links for 2009-04-28

  • Tricks to get 'a feeling' for very large or small quantities. I learned from this post that light travels a foot per nanosecond (12 million miles a minute, according to Monty Python) and that
    "the sensitivity of the human eye is such that it can see a match flame from a mile away"
    and …
    "an ultra-high-energy cosmic ray has about the same energy as a good fastball."
    (tags: physics)