Collisions from Space
During periods where the solar system's gravitational fields go up, this increases the likelihood that collisions will occur between the planets, asteroids, comets, and the sun. Smaller objects such as asteroids will have their orbits disturbed more often, and will be pulled into the sun and planet's gravitational fields more often.
It is now well known among scientists that a huge asteroid or comet hit occurred about 65 million years ago in the area of the northern coast of Mexico's Yucatan Peninsula -- the "Chixcilub" crater. It probably devastated the area and maybe even all of North America with a huge fireball. It possibly even created a huge hurricane -- a mega-huricane -- with winds approaching 500 miles per hour!
However, if such a hit killed off the dinosaurs, it should have done it in a "geological-blink-of-the-eye" -- maybe, within a few years, or at most, within a 100 years. But evidence indicates that the dinosaurs died off over a period of millions of years. Obviously, such a catastrophic hit from space surely wouldn't help situations here on earth. But was it enough by itself? Or, more importantly, was this collision a result of something else? From a broader perspective, was a higher than average gravitational field in our solar system the real culprit? Was this the real answer to the extinction of the dinosaurs?
Previously, it was mentioned that there appears to be a connection between mass extinctions and the 200,000,000 year orbit of the sun around the Galaxy. However, there have been other, lesser extinctions. It is apparent there is a cycle that repeats itself every 30,000,000 years. Since, most impact craters found on earth are less than 200,000,000 years old, it is difficult to use impact craters to study cycles on earth longer than this.
One study -- by Matsumoto and Kubotani -- studied craters going back 300,000,000 years. According to this study, roughly every 30,000,000 years, there is a mass extinction on earth that statistically matches an increase in impact craters.
(The magnetic polarity of the earth is known to flip directions within a period of about 10,000 years. However, the period between flip flops is estimated to be millions of years. Does the 30,000,000 year period mentioned here equal the period between polarity changes? I don't know. I wouldn't be surprised if it did though.)
While these researchers have found that there is a high correlation of impact craters to mass extinctions, there has been no reason given for cyclic increases in impacts. The Ball-of-Light Particle Model predicts the increase is due to cyclic variations in the gravitational field. As mentioned before, the devastation caused by a massive object colliding with earth would occur rather quickly -- over periods of: days; weeks, months, years, maybe even tens of years. Mass extinctions, on the other hand take place over millions of years. They are definitely playing a role but are not totally responsible.