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Sunspots (Astrophysics)
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Chad


In: Ramsbottom
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So what do we know about sunspots?

A) They are darker and cooler than the surrounding surface plasma.
B) They are often associated with nearby faculae which are hotter than the surrounding surface plasma.
C) The magnetic flux density in the vicinity of sunspots is many, many times greater than that of the surrounding surface plasma.
D) They appear to follow an eleven year cycle of activity.

What does orthodoxy deduce from this knowledge?

1) Sunspots are darker and cooler than the surrounding surface plasma, because the increased magnetic flux density in the vicinity reduces the emission of electromagnetic radiation in the visible and infrared part of the spectrum.
2) Sunspots appear to follow an eleven year cycle of activity... but we haven't got a clue why this should be... but the polarity of the solar magnetic field flips, also on an eleven year cycle.

I like (and am happy to go along with) the idea that the increased magnetic flux density in the vicinity of sunspots reduces the emission of electromagnetic radiation... but what causes the increase in magnetic flux density? And if sunspot activity is indeed cyclic, what regulates that cycle?... There must be something... like the pendulum or balance wheel of a clock.

If we can find the answer to these two questions, we can solve the riddle.

I first looked at planetary alignments, but I couldn't find anything that occurred on an eleven year cycle... then I realised the sun could provide its own regulatory mechanism... and it all ties in with Ishmael's ideas.

The solar plasma is extremely electrically conductive and any matter ejected from the sun would be highly magnetic. As this matter accumulates into larger conglomerations it eventually falls out of solar orbit back to the surface (just as volcanic matter in the atmosphere falls back to earth). As these large magnetic conglomerations crash through the normally uniform magnetic flux distribution of the solar plasma, they produce areas of intense flux density (seen as sunspots) and cause new eruptions of matter (the associated faculae) which start the cycle over again. This cycle of disturbances is probably what causes the solar magnetic polarity to flip.

And we don't need to worry about running short of asteroids
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Ishmael


In: Toronto
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DPCrisp wrote:
Well, if the surface of a pond can rebound so strongly that it shoots water droplets back up in the direction of the pebble you dropped...


BRILLIANT!!!!!!!!!!!!!!!!!!!!!!!!!

That's it exactly!
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Ishmael


In: Toronto
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Chad wrote:
The solar plasma is extremely electrically conductive and any matter ejected from the sun would be highly magnetic. As this matter accumulates into larger conglomerations it eventually falls out of solar orbit back to the surface (just as volcanic matter in the atmosphere falls back to earth). As these large magnetic conglomerations crash through the normally uniform magnetic flux distribution of the solar plasma, they produce areas of intense flux density (seen as sunspots) and cause new eruptions of matter (the associated faculae) which start the cycle over again. This cycle of disturbances is probably what causes the solar magnetic polarity to flip.

And we don't need to worry about running short of asteroids

yes. A cycle like that -- without all the sciency talk -- was a notion I toyed with. The Sun ejects matter. The matter cools and falls back into the sun, prompting more eruptions.

What I don't like about it -- and the reason I never posted it -- is that it has shades of perpetual motion: You can't have self-generating splashes on the surface -- not without them coming to a stop eventually. And you have to start the cycle somehow. And pretty soon, any system like that is going to descend into chaos. How could it be regulated? (unless reversals in solar magnetism is what opens the window for impacts?)
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Chad


In: Ramsbottom
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How could it be regulated? (unless reversals in solar magnetism is what opens the window for impacts?)


Yes I thought about that... but then you still need a mechanism to explain why it flips every eleven years.

Anyway, take a look at this:



Solar flares are tremendous explosions on the surface of the Sun. In a matter of just a few minutes they heat material to many millions of degrees and release as much energy as a billion megatons of TNT. They occur near sunspots, usually along the dividing line (neutral line) between areas of oppositely directed magnetic fields.
Flares release energy in many forms - electro-magnetic (Gamma rays and X-rays), energetic particles (protons and electrons), and mass flows
.
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Chad


In: Ramsbottom
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Ishmael wrote:
What I don't like about it -- and the reason I never posted it -- is that it has shades of perpetual motion: You can't have self-generating splashes on the surface -- not without them coming to a stop eventually. And you have to start the cycle somehow. And pretty soon, any system like that is going to descend into chaos.)

We've not been observing this phenomenon for very long. We may simply be seeing reverberations from a much larger impact, someway back in time, that will eventually end or become chaotic.

(Yes I know it violates the "what is, is what was" rule. But we really have no way of knowing whether or not this is just a transient phenomenon.)
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Chad


In: Ramsbottom
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I wrote:
(Yes I know it violates the "what is, is what was" rule. But we really have no way of knowing whether or not this is just a transient phenomenon.)


I will withdraw that statement on the grounds that there is no overwhelming evidence that this is a transient phenomenon and so must be regarded as enduring.

However, what we have here is not a passive system.

While the splashes caused by a pebble on a pond will in turn create their own splashes... the process ends very quickly, because there is no input to keep it going. The sun on the other hand has (as far as this process in concerned) unlimited energy, which it can input into what, is a dynamic system.

Each impact does not create a splash as such, but triggers the release of solar energy (and matter) and there is no reason to assume this will come to an end any time soon.

So why is the phenomenon cyclic rather than chaotic?

This is where the clock pendulum (or balance wheel) comes into play... The ejected solar matter would take a fairly regular amount of time to form critical masses which would then fall from orbit and restart the process - with the polarity flip (caused by the magnetic disturbance) acting to regulate the drive train.

We are not dealing with a perpetual motion machine... we are dealing with a giant piece of clockwork, where the sun's own internal energy plays the part of the mainspring.

It will keep going as long as there is energy to drive it.
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Ishmael


In: Toronto
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Why 11 years?

Or are we off that 11 year cycle orthodoxy?
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Chad


In: Ramsbottom
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Why 11 years?


The actual period is insignificant. It's merely a function of the length of the hairspring.

Or are we off that 11 year cycle orthodoxy?


I was initially sceptical. But looking at the data for the period over which records have been kept, it does seem to follow (roughly) an 11 year cycle. The amplitude is a little inconsistent, but the frequency overall looks more or less reliable (despite the apparent delayed start of the current cycle).

It might be interesting to find out at which point in the solar cycle the magnetic polarity flips.

UPDATE: It happens at the solar maximum, when sunspot activity is at its peak.
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Mallas



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http://sohodata.nascom.nasa.gov/cgi-bin/data_query

Guys this is one awsome tool.

You can make movies between certain dates and there are different image types. I am trying to overlay some of these with some video editing software.

Also not sure if you have seen this one, but if you are interested about aligning planets etc, this is the software for you:

www.shatters.net/celestia/
www.celestiamotherlode.net/

It is free and there is so much customization, you can go backward or forward in time and see positions of planets at certain times. May come in handy.
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DPCrisp


In: Bedfordshire
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"During the sunspot cycle, sunspots drift, on average, toward the equator"

I got this backwards.


2) Sunspots appear to follow an eleven year cycle of activity-- but we haven't got a clue why this should be--but the polarity of the solar magnetic field flips, also on an eleven year cycle.

Per Wiki, they do associate magnetic flux being rolled into tubes with the differential rotation between different latitudes. (I presume they think of these tubes as radial from the centre; or perhaps horizontal, from the axis; but we ought to wonder whether they're vertical, originating along the axis and migrating towards the outside, disappearing or popping out at the equator. If tubes they be.)

If the pole rotates in 41 days and the equator in 25, that's a differential of 16 days. 16 cubed {Dunno why 'cubed' -- maybe because it's a 3-dimensional problem, or something might well go as the cube of the differential...} is 4096. There are 4018 days in 11 years.

>Pssst< Nobody point out to Ishmael that if it's 41 days at the pole, then the equator is going about Phi times faster.
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Ishmael


In: Toronto
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Chad wrote:
UPDATE: It happens at the solar maximum, when sunspot activity is at its peak.


What that suggests to me is that the flip in the polarity is what ends the sunspot cycle. Asteroids would continue to plumet toward the Sun except that the polarity reversal pushes them away, affording the Sun temporary respite from the barrage.

How might that work? I've no idea.
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Chad


In: Ramsbottom
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What that suggests to me is that the flip in the polarity is what ends the sunspot cycle.


Me too.

Asteroids would continue to plumet toward the Sun except that the polarity reversal pushes them away, affording the Sun temporary respite from the barrage.

How might that work? I've no idea.


No, neither have I.
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Chad


In: Ramsbottom
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A while ago I wrote this:

Chad wrote:
It would appear that the wheels may have fallen off the old sunspot cycle.

It should have reached its minimum last year and the number of sunspots should (according to all the expert predictions) by now be on the increase, but instead they continue to fall... and nobody has seen one for months.

{Pretty soon climatologists will announce that the rate of global warming has started to slow and will claim this is due to governments taking action (on their advice) to lower carbon emissions... but maybe that's for another thread.}


Since then I've been keeping tabs on solar activity... and it seems the wheels are still off the cycle.

At the beginning of 2008, when the graph below was drawn, cycle 24 was already regarded as a late starter and as you can see, the experts were predicting that (as we approach 2010) we should be seeing between 40 and 75 sunspots per month.

2009 has produced precisely 11 for the whole year so far (up to mid November.)



Not only has sunspot activity dropped to next to nothing, there has also been a big decline in solar magnetic flux levels. In 2005 there was a sudden drop and the levels have remained low ever since.

What's more, the rate of global warming (which I suggested would soon start to slow down) may have already gone into reverse. Figures show 2008 was globally cooler than 2007.

If I was a betting man I would get down the bookies and lay all my dosh on the International Community abandoning its attempts to reduce global warming by cutting carbon emissions, sometime before 2015.
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Mick Harper
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In: London
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Well done, Chad, another biggie solved by those nice people at the AEL.

I don't know whether I've mentioned it lately but the earth never experiences a reversal of polarity--a quite ludicrous proposition since the polarity arises from the earth's position in space and the direction of spin, and therefore the whole shebang would have to tip completely over to show reversal.. If reversal really did occur it would be registered on contemporary rocks all over the earth.

The reason that it only registers on a tiny number of them is because the pole occasionally shifts across the earth (for reasons which I need not go into here) and any rocks that happened to be between the position of the new and the old pole, and are tolerably magnetised in the first place, will show reversal because from their limited point of view the north pole will now be at their other end.
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Ishmael


In: Toronto
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Mick Harper wrote:
I don't know whether I've mentioned it lately but the earth never experiences a reversal of polarity--a quite ludicrous proposition since the polarity arises from the earth's position in space and the direction of spin, and therefore the whole shebang would have to tip completely over to show reversal.


You don't say....
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