Inflation & Frozen Moss | SciByte 124

Inflation & Frozen Moss | SciByte 124

We take a look at evidence of inflation at the start of the Universe, water in the Earths crust, giant stars, frozen moss, spacecraft updates, Curiosity news, and as always take a peek back into history and up in the sky this week.

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Show Notes:

Gravity, The Big Bang, and Inflation

  • 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.
  • Two People of Note
  • Alan Guth, the originator of the inflationary universe theory | Wikipedia
  • Andrei Linde, one of the main authors of the inflationary universe theory | Wikipedia
  • Looking Back at the Universe
  • Alternative theories to inflation do not produce gravitational waves so this is strong evidence not only of the gravitational wave background but also inflation itself.
  • The BICEP discovery provides further indirect evidence for the existence of gravitational waves
  • 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
  • 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
  • Q: Can you explain the theory of cosmic inflation first put forth in 1980? | Alan Guth
  • The theory of cosmic inflation describes the propulsion mechanism that drove the universe into the period of tremendous expansion that we call the Big Bang, usually describe inflation as a theory of the \”bang\” of the Big Bang
  • It 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.
  • — In Further Detail —
  • 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 conservation energy it actually has 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, 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 and decays into ordinary particles, producing a very hot soup of particles that form the starting point of the conventional Big Bang
  • At that point the repulsive gravity turns off, but the region continues to expand in a coasting pattern for billions of years to come
  • Q: What is the new result announced, and how does it provide critical support for your theory? | Alan Guth
  • 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
  • Temperature nonuniformities, which can correlate to density differences, in the cosmic microwave background were first measured in 1992 by the COBE satellite
  • These 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 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? | Alan Guth
  • These gravity waves can 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
  • While the current result is not by itself conclusive, it does points in the direction of the very simplest inflationary models that can be constructed.
  • Of Note
  • This is not the first evidence os gravitational waves | The 1993 Nobel Prize in Physics was awarded to Russell Hulse and Joseph Taylor for finding a double pulsar that strongly supported \”ripples\” in spacetime
  • The 2006 Nobel Prize in Physics was awarded to the discovery of tiny changes in temperature in the Cosmic Background Radiation that were discovered by the COBE satellite
  • The is not the first discovery of the polarization within the cosmic microwave background, or even the first observations of this type of polarization
  • This IS evidence of primordial gravitational waves, that would only be caused by inflation during the early moments of the Universe
  • While these results are very credible they have not been peer reviewed yet
  • Multimedia
  • YouTube | Stanford Professor Andrei Linde celebrates physics breakthrough | StanfordUniversity
  • YouTube | A Polarizing Discovery About the Big Bang! | minutephysics
  • Further Reading / In the News
  • Kenny MacLeod ‏@siabost9deas | RT @grahamfarmelo: Primordial gravity waves discovery-Nobel 2 follow 4 inflation pioneer Alan Guth? http://nyti.ms/1ivEk8k
  • First hints of gravitational waves in the Big Bang\’s afterglow | Phys.org
  • Alan Guth on new insights into the \’Big Bang\’ | Phys.org
  • We\’ve Discovered Inflation! Now What? | UniverseToday.com
  • That Moment When the \”Father of Inflation\” Learns of the Detection of Gravitational Waves | UniverseToday.com

— NEWS BYTE —

Water Deep in Earth’s Crust

  • The first terrestrial discovery of ringwoodite confirms the presence of massive amounts of water 400 to 700 kilometers beneath Earth\’s surface
  • Ringwoodite
  • Ringwoodite is a form of the mineral peridot, believed to exist in large quantities under high pressures in the transition zone
  • It is notable for being able to contain water within its structure, present not as a liquid but as hydroxide ions (oxygen and hydrogen atoms bound together).
  • 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
  • The Discovery
  • The discovery was almost accidental in that the team had been looking for another mineral when they purchased a three-millimetre-wide, dirty-looking, commercially worthless brown diamond
  • 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 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
  • Significance
  • This discovery confirms about 50 years of theoretical and experimental work by geophysicists, seismologists and other scientists trying to understand the makeup of the Earth\’s interior.
  • One of the world\’s leading authorities in the study of deep Earth diamond host rocks, said that the discovery ranks among the most significant of his career
  • Scientists have been deeply divided about the composition of the transition zone and whether it is full of water or desert-dry, 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, the transition zone, might have as much water as all the world\’s oceans put together
  • 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
  • Further Reading / In the News
  • Water-rich gem points to vast \’oceans\’ beneath Earth\’s surface, study suggests — ScienceDaily | ScienceDaily.com

— TWO-BYTE NEWS —

Largest Yellow \”Hypergiant\” Star Discovered

  • A recent analysis of the star HR 5171 A in the south hemisphere constellation of Centaurus, has revealed the nature of a massive yellow \”hypergiant\” star as one of the largest stars known
  • 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
  • If it was placed 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
  • Only eight yellow hypergiants have been identified in our Milky Way galaxy but are some of the brightest stars known, if you placed a star like HR 5171 A 32 light years from the Earth, it would easily cast a shadow.
  • Companion Star
  • The relatively small companion star orbitis across our line of sight once every 1300 days, and is a large star in its own right at around six solar masses and 400 solar radii in size.
  • 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
  • What we see is not the companion itself, but the regions gravitationally controlled and filled by the wind from the hypergiant
  • The System
  • 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
  • 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.
  • Further Reading / In the News
  • Astronomers Identify the Largest Yellow \”Hypergiant\” Star Known | UniverseToday.com

Frozen Moss Back to Life

  • 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 Discovery
  • This is the first study to show such long-term survival in any plant; similar timescales have only been seen before in bacteria
  • This moss would already have been at least decades old when it was first frozen
  • The team took cores of moss from deep in a frozen moss bank in the Antarctic then placed it in an incubator at a normal growth temperature and light level and 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.
  • Further Reading / In the News
  • Back to life after 1,500 years: Moss brought back to life after 1,500 years frozen in ice | ScienceDaily.com

— SPACECRAFT UPDATE—

Mars Reconnaissance Orbiter

  • 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
  • Images
    • 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
  • Gullies or ravinea landforms are common on Mars, particularly in the southern highlands, these ravines tend to happen in the southern highlands and other mid-latitude regions on
  • It’s unclear in what season the activity occurred because the observations took place more than a Martian year apart
  • 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
  • Further Reading / In the News
  • New Gully Appears On Mars, But It\’s Likely Not Due To Water | UniverseToday.com

— CURIOSITY UPDATE —

  • NASA’s Curiosity rover has just pulled into terrain chock full of curvy rock outcrops at Kimberly that’s suitable for contact science and drilling action
  • The robot’s arm has been deployed to investigate the most scientifically productive spots, and is conducting contact science with the cameras and spectrometers on the terminus of the 7 foot long robotic arm
  • The mast mounted ChemCam laser and high resolution cameras are being used to determine the best spot for drilling and sampling.
  • The team commanded Curiosity to clean out the arms CHIMRA sample handling mechanism in anticipation of boring into the Martian outcrops and delivering samples of cored Martian rocks to the SAM and CheMin miniaturized chemistry labs
  • Scientists directed Curiosity on a pinpoint drive to Kimberly after their interest was piqued by orbital images taken NASA’s Mars Reconnaissance Orbiter (MRO) where they see three terrain types exposed and a relatively dust-free surface
  • The missions science focus has shifted to “search for that subset of habitable environments which also preserves organic carbon
  • To date Curiosity’s odometer stands at 6.2 kilometers and has somewhat over another 4 kilometers to go to reach the base of Mount Sharp
  • It may arrive at the lower reaches of Mount Sharp sometime in mid 2014, but must first pass through a potentially treacherous dune field
  • Multimedia
  • Image Galleries at JPL and Curiosity Mulimedia
  • Social Media
  • Curiosity Rover @MarsCuriosity
  • Further Reading / In the News
  • Curiosity Pulls into Kimberly and Spies Curvy Terrain For Drilling Action | UniverseToday.com

SCIENCE CALENDAR

Looking back

  • Mar 28, 1949 : 65 years ago : “Big Bang” Coined : 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

Looking up this week

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