NASA: Beyond Earth
Reginald L. Goodwin's Posts (3116)
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Polite Stewart, Jr. received his degree in physics Friday at the ripe old age of 18.
Stewart entered Southern four years ago to enormous fanfare. He was under a microscope as his classmates learned of the student on campus who was too young to get a driver’s license and actually too young to live on campus alone.
He had offers from colleges across the country. Who didn’t want a child prodigy on their campus? But, it would have been difficult for his parents to send him across the country at such a young age.
Instead, he enrolled at Southern where he was familiar with the campus, where he had taken high school-level courses at the school’s famous Timbuktu Academy, and more importantly, he would only be a 10-minute drive from campus.
But with all of the local media tracing his first steps on campus, Stewart was an unwilling celebrity. He just wanted to get down to doing his schoolwork and getting to fit in with his classmates. “The attention I got died down pretty quickly,” he said.
He traces his love for academics to the dinosaur books his father bought him as a young child. Later, as a toddler, Stewart said he began watching scientific documentaries where his interest in herpetology, entomology and paleontology grew. “I was pretty much interested in all the sciences,” he said.
Now, barely an adult, Stewart has set his sights on a career in biological and physical engineering. He spent last summer doing research at North Carolina State University, where he worked on developing self-cleaning, anti-glare glass coated with anti-reflective material and designed to repel oils and water.
After continuing his research in a post-grad program next summer, Stewart said he will start graduate school at one of a number of colleges that have shown interest.
His mother, Ava Stewart, isn’t surprised by her son’s success.
“His father and I could tell early on that he wanted information. There was an intensity in his focus. He started reading when he was three,” she said.
Southern University: Polite Stewart, Jr. to receive physics degree at 18 years old
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| Mock-up of Rembrandt's "An old man in military costume" with a portrait painted underneath the final work. Photo: Andrea Sartorius, © J. Paul Getty Trust (free for editorial use if credit is given) |
A sophisticated X-ray technology is paving the way to uncover the secrets of a 380-year-old Rembrandt masterpiece. Underneath the Old Man in Military Costume, painted by the Dutch artist in the years 1630-31, previous investigations spotted another portrait which was only faintly distinguishable with all applied technologies. For years, art historians puzzled over the question of who is depicted on the repainted picture.
Now, an international team of scientists has used a detailed mock-up to test different methods of looking beneath the original painting at DESYs X-ray source DORIS and at the National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory (BNL) in the United States, as well as with a mobile X-ray scanner. The results are published as the cover story of the "Journal of Analytical Atomic Spectrometry" (JAAS) of the British Royal Society of Chemistry.
"Our experiments demonstrate a possibility of how to reveal much of the hidden picture," said first author Matthias Alfeld from the University of Antwerp (Belgium). "Compared to other techniques, the X-ray investigation we tested is currently the best method to look underneath the original painting."
Brookhaven National Labs: Mysterious Rembrandt
Franklin McCain: double major, Chemistry/Biology
Ezell Blair Jr. (later known as Jibreel Khazan): Sociology
Joseph Alfred McNeil: Engineering Physics; US Air Force Veteran (I am proudly both)
David Richmond: Business Administration and Accounting
If I have seen further it is by standing on the shoulders of giants. Found in Letters of Sir Isaac Newton
Site: February One Documentary
North Carolina Museum of History: The Greensboro Four
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| The single-photon detector is characterized by five convincing factors: 91% detection efficiency; direct integration on chip; counting rates on a Gigahertz scale; high timing resolution and negligible dark counting rates. Source: KIT/CFN. |
Ultrafast, efficient, and reliable single-photon detectors are among the most sought-after components in photonics and quantum communication, which have not yet reached maturity for practical application. Physicist Dr. Wolfram Pernice of the Karlsruhe Institute of Technology (KIT), in cooperation with colleagues at Yale University, Boston University, and Moscow State Pedagogical University, achieved the decisive breakthrough by integrating single-photon detectors with nanophotonic chips. The detector combines near-unity detection efficiency with high timing resolution and has a very low error rate. The results have been published by Nature Communications (doi:10.1038/ncomms2307).
Without reliable detection of single photons, it is impossible to make real use of the latest advances in optical data transmission or quantum computation; it is like having no analog-digital converter in a conventional computer to determine whether the applied voltage stands for 0 or 1. Although a number of different single-photon detector models have been developed over the past few years, thus far, none have provided satisfactory performance.
Several new ideas and advanced developments went into the prototype developed within the “Integrated Quantum Photonics” project at the DFG Center of Functional Nanostructures (CFN). The new single-photon detector, tested in the telecommunications wavelength range, achieves a previously unattained detection efficiency of 91%.
Karlsruhe Institute of Technology:
Quantum Communication: Each Photon Counts, Press Release
An article by Scientific American
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| Courtesy of Wallentin et al |
Here's how to make a powerful solar cell from indium and phosphorus: First, arrange microscopic flecks of gold on a semiconductor background. Using the gold as seeds, grow precisely arranged wires roughly 1.5 micrometers tall out of chemically tweaked compounds of indium and phosphorus. Keep the nanowires in line by etching them clean with hydrochloric acid and confining their diameter to 180 nanometers. (A nanometer is one billionth of a meter.) Exposed to the sun, a solar cell employing such nanowires can turn nearly 14 percent of the incoming light into electricity—a new record that opens up more possibilities for cheap and effective solar power.
According to research published online in Science—and validated at Germany's Fraunhofer Institute for Solar Energy Systems—this novel nanowire configuration delivered nearly as much electricity as more traditional indium phosphide thin-film solar cells even though the nanowires themselves covered only 12 percent of the device's surface. That suggests such nanowire solar cells could prove cheaper—and more powerful—if the process could be industrialized, argues physicist Magnus Borgström of Lund University in Sweden, who led the effort.
Nature:
Novel solar photovoltaic cells achieve record efficiency using nanoscale structures, David Biello
A method for laser-cooling magnetically trapped antihydrogen atoms to temperatures of about 20 millikelvin has been proposed by a team of researchers from Canada and the US.
The team claims that cooling the antihydrogen would make it much more stable and so easier to study in experiments. In particular, it could lead to better spectroscopic analysis of antihydrogen, so that its properties can be compared with those of hydrogen.
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| An artist's concept showing a trapped anithydrogen atom being released after 1000 seconds. The new proposal allows for such trapped antimatter to be laser cooled and then studied. (Courtesy: Chukman So/CERN) |
Antihydrogen is an atomic bound state of a positron and antiproton that was first produced at CERN in 1995. Over the past few years, physicists working on the ALPHA experiment at the Geneva lab became the first to capture and store a significant amount of the stuff, holding a total of 309 antihydrogen atoms for 1000 seconds in 2011. In early 2012 the team then showed that it is possible to probe the internal structure of an antihydrogen atom by carrying out the first tentative measurements of the antihydrogen spectrum. By improving such measurements, researchers hope to determine what structural differences, if any, antimatter has compared with ordinary matter.
This, they hope, could eventually explain why the universe currently contains much more matter than antimatter.
Physics World: Lasers could chill antihydrogen
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| a) Spatial images of the photocurrent amplitude and phase as a function of gate voltage. The photocurrent in the graphene channel switches sign twice from negative to positive and back to negative. b) Photocurrent amplitude (red) and phase (blue) in the centre of the graphene channel as a function of gate voltage. Courtesy: Nature Photonics |
Photodetectors – devices that detect light by converting optical signals into electrical current – are routinely employed in applications such as communications, sensing and imaging. Most light detectors are made of III-V semiconductors like gallium arsenide and they work by absorbing photons to produce electron-hole pairs that then separate and generate an electrical current.
Graphene – a sheet of carbon just one atom thick – has a number of unique physical and mechanical properties that make it ideal for detecting light. One important advantage is that electrons move much faster through graphene than through other materials. They behave, in fact, as if they had no mass and travel at 1/300 the speed of light. These particles are called massless Dirac fermions and their behaviour could be exploited in a host of applications, including transistors that are faster than any that exist today.
Nano Tech Web: How does graphene convert light into electricity?
Science Daily: Jan. 24, 2013 — Using a satellite X-ray telescope combined with terrestrial radio telescopes the pulsar was found to flip on a roughly half-hour timescale between two extreme states; one dominated by X-ray pulses, the other by a highly-organised pattern of radio pulses.
The research was led by Professor Wim Hermsen from The Netherlands Institute for Space Research and the University of Amsterdam and will appear in the journal Science on the 25th January 2013.
Researchers from Jodrell Bank Observatory, as well as institutions around the world, used simultaneous observations with the X-ray satellite XMM-Newton and two radio telescopes; the LOw Frequency Array (LOFAR) in the Netherlands and the Giant Meter Wave Telescope (GMRT) in India to reveal this so far unique behaviour.
Pulsars are small spinning stars that are about the size of a city, around 20 km in diameter. They emit oppositely directed beams of radiation from their magnetic poles. Just like a lighthouse, as the star spins and the beam sweeps repeatedly past Earth we see a brief flash.
Science Daily: Chameleon pulsar dramatically changes the way it shines
I saw this briefly, and juxtapose my commentary between Sports Science and Mr. Hayes' Saturday morning commentary.
As someone who loved playing sandlot football, high school football and a sports fan, this is concerning. I present it with no agenda, but post a question: in 2113, will we still be playing football?
Up With Chris Hayes: Is Football Responsible for Junior Seau's Death
The seasonal thawing of carbon dioxide ice near Mars' north pole carves grooves in the region's sand dunes, three new studies reveal.
The discovery, made using observations from NASA's Mars Reconnaissance Orbiter spacecraft (MRO), reinforces that the Red Planet's surface continues to be transformed today, even though Mars' volcanoes have died out and its liquid surface water apparently dried up long ago.
Space.com: Dry Ice 'Smoke' Carves Up Mars Sand Dunes,
Mike Wall, Senior Writer
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| Speaking at the National Society of Black Physicists conference 2011 - UT Austin |
I have this book - The First Three Minutes - he autographed when I was in the Astrophysics department. It was a treat to meet him, and an honor to hear him speak at the NSBP conference.
AMAZON: Nobel Laureate Steven Weinberg combines his exceptional physical insight with his gift for clear exposition to provide a concise introduction to modern quantum mechanics. Ideally suited to a one-year graduate course, this textbook is also a useful reference for researchers. Readers are introduced to the subject through a review of the history of quantum mechanics and an account of classic solutions of the Schrödinger equation, before quantum mechanics is developed in a modern Hilbert space approach. The textbook covers many topics not often found in other books on the subject, including alternatives to the Copenhagen interpretation, Bloch waves and band structure, the Wigner-Eckart theorem, magic numbers, isospin symmetry, the Dirac theory of constrained canonical systems, general scattering theory, the optical theorem, the 'in-in' formalism, the Berry phase, Landau levels, entanglement and quantum computing. Problems are included at the ends of chapters, with solutions available for instructors at www.cambridge.org/9781107028722.
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| Physics World: Bose-Einstein Condensate torus cut by a laser |
Physicists in the US have developed an analogue of a superconducting quantum interference device (SQUID) that replaces the superconductor with a Bose–Einstein condensate and measures rotation rather than magnetic flux. They hope that the research will lead to the development of new, ultra-sensitive gyroscopes.
The SQUID is a well-established and extremely sensitive device for measuring magnetic fields that has found a range of commercial applications. At its heart is a loop of superconductor broken by one or two Josephson junctions. These are thin barriers of non-superconducting material that superconducting pairs of electrons are able to tunnel across. SQUIDs rely on the fact that superconducting electrons are all represented by the same wavefunction, which extends around the loop and includes the junctions. This means that the current that flows around the loop – and therefore the magnetic flux through the loop – is quantized at discrete values. If the magnetic flux in the loop increases or decreases, there is an oscillation in the voltage across the Josephson junctions every time the magnetic flux changes by one quanta. These quanta are very small and therefore an extremely small change in magnetic flux can be measured by counting the voltage oscillations.
Physics World: Physicists create SQUID-like Bose–Einstein condensate
An astronomy teacher at Pomfret School in Connecticut, USA, won first prize in the Hubble's Hidden Treasures image processing competition. The competition invited members of the public to dig out unreleased scientific data from Hubble's vast archive, and to process them into stunning images. Lake's image is of a particularly bright region of the Large Magellanic Cloud, which is located some 200,000 light-years from Earth. The gas within it slowly collapses to form new stars. In turn, the stars light up the gas clouds. In this particular winning image shows both star forming regions as well as dusty, planet-forming regions made of material from stars that have died. The Hubble archive remains open, and the outreach team invites others to search it for more hidden treasures.
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| LMC - see Hubble Telescope below |
Pomfret School: "To Infinity and Beyond" - at Least to Harvard
Hubble Telescope: A hidden treasure in the Large Magellanic Cloud
Almost 100 years after the initial discovery, a team of scientists at the University of Alberta and the National Institute for Nanotechnology in Edmonton have harnessed the Barkhausen Effect as a new kind of high-resolution microscopy for the insides of magnetic materials.
The researchers say the technique has the potential to provide critical information as a rapid prototyper for magnetic computational devices that expand the role of magnetism within computers.
R&D Quantitative magneto-mechanical made possible by the Barkhausen Effect
...as a nation. E pluribus unum: "out of many, one."
From Wiki Answers:
What is the historical significance of interposition and nullification?
Answer:
Interposition: means that a state of the U.S. may oppose any federal action it believes encroaches on its power
Nullification: refers to a U.S state refusing to enforce a federal law on Constitutional grounds.
Their historical significance can be traced back to the Brown v. Board of Education trial, where the Supreme Court declared that racial segregation in public schools violated the Equal Protection clause of the 14th Amendment. In response to this case, State legislatures from Alabama, Georgia, Mississippi, South Carolina, and Virginia adopted resolutions of "interposition and nullification," where they could oppose the ruling and refuse to enforce the desegregation of public schools.
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| Credit: Physics World - Lateral Dose |
Proton therapy is used in the treatment of cancer and hopeful remission from the disease.
There is a significant difference between standard (x-ray) radiation treatment and proton therapy. If given in sufficient doses, x-ray radiation techniques will control many cancers. But, because of the physician's inability to adequately conform the irradiation pattern to the cancer, healthy tissues may receive a similar dose and can be damaged. Consequently, a less- than-desired dose is frequently used to reduce damage to healthy tissues and avoid unwanted side effects. The power of protons is that higher doses of radiation can be used to control and manage cancer while significantly reducing damage to healthy tissue and vital organs.1
*****
A table-top proton accelerator for medical therapy could be one step closer thanks to work done by physicists in Germany. The team's system is based on a compact Ti:sapphire laser, which fires ultrashort light pulses at a diamond-like foil to produce bunches of protons with energies of around 5 MeV.
The team has shown that its device delivers radiation doses to biological cells that are similar to doses created by much larger conventional proton-therapy systems. The researchers say that the technique could also be used to study ultrafast processes in biology and chemistry.2
1. The National Association for Proton Therapy, Official Site
2. Pulsed lasers could make proton therapy more accessible, Physics World
So much for the coolness of near, or at light speed travel.
I'd probably just stay in the Hollow Deck until we got where the ship was going...
You're on board the Millennium Falcon. You give the command to jump to light speed. The stars outside turn into long streaks of light and you're off. It's one of the most memorable images of sci-fi space travel ever created. It's also likely to be pretty far from reality, according to a study by a group of students from the U.K.'s University of Leicester.
The study, titled "Relativistic Optics Strikes Back," was published in the University of Leicester's Journal of Physics Special Topics. You can indulge in all the delicious physics equations in the abstract.
The physics students started by imagining that the Millennium Falcon has accidentally wandered into our solar system, on a direct course for our sun. If it then engaged in near-light speed travel, the stars around it wouldn't appear to stretch out. Instead, it would look more like a disc of light.
W00t:
One concern: navigation. "All I ask is a tall ship and a star to steer her by," John Masefield from the poem "Sea Fever." Definitely not a job for Mr. Sulu, nor battles "pivoting at Warp 2." It would take some sophisticated computing, predicting where stars are before your acceleration (so you wouldn't slam into anything - that ruins any trip).
If we were ever to do it: the thrill would be in getting to the end of the trip, to clearly view the stars from another sky, and eventually the soil of another earth.
CNET: Near-lightspeed space travel: Not as cool-looking as you think
...versus double six and double nine sets: math is quicker, and more fun to play.
The stunt:
The schematic:
The math:
Physics arXiv: Domino Magnification
Site: CDT-domino.com
TECHNOLOGY REVIEW: One of the most promising ways to capture, generate and manipulate photons is with tiny diamonds. The secret is to create nanodiamonds with a defect in their structure where a nitrogen atom has taken the place of a carbon.
Quantum physicists are particularly interested in these so-called nitrogen vacancies because they can capture, store and emit the quantum information that photons carry. What’s more, they do all this at room temperature. It is even possible to manipulate this information using magnetic and electric fields.
In short, nitrogen vacancies are important building blocks for for quantum computers.
But there’s a problem. It’s not hard to make individual nanodiamonds but it is extremely difficult to arrange them next to each other so that the quantum information they store can be processed.
Their idea is to bind nanodiamonds together with the required nanometre precision using biological molecules such as DNA and protein. What’s more, they say they’ve demonstrated the technique for the first time.
Physics arXiv: Self-assembling hybrid diamond-biological quantum devices
