass, is the basis for a unit. Being able to mathematically determine that basis does liberate the unit definition from a physical object.

      Requiring a highly precise balance to figure out the necessary values to compute the kilogram is, well, it’s better than the physical object, but less than ideal.

      These days, we could probably come up with values for units that are easier to measure. The push to separate metric units from physical objects has always been something of an effort to push a round object into a less than round hole*, but I understand it, given how difficult it’s been getting some countries to change unit systems. Getting everyone to toss out their old, say, meter sticks, because the meter is now a bit longer or shorter than before…

      *Instead of the meter being 1/299,792,458 of the distance light travels in a vacuum, it could be 1/300,000,000.Report

      • Avatar Jaybird says:

        I thought that a liter of water weighed a kilogram. Have I been living a lie since high school?Report

        • Avatar James K says:


          A kilogram is a litre of water (or, more precisely 0.001 cubic metres of water, since a litre is defined as a kilogram of water). After that we get into the required precision.

          For day-to-day use, a litre of tap water is basically a kilogram, but to be exactly 1kg you need exactly 0.001 cubic metres of pure water at 4 degrees Celsius (impurities and temperatures change the water’s density). The canonical SI units need to be measurable at extremely high precision to ensure they are consistent. It’s measuring a kg that precisely that is difficult.Report

      • I’m imagining a dystopian future with stringent building codes where an engineer guild controls the apparatus for measuring and thereby the global economy!Report