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One quantum transition makes light at 21 cm

bigthink.com

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Re: One quantum transition makes light at 21 cm

#51

Post by rwmj »

amiga386 wrote: post #18

> precisely 21 cm Imprecise use of "precise" in the strapline. According to https://en.wikipedia.org/wiki/Hydrogen_line the best measurement of it so far is 21.106114054160 +/- 0.000000000030 cm

On the other hand, since it's a property of the universe maybe now's the time to define 21 cm as this value.

Re: One quantum transition makes light at 21 cm

#52

Post by fragmede »

baxtr wrote: post #34
pixelbeat wrote: post #12

Earlier quoted context omitted.

42/2

When I replied, the article had been posted 42 minutes ago and had 42 upvotes. That can’t be a coincidence.

The people running our simulation are just fucking with us at this point.

Re: One quantum transition makes light at 21 cm

#53

Post by raldi »

cluckindan wrote: post #47
raldi wrote: post #37

Earlier quoted context omitted.

That not just imprecise usage of that term; it’s completely incorrect. The correct term would be its exact opposite, “approximately”.

The exact opposite would be ”imprecise” or ”inaccurate”

Accuracy and precision are orthogonal concepts. “Approximately 0 light years” is accurate but not precise.

Re: One quantum transition makes light at 21 cm

#54

Post by dcrazy »

barbazoo wrote: post #45
amiga386 wrote: post #18

> precisely 21 cm Imprecise use of "precise" in the strapline. According to https://en.wikipedia.org/wiki/Hydrogen_line the best measurement of it so far is 21.106114054160 +/- 0.000000000030 cm

Would have been odd if it had magically matched the arbitrary distances we use in the metric system. It's not that 1m is in any way a "natural" distance that was chosen for anything but practical reasons.

I was expecting some spectacular revelation that the definition of the second, the period of a Cesium atom, and the speed of light were somehow related to the definition of a meter by a factor of 0.21.

Re: One quantum transition makes light at 21 cm

#55

Post by wafflemaker »

staticelf wrote: post #50
dang wrote: post #60

[stub for offtopicness] [come on you guys]

Chickens take 21 days to hatch and give us the most protein rich food you can eat. Does this mean that chickens are the magic creature of the universe?

Pretty sure newly hatched chicks are not the most protein rich food you can eat. But the crunch must be amazing.

Is this why cows and horses eat them?

Re: One quantum transition makes light at 21 cm

#58

Post by dang »

nine_k wrote: post #19
dang wrote: post #60

[stub for offtopicness] [come on you guys]

The article gives the answer to the question in the title in the first paragraph. This is really commendable. (Suspense is—wait for it!—overrated.)

We've replaced the magic title with the more informative subtitle now. Standard mod trick.
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