One of the most bizarre theories about 2012 has built up with very
little attention to facts. This idea holds that a cosmic alignment of
the sun, Earth, the center of our galaxy -- or perhaps the galaxy's
thick dust clouds -- on the winter solstice could for some unknown
reason lead to destruction. Such alignments can occur but these are a
regular occurrence and can cause no harm (and, indeed, will not even be
at its closest alignment during the 2012 solstice.)
The details
are as follows: Viewed far from city lights, a glowing path called the
Milky Way can be seen arching across the starry sky. This path is
formed from the light of millions of stars we cannot see individually.
It coincides with the mid plane of our galaxy, which is why our galaxy
is also named the Milky Way.
Thick dust clouds also populate the galaxy. And while infrared
telescopes can see them clearly, our eyes detect these dark clouds only
as irregular patches where they dim or block the Milky Way's faint
glow. The most prominent dark lane stretches from the constellations
Cygnus to Sagittarius and is often called the Great Rift, sometimes the
Dark Rift.
Another impressive feature of our galaxy lies unseen in Sagittarius:
the galactic center, about 28,000 light-years away, which hosts a black
hole weighing some four million times the sun's mass.
The claim for 2012 links these two pieces of astronomical fact with a
third -- the position of the sun near the galactic center on Dec. 21,
the winter solstice for the Northern Hemisphere -- to produce something
that makes no astronomical sense at all.
As Earth makes its way around the sun, the sun appears to move against
the background stars, which is why the visible constellations slowly
change with the seasons. On Dec. 21, 2012, the sun will pass about 6.6
degrees north of the galactic center -- that's a distance that looks to
the eye to be about 13 times the full moon's apparent size -- and it's
actually closer a couple of days earlier. There are different claims
about why this bodes us ill, but they boil down to the coincidence of
the solstice with the sun entering the Dark Rift somehow portending
disaster or the mistaken notion that the sun and Earth becoming aligned
with the black hole in the galactic center allows some kind of massive
gravitational pull on Earth.
The first strike against this theory is that the solstice itself does
not correlate to any movements of the stars or anything in the universe
beyond Earth. It just happens to be the day that Earth's North Pole is
tipped farthest from the sun.
Second, Earth is not within range of strong gravitational effects from
the black hole at the center of the galaxy since gravitational effects
decrease exponentially the farther away one gets. Earth is 93 million
miles from the sun and 165 quadrillion miles from the Milky Way's black
hole. The sun and the moon (a smaller mass, but much closer) are by far
the most dominant gravitational forces on Earth. Throughout the course
of the year, our distance from the Milky Way's black hole changes by
about one part in 900 million – not nearly enough to cause a real
change in gravity's pull. Moreover, we're actually nearest to the
galactic center in the summer, not at the winter solstice.
Third, the sun appears to enter the part of the sky occupied by the
Dark Rift every year at the same time, and its arrival there in Dec.
2012 portends precisely nothing.
Enjoy the solstice, by all means, and don't let the Dark Rift,
alignments, solar flares, magnetic field reversals, potential impacts
or alleged Maya end-of-the-world predictions get in the way.