Positrons

Aether Regained <AetherRegaind@somewhere.in.the.aether> wrote or quoted:
|                                                              The
|evidence for the positron is a lot stronger than the evidence for say
|quarks.

  We probably shouldn't think of these particles as something out
  there on their own. They're more like tools we came up with so
  we could build devices that work off those ideas. So, it's really
  about whether a certain particle actually /comes in handy/.

  The positron turned out to be pretty useful. Just look at the PET
  (Positron Emission Tomography) scanner. There's a lot of solid proof
  that PET scanners have helped save lives by letting doctors spot
  how diseases are moving along and see if treatments are working.

  (We look back now and think folks way back were clueless for
  believing planets moved around the sun on /epicycles/. But
  honestly, the ancient astronomers who came up with epicycles
  - like Apollonius of Perga, Hipparchus, and especially Ptolemy -
  didn't actually buy into that! They knew those were just /handy
  tools/ for figuring out where the planets would be later on.)