Excite News - Scientists: Black Holes Energy-Efficient: "With gasoline hitting $3 per gallon, scientists have just found the most energy-efficient engines in the universe - black holes, those whirling super-dense centers of galaxies that suck in nearly everything.
The jets of energy spurting out of older ultra-efficient black holes also seem to be playing a crucial role as zoning cops in large galaxies, preventing too many stars from sprouting. That explains why there aren't as many burgeoning galaxies chock full of stars as previously expected, said scientists citing results from NASA's Chandra X-ray Observatory that were released Monday.
For the first time, scientists measured both the mass of hot gas that is being sucked into nine older black holes and the unseen super-speedy jets of high energy particles spit out, which essentially form a cosmic engine. Then they determined a rate of how efficient these older black hole engines are and were awe-struck.
These black holes are 25 times more efficient than anything man has built, with nuclear power being the most efficient of man-made efforts, said study lead author Steve Allen of Stanford University and the
Stanford Linear Accelerator Center.
"If you could make a car engine that was as efficient as one of these black hole engines you could get about a billion miles per gallon of gas," Allen said. 'In anyone's book that would be pretty green.'"