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Pioneer Anomaly Solved By 1970s Computer Graphics

Posted by CmdrTaco on from the whats-your-vector-victor dept.

Frans Faase updated us on a Pioneer Mystery we've been following for many years: something is tugging Pioneer 10 & 11. A few years ago a theory surfaced but now "A new computer model of the way heat is emitted by various parts of the Pioneer spacecraft, and reflected off others, finally solves one of the biggest mysteries in astrophysics. Previous calculations have only estimated the effect of reflections. A computer modeling technique called Phong shading was used to work out exactly how the the emitted heat is reflected (PDF) and in which direction it ends up traveling. Taking into account the reflections on the antenna seem to make the anomaly disappear."

5 of 169 comments (clear)

  1. To be fair... by cobrausn · · Score: 4, Informative

    The technique for Phong Shading was introduced in 1973 as an improvement to Gouraud Shading, but was too computationally intensive to be used for graphics back then. This is no longer the case.

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    1. Re:To be fair... by BitterKraut · · Score: 5, Interesting

      It is also interesting to note that Phong shading is based on an empirical formula. That means it has not been derived from any known (i.e. accepted) "laws of nature". It is used in Computer Graphics because it can be calculated efficiently and approximates what we see or measure closely enough. Strictly speaking, it is not possible to scientifically explain any phenomenon by showing that Phong shading explains it. But as it seems, the whole scenario is so complex that showing its compatibility with the Phong model must already be regarded as a remarkable achievement.

  2. Re:tao of physics?? by The+Grim+Reefer2 · · Score: 4, Insightful

    So it seems, the mystery ain't a mystery after all...

    That tends to happen when you solve them.

  3. Here's the article ... by Intron · · Score: 4, Informative

    ... from Slava Turyshev which describes what they did to model the craft and show that heat could be the culprit.

    http://www.planetary.org/programs/projects/pioneer_anomaly/update_20080519.html

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    Intron: the portion of DNA which expresses nothing useful.
  4. Re:tao of physics?? by Chris+Burke · · Score: 4, Informative

    Yes, he said "at least it wasn't the Greeks", because of how often he finds out that something he thought was novel was discovered by them. Which would be 2000 years ago. Merely 300 years ago is better. Thus "at least it wasn't the Greeks".

    Got it now?

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