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Saturday, 12 August 2017
Thursday, 23 March 2017
Aurora
An aurora, sometimes referred to as a polar light or northern light, is a natural light display in the sky, predominantly seen in the high latitude
Most auroras occur in a band known as the auroral zone, which is typically 3° to 6° wide in latitude and between 10° and 20° from the geomagnetic poles at all local times (or longitudes), most clearly seen at night against a dark sky. A region that currently displays an aurora is called the auroral oval, a band displaced towards the nightside of the Earth. Early evidence for a geomagnetic connection comes from the statistics of auroral observations. Elias Loomis (1860), and later Hermann Fritz (1881) and S. Tromholt (1882) in more detail, established that the aurora appeared mainly in the auroral zone. Day-to-day positions of the auroral ovals are posted on the internet.
A geomagnetic storm causes the auroral ovals (north and south) to expand, and bring the aurora to lower latitudes. It was hardly ever seen near the geographic pole, which is about 2000 km away from the magnetic pole. The instantaneous distribution of auroras ("auroral oval")[3] is slightly different, being centered about 3–5 degrees nightward of the magnetic pole, so that auroral arcs reach furthest toward the equator when the magnetic pole in question is in between the observer and the Sun. The aurora can be seen best at this time, which is called magnetic midnight.
Auroras seen within the auroral oval may be directly overhead, but from farther away they illuminate the poleward horizon as a greenish glow, or sometimes a faint red, as if the Sun were rising from an unusual direction. Auroras also occur poleward of the auroral zone as either diffuse patches or arcs, which can be sub-visual.
Causes of auroras
A quiescent solar wind flowing past the Earth’s magnetosphere steadily interacts with it and can both inject solar wind particles directly onto the geomagnetic field lines that are ‘open’, as opposed to being ‘closed’ in the opposite hemisphere, and provide diffusion through the bow shock. It can also cause particles already trapped in the radiation belts to precipitate into the atmosphere. Once particles are lost to the atmosphere from the radiation belts, under quiet conditions new ones replace them only slowly, and the loss-cone becomes depleted. In the magnetotail, however, particle trajectories seem constantly to reshuffle, probably when the particles cross the very weak magnetic field near the equator. As a result, the flow of electrons in that region is nearly the same in all directions ("isotropic"), and assures a steady supply of leaking electrons. The leakage of electrons does not leave the tail positively charged, because each leaked electron lost to the atmosphere is replaced by a low energy electron drawn upward from the ionosphere. Such replacement of "hot" electrons by "cold" ones is in complete accord with the 2nd law of thermodynamics. The complete process, which also generates an electric ring current around the Earth, is uncertain.Colors of auroras
2. Green: At lower altitudes the more frequent collisions suppress the 630.0 nm (red) mode: rather the 557.7 nm emission (green) dominates. Fairly high concentration of atomic oxygen and higher eye sensitivity in green make green auroras the most common. The excited molecular nitrogen (atomic nitrogen being rare due to high stability of the N2 molecule) plays a role here, as it can transfer energy by collision to an oxygen atom, which then radiates it away at the green wavelength. (Red and green can also mix together to produce pink or yellow hues.) The rapid decrease of concentration of atomic oxygen below about 100 km is responsible for the abrupt-looking end of the lower edges of the curtains. Both the 557.7 and 630.0 nm wavelengths correspond to forbidden transitions of atomic oxygen, slow mechanism that is responsible for the graduality (0.7 s and 107 s respectively) of flaring and fading.
3. Blue: At yet lower altitudes, atomic oxygen is uncommon, and molecular nitrogen and ionized molecular nitrogen takes over in producing visible light emission; radiating at a large number of wavelengths in both red and blue parts of the spectrum, with 428 nm (blue) being dominant. Blue and purple emissions, typically at the lower edges of the "curtains", show up at the highest levels of solar activity. The molecular nitrogen transitions are much faster than the atomic oxygen ones.
4. Ultraviolet: Ultraviolet light from auroras (within the optical window but not visible to virtually all humans) has been observed with the requisite equipment. Ultraviolet auroras have also been seen on Mars, Jupiter and Saturn.
Infrared: Infrared light, in wavelengths that are within the optical window, is also part of many auroras.
5. Yellow and pink are a mix of red and green or blue. Other shades of red as well as orange may be seen on rare occasions; yellow-green is moderately common. As red, green, and blue are the primary colours of additive synthesis of colours, in theory practically any colour might be possible but the ones mentioned in this article comprise a virtually exhaustive list.
Monday, 20 February 2017
Standard Model
The Standard Model explains how the basic building blocks of matter interact, governed by four fundamental forces
The theories and discoveries of thousands of physicists since the 1930s have resulted in a remarkable insight into the fundamental structure of matter: everything in the universe is found to be made from a few basic building blocks called fundamental particles, governed by four fundamental forces. Our best understanding of how these particles and three of the forces are related to each other is encapsulated in the Standard Model of particle physics. Developed in the early 1970s, it has successfully explained almost all experimental results and precisely predicted a wide variety of phenomena. Over time and through many experiments, the Standard Model has become established as a well-tested physics theory.
Matter particles
All matter around us is made of elementary particles, the building blocks of matter. These particles occur in two basic types called quarks and leptons. Each group consists of six particles, which are related in pairs, or “generations”. The lightest and most stable particles make up the first generation, whereas the heavier and less stable particles belong to the second and third generations. All stable matter in the universe is made from particles that belong to the first generation; any heavier particles quickly decay to the next most stable level. The six quarks are paired in the three generations – the “up quark” and the “down quark” form the first generation, followed by the “charm quark” and “strange quark”, then the “top quark” and “bottom (or beauty) quark”. Quarks also come in three different “colours” and only mix in such ways as to form colourless objects. The six leptons are similarly arranged in three generations – the “electron” and the “electron neutrino”, the “muon” and the “muon neutrino”, and the “tau” and the “tau neutrino”. The electron, the muon and the tau all have an electric charge and a sizeable mass, whereas the neutrinos are electrically neutral and have very little mass.
Forces and carrier particles
There are four fundamental forces at work in the universe: the strong force, the weak force, the electromagnetic force, and the gravitational force. They work over different ranges and have different strengths. Gravity is the weakest but it has an infinite range. The electromagnetic force also has infinite range but it is many times stronger than gravity. The weak and strong forces are effective only over a very short range and dominate only at the level of subatomic particles. Despite its name, the weak force is much stronger than gravity but it is indeed the weakest of the other three. The strong force, as the name suggests, is the strongest of all four fundamental interactions.
Three of the fundamental forces result from the exchange of force-carrier particles, which belong to a broader group called “bosons”. Particles of matter transfer discrete amounts of energy by exchanging bosons with each other. Each fundamental force has its own corresponding boson – the strong force is carried by the “gluon”, the electromagnetic force is carried by the “photon”, and the “W and Z bosons” are responsible for the weak force. Although not yet found, the “graviton” should be the corresponding force-carrying particle of gravity. The Standard Model includes the electromagnetic, strong and weak forces and all their carrier particles, and explains well how these forces act on all of the matter particles. However, the most familiar force in our everyday lives, gravity, is not part of the Standard Model, as fitting gravity comfortably into this framework has proved to be a difficult challenge. The quantum theory used to describe the micro world, and the general theory of relativity used to describe the macro world, are difficult to fit into a single framework. No one has managed to make the two mathematically compatible in the context of the Standard Model. But luckily for particle physics, when it comes to the minuscule scale of particles, the effect of gravity is so weak as to be negligible. Only when matter is in bulk, at the scale of the human body or of the planets for example, does the effect of gravity dominate. So the Standard Model still works well despite its reluctant exclusion of one of the fundamental forces.
Matter particles
Forces and carrier particles
There are four fundamental forces at work in the universe: the strong force, the weak force, the electromagnetic force, and the gravitational force. They work over different ranges and have different strengths. Gravity is the weakest but it has an infinite range. The electromagnetic force also has infinite range but it is many times stronger than gravity. The weak and strong forces are effective only over a very short range and dominate only at the level of subatomic particles. Despite its name, the weak force is much stronger than gravity but it is indeed the weakest of the other three. The strong force, as the name suggests, is the strongest of all four fundamental interactions.
Three of the fundamental forces result from the exchange of force-carrier particles, which belong to a broader group called “bosons”. Particles of matter transfer discrete amounts of energy by exchanging bosons with each other. Each fundamental force has its own corresponding boson – the strong force is carried by the “gluon”, the electromagnetic force is carried by the “photon”, and the “W and Z bosons” are responsible for the weak force. Although not yet found, the “graviton” should be the corresponding force-carrying particle of gravity. The Standard Model includes the electromagnetic, strong and weak forces and all their carrier particles, and explains well how these forces act on all of the matter particles. However, the most familiar force in our everyday lives, gravity, is not part of the Standard Model, as fitting gravity comfortably into this framework has proved to be a difficult challenge. The quantum theory used to describe the micro world, and the general theory of relativity used to describe the macro world, are difficult to fit into a single framework. No one has managed to make the two mathematically compatible in the context of the Standard Model. But luckily for particle physics, when it comes to the minuscule scale of particles, the effect of gravity is so weak as to be negligible. Only when matter is in bulk, at the scale of the human body or of the planets for example, does the effect of gravity dominate. So the Standard Model still works well despite its reluctant exclusion of one of the fundamental forces.
So far so good, but...
...it is not time for physicists to call it a day just yet. Even though the Standard Model is currently the best description there is of the subatomic world, it does not explain the complete picture. The theory incorporates only three out of the four fundamental forces, omitting gravity. There are also important questions that it does not answer, such as “What is dark matter?”, or “What happened to the antimatter after the big bang?”, “Why are there three generations of quarks and leptons with such a different mass scale?” and more. Last but not least is a particle called the Higgs boson, an essential component of the Standard Model.
On 4 July 2012, the ATLAS and CMS experiments at CERN's Large Hadron Collider (LHC) announced they had each observed a new particle in the mass region around 126 GeV. This particle is consistent with the Higgs boson but it will take further work to determine whether or not it is the Higgs boson predicted by the Standard Model. The Higgs boson, as proposed within the Standard Model, is the simplest manifestation of the Brout-Englert-Higgs mechanism. Other types of Higgs bosons are predicted by other theories that go beyond the Standard Model.
On 8 October 2013 the Nobel prize in physics was awarded jointly to François Englert and Peter Higgs "for the theoretical discovery of a mechanism that contributes to our understanding of the origin of mass of subatomic particles, and which recently was confirmed through the discovery of the predicted fundamental particle, by the ATLAS and CMS experiments at CERN's Large Hadron Collider."
So although the Standard Model accurately describes the phenomena within its domain, it is still incomplete. Perhaps it is only a part of a bigger picture that includes new physics hidden deep in the subatomic world or in the dark recesses of the universe. New information from experiments at the LHC will help us to find more of these missing pieces.
...it is not time for physicists to call it a day just yet. Even though the Standard Model is currently the best description there is of the subatomic world, it does not explain the complete picture. The theory incorporates only three out of the four fundamental forces, omitting gravity. There are also important questions that it does not answer, such as “What is dark matter?”, or “What happened to the antimatter after the big bang?”, “Why are there three generations of quarks and leptons with such a different mass scale?” and more. Last but not least is a particle called the Higgs boson, an essential component of the Standard Model.
On 4 July 2012, the ATLAS and CMS experiments at CERN's Large Hadron Collider (LHC) announced they had each observed a new particle in the mass region around 126 GeV. This particle is consistent with the Higgs boson but it will take further work to determine whether or not it is the Higgs boson predicted by the Standard Model. The Higgs boson, as proposed within the Standard Model, is the simplest manifestation of the Brout-Englert-Higgs mechanism. Other types of Higgs bosons are predicted by other theories that go beyond the Standard Model.
On 8 October 2013 the Nobel prize in physics was awarded jointly to François Englert and Peter Higgs "for the theoretical discovery of a mechanism that contributes to our understanding of the origin of mass of subatomic particles, and which recently was confirmed through the discovery of the predicted fundamental particle, by the ATLAS and CMS experiments at CERN's Large Hadron Collider."
So although the Standard Model accurately describes the phenomena within its domain, it is still incomplete. Perhaps it is only a part of a bigger picture that includes new physics hidden deep in the subatomic world or in the dark recesses of the universe. New information from experiments at the LHC will help us to find more of these missing pieces.
Thursday, 9 February 2017
XJ1500+0154: Black Hole Meal Sets Record for Duration and Size
- A supermassive black hole in a small galaxy 1.8 billion light years away has been partaking in a decade-long binge of a star.
- This is known as a tidal disruption event and happens when an object gets too close to a black hole and is torn apart by gravity.
- Other similar events have been seen before but this one is much longer, representing an unusually massive meal.
- A trio of orbiting X-ray telescopes, including Chandra, was used to make this discovery.
XJ1500+0154 Black Hole |
A trio of X-ray observatories has captured a remarkable event in their data: a decade-long binge by a black hole almost two billion light years away. This discovery was made using data from NASA's Chandra X-ray Observatory, Swift Observatory, and ESA's XMM-Newton, as reported in our press release.
This artist's illustration depicts what astronomers call a "tidal disruption event," or TDE. This is when an object, such as a star, wanders too close to a black hole and is destroyed by tidal forces generated from the black hole's intense gravitational forces. During a TDE, some of the stellar debris is flung outward at high speeds, while the rest (shown as the red material in the illustration) becomes hotter as it falls toward the black hole, generating a distinct X-ray flare. A wind blowing away from this infalling material is shown in blue.
Among observed TDEs, this event involved either the most massive star to be completely ripped apart and devoured by a black hole or the first instance where a smaller star was completely ripped apart. The resulting X-ray source is known as XJ1500+154 and is located in a small galaxy about 1.8 billion light years from Earth. The optical image in the left inset shows this galaxy and a cross to mark the location of XJ1500+0154. This image reveals that XJ1500+0154 is found in the center of the galaxy, implying that the source likely originates from a supermassive black hole that resides there. The image on the right shows XJ1500+0154 in the Chandra image covering the same field.
The source was not detected in a Chandra observation on April 2, 2005, but was detected in an XMM-Newton observation on July 23, 2005, and reached peak brightness in a Chandra observation on June 5, 2008. These observations show that the source became at least 100 times brighter in X-rays. Since then, Chandra, Swift, and XMM-Newton have observed it multiple times.
The X-ray data also indicate that radiation from material surrounding this black hole has consistently surpassed the so-called Eddington limit, defined by a balance between the outward pressure of radiation from the hot gas and the inward pull of the gravity of the black hole.
This TDE may help answer the question as to how supermassive black holes in the early universe grow. If supermassive black holes can grow, from TDEs or other means, at rates above those corresponding to the Eddington limit, this could explain how supermassive black holes were able to reach masses about a billion times higher than the sun when the universe was only about a billion years old.
A paper describing these results appears in the February 6th issue of Nature Astronomy. The authors are Dacheng Lin (University of New Hampshire), James Guillochon (Harvard-Smithsonian Center for Astrophysics), Stefanie Komossa (QianNan Normal University for Nationalities), Enrico Ramirez-Ruiz (University of California, Santa Cruz), Jimmy Irwin (University of Alabama), Peter Maksym (Harvard-Smithsonian), Dirk Grupe (Morehead State University), Olivier Godet (CNRS), Natalie Webb (CNRS), Didier Barret (CNRS), Ashley Zauderer (New York University), Pierre-Alain Duc (CEA-Saclay), Eleazar Carrasco (Gemini Observatory), and Stephen Gwyn (Herzberg Institute of Astrophysics).
NASA's Marshall Space Flight Center in Huntsville, Alabama, manages the Chandra program for NASA's Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory in Cambridge, Massachusetts, controls Chandra's science and flight operations.
Tuesday, 7 February 2017
Wormhole
A wormhole is a theoretical passage through space-time that could create shortcuts for long journeys across the universe. Wormholes are predicted by the theory of general relativity. But be wary: wormholes bring with them the dangers of sudden collapse, high radiation and dangerous contact with exotic matter.
In 1935, physicists Albert Einstein and Nathan Rosen used the theory of general relativity to propose the existence of "bridges" through space-time. These paths, called Einstein-Rosen bridges or wormholes, connect two different points in space-time, theoretically creating a shortcut that could reduce travel time and distance.
Wormholes contain two mouths, with a throat connecting the two. The mouths would most likely be spheroidal. The throat might be a straight stretch, but it could also wind around, taking a longer path than a more conventional route might require.
Einstein's theory of general relativity mathematically predicts the existence of wormholes, but none have been discovered to date. A negative mass wormhole might be spotted by the way its gravity affects light that passes by.
Certain solutions of general relativity allow for the existence of wormholes where the mouth of each is a black hole. However, a naturally occurring black hole, formed by the collapse of a dying star, does not by itself create a wormhole.
Further, "A wormhole is not really a means of going back in time, it's a short cut, so that something that was far away is much closer," NASA's Eric Christian wrote.
The equations of the theory of general relativity have valid solutions that contain wormholes. The first type of wormhole solution discovered was the Schwarzschild wormhole, which would be present in the Schwarzschild metric describing an eternal black hole, but it was found that it would collapse too quickly for anything to cross from one end to the other. Wormholes that could be crossed in both directions, known as traversable wormholes, would only be possible if exotic matter with negative energy density could be used to stabilize them. Wormholes are also a very powerful mathematical metaphor for teaching general relativity.
The Casimir effect shows that quantum field theory allows the energy density in certain regions of space to be negative relative to the ordinary vacuum energy, and it has been shown theoretically that quantum field theory allows states where energy can be arbitrarily negative at a given point. Many physicists, such as Stephen Hawking, Kip Thorne and others, therefore argue that such effects might make it possible to stabilize a traversable wormhole. Physicists have not found any natural process that would be predicted to form a wormhole naturally in the context of general relativity, although the quantum foam hypothesis is sometimes used to suggest that tiny wormholes might appear and disappear spontaneously at the Planck scale, and stable versions of such wormholes have been suggested as dark matter candidates. It has also been proposed that, if a tiny wormhole held open by a negative mass cosmic string had appeared around the time of the Big Bang, it could have been inflated to macroscopic size by cosmic inflation.
Friday, 27 January 2017
HIGGS BOSSON PARTICLE(AKA GOD PARTICLE)
The UNIVERSE is supposed to originate from an event called "Big Bang". All the particles including the sub-atomic particles are supposed to be originated from the same event. In layman’s terms, different subatomic particles are responsible for giving matter different properties. One of the most mysterious and important properties is mass. Some particles, like protons and neutrons, have mass. Others, like photons, do not. The Higgs boson, or “God particle,” is believed to be the particle which gives mass to matter. The “God particle” nickname grew out of the long, drawn-out struggles of physicists to find this elusive piece of the cosmic puzzle.
The “standard model” of particle physics is a system that attempts to describe the forces, components, and reactions of the basic particles that make up matter. It not only deals with atoms and their components, but the pieces that compose some subatomic particles. This model does have some major gaps, including gravity, and some experimental contradictions. The standard model is still a very good method of understanding particle physics, and it continues to improve. The model predicts that there are certain elementary particles even smaller than protons and neutrons. As of the date of this writing, the only particle predicted by the model which has not been experimentally verified is the “Higgs boson,” jokingly referred to as the “God particle.”
Each of the subatomic particles contributes to the forces that cause all matter interactions. One of the most important, but least understood, aspects of matter is mass. Science is not entirely sure why some particles seem mass-less, like photons, and others are “massive.” The standard model predicts that there is an elementary particle, the Higgs boson, which would produce the effect of mass. Confirmation of the Higgs boson would be a major milestone in our understanding of physics.
The “God particle” nickname actually arose when the book The God Particle: If the Universe Is the Answer, What Is the Question? by Leon Lederman was published. Since then, it’s taken on a life of its own, in part because of the monumental questions about matter that the God particle might be able to answer. The man who first proposed the Higgs boson’s existence, Peter Higgs, isn’t all that amused by the nickname “God particle,” as he’s an avowed atheist. All the same, there isn’t really any religious intention behind the nickname.
Currently, efforts are under way to confirm the Higgs boson using the Large Hadron Collider, a particle accelerator in Switzerland, which should be able to confirm or refute the existence of the God particle. As with any scientific discovery, God’s amazing creation becomes more and more impressive as we learn more about it. Either result—that the Higgs boson exists, or does not exist—represents a step forward in human knowledge and another step forward in our appreciation of God’s awe-inspiring universe. Whether or not there is a “God particle,” we know this about Christ: “For by him all things were created: things in heaven and on earth, visible and invisible . . . all things were created by him and for him”
Each of the subatomic particles contributes to the forces that cause all matter interactions. One of the most important, but least understood, aspects of matter is mass. Science is not entirely sure why some particles seem mass-less, like photons, and others are “massive.” The standard model predicts that there is an elementary particle, the Higgs boson, which would produce the effect of mass. Confirmation of the Higgs boson would be a major milestone in our understanding of physics.
The “God particle” nickname actually arose when the book The God Particle: If the Universe Is the Answer, What Is the Question? by Leon Lederman was published. Since then, it’s taken on a life of its own, in part because of the monumental questions about matter that the God particle might be able to answer. The man who first proposed the Higgs boson’s existence, Peter Higgs, isn’t all that amused by the nickname “God particle,” as he’s an avowed atheist. All the same, there isn’t really any religious intention behind the nickname.
Currently, efforts are under way to confirm the Higgs boson using the Large Hadron Collider, a particle accelerator in Switzerland, which should be able to confirm or refute the existence of the God particle. As with any scientific discovery, God’s amazing creation becomes more and more impressive as we learn more about it. Either result—that the Higgs boson exists, or does not exist—represents a step forward in human knowledge and another step forward in our appreciation of God’s awe-inspiring universe. Whether or not there is a “God particle,” we know this about Christ: “For by him all things were created: things in heaven and on earth, visible and invisible . . . all things were created by him and for him”
Tuesday, 24 January 2017
FRB 1221102(continued)
Astronomers
have for the first time pinpointed the location of a "fast radio
burst" - a type of short-duration radio flash of unknown astrophysical
origin - and have used this to identify its home galaxy. The galaxy, located
over 3 billion light years away, is small, a so-called dwarf galaxy, and very
different to our own Milky Way. Also, a persistent, compact radio source is
close to the source of the bursts, which provides important insights into its
astrophysical origin. The results from an international team, including Laura
Spitler from the Max-Planck-Institute for Radio Astronomy in Bonn, Germany,
appear today in three publications in Nature and the Astrophysical Journal
Letters.
A number of radio telescopes were used within the European VLBI Network (EVN) to observe FRB 121102 (artist’s impression). |
A number
of radio telescopes were used within the European VLBI Network (EVN) to observe
FRB 121102 (artist’s impression).
Fast
Radio Bursts (FRBs) are visible for only a fraction of a second, and have
puzzled astronomers since their discovery a decade ago. Precise localization of an FRB requires radio
telescopes separated by large distances, which allow high resolution images to
be made when these telescopes are used in combination with each other. Such
follow-up observations were made possible with the first discovery of a
repeating source of fast radio bursts, FRB 121102, using the 305-m Arecibo
Radio Telescope in Puerto Rico, USA.
Prior
to this discovery, astronomers had only indirect evidence that fast radio
bursts come from far outside our Milky Way galaxy, because poor localization
has prevented them from uniquely identifying their galaxy of origin. The new
finding is critical because it has also allowed astronomers to precisely
measure the distance to the source, and hence how much energy it is producing.
The
Very Large Array in New Mexico, USA detected a total of nine radio bursts from
FRB 121102. This determined its sky position to a fraction of an arc second,
over 200 times more precise than previous measurements. “Near this position,
astronomers found both steady radio and optical sources, which pointed the way
to the galaxy hosting the FRB,” says Shami Chatterjee from Cornell University,
the first author of the paper in “Nature”.
The
team was able to zoom-in on the radio sources with a factor of 10 more
precision using the Arecibo Radio Telescope and the European VLBI Network
(EVN), which links telescopes spread across the world. "With a bit of luck, we were able to
detect bursts from FRB 121102 with the EVN and now we know that the origin of
the bursts is right on top of the persistent radio source", says Benito
Marcote from JIVE in the Netherlands.
The 100-m radio telescope in Effelsberg, Germany, is the largest and
most sensitive member of the EVN. "Bursts from this source are faint, and
Effelsberg played a key role in making this discovery possible," says
Laura Spitler, postdoctoral researcher at the Max-Planck-Institute for Radio
Astronomy (MPIfR), who discovered FRB 121102.
The
team used one of the world's largest optical telescopes, the 8-m Gemini North
on Mauna Kea in Hawaii, to discover that the bursts originate from a host
galaxy, and use its measured spectrum to obtain a redshift value which places
the source at a whopping distance of over 3 billion light-years. "This
gives us incontrovertible confirmation that this FRB originates very deep in
extragalactic space,” says co-author Cees Bassa (ASTRON). Though the mystery of
the FRB’s distance is now solved, astronomers have a new puzzle on their hands.
The galaxy hosting the FRB is surprisingly small - a so-called dwarf galaxy.
The
fact that FRB 121102 is hosted by a dwarf galaxy may be a vital clue to its
physical nature. Such galaxies contain
gas that is relatively pristine compared to that found in the Milky Way. "The conditions in this dwarf galaxy are
such that it may be possible to form much more massive stars than in the Milky
Way, and perhaps the source of the FRB bursts is from the collapsed remnant of
such a star," suggests co-author Jason Hessels (ASTRON, University of
Amsterdam).
Alternatively,
astronomers are considering a very different hypothesis in which the FRB bursts
are generated in the vicinity of a massive black hole that is swallowing
surrounding gas, a so-called active galactic nucleus.
To try
and differentiate between these two scenarios, astronomers are continuing to
study FRB 121102 using the world's premier radio, optical, X-ray and gamma-ray
telescopes. "For example, if we can
find a periodicity to the arrival of the bursts, then we will have strong
evidence that it originates from a rotating neutron star", says Laura
Spitler.
Deciphering
the origin of the FRBs will also depend on localizing more such sources, and
astronomers are debating whether all FRBs detected to date are of a similar
physical origin or whether there are multiple classes of this new cosmic
phenomenon.
The
100-m Effelsberg Radio Telescope of the Max Planck Institute for Radio
Astronomy is located in a valley approximately 40 kilometers southwest of Bonn,
Germany.
The
European VLBI Network (EVN) is a collaboration of the major radio astronomical
institutes in Europe, Asia and South Africa and performs high angular
resolution observations of cosmic radio sources.
The
305-m William E. Gordon Telescope of the Arecibo Observatory is located close
to Arecibo in Puerto Rico, USA.
The
Karl G. Jansky Very Large Array consists of 27 radio antennas in a Y-shaped
configuration on the Plains of San Agustin fifty miles west of Socorro, New
Mexico, USA. Each antenna is 25 meters (82 feet) in diameter.
Sunday, 22 January 2017
FRB 1221102
The space has always been a center of attraction
for physicists and astrologers. It has kept amusing humans with unique
characteristics. Though they are all guided by pre-defined laws, it is not easy
to predict them. It has always shown us that what we think need not be always
right. Recently, one such incident took place, which rendered the scientist
speechless.
They kept searching that same spot in the sky. In 2015, they found 16 additional flashes. Then, in August and September 2016, nine more appeared. And this week, astronomers announced that these newest measurements helped them finally zero in on the bursts’ home: a dim dwarf galaxy three billion light-years away. Something inside this tiny galaxy was sending pulses that lasted just milliseconds but packed enormous energy, members of a still-mysterious class called “fast radio bursts.”
Learning that these particular bursts came from long ago, from some bursting object in a galaxy far, far (far) away, is an important step for this field of research. But it’s also like playing Clue and concluding that the crime was committed in the conservatory. To solve the crime, you still have to determine whether the dastardly deed was done by Mrs. Peacock with the candlestick or Colonel Mustard with the rope.
That continuing conundrum shows off the way science works, in a way we don’t usually get to see. Astronomers don’t often happen upon a total mystery. Much of their work involves looking directly at objects they know exist—stars, planets, supernovae—and studying processes and properties. Fast radio bursts, though, appeared out of nowhere, unexpected and un-asked-for, coming from question-mark objects with question-mark properties because of question-mark processes. Astronomers now have the privilege of figuring out the what, where, why, and how—from total scratch—and we have the privilege of watching the discovery process take place from its start.
To forecast what will likely happen next in the ongoing case of the super-energetic fast radio bursts, history helps. Specifically, the twentieth-century discoveries of pulsars and gamma-ray bursts, which also began with on-and-off flashes from unknown entities.
The very first on-off from a fast radio burst came in 2007, when astronomer Duncan Lorimer was sifting through archived data, searching for undiscovered pulsars. But instead, he found something that flashed just once, brighter than a pulsar and seemingly much farther away. He didn’t know what he was looking at. Neither did anyone else.
This is a familiar story arc in astronomy. It’s really the best way to find something utterly new: by accident, while searching for something known. It happened to Jocelyn Bell, who was looking for the twinkling of quasars—the super bright cores of galaxies with super massive black holes in feeding mode—when she stumbled upon a repeating radio blip. It blipped too fast to be any regular star. Was it aliens? Human technology? A planet? A mistake? It wasn’t until she found another blipper that she felt confident it was part of the natural universe at all. Then, when she and her adviser found two more, the blippers became a Thing. After they went public, people proposed more explanations, including the correct one—pulsars, the fast-spinning neutron stars left over after supernova explosions.
Artist rendition of the dishes of the Karl G. Jansky Very Large Array are seen making the first-ever precision localization of a Fast Radio Burst, and thereby pointing the way to the host galaxy of FRB121102. |
Gamma-ray bursts, too, are in encyclopedias because of an accident. In the 1960s, US government satellites were hanging out, watching for the high-energy indications of Soviet nuclear tests. They picked up 16 weird bursts of gamma rays that didn’t match up with nukes’ characteristics. In 1973, the government declassified the discovery and declared that the bursts must have come from space.
But after Lorimer saw his first burst, he didn’t get more of the same from the sky, as Bell and the Soviet-watchers did. No one saw any more fast radio bursts, from anywhere in the sky, for years. People doubted the astronomical origin of the original specimen, suggesting it came from Earth—and, indeed, astronomers in Australia accidentally produced a set of similar radio bursts by opening their microwave door before cooking was complete. There wasn’t even a category for that kind of behavior.
Since then, astronomers have found 18 sources of fast radio bursts—including the only one that repeats, the one first spotted in 2012. Shami Chatterjee, the lead in this latest discovery, decided to focus efforts there. “This is a good place to go fishing because you’re more likely to see a fast radio burst at this spot,” says Chatterjee. The team began watching the area with the Very Large Array in late 2015, searching for the burster’s precise location in space.
They watched for another burst for dozens of hours, in observations in November 2015 and April and May 2016, and saw nothing. “The field of transients is special in that we need to wait for the universe to provide an event for us,” says Casey Law of the University of California, Berkeley, who led the project’s software and data-taking developments. Finally, a burst appeared, in a set of observations that began in August. Then, so did eight more. That dataset allowed the team to pinpoint where the signals came from, a position they later zoomed in on even more precisely with radio telescopes around the world. And once they got images of that same spot from an optical telescope called Gemini North, they saw a faint smudge of shine, more like something you’d try to wipe off your screen than the answer to a big astronomical question. But that smudge was actually a tiny galaxy, around 3 billion light-years distant. Somewhere inside, the astronomers knew lurked the burster.
To be continued.............
Wednesday, 11 January 2017
The Philadelphia Experiment(continued)
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The ship was commissioned on 27 August 1943 but the July experiment was conducted on 22nd. People claimed that the experiment was conducted before the ship was officially commissioned, but there were sailors who claimed that the ship was in front of their eyes right from when it was just a sheet of metal to the day when it sailed in the sea. The believers of the experiment said that they were compelled by the navy to confess it.
In 1955, Morris K. Jessup, an amateur astronomer and former graduate-level researcher, published The Case for the UFO, a book about unidentified flying objects which contained some theorizing about the means of propulsion that flying-saucer-style UFOs might use. Jessup speculated that anti-gravity and/or manipulation of electromagnetism may have been responsible for the observed flight behavior of UFOs. He lamented, both in the book and the publicity tour which followed, that space flight research was concentrated in the area of rocketry, and that little attention was paid to these other theoretical means of flight, which he felt would ultimately be more fruitful.
On January 13, 1955, Jessup received a letter from a man identifying himself as Carlos Allende. In the letter, Allende informed Jessup of the Philadelphia Experiment, alluding to poorly sourced contemporary newspaper articles as proof. Allende also said that he had witnessed the Eldridge disappear and reappear while serving aboard the SS Andrew Furuseth, a nearby merchant ship. Allende further named other crew with which he served aboard the Andrew Furuseth, and claimed to know of the fates of some of the crew members of the Eldridge after the experiment, including one whom he witnessed disappear during a chaotic fight in a bar. Jessup replied to Allende by postcard, asking for further evidence and corroboration for the story.
The reply came months later; however, this time the correspondent identified himself as Carl M Allen. Allen said that he could not provide the details for which Jessup was asking, but implied that he might be able to recall by means of hypnosis. Suspecting that Allende/Allen was a crank, Jessup decided to discontinue the correspondence.
In the spring of 1957, Jessup was contacted by the Office of Naval Research (ONR) in Washington, D.C. and asked to study the contents of a parcel that they had received. Upon arrival, a curious Jessup was astonished to find that a paperback copy of his UFO book had been mailed to ONR in a manila envelope marked "Happy Easter". Further, the book had been extensively annotated by hand in its margins, and an ONR officer asked Jessup if he had any idea as to who had done so.
The lengthy annotations were written in three different colors of ink, and appeared to detail a correspondence between three individuals, only one of which is given a name: "Jemi". The ONR labeled the other two "Mr A" and "Mr B". The annotators refer to each other as "Gypsies", and discuss two different types of "people" living in outer space. Their text contained nonstandard use of capitalization and punctuation, and detailed a lengthy discussion of the merits of various suppositions that Jessup makes throughout his book, with oblique references to the Philadelphia Experiment, in a way that suggested prior or superior knowledge.
Based on the handwriting style and subject matter, Jessup identified "Mr A" as Allende/Allen. Others have suggested that the three annotations are actually from the same person, using three pens.
A transcription of the annotated "Varo edition" is available online, complete with three-color notes.
Later, the ONR contacted Jessup, claiming that the return address on Allende's letter to Jessup was an abandoned farmhouse. They also informed Jessup that the Varo Corporation, a research firm, was preparing a print copy of the annotated version of The Case for the UFO, complete with both letters he had received. About a hundred copies of the Varo Edition were printed and distributed within the Navy. Jessup was also sent three for his own use.
Jessup attempted to make a living writing on the topic, but his follow-up book did not sell well and his publisher rejected several other manuscripts. In 1958 his wife left him, and friends described him as being depressed and somewhat unstable when he travelled to New York. After returning to Florida he was involved in a serious car accident and was slow to recover, apparently increasing his despondency. Morris Jessup committed suicide in 1959.
In 1965, Vincent Gaddis published Invisible Horizons: True Mysteries of the Sea, in which the story of the experiment from the Varo annotation is recounted. Later, in 1977, Charles Berlitz, an author of several books on paranormal phenomena, included a chapter on the experiment in his book Without a Trace: New Information from the Triangle.
In 1978, a novel, Thin Air by George E Simpson and Neal R Burger was released. This was a dramatic fictional account, clearly inspired by the foregoing works, of a conspiracy to cover up an horrific experiment gone wrong on board the Eldridge in 1943. In 1979, Berlitz and a co-author, William L. Moore, published The Philadelphia Experiment: Project Invisibility, the best known and most cited source of information about the experiment to date.
The authors claim to have interviewed at least one of the approximately forty-man crew during the July/August experiment, Engineer First Class Victor Silverman, who says he was on board when the vessel ‘teleported’ from Philadelphia to Norfolk and back. The materialization of the Eldridge at Norfolk was witnessed by five British merchant seamen who were awaiting transport back to the United Kingdom. As corroborating evidence, Moore and Berlitz insist that the experiment later became the subject of a Special Memorandum from the Secretary of the Navy to Captain James R. Teague of the aircraft carrier USS Antietam in May 1945. Antietam was then at the Philadelphia Navy Yard for standard maintenance after its shakedown cruise and its crew was concerned that the Navy would try another Philadelphia experiment on them during the standard degaussing procedures. According to Moore and Berlitz, the secretary’s memo instructed the crew of the Anitetam not to discuss the Philadelphia experiment outside the confines of their vessel. Captain Teague read the memo to the crew and entered that fact in the ship’s log.
After the alleged July/August 1943 experiment, USS Eldridge was commissioned with a full crew of 216 officers and men, and went on a shakedown cruise in the Bermuda area from early September through December 28, 1943. While on this cruise Eldridge was assigned to protest convoy GUS- 22 going east from New York to Casablanca from 2 to 12 November, 1943. On the return leg of the voyage, according to Moore and Berlitz, Eldridge escorted convoy UGS-23 from Casablanca west to New York. During this return leg, Eldridge depth-charged a suspected enemy submarine on 20 November 1943, and filed an action report on the encounter which listed the ship’s position as latitude 34° 03' N and longitude 08° 57' W, about 200 miles west of Casablanca. The position of the ship at this point is critical for the Philadelphia experiment thesis, because it was during escorting convoys GUS-22 and UGS-23 that the Eldridge supposedly disappeared and reappeared for a second time. This event, we are told, was witnessed by one Carlos Miguel Allende (aka Carl Allen), an individual with at least five aliases, who was a merchant seaman on board the freighter SS Andrew Furuseth during its passage with both GUS-22 and UGS-23.
On the basis of the USS Eldridge’s action report, Moore and Berlitz conclude that “the official history [of the vessel] for the period up to January 4, 1944, is almost certainly false!” The “official history,” as Moore and Berlitz summarize it, has the USS Eldridge only in the “Bermuda area.”
Based partially on the conflicting information between the “official history” (they give no more specific citation) and the action report, and partially on their contention that the ship’s deck log is missing,Moore and Berlitz imply that the US Navy had engaged in a massive cover-up of the Philadelphia experiment.
Thus there is a big dilemma over whether the experiment was conducted or not, nevertheless if the experiment was conducted the world looks forward to fine tune the technique of teleportation and use it without any hazardous effect.
The ship was commissioned on 27 August 1943 but the July experiment was conducted on 22nd. People claimed that the experiment was conducted before the ship was officially commissioned, but there were sailors who claimed that the ship was in front of their eyes right from when it was just a sheet of metal to the day when it sailed in the sea. The believers of the experiment said that they were compelled by the navy to confess it.
In 1955, Morris K. Jessup, an amateur astronomer and former graduate-level researcher, published The Case for the UFO, a book about unidentified flying objects which contained some theorizing about the means of propulsion that flying-saucer-style UFOs might use. Jessup speculated that anti-gravity and/or manipulation of electromagnetism may have been responsible for the observed flight behavior of UFOs. He lamented, both in the book and the publicity tour which followed, that space flight research was concentrated in the area of rocketry, and that little attention was paid to these other theoretical means of flight, which he felt would ultimately be more fruitful.
On January 13, 1955, Jessup received a letter from a man identifying himself as Carlos Allende. In the letter, Allende informed Jessup of the Philadelphia Experiment, alluding to poorly sourced contemporary newspaper articles as proof. Allende also said that he had witnessed the Eldridge disappear and reappear while serving aboard the SS Andrew Furuseth, a nearby merchant ship. Allende further named other crew with which he served aboard the Andrew Furuseth, and claimed to know of the fates of some of the crew members of the Eldridge after the experiment, including one whom he witnessed disappear during a chaotic fight in a bar. Jessup replied to Allende by postcard, asking for further evidence and corroboration for the story.
The reply came months later; however, this time the correspondent identified himself as Carl M Allen. Allen said that he could not provide the details for which Jessup was asking, but implied that he might be able to recall by means of hypnosis. Suspecting that Allende/Allen was a crank, Jessup decided to discontinue the correspondence.
In the spring of 1957, Jessup was contacted by the Office of Naval Research (ONR) in Washington, D.C. and asked to study the contents of a parcel that they had received. Upon arrival, a curious Jessup was astonished to find that a paperback copy of his UFO book had been mailed to ONR in a manila envelope marked "Happy Easter". Further, the book had been extensively annotated by hand in its margins, and an ONR officer asked Jessup if he had any idea as to who had done so.
The lengthy annotations were written in three different colors of ink, and appeared to detail a correspondence between three individuals, only one of which is given a name: "Jemi". The ONR labeled the other two "Mr A" and "Mr B". The annotators refer to each other as "Gypsies", and discuss two different types of "people" living in outer space. Their text contained nonstandard use of capitalization and punctuation, and detailed a lengthy discussion of the merits of various suppositions that Jessup makes throughout his book, with oblique references to the Philadelphia Experiment, in a way that suggested prior or superior knowledge.
Based on the handwriting style and subject matter, Jessup identified "Mr A" as Allende/Allen. Others have suggested that the three annotations are actually from the same person, using three pens.
A transcription of the annotated "Varo edition" is available online, complete with three-color notes.
Later, the ONR contacted Jessup, claiming that the return address on Allende's letter to Jessup was an abandoned farmhouse. They also informed Jessup that the Varo Corporation, a research firm, was preparing a print copy of the annotated version of The Case for the UFO, complete with both letters he had received. About a hundred copies of the Varo Edition were printed and distributed within the Navy. Jessup was also sent three for his own use.
Jessup attempted to make a living writing on the topic, but his follow-up book did not sell well and his publisher rejected several other manuscripts. In 1958 his wife left him, and friends described him as being depressed and somewhat unstable when he travelled to New York. After returning to Florida he was involved in a serious car accident and was slow to recover, apparently increasing his despondency. Morris Jessup committed suicide in 1959.
In 1965, Vincent Gaddis published Invisible Horizons: True Mysteries of the Sea, in which the story of the experiment from the Varo annotation is recounted. Later, in 1977, Charles Berlitz, an author of several books on paranormal phenomena, included a chapter on the experiment in his book Without a Trace: New Information from the Triangle.
In 1978, a novel, Thin Air by George E Simpson and Neal R Burger was released. This was a dramatic fictional account, clearly inspired by the foregoing works, of a conspiracy to cover up an horrific experiment gone wrong on board the Eldridge in 1943. In 1979, Berlitz and a co-author, William L. Moore, published The Philadelphia Experiment: Project Invisibility, the best known and most cited source of information about the experiment to date.
The authors claim to have interviewed at least one of the approximately forty-man crew during the July/August experiment, Engineer First Class Victor Silverman, who says he was on board when the vessel ‘teleported’ from Philadelphia to Norfolk and back. The materialization of the Eldridge at Norfolk was witnessed by five British merchant seamen who were awaiting transport back to the United Kingdom. As corroborating evidence, Moore and Berlitz insist that the experiment later became the subject of a Special Memorandum from the Secretary of the Navy to Captain James R. Teague of the aircraft carrier USS Antietam in May 1945. Antietam was then at the Philadelphia Navy Yard for standard maintenance after its shakedown cruise and its crew was concerned that the Navy would try another Philadelphia experiment on them during the standard degaussing procedures. According to Moore and Berlitz, the secretary’s memo instructed the crew of the Anitetam not to discuss the Philadelphia experiment outside the confines of their vessel. Captain Teague read the memo to the crew and entered that fact in the ship’s log.
After the alleged July/August 1943 experiment, USS Eldridge was commissioned with a full crew of 216 officers and men, and went on a shakedown cruise in the Bermuda area from early September through December 28, 1943. While on this cruise Eldridge was assigned to protest convoy GUS- 22 going east from New York to Casablanca from 2 to 12 November, 1943. On the return leg of the voyage, according to Moore and Berlitz, Eldridge escorted convoy UGS-23 from Casablanca west to New York. During this return leg, Eldridge depth-charged a suspected enemy submarine on 20 November 1943, and filed an action report on the encounter which listed the ship’s position as latitude 34° 03' N and longitude 08° 57' W, about 200 miles west of Casablanca. The position of the ship at this point is critical for the Philadelphia experiment thesis, because it was during escorting convoys GUS-22 and UGS-23 that the Eldridge supposedly disappeared and reappeared for a second time. This event, we are told, was witnessed by one Carlos Miguel Allende (aka Carl Allen), an individual with at least five aliases, who was a merchant seaman on board the freighter SS Andrew Furuseth during its passage with both GUS-22 and UGS-23.
On the basis of the USS Eldridge’s action report, Moore and Berlitz conclude that “the official history [of the vessel] for the period up to January 4, 1944, is almost certainly false!” The “official history,” as Moore and Berlitz summarize it, has the USS Eldridge only in the “Bermuda area.”
Based partially on the conflicting information between the “official history” (they give no more specific citation) and the action report, and partially on their contention that the ship’s deck log is missing,Moore and Berlitz imply that the US Navy had engaged in a massive cover-up of the Philadelphia experiment.
Thus there is a big dilemma over whether the experiment was conducted or not, nevertheless if the experiment was conducted the world looks forward to fine tune the technique of teleportation and use it without any hazardous effect.
Sunday, 8 January 2017
The Philadelphia Experiment
The "Philadelphia Experiment" AKA "Project rainbow" is a very well-known but classified experiment in the history of modern physics. There are two categories of people, one who think that it was an intended hoax created by the U.S. Government, to which they denied later, some think it was a real experiment that took place in the Philadelphia Ship Yard. They believe it was meant for teleportation, but........ was it really for teleportation or was it just an outcome of the experiment? Let's find it out by the description of the only known eyewitness of the experiment, Callous Allende.
The story backs to World War II, in which the U.S. and Germany had also participated. The navies of both the countries often faced each other. The Germans had submarine which could make the U.S. ships their target. The main advantage of submarines was that they could attack the ships from below the water without being noticed. This was very threatening for the navy. During this time, Albert Einstein was serving in the U.S. Navy and he was working on the "Unified field Theory".
The experiment was conducted by a Dr Franklin Reno AKA Rinehart as a military application of a Unified Field Theory. The theory, briefly, postulates the interrelated nature of the forces that comprise electromagnetic radiation and gravity. Through a special application of the theory, it was thought possible, with specialised equipment and sufficient energy, to bend light around an object in such a way as to render it essentially invisible to observers. The Navy considered this application of the theory to be of obvious military value (especially as the United States was engaged in World War II at the time) and both approved and sponsored the experiment. A navy destroyer escort, the USS Eldridge, was fitted with the required equipment at the naval yards in Philadelphia.
Testing began in summer 1943, and was successful to a limited degree. One test, on July 22, resulted in the Eldridge being rendered almost completely invisible, with some witnesses reporting a "greenish fog" in its place. However, crew members complained of severe nausea afterwards. The crew of the USS Eldridge suffered from unexpected and bizarre side effects such as parts of the crew got buried in the hull of the ship. Some the crew members went missing, their families were never told the truth.
Testing began in summer 1943, and was successful to a limited degree. One test, on July 22, resulted in the Eldridge being rendered almost completely invisible, with some witnesses reporting a "greenish fog" in its place. However, crew members complained of severe nausea afterwards. The crew of the USS Eldridge suffered from unexpected and bizarre side effects such as parts of the crew got buried in the hull of the ship. Some the crew members went missing, their families were never told the truth.
Due to this horrible outcomes the navy decided to just render the ship invisible to radar by bending radio waves around the ship, so the ship won't be visible to radar. Large electromagnetic fields were produced around the ship which supposedly caused light to bend around and make the ship completely invisible.
Equipment was not properly re calibrated to this end, but in spite of this, the experiment was performed again on October 28. This time, Eldridge not only became almost entirely invisible to the naked eye, but actually vanished from the area in a flash of blue light. Simultaneously, the US naval base at Norfolk, Virginia, just over 600 km (375 miles) away, reported sighting the Eldridge offshore for several minutes, whereupon the Eldridge vanished from their sight and reappeared in Philadelphia, at the site it had originally occupied in an apparent case of accidental teleportation. It was supposed that the ship had traveled back in time.
The physiological effects on the crew were profound. Almost all of the crew were violently ill. Some suffered from mental illness as a result of their experience; behavior consistent with schizophrenia is described in other accounts. Still other members were physically unaccounted for or supposedly vanished, and five of the crew were allegedly fused to the metal bulkhead or deck of the ship. Still others were said to fade in and out of sight. Horrified by these results, Navy officials immediately cancelled the experiment. All of the surviving crew involved were discharged; in some accounts, brainwashing techniques were employed in an attempt to make the remaining crew members lose their memories concerning the details of their experience.
But, the USS Eldridge was officially commissioned on 27 August 1943 then how was the first experiment conducted on 22 July 1943?.........
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