Of the three cycles identified, the latter two can be predicted—and perhaps have been for many generations. If we look to India, there are records going back many thousands of years. They indicate that there are two cycles, known as “Yugas.” A minor yuga is about 6,000 years. A major yuga is 4 minor yugas, or 24,000 years. I believe these represent approximations of the 2nd and 3rd destructive cycles of the core.
On the other side of the world, we have the sacred calendar of the Aztec and Maya, handed down from their ancestors, the Toltec, handed down from the people of Iltar, who migrated there when their home of Aztlan was destroyed. The Maya also have similar cycles, but hold a great deal more precision. The minor cycle occurs every 1,872,000 days, or about 5,125 years. The major cycle is 5 of the minor cycles, or 25,627 years (which is also a very close figure for the precession of the equinoxes).
Both systems indicate that the current major cycle will end within the next 20 years, around 2000 for the Yuga cycle, and on December 23, 2012 for the Mayan cycle. The Mayan date, though precise, may not be as accurate as hoped for, because there are errors in the current Julian calendar that may have caused an erroneous start date for the Mayan calendar. The actual Mayan “end time” could be as early as 2003.
As for a more scientific determination, it is difficult, as there is no prior data to base a theory on. Several features can be isolated, to aid in determining a date. For example, there will be a large drop in the Earth’s magnetic field (the geomagnetic field has dropped 38% in the last 2000 years). A new south magnetic pole will begin to form in the northern hemisphere, near 50° N latitude (according to KVK Nehru’s sunspot research, extrapolated for the Earth’s core). This new south pole will cause some unusual phenomena, and being co-magnetic in nature, will cause the existing magnetic field to collapse at that point, allowing gamma rays to penetrate to ground level, causing sterility in the area of the new pole, as well as unusual magnetic, electric, and gravitational effects. There is one particular area on the Earth, at 52° N latitude, that fits this description—the Salisbury plains in England, in the area of Stonehenge, where the crop circle phenomenon is building. Observation agrees with mysticism—a “pole shift” is coming sometime soon.