Space Elevators Could Totally Work—If Earth Days Were Much Shorter

The article explores the hypothetical scenario of Earth rotating twice as fast, resulting in a 12-hour solar day instead of the current 24-hour day. While such a rapid rotation is unrealistic, considering this counterfactual helps physicists understand fundamental concepts about Earth's rotation and its effects. The distinction between a solar day (24 hours, based on the sun’s position) and a sidereal day (about 23 hours 56 minutes, based on Earth's full rotation relative to distant stars) is explained, highlighting how Earth's orbit around the sun affects the length of a day. One key implication of a shorter day is the change in centrifugal force experienced at the equator, making people feel lighter there compared to the poles. This difference in apparent weight arises because the faster rotation increases the outward centrifugal force, which partially counteracts gravity. The article connects this thought experiment to the concept of space elevators—tethers extending from Earth to geosynchronous orbit that could enable easier access to space without rockets. The feasibility