🕐 What if a day lasted 48 hours?
Slower spin: hotter afternoons, colder nights, calmer Coriolis.
Try it: Earth Rotation Laboratory
- Day length (sidereal)
- 23.934 hours
- Equatorial surface speed
- 1,672.52 km/h
- Centrifugal acceleration (equator)
- 0.0338791 m/s²
- Effective gravity (equator)
- 9.77277 m/s²
Simplified: spherical Earth, equator only. Does not model shape change, oceans, atmosphere or geology.
Equations: T = T₀/f · v = f·ω₀·R · a = (f·ω₀)²·R · g_eff = g − a. Reference: sidereal day 23.934 h, Earth radius 6,371 km.
The science
A 48-hour day means rotation at 0.5×. Equatorial speed halves to ~835 km/h, centrifugal acceleration quarters, and each side of Earth bakes/cools twice as long. Set the laboratory slider to 0.5×.
Immediate consequences (modelled)
Longer, hotter days and longer, colder nights; weather systems grow larger and slower.
Possible long-term consequences (hypotheses)
This is Earth's real future in miniature: tidal friction with the Moon is lengthening our day by about 2.3 ms per century.
Assumptions: Day length change from spin only.
Limitations: Does not model climate, geology, biology or engineering in full detail.
Reference: NASA / peer-reviewed planetary science