Sadler effect
... that the Sadler effect explains why more ancient geological periods are longer than more recent ones?
... that the <b id="mwig"><a href="./Sadler_effect" id="mwiw" rel="mw:WikiLink" title="Sadler effect">Sadler effect</a></b> explains why more ancient geological <a class="mw-redirect" href="./Period_(geology)" id="mwjA" rel="mw:WikiLink" title="Period (geology)">periods</a> are longer than more recent ones?