tag:blogger.com,1999:blog-22973357.post1554196946927708734..comments2023-09-27T07:44:19.769-04:00Comments on Sabine Hossenfelder: Backreaction: Counting Atoms in a SphereSabine Hossenfelderhttp://www.blogger.com/profile/06151209308084588985noreply@blogger.comBlogger30125tag:blogger.com,1999:blog-22973357.post-81159088867467282702009-08-23T08:00:33.842-04:002009-08-23T08:00:33.842-04:00Hi everybody
Might be worth to mention that, for ...Hi everybody<br /><br />Might be worth to mention that, for the kilogram redefinition, also a third experiment is on the way, which is the GAMS experiment at ILL (Grenoble, France) where I'm currently working. I both work on the avogadro project, for the Si d220 determination, and the GAMS experiment, for the molar Planck constant determination.<br />This latter is of main importance, since, Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-22973357.post-75658183893991341972009-05-14T11:05:00.000-04:002009-05-14T11:05:00.000-04:00I was at a conference in Bad Honnef a couple of ye...I was at a conference in Bad Honnef a couple of years ago discussing (among others) precisely this question http://www.ptb.de/ACFC2007/aims.html#topics<br />and we got a nice talk about the silicon spheres .. including how they were transported from Australia (or was it the other way).<br />Apparently they went (in special boxes, of course) in the hand luggage and the guy just hoped that Thomas Denthttps://www.blogger.com/profile/16355010444546331416noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-48028922097607895922009-05-06T07:40:00.000-04:002009-05-06T07:40:00.000-04:00Hi Arun,
“We are always on the edge of a dark age...Hi Arun,<br /><br />“We are always on the edge of a dark age.”<br /><br />True enough and better still would be to suggest that for the overwhelming majority, even if only the first world considered we have not yet entered an enlightened age. What I mean is if you stopped random people in the street to be given the problem of the king’s crown that Archimedes had been presented, what solution Phil Warnellhttps://www.blogger.com/profile/15671311338712852659noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-15160761515863699352009-05-06T07:35:00.000-04:002009-05-06T07:35:00.000-04:00This comment has been removed by the author.Phil Warnellhttps://www.blogger.com/profile/15671311338712852659noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-54095605486047155472009-05-05T05:50:00.000-04:002009-05-05T05:50:00.000-04:00Hello Kaleberg,
Stefan wrote:
"And second, the cub...Hello Kaleberg,<br />Stefan wrote:<br />"And second, the cube has edges which probably wear down much more easily than a sphere would loose mass when handled..."<br />This is right, and in addition this <br />effects start their evil work already <br />during grinding of prisms. <br />Look into a catalog for optic <br />materials, You will find prisms <br />less precise, more expensive than <br /Georghttps://www.blogger.com/profile/02538391164351204407noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-21266864223855498592009-05-04T23:52:00.000-04:002009-05-04T23:52:00.000-04:00Hmmm...just thinking.
Ancient ways of ingenuity f...Hmmm...just thinking.<br /><br />Ancient ways of ingenuity flooding over, or, new robotic adventures in information transfer?<br /><br />Discrete measures, can then be counted by a wave, as the wave "passes through and over" as a distinction of any discrete measure?? An "emotive quality" that sends signals to "other parts" of the system?<br /><br />You see...it fills all space? Has reductionism PlatoHagelhttps://www.blogger.com/profile/00849253658526056393noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-33704173233131194362009-05-04T23:46:00.000-04:002009-05-04T23:46:00.000-04:00OK, it makes sense to try for a sphere. Minimum su...OK, it makes sense to try for a sphere. Minimum surface and great symmetry are good arguments.<br /><br />Of course, with all the cosmologists here, I would expect someone to propose using a 1 kilogram black hole as the standard. After all, we have good measures for distance and time. Maybe we'll luck out, and a suitable black hole will pop out of the LHC. Of course, the real problems will start Kalebergnoreply@blogger.comtag:blogger.com,1999:blog-22973357.post-59601991547620078962009-05-04T20:34:00.000-04:002009-05-04T20:34:00.000-04:00Fascinating. Any scoop from anyone on a related is...Fascinating. Any scoop from anyone on a related issue I've heard about, that the standard meter bar doesn't match up the way it should?Neil Bateshttps://www.blogger.com/profile/04564859009749481136noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-20155455651910706762009-05-04T18:35:00.000-04:002009-05-04T18:35:00.000-04:00Hi Count,
Due to the binding energy, the mass of ...Hi Count,<br /><br /><I>Due to the binding energy, the mass of a crystal consisting of N atoms will be less than N times the mass of a single atom.</I>Good point! <br /><br />I am now just a bit confused... the mole, in SI, is <A HREF="http://www.bipm.org/en/si/si_brochure/chapter2/2-1/mole.html" REL="nofollow">defined</A> as <I>the amount of substance of a system which contains as many stefanhttps://www.blogger.com/profile/09495628046446378453noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-54955187717405606272009-05-03T22:03:00.000-04:002009-05-03T22:03:00.000-04:00Phil,
We are always on the edge of a dark age.Phil,<br />We are always on the edge of a dark age.Arunhttps://www.blogger.com/profile/03451666670728177970noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-31170301568890402892009-05-03T21:32:00.000-04:002009-05-03T21:32:00.000-04:00Due to the binding energy, the mass of a crystal c...Due to the binding energy, the mass of a crystal consisting of N atoms will be less than N times the mass of a single atom. <br /><br />This effect is almost of the same order as the accuracy that one demands for the new mass standard.Count Iblishttps://www.blogger.com/profile/07429017672028256731noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-30051042279339267332009-05-03T17:22:00.000-04:002009-05-03T17:22:00.000-04:00Pt as a mass standard is historically faulty. Con...Pt as a mass standard is historically faulty. Consider: Trace hydrogen in air will diffuse in after casting. Steel frame buildings have iron corrosion from plumbing, roof leakage, and condensing humidity (air conditioning). They vent hydrogen - as do mammal and termite posteriors.<br /><br />http://en.wikipedia.org/wiki/Kilogram#Stability_of_the_International_Prototype_Kilogram<br /><br />A Uncle Alhttp://www.mazepath.com/uncleal/noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-54323054777329210112009-05-03T16:44:00.000-04:002009-05-03T16:44:00.000-04:00Hi Stefan,
It’s nice to know there be some others...Hi Stefan,<br /><br />It’s nice to know there be some others who still give thanks to Archimedes as it rates to what he left for us all. Even more to the point, as it’s been more recently discovered that he also had imagined and utilized one of the core ideas of calculus some two millennia before being redinvented and expanded upon by Newton and Leibnitz. Thus I am often brought to wonder, what Phil Warnellhttps://www.blogger.com/profile/15671311338712852659noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-81833111656132015462009-05-03T15:49:00.001-04:002009-05-03T15:49:00.001-04:00Hi Kaleberg,
“ I wonder why they chose to make si...Hi Kaleberg,<br /><br />“ I wonder why they chose to make silicon spheres when there is so much technology dedicated to making rectangular solids?”<br /><br />I can certainly see your point in one respect and yet in another when it comes to physics where symmetry plays such an important role one can’t do better than a sphere as being your starting point. In a way the <A HREF="http://Phil Warnellhttps://www.blogger.com/profile/15671311338712852659noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-21330491369307669232009-05-03T15:49:00.000-04:002009-05-03T15:49:00.000-04:00Hi Phil
It seems that with all their x-rays and l...Hi Phil<br /><br /><I>It seems that with all their x-rays and laser beams, Archimedes's Principle of Buoyancy cannot be negated in the overall consideration.</I>Exactly! I had a similar feeling when I read that: All high-tech to produce the sphere, and in the end, when it comes to compare to the prototype, you have to take care of old Archimedes ;-)<br /><br />Best, Stefanstefanhttps://www.blogger.com/profile/09495628046446378453noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-25497891965757231842009-05-03T15:38:00.000-04:002009-05-03T15:38:00.000-04:00Hi Georg,
What about melting one kg of silicon in...Hi Georg,<br /><br /><I>What about melting one kg of silicon in an oven on board of ISS? Would the silicon make a sphere on cooling and crystallizing?</I>Sounds like a cool suggestion! Actually, how defect-free are the crystals grown in microgravity? And how exact would by the sphere? <br /><br />Cheers, Stefanstefanhttps://www.blogger.com/profile/09495628046446378453noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-59136594840959264562009-05-03T15:35:00.000-04:002009-05-03T15:35:00.000-04:00Dear all,
thanks for the feedback, and sorry for ...Dear all,<br /><br />thanks for the feedback, and sorry for the somewhat late response...<br /><br /><br />Dear Bee,<br /><br /><I>I wonder though why they take 1 kilogram and not something more handy, like a gram or so?</I> <br /><br />Hm, I've been wondering about this too... Maybe it is technically not that much more easy to produce a sphere of just one gram. And, as Georg explains, they stefanhttps://www.blogger.com/profile/09495628046446378453noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-17446313704046162792009-05-03T10:46:00.000-04:002009-05-03T10:46:00.000-04:00"Kepler Conjecture is speaking about cannon balls...."Kepler Conjecture is speaking about cannon balls. <A HREF="http://www.math.pitt.edu/~thales/kepler98/announce" REL="nofollow" TITLE="This was the subject of a famous disagreement between mathematicians Isaac Newton and David Gregory. Newton thought that the limit was 12, and Gregory that a 13th could fit. The question was not resolved until 1874">Tom Hales writes</A>,"Nearly four hundred years PlatoHagelhttps://www.blogger.com/profile/00849253658526056393noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-48020768337273427402009-05-03T07:09:00.000-04:002009-05-03T07:09:00.000-04:00What about melting one kg of
silicon in an ove...What about melting one kg of<br /> silicon in an oven on board of<br /> ISS?<br /> Would the silicon make a sphere<br /> on cooling and crystallizing?<br /> Regards<br /> GeorgGeorghttps://www.blogger.com/profile/02538391164351204407noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-37910511019498346202009-05-02T18:52:00.000-04:002009-05-02T18:52:00.000-04:00I wonder why they chose to make silicon spheres wh...I wonder why they chose to make silicon spheres when there is so much technology dedicated to making rectangular solids. Chip makers have been building circuits out of blocks of silicon with accuracy on the order of few atoms this way and that. They even have all sorts of clever imaging techniques for studying the surface layers to check for flaws in the well understood packing structure. SiliconKalebergnoreply@blogger.comtag:blogger.com,1999:blog-22973357.post-52381962037307134312009-05-02T13:35:00.000-04:002009-05-02T13:35:00.000-04:00Hi Stefan,
As a further follow up after reading t...Hi Stefan,<br /><br />As a further follow up after reading <A HREF="http://www.europhysicsnews.org/index.php?option=article&access=standard&Itemid=129&url=/articles/epn/pdf/2009/01/epn20091p23.pdf" REL="nofollow">the article you pointed to</A> I discovered what is quoted here at the end. It seems that with all their x-rays and laser beams, <A HREF="http://en.wikipedia.org/wiki/Buoyancy" REL="Phil Warnellhttps://www.blogger.com/profile/15671311338712852659noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-34332685898002750392009-05-02T11:18:00.000-04:002009-05-02T11:18:00.000-04:00This spheres have to be single
crystals of a elem...This spheres have to be single <br />crystals of a element, hard enough to be ground <br />and polished, stable enough to react <br />(and change weight thereby) less <br />than the old standards. <br />(At least within the time needed to <br />make the spheres and do the measurements)<br />At the end of the project the spheres <br />have to be weighed against the old <br />kilogram prototypes, Georghttps://www.blogger.com/profile/02538391164351204407noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-47634000745583811912009-05-02T11:16:00.000-04:002009-05-02T11:16:00.000-04:00Hi Uncle Al,
“Does mass exist? The Standard Model...Hi Uncle Al,<br /><br />“Does mass exist? The Standard Model is massless.”<br /><br />This all boils down to QM for most being of a singular ontological nature rather a dualistic one. In as my metaphysical center has this ontology as being dual I have no problem with the standard model representing mass as being a measureable consequence in the responsive nature of the two.<br /><br />Best,<br Phil Warnellhttps://www.blogger.com/profile/15671311338712852659noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-15303122049787046282009-05-02T10:59:00.000-04:002009-05-02T10:59:00.000-04:00Does mass exist? The Standard Model is massless. ...Does mass exist? The Standard Model is massless. No gravitation theory contains composition, only geometry or fields. Perhaps mass is a spacetime anomaly that requires a more fundamental model - the reason why mass is tied to a physical artifact rather than a theoretical constuct.Uncle Alhttp://www.mazepath.com/uncleal/noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-75423218064010866292009-05-02T10:44:00.000-04:002009-05-02T10:44:00.000-04:00Hi Arun,
Yes all those things you mention are tru...Hi Arun,<br /><br />Yes all those things you mention are true and I acknowledge that in our world silicon to be more significant at times then water. In fact what I do for a living is highly related to the importance and utilization of this most abundant element. Still though if one is required to build a scale with the simplest of materials and utilizing the most available means of measure, Phil Warnellhttps://www.blogger.com/profile/15671311338712852659noreply@blogger.com