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Thursday Thrashing
Topic Started: Jan 26 2017, 12:18 PM (447 Views)
ragnarokio
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time, physically, refers to "rate of change", which is a fairly simple concept.

Time as it relates to the mind, to qualia, or even to bioneurological mechanisms, is probably a more complicated idea, and measuring "how much time someone feels has passed" is a difficult question, especially when considering other lifeforms which might use different mechanisms for tracking "the passage of time"

dogs can even smell time
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pantsukun
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wow i wonder if they ever test that somehow i mean i guess it's mostly theoretical as opposed to those kilogram weight things

https://en.wikipedia.org/wiki/Kilogram#International_prototype_kilogram

this all seems a bit tedious i mean do they even use these things

Following several years of work, Louis Essen from the National Physical Laboratory (Teddington, England) and William Markowitz from the United States Naval Observatory (USNO) determined the relationship between the hyperfine transition frequency of the caesium atom and the ephemeris second.[18][20]

several years of work what

and then there are those leap seconds that are a completely different thing but it's still weird to think about
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pantsukun
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dogs are cool

the feeling of time passing is a weird thing, like how it's already friday but it feels like wednesday or something like wha this week tho
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ragnarokio
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it is an important movement for the longevity of science. Using measurements that relate to aspects of the natural world that probably won't change means people billions of years in the future or people who live billions of lightyears away will potentially be able to understand what your measurements mean where if you use something more transient like the speed the sun resolves around the earth, then they won't.

You can create a specific object, and define a kilogram as however much it weighs, but that object might decay eventually, and there might never be a way to truly find out how much it weighs ever again. As hard as it is to measure the radioactive period of a cesium atom in ideal coditions, its easier than measuring the weight of an object that doesn't exist anymore.
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ragnarokio
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and of course objective measurements are important for anything that requires precision, which is why people use things like that international prototype kilogram to begin with.
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pantsukun
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tru it seems like the cesium thing is a lot easier to replicate than having a bunch of weights stashed all over the world

also i wonder if anyone's ever thought about stealing all these things i mean they are made out of platinum and that would b pretty difficult to pull off and not worth 900g of platinum probably, but maybe like a plot in a tv show or something
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pantsukun
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https://en.wikipedia.org/wiki/Kilogram#Dependency_of_the_SI_on_the_IPK

this is all pretty epic wha

The long-term solution to this problem, however, is to liberate the SI system's dependency on the IPK by developing a practical realization of the kilogram that can be reproduced in different laboratories by following a written specification. The units of measure in such a practical realization would have their magnitudes precisely defined and expressed in terms of fundamental physical constants. While major portions of the SI system would still be based on the kilogram, the kilogram would in turn be based on invariant, universal constants of nature. Much work towards that end is ongoing, though no alternative has yet achieved the uncertainty of 20 parts per billion (~20 µg) required to improve upon the IPK. However, as of April 2007, the US's National Institute of Standards and Technology (NIST) had an implementation of the Watt balance that was approaching this goal, with a demonstrated uncertainty of 36 µg.[57]

they're gettin therre faighto dayo
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ragnarokio
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the cesium thing is probably harder to replicate than using an artifact, although i don't know anything about atomic physics so i don't really have any confidence in that.

Artifacts are more susceptible to being lost or damaged than cesium's radioactive period is, though, which makes cesium a safer standard to define time by than an artifact.
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pantsukun
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yeh the kilogram weight thing seems simpler tho i guess if these ppl have all this monayyyyyyy to spend on having a crapton of platinum weight things then they would also have the monayyyyyyy to spend on having a watt balance thing w/e that is

The watt balance is essentially a single-pan weighing scale that measures the electric power necessary to oppose the weight of a kilogram test mass as it is pulled by Earth's gravity.

whoa
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ragnarokio
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science is restricted to money too. international kilogram standards will still be used to determine a kilogram because they'll probably be cheaper than the watt balance thing, while being essentially as accurate. In fact, people will probably just keep on using regular kilogram scales that aren't super fancy, because they probably work just as well for 99.999% of all things.

it is just important to have a standard.
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