The coverage of the relationship between an electric current and a magnetic field in the essay Planetary Magnetism - A Heretic's View applies equally to other astronomical phenomena. For example, the relationships between sunspots, solar prominences and the magnetic fields around sunspots conform to the basic rules of electricity and magnetism. A prominence starts as an upward jet emerging from the sun's depths at a high velocity. The jet is ionised and thus creates a constrictive magnetic field around itself. The intensity of the magnetic field falls off as the jet decelerates. The jet widens. As the jet loses upward speed, coriolis force moves it sideways, giving it some sideways speed.. This provides a weak magnetic field that still offers some constraint on the jet's width. It is now broad and horizontal. Gravity pulls the jet back towards the sun at an increasing speed. Correspondingly the magnetic field around the jet becomes stronger and more constrictive. The jet narrows again. As the jet returns to the sun's 'surface' it has regained most of its upward speed in a downward direction. It makes a hole comparable to the one it emerged from. The magnetic field around this hole is opposite to that around the hole from which it emerged.

The narrow high speed jet penetrates downward, near to the region from which it originated. It thus provides heat and material to replenish its original source. This replenishment can explain why some prominences and sunspots last for days on end.

The sunspot movement is explained by the action of coriolis force on the jet. Some jets are clearly visible but many are invisible against the brightness of the sun's photosphere. This is why most prominences are only seen sideways on during an eclipse.

Sunspots are always in pairs and of opposite magnetic polarities. The movement of sunspots around the sun is a function of the suns's rotation. Coriolis force caused by the sun's rotation deflects the upward jet sideways. The downward jet is thus displaced from the source of the upward jet. The replenishment of the source of the upward jet by the downward jet is one-sided, tending to pull the upward jet towards the point of penetration of the downward jet. The pair of sunspots thus move around the sun at a speed which is different to the sun's rotational speed.

It may be noted that sunspots move diagonally towards the poles. The prevailing winds on Earth move likewise, also because of coriolis force. It is therefore illogical to say that the sun rotates at the same speed as the sunspots rotate. It would be as logical to say that the Earth rotates as fast as the prevailing winds rotate. Nevertheless, I have found that the sun's rotation is claimed to be the same as the sunspot rotation in books on astronomy.

Conventional explanations of sunspots refer to magnetic loops. What sort of movement of ionised gas could produce a magnetic loop (like a small rainbow) above the surface of the sun?

Moving ionised gas makes the magnetism. What is more likely to emerge from a boiling surface - gas or magnetism? Are the gases more likely to be moving up and down or sideways? Isn't it more likely that the gases should move like miniature solar prominences and make arcs?

Have a look at some (savoury) rice boiling in a saucepan, just before all the water has gone. You may see some similarities with sunspots. The action of heat is similar. The released steam makes holes. However, the emerging steam is not ionised and does not fall back into the rice to make more holes.

Wilf James BSc.

wilf.james@ntlworld.com