91–100 of 196 posts
Interesting article but left me wondering why they don't use ¹H₂¹⁶O as the "standard water"? Surely you can make that (relatively) easily in a centrifuge by spinning out the lightest fraction of water.
Earlier quoted context omitted.
For more context, sample reference materials from the NIST reference catalogue are not meant to be exceptionally high purity examples of the sample -- SRMs are usually commercially-produced products. The real value is that each sample comes with a datasheet with incredibly detailed and accurate measurements that are (as you said) used for calibration of measuring devices in industrial settings. To quote a Veritasium…
Truth. I once paid nearly $500 for a set of 17 certified, calibrated wooden pencils, with documentation showing that each one met their rated hardness levels of 9H thru 6B. And for $500, they don't even come with erasers, that is an added-cost option. https://www.gardco.com/product/pencil-hardness-test-kit-astm...
Why offer erasers on these things? The procedure described below has nothing to do with using these as pencils, and at $500 for a pack I can't imagine anyone, anywhere casually drawing with these.
(Is there another procedure, similar to the one described below, except instead of dragging the pencil tip across a surface you drag the eraser across it? )
Earlier quoted context omitted.
You want numbers to be understandable and K produces illogical numbers. (There is a reason it is common to drop the century when talking about years, humans are less skilled at numbers over 100) And I know temperatures in Fahrenheit go higher but it is common to refer to Phoenix as "over 100" even when it's high can peak over 120.
> (There is a reason it is common to drop the century when talking about years, Yep. > humans are less skilled at numbers over 100) No, the reason is that the century is constant and therefore carries no information. Where the century isn't constant, it never gets dropped.
A US gallon of deuterium water costs roughly $2,600 to $3,800, while a gallon of pure tritium water (super-heavy water) would cost about $44 million.
How much volume is that for the rest of the world? Really unscientific article.
Earlier quoted context omitted.
Truth. I once paid nearly $500 for a set of 17 certified, calibrated wooden pencils, with documentation showing that each one met their rated hardness levels of 9H thru 6B. And for $500, they don't even come with erasers, that is an added-cost option. https://www.gardco.com/product/pencil-hardness-test-kit-astm...
Can I ask why :-) Sounds like an interesting project.
Earlier quoted context omitted.
Makes me want to go to the ocean and start filtering out water somehow.
You can centrifuge it. Heavier molecules move closer to the bottom. Repeat until you reach the desired purity. You need shitloads of ordinary water to extract a liter of heavy water. And I'd be surprised if there's any superheavy water in that, because tritium radioactively decays. Fun fact: Heavy water is slightly toxic to humans. If you only drank heavy water, you'd die as it shifts the chemical reactions in your b…
Obviously the luxury bottled water industry is missing out on the potential of D2O and T2O.
Earlier quoted context omitted.
Can I ask why :-) Sounds like an interesting project.
You use the kit to test the harness of a finish coating, like a paint or a ceramic coating for cars. Pencils have their own hardness scale which can be used to gauge the hardness of the coating. Its really more of a relative qualitative test than quantitative as you'd use this for sample/coupon testing identical coatings. There are more absolute, quantitative methods to measure various hardness characteristics (scrat…
and you dont need to fit the car into a proper harness tester?
This is why we should ditch Celsius for Kelvin. I never liked how we coupled 0 and 100 to where water freezes and boils under certain conditions. Kelvin doesn't rely on non-invariant reference points.
You want numbers to be understandable and K produces illogical numbers. (There is a reason it is common to drop the century when talking about years, humans are less skilled at numbers over 100) And I know temperatures in Fahrenheit go higher but it is common to refer to Phoenix as "over 100" even when it's high can peak over 120.
Earlier quoted context omitted.
this is actually why i like fahrenheit the most... 0F is "really cold" and 100F is "really hot", whereas in celsius 0C is "kind of cold" and 100C is "uninhabitable". it makes sense for the 0-100 range to be reserved for temperatures frequently encountered in our habitat as humans i think...
OF will still kill you faster than 100F, and most folks aren't comfortable at 50F. It inspires the following idea: A nonlinear scale where ~72F is 0, and +X represents the same level of heat discomfort as -X represents cold discomfort.
youd still need to include where the discomfort is measured
How does the water taste?