Some articles on billion years, billions, years, billion:
... orogeny formed the cratonic nucleus approximately 4 billion years ago ... Radiometrically dated to as old as 3.8 billion years, some of the zircons collected from the orthogneisses of the Napier Complex are among the oldest rock specimens ... Billions of years of erosion and tectonic deformation have exposed the metamorphic rock core of these ancient mountains ...
... expansion is estimated to have begun 13.798 ± 0.037 billion years ago ... Some researchers call the development of all this physical structure over billions of years "cosmic evolution." Other, more interdisciplinary, researchers refer to "cosmic evolution ... the present day, scientists anticipate that the Earth will cease to support life in about a billion years, and will be drawn into the Sun in about 5 ...
... attempts" include Methane poisoning, 3.5 billion years ago The oxygen catastrophe, 2.7 billion years ago Snowball earth, twice, 2.3 billion years ago and 790–630 million ...
... The solar minimum around 2.4 billion years ago is consistent with an established cosmic ray flux modulation by a variable star formation rate in the Milky Way and ... Within the last billion years the solar wind has significantly diminished ... output of the sun has gradually increased, on the order of 5% per billion (109) years, and will continue to do so until it reaches the end of its current phase of stellar evolution ...
... evolution and extrapolating backwards, propose that life began "9.7±2.5 billion years ago", billions of years before the Earth was formed ... case of evolution, empirical evidence suggested a doubling of complexity every 376 million years ... one nucleotide) at "9.7±2.5 billion years ago" ...
Famous quotes containing the words billion years, years and/or billion:
“Imagine spending four billion years stocking the oceans with seafood, filling the ground with fossil fuels, and drilling the bees in honey productiononly to produce a race of bed-wetters!”
—Barbara Ehrenreich (b. 1941)
“He sighed with relief. He had got the job. He was safe.
Putting on his gown, he prepared for the long years to come....”
—Philip Larkin (19221986)
“Nights brittle song, silver-thin
Shatters into a billion fragments
Of quiet shadows
At the blaring jazz
Of a morning sun.”
—Frank Marshall Davis (b. 1905)