Speaking of black holes, what could be stranger?Beyond a black hole's gravitational border -- or event horizon -- neither matter nor light can escape. Astrophysicists think dying stars about three to 20 times the mass of the sun can form these strange objects. At the center of galaxies, black holes about 10,000 to 18 billion times heavier than the sun are thought to exist, enlarged by gobbling up gas, dust, stars and small black holes.
What about mid-sized types? Perhaps surprisingly, evidence is both scarce and questionable for their existence.
Caption: Conception of a black hole pulling gas off of a nearby star. Credit: ESA/NASA
From New Scientist:
THE mammoth black holes at the centre of most galaxies may be pushing the universe closer to its final fade-out. And it is all down to the raging disorder within those dark powerhouses.
Disorder is measured by a quantity called entropy, something which has been on the rise ever since the big bang. Chas Egan and Charles Lineweaver of the Australian National University in Canberra used the latest astrophysical data to calculate the total entropy of everything in the universe, from gas to gravitons. It turns out that supermassive black holes are by far the biggest contributors to the universe's entropy. Entropy reflects the number of possible arrangements of matter and energy in an object. The number of different configurations of matter a black hole could contain is staggering because its internal state is completely mysterious.
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