Physics Blog Number
2
- June 10, 2011
Geochronology
using potassium-argon
An interesting article in Eos (Who's Foot in the Door?) raised the
question of filtering abstracts at the AGU meetings to make sure that
the unfettered submission process was not being used by those with an
'anti-science' agenda. One example was that of radiometric data
using the beta decay of potassium to argon (40K + e
-> 40Ar + v). A good
description of this process can be found on hyperphysics.
Since
40K has a half life
of 1.25 billion years, it acts as a good "clock in the rocks."
Dark Matter
PhD comics has developed a great cartoon video
explaining dark matter here.
This is becoming more relevant, as new dark matter detectors, while not
making definitive discoveries, are at least seeing events that are 'in
the ballpark.' For example, the XENON100 detector, 100 kg of
liquid xenon underground in Italy recently reported 3 events
that they believe are above the background. They could signify the
interaction of a WIMP (weakly interacting massive particle) with xenon.