This is a guest post by Nathan Sanders, a PhD student at Harvard University and a writer at Astrobites.
Sometimes it seems like scientists and the general …
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Electrical engineer and entrepreneur Louis Michaud’s AVEtec company has received funding from PayPal cofounder Peter Thiel’s Breakout Labs program to build an experimental Atmosphere Vortex Engine (AVE). The $300,000 in startup funds is to go towards building a working engine to dispel or prove the viability of using such technology to produce electricity with virtually no carbon footprint.
Michaud’s idea is to use a fan to blow some of the excess heat produced by conventional power plants, into a cylindrical hollow tower, at an angle. Doing so should create a circular air current, which he says will grow stronger as it moves higher. The higher it goes the more energy it draws due to differences in temperature. The result would be a controlled man-made tornado. To put it to good user, turbines would be installed at the base of the vortex to create electricity. The original test will be conducted at Lambton College in Ontario – the tower will be 131 feet tall with a 26 foot diameter. That should be enough to create a vortex about a foot in diameter – enough to power a small turbine. It’s just a proof of concept, Michaud notes on his site, a real-world tower would be about 25 meters in diameter, and would be capable of producing up to 200 megawatts of power using only the excess heat generated by a conventional 500 megawatt plant. Power goes up geometrically, he says, as the size of tower grows. He adds that the cost of producing electricity this way would be about 3 cents per kilowatt hour, well below the typical 4 or 5 cents for coal plants.
Michaud has been investigating the idea of harnessing the power of tornado’s to provide electricity for several decades but until now has had problems being taken seriously by venture capitalists. He adds that his company built and successfully tested an AVE prototype in 2009, hinting that he has no doubts that the new tower and turbines will work as advertised.
See on phys.org
A new study supports Einstein’s view over that of some quantum theorists.
A team of researchers came to this conclusion after tracing the long journey three photons took through intergalactic space. The photons were blasted out by an intense explosion known as a gamma-ray burst about 7 billion light-years from Earth. They finally barreled into the detectors of NASA’s Fermi Gamma-ray Space Telescope in May 2009, arriving just a millisecond apart.
Their dead-heat finish strongly supports the Einsteinian view of space-time, researchers said. The wavelengths of gamma-ray burst photons are so small that they should be able to interact with the even tinier “bubbles” in the quantum theorists’ proposed space-time foam.
If this foam indeed exists, the three protons should have been knocked around a bit during their epic voyage. In such a scenario, the chances of all three reaching the Fermi telescope at virtually the same time are very low, researchers said.
So the new study is a strike against the foam’s existence as currently imagined, though not a death blow. “If foaminess exists at all, we think it must be at a scale far smaller than the Planck length, indicating that other physics might be involved,” study leader Robert Nemiroff, of Michigan Technological University, said in a statement. The Planck length is an almost inconceivably short distance, about one trillionth of a trillionth the diameter of a hydrogen atom.
“There is a possibility of a statistical fluke, or that space-time foam interacts with light differently than we imagined,” added Nemiroff, who presented the results Wednesday (Jan. 9) at the 221st meeting of the American Astronomical Society in Long Beach, Calif.
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Chemical and nanoengineers at Rice University have become the first team to create long (hundreds of meters), macroscopic, mass-producible carbon nanotube thread. This thread is about the thickness of a human hair, but has the conductivity of metal and the strength of carbon fiber. If you were looking for a material to fuel smart clothing and other digital textiles, this is it. An LED lamp is being suspended, and powered, by the tiny thread.
See on www.extremetech.com
An international team of astronomers, led by academics from the University of Central Lancashire (UCLan), has found the largest known structure in the universe. The large quasar group (LQG) is so large that it would take a vehicle travelling at the speed of light some 4 billion years to cross it. The team publish their results in the journal Monthly Notices of the Royal Astronomical Society.
Quasars are the nuclei of galaxies from the early days of the universe that undergo brief periods of extremely high brightness that make them visible across huge distances. These periods are ‘brief’ in astrophysics terms but actually last 10-100 million years. Since 1982 it has been known that quasars tend to group together in clumps or ‘structures’ of surprisingly large sizes, forming large quasar groups or LQGs.
The team, led by Dr. Roger Clowes from UCLan’s Jeremiah Horrocks Institute, has identified the LQG which is so significant in size it also challenges the Cosmological Principle: the assumption that the universe, when viewed at a sufficiently large scale, looks the same no matter where you are observing it from.
The modern theory of cosmology is based on the work of Albert Einstein, and depends on the assumption of the Cosmological Principle. The Principle is assumed but has never been demonstrated observationally ‘beyond reasonable doubt’.
To give some sense of scale, our galaxy, the Milky Way, is separated from its nearest neighbour, the Andromeda Galaxy, by about 0.75 Megaparsecs (Mpc) or 2.5 million light-years. Whole clusters of galaxies can be 2-3 Mpc across but LQGs can be 200 Mpc or more across. Based on the Cosmological Principle and the modern theory of cosmology, calculations suggest that astrophysicists should not be able to find a structure larger than 370 Mpc.
Dr. Clowes’ newly discovered LQG however has a typical dimension of 500 Mpc. But because it is elongated, its longest dimension is 1200 Mpc (or 4 billion light years) – some 1600 times larger than the distance from the Milky Way to Andromeda.
See on www.ras.org.uk
Astronomers have discovered a Methuselah of stars — a denizen of the Solar System’s neighbourhood that is at least 13.2 billion years old and formed shortly after the Big Bang.
“We believe this star is the oldest known in the Universe with a well determined age,” says Howard Bond, an astronomer at Pennsylvania State University in University Park, who announced the finding on 10 January at a meeting of the American Astronomical Society in Long Beach, California.
The venerable star, dubbed HD 140283, lies at a comparatively short distance of 190 light years from the Solar System and has been studied by astronomers for more than a century. Researchers have long known that the object consists almost entirely of hydrogen and helium — a hallmark of having formed early in the history of the Universe, before successive generations of stars had a chance to forge heavier elements. But no one knew exactly how old it was.
See on www.nature.com