Black holes are regions in space characterized by gravitational fields so intense that no matter or radiation can escape from them. They are solutions to Einstein's field equations, with a point of unphysical infinite density ...
Black holes are regions in space where gravity is very strong—so strong that nothing that enters them can escape, including light. Theoretical predictions suggest that there is a radius surrounding black holes known as ...
One idea for how the universe began is that the universe may have appeared out of nothing due to some quantum effect, such as quantum tunneling. In the 1980s, Stephen Hawking and James Hartle further elaborated on this idea ...
(Phys.org) —Last week was a big one for space science, as it was announced that astronomers created the first realistic virtual universe—a computer simulation called "Illustris" that is able to recreate 13 billion years ...
(PhysOrg.com) -- Black holes get their name because they absorb all incoming light, and are so dense that none of that light can escape their event horizon. In a new study, scientists have created a sonic analogue of a black ...
A study published this week in Nature Communications shows how hunting hawks solve the problem of intercepting a single bat within a dense swarm. The findings increase our understanding of how predators select and track a ...
Plants & Animals
Aug 23, 2022
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A quartet of researchers at the University of Oxford's Department of Zoology has found that a careful look at the way large birds perch could perhaps lead to improvements in the ways that drones are programmed to land. In ...
There are certain rules that even the most extreme objects in the universe must obey. A central law for black holes predicts that the area of their event horizons—the boundary beyond which nothing can ever escape—should ...
General Physics
Jul 1, 2021
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(Phys.org)—Jeff Steinhauer, a physicist at the Israel Institute of Technology, has published a paper in the journal Nature Physics describing experiments in which he attempted to create a virtual black hole in the lab in ...
(Phys.org)—An international team of researchers working in a part of Arizona has found evidence of a hummingbird species benefiting by building nests in trees beneath hawk hunting grounds. In their paper published in the ...
The term hawk can be used in several ways:
The common names of birds in various parts of the world often use hawk in the second sense. For example, the Osprey or "fish hawk"; or, in North America, the various Buteo species (e.g., the Red-tailed Hawk, B. jamaicensis).
In February 2005, the Canadian ornithologist Louis Lefebvre announced a method of measuring avian "IQ" in terms of their innovation in feeding habits. Hawks were named among the most intelligent birds based on his scale. Hawks are widely reputed to have visual acuity several times that of a normal human being. This is due to the many photoreceptors in the retina (up to 1,000,000 per square mm for Buteo, against 200,000 for humans), an exceptional number of nerves connecting these receptors to the brain, and an indented fovea, which magnifies the central portion of the visual field.
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