Assuming a constant force of friction the slowing of Earth’s rotation would be linear ~ t and the lengthening of our days would be the inverse ~ 1/t so we canno

Assuming a constant force of friction the slowing of Earth’s rotation would be linear ~ t and the lengthening of our days would be the inverse ~ 1/t so we cannot simply divide 4,500,000,000 by 70,000,000 to estimate the original length of a day. Still, extrapolating back to Earth’s early years would yield a rather short day. Sources from Wikipedia [1] [2] estimate a 5 hour day after the Theia Impact that created the Moon. [1]: https://en.wikipedia.org/wiki/Earth's_rotation#Origin https://en.wikipedia.org/wiki/Earth's_rotation#Origin [2]: https://www.annualreviews.org/doi/10.1146/annurev.ea.15.050187.001415 https://www.annualreviews.org/doi/10.1146/annurev.ea.15.0501...