Building on a 1981 proposal by three Russian theorists and more recent work that brought that proposal into the realm of possibility, the team first fired two lasers at hydrogen atoms inside a chamber, kicking off electrons at speeds and directions that depended on
their underlying wave functions.
Using a new technique called S -
wave receiver
function, which can distinguish how long seismic
waves take to travel through the lithosphere versus through the
underlying semimolten layer called the asthenosphere, the researchers were able to compute plate thicknesses by comparing the travel times of the
waves.