Long-Standing Unsolved Problems in Solar–Terrestrial Physics

This paper is not intended for firm believers of magnetic reconnection. It calls for attention of the young generation to the following facts: (1) there are a number of unsolved problems such as sunspots, solar flares, and magnetospheric substorms in spite of almost 50 years of effort; (2) one of the reasons for this failure to solve them may be because the guiding principles in understanding those phenomena are not well founded and are misleading; (3) thus, it is encouraged to cast doubt on the leading paradigms and develop new ideas.