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Atomic Clocks

nist.gov

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Re: Atomic Clocks

#81

Post by ahazred8ta »

rcxdude wrote: post #33
isolli wrote: post #7

Earlier quoted context omitted.

What are these atomic clocks measured against?

Generally, other atomic clocks. The fact they they tick consistently compared to each other is the main thing (though at these scales, you need to account for time dilation!).

Clocks at NIST Boulder in Colorado run faster than NIST Gaithersburg in Maryland by about 1.55 microseconds per year because of the 1500 meter altitude difference. It's about 1 nanosecond per year per meter. They both have to use a fudge factor to adjust down to sea level.

Re: Atomic Clocks

#82

Post by ahazred8ta »

globular-toast wrote: post #23
tomcam wrote: post #15

Long before most of you were born there was a special number you could call to get the time here in the USA. It would give you a localized time every 10 seconds. It was considered an authoritative value, but I knew that normal analog clocks drifted a fair amount, and I was fascinated by the Time voice. There was also a special number to dial that was called Information. When I was about 12, I suddenly thought that’s…

That's brilliant. Sometimes talking to real humans is great. It reminds me of two things. When I was a child I was given a postage stamp and wrote a letter to "Wallace and Gromit Ltd" and posted it. Remarkably, I got a reply from Aardman Animations with a card signed by Nick Park himself. Someone at Royal Mail obviously understood and looked up the real address of the studio. Later as a teen I noticed the clock on ou…

In Canada, Santa's postcode is H0H 0H0. In the 1800s a letter addressed Sromfidevi England was eventually delivered to Sir Humphry Davy.

Re: Atomic Clocks

#83

Post by dyauspitr »

r3trohack3r wrote: post #4

> Today’s best atomic clocks are billions of times more accurate and precise than any other type of clock. If they had been running since the Big Bang, 13.8 billion years ago, they would have lost or gained less than a second. Absolutely incredible, but then confused by the next assertion that is made without context: > New kinds of clocks may soon open up capabilities that previous generations could only dream about…

I’m not well versed in this field but if you take GPS using time as one of its parameters I could imagine being able to pinpoint the location of an atom from space to be one avenue of an endgame in making time so precise we would lose less than a Planck second in time over that period. That being said I don’t even know if time is the bottleneck for accurate GPS coordinates.

Re: Atomic Clocks

#84

Post by dyauspitr »

snypher wrote: post #80
AlotOfReading wrote: post #63

Earlier quoted context omitted.

Probably one of the numerous companies making qualified receivers? E.g. [0]. There's even a published table comparing basically all of them [1]. [0] https://www.aac-clyde.space/what-we-do/space-products-compon... [1] https://www.mdpi.com/1424-8220/23/17/7648#app1-sensors-23-07...

So that poster asked where to get blue carrots, and you replied 'probably one of the numerous companies making blue carrots?'. It seems they were unaware of these products, you don't have to be fake incredulous about it.

A little bit of hostility is healthy to an incredibly basic question like that. Plus I’ve encountered that user a few times, it’s always the same tier of asinine comment.

Re: Atomic Clocks

#85

Post by goodmythical »

dyauspitr wrote: post #84
snypher wrote: post #80

Earlier quoted context omitted.

So that poster asked where to get blue carrots, and you replied 'probably one of the numerous companies making blue carrots?'. It seems they were unaware of these products, you don't have to be fake incredulous about it.

A little bit of hostility is healthy to an incredibly basic question like that. Plus I’ve encountered that user a few times, it’s always the same tier of asinine comment.

I'm always astounded by this particular activity. If you're curious about the existence of a thing, the activity required is typing some such "where can I get". But you could type that in a search bar and be gauranteed an immediate result or type it in a comment section and possibly get a definitely delayed result.

I suppose the interaction could be the point, but if the curiosity is the only factor, why choose the comment section?

Re: Atomic Clocks

#87

Post by NetMageSCW »

aftbit wrote: post #71
inigyou wrote: post #37

Earlier quoted context omitted.

Also known as an ordinary recipe everywhere else. Well, recipes do often use measurements like teaspoons and cups, but they have straightforward metric equivalents - a teaspoon being 5mL and a cup 250mL.

You should really measure mass rather than volume.

That depends on the state of what you are measuring. For some ingredients mass and volume will always be equivalent.

Re: Atomic Clocks

#88

Post by NetMageSCW »

tomcam wrote: post #15

Long before most of you were born there was a special number you could call to get the time here in the USA. It would give you a localized time every 10 seconds. It was considered an authoritative value, but I knew that normal analog clocks drifted a fair amount, and I was fascinated by the Time voice. There was also a special number to dial that was called Information. When I was about 12, I suddenly thought that’s…

I built a phone accessed service for a school system some time ago, programming an off-the-shelf call handler and adding an industrial thermometer. When you called it would tell you the time and temperature and whether school would open normally, open late or be closed due to weather. School staff could call in and change the message setting.

Re: Atomic Clocks

#89

Post by dyauspitr »

goodmythical wrote: post #85
dyauspitr wrote: post #84

Earlier quoted context omitted.

A little bit of hostility is healthy to an incredibly basic question like that. Plus I’ve encountered that user a few times, it’s always the same tier of asinine comment.

I'm always astounded by this particular activity. If you're curious about the existence of a thing, the activity required is typing some such "where can I get". But you could type that in a search bar and be gauranteed an immediate result or type it in a comment section and possibly get a definitely delayed result. I suppose the interaction could be the point, but if the curiosity is the only factor, why choose the c…

It’s almost always a secondary motivation on forums, someone with an agenda trying to undermine the GP in some attempted subtle way that’s not immediately apparent to most casual browsers.
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