Extensive air showers produced by cosmic rays were first discovered when...Pierre Auger, in 1938, observed coincidence measurements between detectors to occur when the detectors were separated by large distances (d). Everyone expected coincidence measurements to be made when detectors were separated vertically, since energetic muons are not easily stopped by matter. However, Auger found coincidence rates even when his detectors were separated by 300 meters! These measurements could not be random occurrences and thus he determined that air showers were being produced. A photo of Pierre Auger is shown below.
Jocelyn Bell, in 1967, DID NOT observe particle showers with an array of cloud chambers (a). Rather, she discovered pulsars, spinning neutron stars, although she originally thought her signals to be coming from Little Green Men...read up on your astrophysics if you don't know this story.
Researchers at Bucknell University (b) did not conduct an experiment in 1934 with hydrogen balloons. Since I attend Bucknell University, I thought it would be appropriate to mention them in this quiz, even in a facetious context.
Oh, and particles were NOT detected with Geiger counters simultaneously on three different continents in 1929 (c). They did not have GPS systems back then, so simultaneous measurements on three different continents would be rather difficult, to say the least. That would be one extensive air shower though!
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