Question
In 2010, a team led by Tom Murphy rediscovered one of these objects via brute force search. For 10 points each:
[10h] Name these objects. Experiments involving these objects have placed a lower bound on a violation of general relativity through the Nordtvedt effect.
ANSWER: lunar retroreflectors [or lunar mirrors; accept answers referring to the retroreflectors or mirrors on the Moon; prompt on mirrors or retroreflectors; prompt on, BUT DO NOT OTHERWISE REVEAL, lasers with, "which are used in conjunction with what objects?"]
[10e] In the LIDAR-like "ranging" technique used to bound the Nordtvedt effect, one of these devices produces a pulse directed at the moon and the time to return is measured. Interferometry using these devices directly detected gravitational waves for the first time.
ANSWER: lasers [or lunar laser ranging; or laser interferometry; prompt on LIGO]
[10m] Two answers required. The Nordtvedt effect implies that these two forms of mass are not the same, in violation of the equivalence principle.
ANSWER: gravitational mass AND inertial mass
<Chen, Physics>
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