Expert: James Gort - 1/7/2009

Question
Hello Professor Gort

Professor Gort i'm not going to be very popular i think. I want to question the present sun theory.

I understand the sun is a ball of hot plasma and it's believed that this is due to it's mass. But couldn't it be because of something else? It's magnetic field?
Couldn't the sun, the mysterious glow on saturn, the glow on Venus (ashen lights) all be produced from the planets magnetic fields. But while the sun is hot plasma the others might be colder plasmas? See: http://www.ipp.mpg.de/ippcms/eng/presse/pi/05_06_pi.html

Secondly, if magnetic fields could produce plasma. Doesn't this suggest that suns could be small, and cold?

Sorry if this sounds silly?

Thanks
David


Answer
Hello David,

Believe me - there are no silly questions - only silly answers!  And I hope this answer isn't one of them!

Charged particles from the sun (comprising a plasma) collide with earth's atmosphere (or Saturn's or Venus') and excite the atoms to produce a glow.  The energy source for the magnetic field in cold bodies is generally a moving liquid core.  In this case, the magnetic field doesn't ionize the atoms, but the field "directs" the charged particles as they enter the atmosphere, producing glows which appear like curtains or other formations.  

In the ball lightning experiment, an electrical energy source was used to ionize the water molecules and produce a plasma.  The electrical current in the water (which are fast moving electrons) collides with the water molecules and ionizes them (knocks off their electrons).  As the plasma (water vapor molecules and their free electrons) then recombine, light is emitted.

A strong magnetic field can also ionize atoms (pull off their electrons), producing a plasma.  But a planet's magnetic field is not strong enough to do that.  Neither is the sun's - its atmospheric plasma is caused by the heat from the core (the nuclear furnace) thermally exiting the gas enough to remove some of its electrons (producing a plasma).  So the energy source to ionize the gas in the sun's atmosphere is the heat from the sun's interior.

The energy source for planetary glows is actually the fast particles hitting the atmosphere.  The magnetic field only plays a part in determining the path those charged particles travel.  

To answer the last part of your question, could there be a small, cold star with a strong magnetic field which is surrounded by a plasma?  It turns out that some white dwarf stars are very magnetic, and eventually cool down to a brown or black dwarf.  When it is white, its small atmosphere is very ionized (i.e., a plasma).  As it cools further, it becomes brown or black because its atmosphere no longer emits light.  In other words, the plasma disappears.  I don't know of any case where an atmosphere continued to glow, with a plasma powered only by a strong magnetic field.  It's not impossible - I just don't know of any.  That sounds like a topic for research - not so silly after all!!

Hope that helps.

Prof. James Gort