Tuesday, March 18, 2008

Sunspot Genesis

I extracted this out of an article in Viewzone on the web. This is the first time that I have seen the unexplained sunspot activity and eleven year cycle tied directly to the eleven year cycle of Jupiter. I should have thought of it actually. It is not a perfect match but it certainly a very close fit and a slow cyclic drift would handily accommodate the effect of the remaining material in the solar system.

These subtle variations and the apparent linkage of sunspot activity to slight changes in the sizing of the solar disc if true gives us a direct tie between earth’s climate and celestial mechanics. Who would have thought that could hold water? Of course, the effect may simply be far too small to be ultimately significant.

The article goes on to scare up a hypothesis that the combined effects will hit some sort of maxima in mid December 2012. This means we will be hearing a lot more of 2012 as the chattering classes wind themselves up. At best we will catch a sunspot maximum if the ideas stand up slightly.

This article has some good pictures to describe the ideas and these will likely not translate into the blog. Do go visit Viewzone and read doomsday 2012. Also read my article Pleistocene Nonconformity.

It's all about the Sun

It's ironic (or maybe not) that the Mayan Calendar is often called the "sun stone." While the calendar does have "solar" days, acknowledging the 365 days it takes for Earth to rotate around the Sun, it is also true that the Sun plays a key role in the final day of the "long count." To understand what will happen to the Sun on December 21, 2012, we need to review some scientific terms like "ecliptic," "barycenter," and "sunspots." These are important in the discussion that follows. We'll start with the most difficult one first.

Terms we will encounter...

What is the Barycenter?

You've no doubt heard that Earth revolves around the sun. Well, actually, that's not quite true!

Have you heard the term "center of gravity"? It's a technical-sounding term for something pretty simple. It's the exact center of all the material (that is, mass) that makes up the object. For example, if you have a straight stick, like a ruler or yardstick, there's a place at the middle where you can balance it on your finger. That's its center of gravity.

Ruler's center of gravity

But the center of gravity may or may not be the point that is exactly in the middle, distance-wise, of the object. Some parts of the object may be heavier (denser) than others. If you have something like a sledge hammer that is heavier on one end than the other, the center of gravity will be much closer to the heavy end than the lighter end.

Hammer's center of gravity

To get an idea of where the center of gravity is, rest the ends of any object like the ruler or a pencil on one finger from each hand. Slowly move your fingers together without dropping the object. Your fingers will meet underneath the object's center of gravity. You can balance the object on one finger at that special place.

The actual center of gravity could be close to the surface or deep inside, depending on whether the object is flat like a ruler or a dinner plate, or "three-dimensional," like a box or a ball. And if you let the object spin (like when you throw it), it will try to spin about that point.

In the case of the Earth and the sun, both bodies actually revolve, or spin, around the very center of the mass (similar to center of gravity) between them. This point is called the "barycenter." Earth and the sun are "connected" by the gravity pulling them together. It's just like the light end and heavy end of the sledge hammer. Compared to the size of the sun, Earth is about like a flea on a cat! So the center of mass between the Earth and the sun is almost--but not quite--the very center of the sun.

In the case of a planet the size of Jupiter, which is 318 times as massive as Earth, the barycenter of Jupiter and the sun is a bit further from the sun's center. So, as Jupiter revolves around the sun, the sun itself is actually revolving around this slightly off-center point, located just outside its center. Thus, a planet the size of Jupiter will make the sun (or any star) appear to wobble a tiny bit. This picture shows you that the center of mass and barycenter can be slightly different points. It isn't meant to be very accurate!

We can take advantage of this bit of knowledge and look for large planets in other solar systems by learning to detect this type of tiny wobble in the star's position.

For now, let's forget all the small planets and focus on Jupiter. It makes one complete trip around the Sun every 11.861773 years. There's a new theory put forth by Dr. Rollin Gillespie which shows that Jupiter, and to a smaller degree the other less massive planets, may trigger the 11 year cycle of sunspots and solar flares.

Here's how it works.

The barycenter is not a single point in the Sun. Because the Sun is a rotating gaseous sphere, the barycenter forms a vertical, cylindrical "sleeve" that is partially inside and outside the main solar body. All of the planets have such a "sleeve," one inside the other, depending on their relative mass and the location of their barycenters. The particular sleeve representing the mass of Jupiter intersects the solar surface at 35.9 degrees North and South. This is precisely where sunspot and flare activity begin and end during each 11 year cycle. [Update: The new cycle has already begun!]

Scientists have noted that when Jupiter and Saturn are aligned on the same side of the Sun, the solar activity is at its minimum; when they are on opposite sides of the Sun the solar activity is at its maximum.

These cylinders are usually quite orderly because the planets adhere to a narrow plane, called the ecliptic which resembles a thin plate extending from the equator of the Sun. The planets hang out here because (in simple terms) this is the zone where the gravitation of the system is the strongest. (see below)

But nature is never perfect. The Sun rotates at a slight angle (7.25 degrees), much as our Earth does. As it wobbles, it tilts the sleeves, causing them to clash with eachother and eventually disrupt the surface. Havine the barycenters of the to most massive planets, Jupiter and Saturn, in maximum misalignment is especially disruptive. This disturbance, to put it simply, works its way to the surface and erupts in sun spots and solar flares or CME's (Coronal Mass Ejections).

The last solar cycle was at its maximum in 2001. Each active solar cycle has a period when the flares are strongest, usually happening near the solar equator, called the "solar maximum." This is significant because the next "solar maximum" event will coincide with December 21, 2012. But wait -- there's much more!

Solar flares are pieces of the sun which leap into space, discharging radiation and strong electrical currents that travel outward into space. They often fall back to the surface of the Sun. Sometimes, a very strong flare, called a Coronal Mass Ejection (CME), actually leaves the Sun and this deadly mass shoots out from the Sun towards the planets like a bullet. Usually these CME's don't hit anything but occasionally they hit a planet like Earth. Some believe a powerful CME once hit Mars.

Most solar flares are small. But even a small flare can be dangerous. In 1989 a flare hit the North American continent and fried electric lines, zapped power grids in the US and Canada, and created large power backouts. Flares can also effect our moods and physical health. In theory, a large flare impacting the Earth could zap the ionosphere (there goes all the satellites, cellphones, GPS...) and irradiate the surface, killing every living organism that it touched.

Solar flares and sun spots have an average cycle of 11.120412 years (estimated from one "solar maximum" to the next). Right now, 2007, we are in a relatively quiet part of the cycle. The small discrepancy between this figure and the 11.861773 year period of Jupiter is close enough to be significant but suggests that something else is also influencing solar disturbances. Sure, it could be attributed to the various positions of the other less massive planets, but it could also be something even more significant -- the Milky Way.

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