How To Measure The Tiniest Forces In The Universe

this is 10 micrograms you think that I might be able to see I think you might be able to oh boy it's an arrow right there yeah the flashlight will help I feel like I need to to get video of this I don't know how it kind of looks like a hair like a tiny like a smaller than an eyelash if you want to measure a force like the weight of an object the way it has always been done has been to balance it with some known standards and the most precise standard weight people ever created was the kilogram of platinum idium cylinder stored in a vault on the outskirts of Paris replicas of this kilogram were sent to countries around the world to use as their Mass standards here is K20 the United States Mass standard and yes the US is secretly metric they just apply a conversion factor to get to Freedom Units it's just a little translation that we do here but our country is actually on the metric system doesn't that seem crazy yes it's stupid the uncertainty in the mass of a standard kilogram is on the order of tens of micrograms so that's tens of parts per billion or about 0.00001% it's pretty good but there's a problem if you want to weigh something lighter than a kilogram the uncertainty increases this little object here is a 50 g test weight so it's a reference Mass can I pick it up uh with tweezers yeah if you don't mind sure we tried to keep the fingerprints off so it's got a little bit of heft you can feel that a little yeah what about this one what's this this this is 10 G here yeah that's pretty light that's pretty light and paper clip here is about 1 G and so how you might use one of these test masses so if you're you know working in a laboratory or something like that you could take one of these little weights and put it on here and you can look at the scale and say oh okay my scale is reasonably well calibrated here that last digit might you know change a little bit but you could sort of make some statement about whether or not your scale is accurate when we're talking about the kilogram you know these ...