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Back to life after 1,500 years: Moss brought back to life after 1,500 years frozen in i... - 0 views

  • Researchers from the British Antarctic Survey and Reading University have demonstrated that, after over 1,500 years frozen in Antarctic ice, moss can come back to life and continue to grow
  • The team,
  • observed moss regeneration after at least 1,530 years frozen in permafrost
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  • This is the first study to show such long-term survival in any plant; similar timescales have only been seen before in bacteria
  • Mosses are
  • the dominant plants over large areas and are a major storer of fixed carbon
  • The team took cores of moss from deep in a frozen moss bank in the Antarctic
  • This moss would already have been at least decades old when it was first frozen
  • in an incubator at a normal growth temperature and light level
  • After only a few weeks,
  • the moss began to grow
  • Using carbon dating, the team identified the moss to be at least 1,530 years of age, and possibly even older, at the depth where the new growth was seen.
Mars Base

New Gully Appears On Mars, But It's Likely Not Due To Water - 0 views

  • images from NASA’s Mars Reconnaissance Orbiter show a new channel in the southern hemisphere region of Terra Siernum that appeared between November 2010 and May 2013.
  • this particular feature is likely not due to that liquid
  • Gully or ravine landforms are common on Mars, particularly in the southern highlands
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  • This pair of images shows that material flowing down from an alcove at the head of a gully broke out of an older route and eroded a new channel
  • It’s unclear in what season the activity occurred because the observations took place more than a Martian year apart
  • These ravines tend to happen in the southern highlands and other mid-latitude regions on Mars
  • this type of activity generally occurs in winter, at temperatures so cold that carbon dioxide, rather than water, is likely to play the key role
Mars Base

March 28 - Today in Science History - Scientists born on March 28th, died, and events - 0 views

  • Hoyle coined “Big Bang”
  • In 1949, Fred Hoyle unintentionally coined the term “Big Bang” as a household name, in a scripted radio broadcast on the BBC Third Programme. His talk was printed in the The Listener (7 Apr 1949). He compared his own belief in a “steady state” universe, saying, “earlier theories … were based on the hypothesis that all the matter in the universe was created in one big bang at a particular time in the remote past.” He repeated its use in a 1950 broadcast published in The Listener (9 Mar 1950): “One [idea] was that the Universe started its life a finite time ago in a single huge explosion… This big bang idea seemed to me to be unsatisfactory.” His critics found the “big bang” term pejorative, yet Hoyle has said his intention was to make a vivid description for the radio audience. The term stuck
Mars Base

March 27 - Today in Science History - Scientists born on March 27th, died, and events - 0 views

  • Alaska earthquake
  • In 1965, south central Alaska was rocked by North America's greatest earthquake. (At 8.3-8.5 on the Richter scale, it released over twice the energy of the 1906 San Francisco earthquake.) Its epicenter was near Price William Sound, along a 1,000 km thrust fault where the Pacific plate subducts under the North american plate. The earthquake tilted at least 120,000 sq km. Some landmasses were thrust up locally as high as 25 m; elsewhere land sank as much as 2.5m. The shock was felt over almost 1,300,000 sq km. Extensive coastal damage resulted from submarine landslides and tsunamis which caused 122 of the 131 deaths. Property damage cost was about $311 million. Tsunami damage reached Crescent City, Calif. Tens of thousands of aftershocks indicated that the region of faulting extended about 1,000 km.
Mars Base

March 29 - Today in Science History - Scientists born on March 29th, died, and events - 0 views

  • Coca-Cola
  • In 1886, the first batch of Coca Cola was brewed over a fire in a backyard in Atlanta, Georgia. Dr. John Pemberton had created the concoction as a cure for "hangover," stomach ache and headache. He advertised it as a "brain tonic and intellectual beverage," and first sold it to the public a few weeks later on 8 May. Coke contained cocaine as an ingredient until 1904, when the drug was banned by Congress.
  •  
    Coca-Cola
Mars Base

Astronomers Identify the Largest Yellow "Hypergiant" Star Known - 0 views

  • A recent analysis of a star in the south hemisphere constellation of Centaurus has highlighted the role that amateurs play in assisting with professional discoveries in astronomy.
  • The stats for
  • the binary system weighs in at a combined 39 solar masses, has a radius of over 1,300 times that of our Sun, and is a million times as luminous
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  • Located 3,600 parsecs or over 11,700 light years distant, the star is 50% larger than the famous red giant Betelgeuse
  • down into the center of our own solar system, and it would extend out over 6 astronomical units (A.U.s) past the orbit of Jupiter
  • also has a relatively small companion star orbiting across our line of sight once every 1300 days
  • The companion star
  • is also a large star in its own right at around six solar masses and 400 solar radii in size.
  • the surface-to-surface distance for the A and B components of the system are “only” about 2.8 A.U.s apart
  • This all means that these two massive stars are in physical contact, with the expanded outer atmosphere of the bloated primary contacting the secondary, giving the pair a distorted peanut shape.
  • yellow hypergiants are some of the brightest stars known
  • That’s just 16x times fainter than the apparent visual magnitude of a Full Moon but over 100 times brighter than Venus
  • if you placed a star like HR 5171 A 32 light years from the Earth, it would easily cast a shadow.
  • the discovery of a companion around such a bright star was a big surprise since any ‘normal’ star should at least be 10,000 times fainter than the hypergiant
  • the hypergiant was much bigger than expected
  • What we see is not the companion itself, but the regions gravitationally controlled and filled by the wind from the hypergiant
  • These latest measurements place HR 5171 A firmly in the “Top 10” for largest stars in terms of size known, as well as the largest yellow hypergiant star known
  • Only eight yellow hypergiants have been identified in our Milky Way galaxy
Mars Base

Water-rich gem points to vast 'oceans' beneath Earth's surface, study suggests -- Scien... - 0 views

  • The first terrestrial discovery of ringwoodite confirms the presence of massive amounts of water 400 to 700 kilometers beneath Earth's surface
  • Ringwoodite is a form of the mineral peridot, believed to exist in large quantities under high pressures in the transition zone
  • Ringwoodite has been found in meteorites but, until now, no terrestrial sample has ever been unearthed because scientists haven't been able to conduct fieldwork at extreme depths
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  • An international team of scientists
  • has discovered the first-ever sample of a mineral called ringwoodite
  • Analysis of the mineral shows it contains a significant amount of water -- 1.5 per cent of its weight
  • finding that confirms scientific theories about vast volumes of water trapped 410 to 660 kilometres beneath Earth's surface, between the upper and lower mantle.
  • This sample really provides extremely strong confirmation that there are local wet spots deep in the Earth
  • particular zone in the Earth, the transition zone, might have as much water as all the world's oceans put together
  • The diamond had been brought to the Earth's surface by a volcanic rock known as kimberlite -- the most deeply derived of all volcanic rocks.
  • the discovery was almost accidental in that
  • team had been looking for another mineral when they purchased a three-millimetre-wide, dirty-looking, commercially worthless brown diamond
  • The ringwoodite itself is invisible to the naked eye, buried beneath the surface, so it was fortunate that it was found
  • The sample underwent years of analysis using Raman and infrared spectroscopy and X-ray diffraction before it was officially confirmed as ringwoodite
  • one of the world's leading authorities in the study of deep Earth diamond host rocks, the discovery ranks among the most significant of his career
  • confirming about 50 years of theoretical and experimental work by geophysicists, seismologists and other scientists trying to understand the makeup of the Earth's interior.
  • Scientists have been deeply divided about the composition of the transition zone and whether it is full of water or desert-dry
  • Knowing water exists beneath the crust has implications for the study of volcanism and plate tectonics, affecting how rock melts, cools and shifts below the crust
Mars Base

Alan Guth on new insights into the 'Big Bang' - 0 views

  • Q: Can you explain the theory of cosmic inflation that you first put forth in 1980?
  • usually describe inflation as a theory of the "bang" of the Big Bang
  • describes the propulsion mechanism that drove the universe into the period of tremendous expansion that we call the Big Bang
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  • The original Big Bang theory was really a theory of the aftermath of the bang
  • described how the universe was cooled by the expansion, and how the expansion was slowed by the attractive force of gravity
  • Inflation proposes that the expansion of the universe was driven by a repulsive form of gravity.
  • According to Newton, gravity is a purely attractive force, but this changed with Einstein and the discovery of general relativity
  • General relativity describes gravity as a distortion of spacetime, and allows for the possibility of repulsive gravity
  • Modern particle theories strongly suggest that at very high energies, there should exist forms of matter that create repulsive gravity
  • Inflation
  • proposes that at least a very small patch of the early universe was filled with this repulsive-gravity material
  • During the period of exponential expansion, any ordinary material would thin out, with the density diminishing to almost nothing
  • The repulsive-gravity material actually maintains a constant density as it expands, no matter how much it expands
  • While this appears to be a
  • violation
  • of the conservation of energy, it is actually
  • consistent
  • a peculiar feature of gravity: The energy of a gravitational field is negative
  • As the patch expands at constant density, more and more energy, in the form of matter, is created
  • But at the same time, more and more negative energy appears in the form of the gravitational field that is filling the region
  • The total energy remains constant, as it must, and therefore remains very small.
  • It is possible that the total energy of the entire universe is exactly zero, with the positive energy of matter completely canceled by the negative energy of gravity
  • At some point the inflation ends because the repulsive-gravity material becomes metastable
  • decays into ordinary particles, producing a very hot soup of particles that form the starting point of the conventional Big Bang
  • point the repulsive gravity turns off, but the region continues to expand in a coasting pattern for billions of years to come
  • inflation is a prequel to the era that cosmologists call the Big Bang, although it of course occurred after the origin of the universe, which is often also called the Big Bang.
  • Q: What is the new result announced this week, and how does it provide critical support for your theory?
  • The early universe, as we can see from the afterglow of the cosmic microwave background (CMB) radiation, was incredibly uniform,
  • to have structure form at all, there needed to be small nonuniformities at the end of inflation
  • The tiny nonuniformities that did exist were then amplified by gravity
  • these nonuniformities—which later produce stars, galaxies, and all the structure of the universe—are attributed to quantum theory
  • The temperature nonuniformities in the cosmic microwave background were first measured in 1992 by the COBE satellite
  • have not generally been seen as proof of inflation, in part because it is not clear that inflation is the only possible way that these fluctuations could have been produced.
  • The stretching effect of inflation,
  • also acts on the geometry of space itself, which according to general relativity is flexible
  • Space can be compressed, stretched, or even twisted.
  • The geometry of space also fluctuates on small scales, due to the physics of quantum theory, and inflation also stretches these fluctuations, producing gravity waves in the early universe.
  • The new result,
  • is a measurement of these gravity waves, at a very high level of confidence.
  • They do not see the gravity waves directly, but instead they have constructed a very detailed map of the polarization of the CMB in a patch of the sky.
  • They have observed a swirling pattern in the polarization (called "B modes") that can be created
  • by gravity waves in the early universe
  • This is the first time that even a hint of these primordial gravity waves has been detected
  • it is also the first time that any quantum properties of gravity have been directly observed.
  • Q: How would you describe the significance of these new findings, and your reaction to them?
  • The significance of these new findings
  • help tremendously in confirming the picture of inflation.
  • As far as we know, there is nothing other than inflation that can produce these gravity waves
  • it tells us a lot about the details of inflation that we did not already know
  • it determines the energy density of the universe at the time of inflation, which is something that previously had a wide range of possibilities.
  • By determining the energy density of the universe at the time of inflation, the new result also tells us a lot about which detailed versions of inflation are still viable, and which are no longer viable
  • The current result is not by itself conclusive, but it points in the direction of the very simplest inflationary models that can be constructed.
Mars Base

First hints of gravitational waves in the Big Bang's afterglow - 0 views

  • As the last untested prediction of Einstein's Theory of General Relativity, finding gravitational waves is a big deal.
  • Scientists at the Harvard-Smithsonian Centre for Astrophysics in the US have announced
  • what they believe is the indirect detection of gravitational waves in the afterglow of the Big Bang.
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  • The BICEP discovery provides further indirect evidence for the existence of gravitational waves
  • the 1993 Nobel Prize in Physics was awarded to Russell Hulse and Joseph Taylor for finding a double pulsar that strongly supported these "ripples" in spacetime
  • Before this announcement
  • we could measure the universe back to about a minute after the Big Bang.
  • The finding
  • has allowed us to study the universe when it was a trillionth of a trillionth of a trillionth of a second old
  • tiny changes in temperature that were discovered by the COBE satellite (winning the 2006 Nobel Prize)
  • Alternative theories to inflation do not produce gravitational waves so
  • is strong evidence not only of the gravitational wave background but also inflation itself.
  • there has still been no direct detection of the gravitational radiation.
  • The first direct detection should follow in a few months
  • It is envisaged that the experiment will directly detect gravitational radiation coming from astrophysical sources from nearby galaxies
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