Spheres of Influence: A Collection of Spherical Sites

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37 Responses to “Spheres of Influence: A Collection of Spherical Sites”

  1. oyvinja says:

    Once upon a time (1977), a professor at the university where I work developed a process for creating perfectly round and uniform spheres.
    They were at one point (though possibly not today) the most perfect spheres man could create.
    They are manufactured under the name Dynabeads today.
    http://en.wikipedia.org/wiki/Dynabeads

  2. Anonymous says:

    Another candidate for the most spherical objects on Earth are the targets hit by Lawrence Livermore Lab’s $2B laser. When the laser hits, the outside layers expand, flying outward and creating pressure on the inside, hopefully enough pressure to start a fusion reaction. But if the target isn’t round enough, the insides will just sorta squirt out one side before enough pressure builds up.

    “To meet NIF specifications, these shells must be no more than 1 micrometer, or a millionth of a meter, out of round; that is, the radius to the outer surface can vary by no more than 1 micrometer (out of 1,000) as one moves across the surface. Solving this extremely difficult problem will require significant improvements in current micro-encapsulation technology.” — https://www.llnl.gov/str/Letts.html

  3. Anonymous says:

    The project to define Avagadro’s number in terms of a fixed number of silicon-28 atoms is worth a look, also.

    We have a small sample ultrapure silicon-28 in Oxford for nuclear / electron resonance experiments – a neat side-effect of the extreme purification required to get the mass of the sphere right is that the few remaining impurities are so well isolated from each other that they display quantum coherences lasting seconds (!)

  4. rak0ribz says:

    DREW #10
    I think Gravity Probe B deserves mention for sure (Probe homepage at Stanford) but I imagine the new roundest spheres beat its quartz/niobium ones by dint of having been made more recently. The explanation on that page of the way those gyroscopes work is pretty mind-blowing; they take advantage of zero-viscosity Helium-III and superconductivity to maintain their accuracy.

  5. rak0ribz says:

    My bad – I was going from memory on Gravity Probe B. They don’t use Helium III for suspension; they electrically levitate the spheres in a vacuum. The engineering section of that website is fascination multiplied by awesome, by the way.

  6. djn says:

    @4:
    It doesn’t seem like it. Their scale sun is a 37m (what? tall? diameter? circumference?) observatory dome, while the Swedes use the 110m diameter Globe hall.

    This also fits with the Australian Pluto model being “less than 200km away”, while the Swedish one is about 300km distant.

  7. Anonymous says:

    @ 4, 24: You are both wrong. The Lakeview Museum in Peoroa, Il. claims to have the biggest solar model in the world (see: http://www.lakeview-museum.org/planetarium.html ) which is quite understandable, since anything american is by definition the best & biggest.

  8. Falcon_Seven says:

    @18 Wrap your mind around this as a possible cause (sixteen (16) years ago) -your favorite morning stimulant may be needed:

    http://www.iop.org/EJ/abstract/0026-1394/31/1/004

    This may be considered as more ‘reputable’ than Faux News, but lay reporting just the same -also six years old.:

    http://www.nytimes.com/2003/05/27/science/27KILO.html

    Also covered on the most reputable source ever -nearly two years ago:

    http://www.boingboing.net/2007/09/13/kilogram-has-lost-th.html

  9. Anonymous says:

    Here’s the Advanced Inertial Reference Sphere, the most accurate inertial navigation system ever built:

    http://nuclearweaponarchive.org/Usa/Weapons/Airs3.jpg

    Too bad it’s a missile part.

  10. Jim Terr says:

    If the “blown up to size of the earth” info is correct, this would make it not only the roundest, but perhaps more remarkably, the SMOOTHEST.

  11. Takuan says:

    but will it blend?

  12. Anonymous says:

    a neat side-effect of the extreme purification required to get the mass of the sphere right is that the few remaining impurities are so well isolated from each other that they display quantum coherences lasting seconds (!)

    So that’s how a Palantír works.

  13. jfrancis says:

    @ 28:

    (potentially) spherical images or video tiled without stitching

    http://www.digitalartform.com/archives/2009/04/panorama_nodal.html

  14. hokano says:

    Escher.

  15. Takuan says:

    must say, this is certainly a ballsy post comments collection, some fascinating stuff in all the links above, do explore them.

  16. Anonymous says:

    Any collection of great spheres of the world that does not include Buckminster Fuller’s American Pavilion in Montreal is woefully incomplete:

    http://tinyurl.com/ks7x3s

  17. Anonymous says:

    I think this may be the largest model of the solar system:

    http://www.solarsystemdrive.com/

  18. Mr. Customer says:

    No Moeraki Boulders? Maybe a little mundane for the atlas, but interesting nonetheless.

    http://en.wikipedia.org/wiki/Moeraki_boulders

  19. oskay says:

    Saying “the weight of the metal has been changing ever so slowly” is not exactly correct.

    The kilogram still weights one kilogram– By definition.

    Even if seems absurd, it’s more correct to say that it is everything else that’s slowly changing weight.

  20. Falcon_Seven says:

    The problem is not that the kilogram doesn’t have the same mass, it’s that the reference kilo -housed in a chateau outside of Paris- has changed in mass with respect to the average of a dozen others just like it around the world. The difference is about fifty (50) micrograms. They were all made at approximately the same time and of the same material. Scientists who have been studying this issue for more than sixteen years -yes, it’s not news- are puzzled as to why this is happening. European scientists have been working on the new reference kilos mentioned in the post -which is made from Silicon-28- for over three years now. Here’s a story from Faux News from September of 2007:

    http://www.foxnews.com/story/0,2933,296703,00.html

  21. kenahoo says:

    A little more info please – where are those new reference spheres being created, who’s saying that pull-quote, etc.?

  22. Drew from Zhrodague says:

    I thought the gyros from the Gravity Probe B ( http://en.wikipedia.org/wiki/Gravity_Probe_B ) were the roundest man-made things, though they’re not on earth.

  23. Dylan Thuras says:

    Hey Kenahoo,

    The spheres are being made by the Australian Center for Precision Optics and the quote is from engineer Achim Leistner.

    http://www.newscientist.com/article/dn14229-roundest-objects-in-the-world-created.html?feedId=online-news_rss20

  24. Nocterro says:

    #7 – The spheres were created by the CSIRO’s Australian Centre for Precision Optics, a government funded body here in Australia.

    There’s a fair bit of info around about the project, but the CSIRO press release is probably a good start.

  25. Anonymous says:

    Free spirit tree houses in spherical form (Vancouver Island, BC) http://www.freespiritspheres.com

  26. hokano says:

    I can understand why they went with a sphere as it minimizes surface area and absolutely minimizes edges. But Oskay above raises an interesting question. How did they determine that the statndard kilogram was changing its mass as opposed to oh, anything else they were measuring against it?

  27. djn says:

    @26:
    On one hand, their reference sun is just 36 feet – almost exactly a tenth of the Swedish one.

    On the second hand, you are of course, per definition, right.

  28. hokano says:

    ‘statnard’ s/b ‘standard’

  29. hokano says:

    And, sorry, Falcon Seven, but I just don’t accept Fox News as a source for facts about this universe.

  30. PolishQ says:

    Wouldn’t the Mapparium technically be outside-in?

  31. oskay says:

    #16 – Overwhelming common sense indicates that it’s the kilogram that’s changing mass with respect to the average mass of its first-generation copies, but since the unit is defined with respect to that artifact, it’s really only correct to say that the mass of the other objects– as measured in kilograms — is changing.

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