If a time machine could take us back 4.6 billion years to the Earths birth, wed see our sun shining 20 to 25 percent less brightly than today. Without an earthly greenhouse to trap the suns energy and warm the atmosphere, our world would be a spinning ball of ice. Life may never have evolved.
But life did evolve, so greenhouse gases must have been around to warm the Earth. Evidence from the geologic record indicates an abundance of the greenhouse gas carbon dioxide. Methane probably was present as well, but that greenhouse gas doesnt leave enough of a geologic footprint to detect with certainty. Molecular oxygen wasnt around, indicate rocks from the era, which contain iron carbonate instead of iron oxide. Stone fingerprints of flowing streams, liquid oceans and minerals formed from evaporation confirm that 3 billion years ago, Earth was warm enough for liquid water.
Now, the geologic record revealed in some of Earths oldestrocks is telling a surprising tale of collapse of that greenhouse -- and its subsequent regeneration. But even more surprising, say the Stanford scientists who report these findings in the May 25 issue of the journal Geology, is the critical role that rocks played in the evolution of the early atmosphere.
Dawn Levy | Stanford University
Ice shelf vibrations cause unusual waves in Antarctic atmosphere
25.10.2016 | American Geophysical Union
Enormous dome in central Andes driven by huge magma body beneath it
25.10.2016 | University of California - Santa Cruz
Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.
This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...
Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion
Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
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