In 2022, Jun Ye’s group detected a form of this phenomenon over a distance of just 1 millimeter in ultracold strontium. The TCB and TCG coordinate systems are useful for calculations because they are unaffected by this phenomenon. This phenomenon causes an effect named for Irwin Shapiro whose magnitude is proportional to the Schwarzchild radius. The strong equivalence principle implies both gravitational redshift and the gravitational form of this phenomenon, which was measured on a pair of airplanes in the Hafele–Keating experiment. GPS satellites must account for this phenomenon to accurately compute signal delay. This phenomenon implies that a sibling on a rocket ages less in the twin paradox. For 10 points, name this relativistic phenomenon that causes moving clocks to tick more slowly. ■END■
ANSWER: time dilation [or gravitational time dilation; prompt on gravity or gravitation or relativity until read by asking “what specific phenomenon?”; accept gravitational redshift or gravitational blueshift until “redshift” is read; prompt on redshift or blueshift until “redshift” is read]
<Physics>
= Average correct buzz position