tag:blogger.com,1999:blog-22973357.post2499008664088991913..comments2023-09-27T07:44:19.769-04:00Comments on Sabine Hossenfelder: Backreaction: SphereSabine Hossenfelderhttp://www.blogger.com/profile/06151209308084588985noreply@blogger.comBlogger24125tag:blogger.com,1999:blog-22973357.post-47270256352103772082007-08-03T18:54:00.000-04:002007-08-03T18:54:00.000-04:00Dear Bee, And to go to infinity.. (!), another ver...Dear Bee, And to go to <A HREF="http://www.flickr.com/photos/arenamontanus/967520284/" REL="nofollow">infinity</A>.. (!), another version of the Cloud Gate, this time by Anders Sandberg.amaragrapshttps://www.blogger.com/profile/15769062084934190681noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-29382012795574556112007-08-03T08:08:00.000-04:002007-08-03T08:08:00.000-04:00Hi Amara:What a nice photo! I was totally fascinat...Hi Amara:<BR/><BR/>What a nice photo! I was totally fascinated by the <A HREF="http://www.millenniumpark.org/artandarchitecture/cloud_gate.html" REL="nofollow">'Cloud Gate'</A> in Chicago, see e.g. <A HREF="http://www4.ncsu.edu/~grhess/photo/PhotoOfTheMonth/archive/CloudGateChicagoThumb.jpg" REL="nofollow">here</A>. Best,<BR/><BR/>B.Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-70343729309754575532007-08-03T04:08:00.000-04:002007-08-03T04:08:00.000-04:00The New Scientist has a short note about the "perf...The New Scientist has a <A HREF="http://www.newscientist.com/article.ns?id=mg19526142.300&feedId=fundamentals_rss20" REL="nofollow">short note</A> about the "perfect spheres" of silicon used in metrology. It says the <A HREF="http://www.measurement.gov.au/index.cfm?event=object.showContent&objectID=D38E2B78-65BF-4956-B2508407507631E2" REL="nofollow">National Measurement Institute of Australia</A>stefanhttps://www.blogger.com/profile/09495628046446378453noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-5605459611263707812007-08-03T01:39:00.000-04:002007-08-03T01:39:00.000-04:00The Cosmic Microwave Background varies by one part...The Cosmic Microwave Background varies by one part in 10^5. That is equivalent to Earth's altitude varying by 63 meters. One could argue that the cosmos forms a nearly perfect sphere.L. Riofriohttps://www.blogger.com/profile/02692071626849849079noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-20681633139426874502007-07-30T18:22:00.000-04:002007-07-30T18:22:00.000-04:00I also misspelled "principal investigator." But m...I also misspelled "principal investigator." But maybe you could say Francis Everitt really is a "principle investigator."Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-22973357.post-35887945361792541132007-07-30T17:44:00.000-04:002007-07-30T17:44:00.000-04:00Hi Kris,thanks again for your comments, and...Sorr...Hi Kris,<BR/><BR/>thanks again for your comments, and...<BR/><BR/><I>Sorry for misspelling your name!</I><BR/><BR/>Keine Ursache :-) Happens quite often, even here in Germany.stefanhttps://www.blogger.com/profile/09495628046446378453noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-11138814868502172722007-07-30T15:59:00.000-04:002007-07-30T15:59:00.000-04:00Oops. Sorry for misspelling your name!Oops. Sorry for misspelling your name!Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-22973357.post-55434058684100995622007-07-30T15:52:00.000-04:002007-07-30T15:52:00.000-04:00Hi Stephan,It's true the geodetic and de Sitter ef...Hi Stephan,<BR/><BR/>It's true the geodetic and de Sitter effects are different names for the same thing. The other precession GP-B is measuring can be called the Lense-Thirring effect, gravitomagnetism, or frame-dragging, depending on how you feel that day!<BR/><BR/>Best, KrisAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-22973357.post-56773011567579606832007-07-29T19:17:00.000-04:002007-07-29T19:17:00.000-04:00Hi Kris,thank you for these explanations, and the ...Hi Kris,<BR/><BR/>thank you for these explanations, and the link! So what is seen in the data so far is the <A HREF="http://en.wikipedia.org/wiki/De_Sitter_effect#De_Sitter_precession" REL="nofollow">de Sitter precession</A>, which is not so spectacular ...<BR/><BR/>Best,<BR/>stefanstefanhttps://www.blogger.com/profile/09495628046446378453noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-10517674931211006362007-07-29T15:11:00.000-04:002007-07-29T15:11:00.000-04:00I should add the quotation marks around "glimpses"...I should add the quotation marks around "glimpses" are not mine, but were on the original poster.<BR/><BR/>Cheers,<BR/><BR/>KrisAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-22973357.post-67466282627057359182007-07-29T15:01:00.000-04:002007-07-29T15:01:00.000-04:00Hi Stephan,As Bee noted, Gravity Probe B measures ...Hi Stephan,<BR/><BR/>As Bee noted, Gravity Probe B measures two effects: A geodetic precession, where the gyros precess north-south, and frame-dragging, where they move east-west. The first is orders-of-magnitude larger and requires much less precision to be detected.<BR/><BR/>So far, the only result announced has been confirmation of the geodetic effect. (Already confirmed to comparable Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-22973357.post-44485745431081210532007-07-29T14:11:00.000-04:002007-07-29T14:11:00.000-04:00Oooooh, smooth reflective spheres! They also funct...Oooooh, smooth reflective spheres! They also function perfectly as an abstract <A HREF="http://flickr.com/photos/spaceviolins/598238402/" REL="nofollow">photographer's device</A>.amaragrapshttps://www.blogger.com/profile/15769062084934190681noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-14994621129206554492007-07-29T10:00:00.000-04:002007-07-29T10:00:00.000-04:00Dear Bee,thank you for reminding us of this! By th...Dear Bee,<BR/><BR/><BR/>thank you for reminding us of this! <BR/><BR/>By the way, I remember that attempts to provide new standards for the Avogadro constant and the mass of a "kilogram" also involve nearly-perfect spheres, made of silicon, in this case - see <A HREF="http://www.ptb.de/en/org/4/43/434/index_e.htm" REL="nofollow">this link from the PTB</A>, the German equivalent of NIST.<BR/><BR/>stefanhttps://www.blogger.com/profile/09495628046446378453noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-86882249558905216192007-07-29T03:19:00.000-04:002007-07-29T03:19:00.000-04:00Due to the first effect Uncle Al mentioned, the pr...Due to the first effect Uncle Al mentioned, the preliminary results announced for Gravity Probe B last April were a disappointment, with no measurement of frame dragging. Fortunately the system is redundant (4 identical gyros) and they say it will be possible to model and subtract most of the unexpected electromagnetic perturbations. <BR/><BR/>A frame-dragging measurement is expected by year's Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-22973357.post-74009764953396942762007-07-28T20:46:00.000-04:002007-07-28T20:46:00.000-04:00soooo shiny...must pick up and play with...soooo shiny...<BR/><BR/>must pick up and play with...eric gissehttps://www.blogger.com/profile/10598878490537720448noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-57792877047073844932007-07-28T11:42:00.000-04:002007-07-28T11:42:00.000-04:00June 2007 mission updatehttp://einstein.stanford.e...June 2007 mission update<BR/>http://einstein.stanford.edu/<BR/> "known as 'misalignment torques'<BR/><BR/>Somebody didn't tell them about patch potentials and static tribocharging of dielectric surfaces in a dry gas stream. Blessed are the paranoid for they will have made backups.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-22973357.post-86839298244533309592007-07-28T09:37:00.000-04:002007-07-28T09:37:00.000-04:00Wow, look up Benjamin Lange, writing about this."I...Wow, look up Benjamin Lange, writing about this.<BR/><BR/>"In addition if a nearby reference star is chosen, it is sensitive enough to possibly detect earth-sized planets."<BR/><BR/>Simply follow a star with a telescope coupled to this gyroscope and the gyroscope will detect the wobble of the star 'cause of orbiting planets!!!!!Arunhttps://www.blogger.com/profile/03451666670728177970noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-25792713958195381472007-07-28T09:28:00.000-04:002007-07-28T09:28:00.000-04:00Black hole on my desktop.I am wondering how they v...Black hole on my desktop.<BR/><BR/>I am wondering how they verify that the drift is only 10^-12 degrees per hour.Arunhttps://www.blogger.com/profile/03451666670728177970noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-79850410188587446542007-07-28T09:13:00.000-04:002007-07-28T09:13:00.000-04:00BTW, if you never want to complain about rain agai...BTW, if you never want to complain about rain again, spend a year in England, after that everywhere else will seem just perfect to you ;)Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-22973357.post-39519014045837142332007-07-28T09:12:00.000-04:002007-07-28T09:12:00.000-04:00I looked itup, and a typical Quartz crystal has a ...I looked itup, and a typical Quartz crystal has a lattice spacing of about 0.5 nm so they polished it to an accuracy of about 200 atomic layers. Which compared to the 76 million atomic layers the whole thing has is certainly, "a few".Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-22973357.post-40348617460541695842007-07-28T07:34:00.000-04:002007-07-28T07:34:00.000-04:00Hi,"to only a few atomic layers away from perfect ...Hi,<BR/><BR/>"to only a few atomic layers away from perfect spherity"<BR/><BR/>"0,1 micron (0,0001mm)between highest and lowest"<BR/><BR/>And they couldn't do better??!<BR/><BR/>How thick are your atomic layers Bee? <BR/><BR/>best<BR/><BR/>Klaus<BR/><BR/>best<BR/>KlausAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-22973357.post-61438982389184279632007-07-28T04:59:00.000-04:002007-07-28T04:59:00.000-04:00Dear Quasar: Thanks :-) Unfortunately it looks rat...Dear Quasar: <BR/><BR/>Thanks :-) Unfortunately it looks rather rainy here (a typical German summer I'm afraid). What I see in that sphere? R2 completed at infinity is what comes into my mind. What do you see?<BR/><BR/>Have a great day,<BR/><BR/>B.Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-51466459960769816002007-07-28T04:39:00.000-04:002007-07-28T04:39:00.000-04:00Beeautiful Sun filled day here, hope its headed yo...Beeautiful Sun filled day here, hope its headed your wayQUASAR9https://www.blogger.com/profile/00593390598251093182noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-25539108164061653502007-07-28T04:38:00.000-04:002007-07-28T04:38:00.000-04:00Now wave your hands around it BEELook into the gaz...Now wave your hands around it BEE<BR/>Look into the gazing ball, and tell me what you see ...<BR/><BR/>Gravity is it Real<BR/>Is it particulate realityQUASAR9https://www.blogger.com/profile/00593390598251093182noreply@blogger.com