I just wonder if they redefined the meter expressed by a fraction of the speed of light, and the value is so close to 1/300000000, why did not they chose that value? The difference would be negligible in everyday life (perhaps not in astronomy, but there are other units used there anyway), and it would be nicer. Easier to remember for sure.
Accurate length measurement requires precise definition.
These are needed for the tiniest features on a microchip as well as the standard threads on nuts and bolts.
3 x 10^8 m/s is simply not precise enough for such purposes.
same reason PI wasn't defined as 3. it's just not close. and these aren't done for convenience, they have real world implications as in GPS
I have a roadmap to be president ! Give each american a Fiat 500 and a mini fridge ! Global Warming solved ! But of course as a future half president, give me the Chevrolet ! Vice President will be Greta Midget MK I (I miss social media exposition for the moment)...oups I forgott her pun about cars on Twitter !
For the next 4 years, we will put wheels on the mini fridges or cooler compressors in the Fiat 500s ! 🤔
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They tried that. The Meter started as one ten-millionth of the shortest distance from the North Pole to the equator passing through Paris. They cut and scratched a stick that long..... then discovered that their distance was in error. Ever since then they really mean "the length of our stick" but express it in ways more precise than two stick-scratches, a microscope, and a good thermometer.
Had the speed of light been a tangible thing when the metric system was established it could have been decided to make it a round number of meters per second. With 200+ years of metric system history it would be chaos to move the actual length of the meter by more than trivial roundoff at the last digit.
Oh, and you'd better not tell any voter of your plan if you want any chance of being elected...a FIAT 500 and mini-fridge ain't gonna cut it.
Oh, and you'd better not tell any voter of your plan if you want any chance of being elected...a FIAT 500 and mini-fridge ain't gonna cut it.
I think there are Modulo screwdrivers for this. Don't understand why tey are not popular 🙂
From Wiki:
"Since 1983, the constant c has been defined in the International System of Units (SI) as exactly 299792458 m/s; this relationship is used to define the metre as exactly the distance that light travels in vacuum in 1⁄299792458 of a second. By using the value of c, as well as an accurate measurement of the second, one can thus establish a standard for the metre."
But if the meter is defined as c x second, then what is the definition of the second? From Wiki:
"Since 1967, the second has been defined as exactly "the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium-133 atom". This length of a second was selected to correspond exactly to the length of the ephemeris second previously defined. Atomic clocks use such a frequency to measure seconds by counting cycles per second at that frequency. Radiation of this kind is one of the most stable and reproducible phenomena of nature. The current generation of atomic clocks is accurate to within one second in a few hundred million years. Since 1967, atomic clocks based on atoms other than caesium-133 have been developed with increased precision by a factor of 100. Therefore a new definition of the second is planned."
Nah...it kills the wines but some white ones. And bottles should always been near a seat. By the way a cork has no problems like a screw and bolt have as its raison d'être is to be outside the bolt...uh sorry the bottle I mean.
since the gravity constant is not anymore, the second seems to be the last branch to hold. Always wondered if the metrology inside an atomic clock was precise enough due to the manufacturing and infinite variation of the substract inside to fix a precision limit digit limit after the dot ?
No, no ...the horseman riding had the reins in their left hand & early warriors had his sword in the right...later it became the gun. For the right hand drive cars, the left is on the steering-wheel, the right out the open window with the weapon of choice....sword, gun, or as now, their cafe-latte thrown in anger.
-----------------------------------------------------------------------------------------------------------------------------------------------------------------Rick...
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I've only just found out that the code for carbide inserts is in imperial, and in fractions. I think that carbide is one of the unsung heroes of the modern world, try manufacturing a car with HSS.
A great read on this topic: https://www.amazon.com/Exactly-Precision-Engineers-Created-Modern-ebook/dp/B076FTNNXN
Imperial measurements seem more suited for measuring flat objects while the metric system is better for measuring spheres...😈
Imperial measurements seem more suited for measuring flat objects while the metric system is better for measuring spheres...😈