Wednesday, October 24, 2012

Fascinating story

The maths that made Voyager possible
Must-read story about the mathematics grad student who solved the three body problem for spacecraft exploring the outer planets, making such voyages possible.

(And why do our Brit friends always call math "maths"?) 


  1. Because it's short for "mathematics" not "mathematic".

    First Time Caller (Calling Again)

  2. And they wonder why Americans say "sports" instead of "sport".

  3. To the best of my knowledge, the 3-body problem hasn't been solved. Solutions can be approximated on a computer by performing a large number of repeated calculations.

    The spaceship slingshot isn't an example of a solution to the 3-body problem, which involves bodies of comparable masses. In comparison to Venus, let alone Jupiter or Saturn, the mass of Voyager is extremely negligible.

  4. Well, now we can mathematics to the growing list of topics Egnor doesn't understand.

    How did he get to be a surgeon, anyway?

    1. I personally blame the BBC site for Michael's incorrect statement that the three-body problem had been solved. The journalists clearly stated that scientists starting with Newton hadn't been able to solve it.

      The slingshot method was a neat advance. Voyager 1 reached interstellar space because of it. It was refined at exactly the right time (1961) - when humans were beginning to develop rockets adequate for interplanetary missions - and not a moment earlier. The Wikipedia has a nice article on gravity slingshots noting that Russian scientists had discussed the method back in the 1920s. But having computers to do the calculations helped considerably.

      Anyway, you don't need to know much mathematics to be a surgeon. A little common sense (which Michael lacks) is of much more help. You don't need to be able to calculate statistics for example (there's professional medical statisticians who are more than willing to help out). Instead, you need to know the use and misuse of numbers such as p-values.