Is it possible for earth to spin in the opposite direction?
There is a 41,000 year cycle during which Earth’s axis alternates between a 22 and 24 1/2 degree tilt (it’s at 23 degrees at the moment). The moon is gradually moving further away from Earth, which means that the Earth’s axial tilt will oscillate between 27 and 60 degrees (a lot), after two billion years, which will have a massive effect on the climate. There’s also evidence for massive tilt in the past (see link below), which may have caused the continents to move round relatively quickly at that time, but I don’t think it’s ever been upside down – there’s no known cycle of the Earth’s movement tending towards that. If it did happen, it would be a slow process. Needless to say, the effects would be huge. It’s not actually impossible, but it would take an immense force, even more immense to make it happen more quickly. (Assuming there’s not some cycle we don’t know about, to make it happen naturally – but almost certainly there isn’t one with such an extreme effect. (Another answerer s
