378 day year?

The following article appeared on page 18 of The Triangle, Drexel University�s Newspaper 27 February 2004. (It also is an effort to interest students in physics and astronomy.) If you have access to bulletin boards that high school students view, please print and post it. Thanks.

No escape: a black hole is coming for you



You are doomed by the laws of physics and ancient history.

Your fate was sealed when the universe was young � back when stars first began to form, long before our sun was born. The universe was much smaller and denser then. For many stellar generations, the typical star was much bigger than the sun. These large stars run through their life cycles much more rapidly than the sun. They first convert hydrogen to helium, then helium to carbon using unstable beryllium as an intermediary. Finally, at the end of their exothermic nuclear fusion cycles, they produce iron cores that implode. - The outer layers of a massive star�s iron core weigh so much that the iron below them can not support their weight. The core begins to collapse. When it is half its initial size, these outer layers weigh four times more. Thus the collapse accelerates as it progress. In the final stages of the collapse, the outer layers are falling inward to a single point at essentially the speed of light. In less than a minute, a mass greater than the sun collapses into a space much smaller than the period that ends this sentence. That is, a "black hole" is formed.

All of the mass in a black hole is concentrated in zero volume, but a roughly spherical space around this mass is so distorted that nothing, not even light, can escape. Because of this fact, an approaching black hole would not reflect sunlight nor be visible in telescopes. The first indication that a black hole was approaching our solar system would be slight perturbation in the orbits of Oort Cloud objects (small "planetesimals" more distant than Pluto) These objects and Pluto are frequently perturbed because they are small and weakly bound to the sun. Recent perturbations of Pluto can be interpreted as the approach of a still very distant black hole. Read Dark Visitor, for one such interpretation. It predicts that the second member of a pair of black holes will pass through the solar system in late 2007 and tip the earth back into an ice age, even though the approaching black hole is small (2.2 solar masses) and passes by the sun more distant than Saturn�s orbit. Is there any reason to think that this could be true? Unfortunately there is, as the next paragraph demonstrates.

First note that in the early universe many generations of typical stars formed black holes and that stars usually form in pairs. Thus there are currently more pairs of small stellar-core black holes than all the current stars. One probably passed by our solar system in the late 1920s. Neptune�s orbit was disturbed then. Pluto was discovered in 1930 after a yearlong search for the origin of this perturbation, but it is now known that Pluto was not the cause. (Pluto is smaller than the moon and Neptune is 17.2 times greater than the earth.) Any knowledgeable astronomer will confirm this fact. Although other explanations are possible, it seems probable that: (1) a stellar-core black hole was the cause and if this is true, then (2) the authors of Dark Visitor may be correct and we are doomed.