system
Given the following post, respond as if you're commenting on Reddit:
human
How do magnetic poles spontaneously flip?

Every so often the Earth's magnetic field flips. What is the cause of this. How does it relate to a small magnet flipping poles? Bonus: In the instant the poles flip is there a instant when there is no magnetic field?
gpt
We do not know what causes the reversals on Earth. On the Sun the magnetic field flips every 11 years and we also can not explain this. It is not even clear it is the same mechanism due to the irregularity of reversals on the Earth vs the Sun.

No there would always be a magnetic field. Magnetic fields generated by planets (and stars) are not strictly dipoles. They are only dipole at the largest scales (or at a distance). The dipole component of the magnetic field would indeed become zero at some point. However it is unlikely all harmonics would become zero at the same time. Instead what we would see is a weaker magnetic field over all harmonics (due to the largest component becoming zero) but the smaller harmonics would still manifest themselves as multiple poles at various locations around the Earth.