this post was submitted on 15 Oct 2023
247 points (95.2% liked)

Technology

69346 readers
3192 users here now

This is a most excellent place for technology news and articles.


Our Rules


  1. Follow the lemmy.world rules.
  2. Only tech related news or articles.
  3. Be excellent to each other!
  4. Mod approved content bots can post up to 10 articles per day.
  5. Threads asking for personal tech support may be deleted.
  6. Politics threads may be removed.
  7. No memes allowed as posts, OK to post as comments.
  8. Only approved bots from the list below, this includes using AI responses and summaries. To ask if your bot can be added please contact a mod.
  9. Check for duplicates before posting, duplicates may be removed
  10. Accounts 7 days and younger will have their posts automatically removed.

Approved Bots


founded 2 years ago
MODERATORS
all 38 comments
sorted by: hot top controversial new old
[–] [email protected] 98 points 2 years ago

The most relevant paragraph:

Now, using a new way of linking the clocks with ultra-fast lasers, researchers have shown that different kinds of optical atomic clocks can be placed a few kilometres apart and still agree within 1 part in 10¹⁸. This is just as good as previous measurements with pairs of identical clocks a few hundred metres apart, but about a hundred times more precise than achieved before with different clocks or large distances.

[–] [email protected] 83 points 2 years ago (1 children)

Tl;Dr They are trying to make a better atomic clock that could provide a more precise definition of a second then we currently have.

[–] [email protected] 30 points 2 years ago (3 children)

At first I was like: The second what?

[–] [email protected] 9 points 2 years ago

This. Same... 😅

[–] [email protected] 1 points 2 years ago

That's the problem when your language doesn't have capitalization for nouns

[–] [email protected] 1 points 2 years ago

The second division of the hour.

[–] [email protected] 29 points 2 years ago (3 children)

Can't wait for decimal time with 100,000 seconds/day /s

[–] [email protected] 15 points 2 years ago (1 children)

Decimal time exists, thanks to the French Revolution.

There are 100 decimal seconds in a decimal minute, 100 minutes in a decimal hour, and 10 hours in a decimal day. Each second is slightly shorter than a SI second.

[–] [email protected] 2 points 2 years ago

I know and nobody uses it.

[–] [email protected] 5 points 2 years ago (1 children)

Unfortunately, there is no easy way to decimalise time for human use. If you make it useful for humans, it doesn't sync well to a day. If you make it sync to a day, the resulting units are awkward for the human mind.

Amusingly, for computers, time is decimalised! UTC is a fully metric time. It's just simpler to constantly remap to and from UTC to a user's time, than to train the user to use UTC.

[–] [email protected] 5 points 2 years ago* (last edited 2 years ago) (1 children)

For computers, Unix time is in binary. But yes.

However, humans can get used to longer/shorter seconds, minutes and hours. Arguing the opposite is like saying the meter would never work because it doesn't have a human body relation like feet. The problem is the sheer amount of documents, equipment and SI using the 24/60/60 system, and the indivisibility of 365.24.

[–] [email protected] 1 points 2 years ago

The divisibility of 60 is useful, too. It has 1, 2, 3, 4, 5, and 6 (plus any combination of the above) as factors making dividing time a relatively simple operation.

[–] [email protected] 3 points 2 years ago (1 children)

It'll likely happen once we move to living mostly in space (if we survive that long ofc)

[–] [email protected] 3 points 2 years ago (1 children)

With a full switch to metric, hopefully. We’ve lost a Mars probe to unit confusion already.

[–] [email protected] -2 points 2 years ago (1 children)

Not everything needs to be base 10.

[–] [email protected] 3 points 2 years ago

No but everyone's life will be easier. Fortunately, most space agency empoloyees are scientists who embrace the metric system because it is less error-prone and does away with arbitrary conversion like in^3^ / floz. Space civilians will hopefully follow suit.

Metric also has a different unit name for force (N) and mass (kg) as opposed to the ambiguous pound – which works well enough on Earth but not on bodies with different gravity.

[–] [email protected] 21 points 2 years ago (3 children)

Is this like when they made the kilogram some function of the speed of light instead of the weight of a metal ball in a French museum?

[–] [email protected] 12 points 2 years ago (2 children)

They linked the kilogram to the gravitational force.

It's part of an effort to clarify how we define things. We're now trying to link our recorded units to the basic forces they are related to. So now, the kilogram is defined by the gravitational force, the meter by how fast light travels, etc etc

[–] [email protected] 8 points 2 years ago

The kilogram is defined as the mass equivalent of a photon of a specific energy via the Planck constant h thus linking the speed of light and the frequency of the hyperfine level of caesium-133. The relative uncertainty of the measured value of the gravitational constant G is 10^-5 which would lead to a definition of the kilogram that has a worse relative uncertainty than using the former definition defined via an international prototype. The Wikipedka article is more detailed than this short summary.

[–] [email protected] 6 points 2 years ago (1 children)
[–] [email protected] 2 points 2 years ago

TiL

I knew about redifining the kilogram as it's related to gravity beforehand

But not the next part about kg and photons and planck etc etc. I learned all that just now by reading a response to my comment

I genuinely did not know about the relationship to light until just now.

So, yes. But again, your comment alone didn't help me understand about the relationship beforehand. I wasn't sure what you meant at all, so just responded with my understanding of it

[–] [email protected] 5 points 2 years ago (1 children)

I misread that as "meat ball", and now I'm kind of disappointed that we don't use meatballs as a standard unit. "I'm 6 meatball subs and 3 balls high", "The yacht is about 18 giant party subs long", etc.

[–] [email protected] 8 points 2 years ago (1 children)

Unfortunately this is a bit like the imperial system where you get multiple units of measurement. There is the standard foot-long, which is twelve inches, and there is the $5 foot-long™, which is only 11 inches

[–] [email protected] 1 points 2 years ago* (last edited 2 years ago)

Which is also further befuddled by bragging teenage boy foot long which is around 5"

[–] [email protected] 4 points 2 years ago* (last edited 2 years ago)

Not exactly. The kilogram was redefined in a fundamentally different way, moving from an artifact, which will change with time, to a fundamental property of nature, that as far as anyone knows, will be the same at all times. The second was already defined in such a way. Any such definition still requires some sort of measurement though to get something usable. Different ways of measuring the same type of definition can be more precise, and in this redefinition they think they've found a more precise method that works in the same fundamental manner. Both measure the oscillation rate of atoms, but the proposed element is thought to give better precision.

[–] [email protected] 19 points 2 years ago (1 children)
[–] [email protected] 3 points 2 years ago

Could you be more specific?

[–] [email protected] 9 points 2 years ago (4 children)

Would this affect our lives on Earth?

[–] [email protected] 32 points 2 years ago

Most likely indirectly, like how GPS has to account for satellites not matching the passage of time on earth due to relatively.

[–] [email protected] 14 points 2 years ago

You can now be more accurately late for work. Or your coffee is more accurately taking a long time to come out.

[–] [email protected] 10 points 2 years ago

Relativistically.

[–] [email protected] 5 points 2 years ago

I better not have to buy a new watch because of this.

[–] [email protected] 2 points 2 years ago

Wont that fuck up the other measures that use the second as a basis?