From ScienceDaily:
“We have a pretty good understanding of the overall population of stars in the universe and their mass distribution as they’re born, so we can tell how many black holes should have formed with 100 solar masses versus 10 solar masses,” Bullock said. “We were able to work out how many big black holes should exist, and it ended up being in the millions — way more than I anticipated.”
In addition, to shed light on subsequent phenomena, the UCI researchers sought to determine how often black holes occur in pairs, how often they merge, and how long it takes. They wondered whether the 30-solar-mass black holes detected by LIGO were born billions of years ago and took a long time to merge or came into being more recently (within the past 100 million years) and merged soon after.
“We show that only 0.1 to 1 percent of the black holes formed have to merge to explain what LIGO saw,” Kaplinghat said. “Of course, the black holes have to get close enough to merge in a reasonable time, which is an open problem.”
Elbert said he expects many more gravitation wave detections so that he and other astronomers can determine if black holes collide mostly in giant galaxies. That, he said, would tell them something important about the physics that drive them to coalesce.
According to Kaplinghat, they may not have to wait too long, relatively speaking. “If the current ideas about stellar evolution are right, then our calculations indicate that mergers of even 50-solar-mass black holes will be detected in a few years,” he said. Paper. (paywall) – Oliver D. Elbert, James S. Bullock, Manoj Kaplinghat. Counting Black Holes: The Cosmic Stellar Remnant Population and Implications for LIGO. Monthly Notices of the Royal Astronomical Society, 2017; DOI: 10.1093/mnras/stx1959
More.
Write this down: “”If the current ideas about stellar evolution are right, then our calculations indicate that mergers of even 50-solar-mass black holes will be detected in a few years,” he said.”
It’s nice when people in science make specific predictions we can test as opposed to empty claims like this:
It’s important to figure out whether consciousness is “an easily produced product of the universe” or “an insanely strange fluke, a completely weird anomalous event,” says Godfrey-Smith. Based on the current evidence, it seems that consciousness is not particularly unusual at all, but a fairly routine development in nature. “I suspect animal evolution, if were replayed again, it would produce subjectivity of a somewhat similar kind,” he adds. “You can see why it makes biological sense.”
See also: Supermassive black holes orbiting each other