Imagine, if you will, a black hole the size of the period at the end of this sentence. A tiny black hole the width of a human hair having the mass of Earth’s moon. Imagine further, a universe teeming with these primordial black holes formed at its beginning and still hurdling haphazardly through space. Mini black holes that a NASA scientists says could theoretically pass through the Earth about once every 1,000 years. Wait, what?
Alexander Kashlinsky, an astrophysicist at NASA's Goddard Space Flight Center in Maryland, is one of a group of scientists who believe primordial mini black holes were formed shortly after the big bang and were not caused by the death of a star. Furthermore, they speculate that these pinpoint - possibly even atom-sized - black holes with the mass of an asteroid or larger are the essence of dark matter.
Kashlinsky and other researchers used NASA's Spitzer Space Telescope and the Chandra X-ray Observatory to collect and compare the cosmic infrared background (CIB) and the cosmic X-ray background (CXB) – the light and radiation from space whose sources haven’t been identified yet. They determined that patches in the glows (a great name for a band) were caused by primordial black holes and there were lots of them – they estimated one in five of the patches in the CIB were early black holes.
This sounds tame so far, but Timothy Brandt, an astrophysicist at the Institute for Advanced Study, throws in his warning about these high-density ancient mini black holes:
Asteroid-mass black holes, if they were all of the dark matter, might pass through the Earth once a millennium or so, but would be very, very hard to detect. We certainly would notice if one passed near the Earth, since it would affect the orbits of all of our satellites. I imagine that it would mess up GPS for example.
What about people?
[Getting hit by a mini black hole would be] a bit like a bullet, but with the damage being done by tidal forces deforming the object and generating intense heat.
That doesn’t sound good. Fortunately, scientists like Brandt and Kashlinsky are watching the cosmic background and will give us plenty of warning to put on our Mini Black Hole Deflectors (patent pending), right?
It's possible there is no interaction of dark matter [with normal matter] except through gravity. If that's the case, we're in trouble. We've never come to that point where we know something is out there but is completely invisible to our experiments.
This is all still theoretical. However, as astrophysicists eliminate other explanations for dark matter, primordial mini black holes the size of punctuation marks buzzing about the universe may hold up.
For now, be advised to wear your Mini Black Hole Deflectors at outdoor concerts by the Patches in the Glows.