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Chinese team syncs clocks over record distance using lasers
Nature ^ | 18 October 2022

Posted on 10/19/2022 7:35:41 AM PDT by BenLurkin

The feat is a step towards redefining the second using optical clocks — timekeepers that are 100 times more precise than the atomic clocks on which coordinated universal time (UTC) is currently based.

Metrologists hope to use optical clocks to redefine the second in 2030. But a hurdle standing in their way is the need to find a reliable way to transmit signals between optical clocks in laboratories on different continents, to compare their outputs. In practice, this will probably mean transmitting the clocks’ time through air and space, to satellites. But this is a challenge because the atmosphere interferes with signals.

Since 1967, the second has been defined by atomic clocks using caesium-33 atoms: a second is the time it takes to cycle through 9,192,631,770 oscillations of the microwave radiation the atoms absorb and emit when they switch between certain states. Today, optical clocks use the higher-frequency ‘ticking’ of elements such as strontium and ytterbium, which allows them to slice time into even finer fractions.

However, official time can’t be generated using just one clock. Metrologists must average the output of hundreds of timepieces across the world. For caesium clocks, the time can be transmitted through microwave signals, but microwave radiation is too low-frequency to convey the high-frequency tick of optical clocks.

Sending signals through the air at optical wavelengths is not as easy as sending microwaves, because molecules in the air readily absorb the light, drastically reducing the strength of the signal. Furthermore, turbulence can send a laser beam off target. To compare optical clocks, physicists have so far relied mostly on transmitting signals through fibre-optic cables, or transporting the bulky, complex timepieces themselves, to compare them side by side. But these methods are impractical for creating the kind of global network needed to define the second.

(Excerpt) Read more at nature.com ...


TOPICS: Science
KEYWORDS:

1 posted on 10/19/2022 7:35:41 AM PDT by BenLurkin
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To: SunkenCiv
ping


2 posted on 10/19/2022 7:38:27 AM PDT by BenLurkin (The above is not a statement of fact. It is either opinion, or satire, or both.)
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To: BenLurkin

https://www.youtube.com/watch?v=Q0LuMAMZXEE


3 posted on 10/19/2022 7:38:44 AM PDT by Red Badger (Homeless veterans camp in the streets while illegal aliens are put up in hotels.....................)
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To: Red Badger

https://www.youtube.com/watch?v=WbuqNuZHsFo


4 posted on 10/19/2022 7:39:45 AM PDT by BenLurkin (The above is not a statement of fact. It is either opinion, or satire, or both.)
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To: BenLurkin

Time Is on My Side
Rolling Stones

[Verse 1]
Time is on my side, yes it is
Time is on my side, yes it is
Now you always say
That you want to be free
But you’ll come running back (said you would baby)
You’ll come running back (I said so many times before)
You’ll come running back to me

[Verse 2]
Oh, time is on my side, yes it is
Time is on my side, yes it is
You’re searching for good times
But just wait and see
You’ll come running back (I won’t have to worry no more)
You’ll come running back (spend the rest of my life with you, baby)
You’ll come running back to me

[Bridge]

Go ahead, go ahead and light up the town
And baby, do everything your heart desires
Remember, I’ll always be around
And I know, I know
Like I told you so many times before
You’re going to come back, baby
Because I know
You’re going to come back knocking
Yeah, knocking right on my door
Yes, yes!

[Verse 3]
Well, time is on my side, yes it is
Time is on my side, yes it is
‘Cause I got the real love, the kind that you need
You’ll come running back (said you would, baby)
You’ll come running back (I’d always said you would)
You’ll come running back (I won’t have to worry no more)

[Outro]
Yes time, time, time is on my side, yes it is
Time, time, time is on my side, yes it is
Oh, time, time, time is on my side, yes it is
I said, time, time, time is on my side, yes it is
Oh, time, time, time is on my side
Yeah, time, time, time is on my side


5 posted on 10/19/2022 7:40:44 AM PDT by Red Badger (Homeless veterans camp in the streets while illegal aliens are put up in hotels.....................)
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To: BenLurkin

6 posted on 10/19/2022 7:41:33 AM PDT by Red Badger (Homeless veterans camp in the streets while illegal aliens are put up in hotels.....................)
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To: BenLurkin

https://www.youtube.com/watch?v=V1ubKUk39GQ


7 posted on 10/19/2022 7:42:39 AM PDT by Red Badger (Homeless veterans camp in the streets while illegal aliens are put up in hotels.....................)
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To: BenLurkin
https://www.youtube.com/watch?v=cn0ZofphEzE

https://www.youtube.com/watch?v=sEj8lUx0gwY

Time is on my side
Yes, it is
Time is on my side
Yes, it is

Now you always say that you want to be free
But you'll come running back
(Said you would baby)
You'll come running back
(I said so many times before)
You'll come running back to me

Oh, time is on my side
Yes, it is
Time is on my side
Yes, it is

You're searching for good times
But just wait and see
You'll come running back
(I won't have to worry no more)
You'll come running back
(Spend the rest of my life with you, baby)
You'll come running back to me

Go ahead, go ahead and light up the town
And baby, do everything your heart desires
Remember, I'll always be around
And I know, I know
Like I told you so many times before

You're gonna come back, baby
'Cause I know
You're gonna come back knocking
Yeah, knocking right on my door
Yes, yes!

Well, time is on my side
Yes, it is
Time is on my side
Yes, it is

'Cause I got the real love
The kind that you need
You'll come running back
(Said, you would, baby)
You'll come running back
(I always said, you would)
You'll come running back to me

Yes, time, time, time is on my side
Yes, it is
Time, time, time is on my side
Yes, it is
Oh, time, time, time is on my side
Yes, it is
I said, "Time, time, time is on my side"
Yes, it is
Oh, time, time, time is on my side
Yeah, time, time, time is on my side

8 posted on 10/19/2022 7:48:34 AM PDT by Yo-Yo (Is the /Sarc tag really necessary? Pray for President Biden: Psalm 109:8)
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To: Red Badger

Too Much Time on My Hands
by Styx

Yeah, here I am sitting on this bar stool,
Talking like a damn fool
Got the twelve o’clock news blues
And I’ve given up hope for the afternoon soaps
And a bottle of cold brew
Is it any wonder I’m not crazy
Is it any wonder I’m sane at all
Well I’m so tired of losing
I’ve got nothing to do and all day to do it
Well I’d go out cruising, but I’ve no place
To go and all night to get there
Is it any wonder I’m not a criminal
Is it any wonder I’m not in jail
Is it any wonder I’ve got too much time on my hands
It’s ticking away with my sanity
I’ve got too much time on my hands
It’s hard to believe such a calamity
I’ve got too much time on my hands
And it’s ticking away, ticking away from me
Too much time on my hands
It’s tick tick tick tick ticking away (Too much time on my hands)
Now I don’t know what to do with myself (Too much time on my hands)
Too much time on my hands
Too much time on my hands
Too much time on my hands


9 posted on 10/19/2022 11:42:11 AM PDT by know.your.why (If you dont watch the MSM you are uninformed. If you do watch the MSM you are misinformed.)
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To: BenLurkin

They have already demonstrated clocks that are effectively so accurate, that no two clocks would keep the same time because of differences in gravitation from one spot to another. i.e., a clock on the wall would run faster than a clock on the floor due to the effects of gravity warping space. There is really no purpose to making clocks more accurate than that.


10 posted on 10/19/2022 12:17:23 PM PDT by zeugma (Stop deluding yourself that America is still a free country.)
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