BLOGS

All Posts (6487)

Sort by

Musing Hydrogen...

Posted by Reginald L. Goodwin on January 31, 2017 at 10:49am
Harvard physicists say they photographed hydrogen in three different forms, from left to right: transparent hydrogen, black hydrogen, and finally, shiny metallic hydrogen. (R. Dias and I.F. Silvera) Source: Forbes.com

Topics: Condensed Matter Physics, Materials Science, Research, Theoretical Physics

Disclaimer: I was just as initially psyched by the reports of Metallic Hydrogen at Harvard. It's been theoretical since I was an undergrad (and that was a long time ago). Then, I remembered all the hype over cold fusion and calmed down. The key to my skepticism is repetition: another lab (several, in fact) will have to repeat the experiment to within an acceptable degree of error to one another. It will have to face grueling peer review that won't be kind, or for the squeamish. It's through this process we can distinguish science from malarkey.



Two physicists say that they have crushed hydrogen under such immense pressures that the gas became a shiny metal — a feat that physicists have been trying to accomplish for more than 80 years.

But other researchers have serious doubts about the claim, the latest in a field with a long history of failed attempts.

Ranga Dias and Isaac Silvera, both physicists at Harvard University in Cambridge, Massachusetts, first posted a report of their results on the arXiv preprint server last October [1], which attracted immediate criticism. A peer-reviewed version of the report was published on 26 January in Science [2], but sceptics say that it includes little new information.

Five experts told Nature’s news team that they do not yet believe the claim, and need more evidence. “I don’t think the paper is convincing at all,” says Paul Loubeyre, a physicist at France’s Atomic Energy Commission in Bruyères-le-Châtel.

Silvera and Dias say that they wanted to publish their first observation before making further tests on their fragile material.

Nature: Physicists doubt bold report of metallic hydrogen, Davide Castelvecchi

Read more…

The Minutes...

Posted by Reginald L. Goodwin on January 30, 2017 at 7:49am
Image Source: Giphy.com

Topics: Commentary, Existentialism, Nuclear Power, Politics



70 years...1947 to 2017.

Clearly in my fifth decade of life, I have vivid disturbing memories of the world post Hiroshima and Nagasaki, 1945:

"Duck and cover drills": the most asinine exercise to bend-over-and-kiss-your-ass-goodbye I recall with a certain level of disdain.

The Red Scare: Post the McCarthy era, ALL things Russian were bad. COINTELPRO used the scare as raison d'être to infiltrate Civil Rights organizations like the Black Panther Party of Self Defense, the Congress Of Racial Equality (C.O.R.E.), the NAACP, the Nation of Islam, the Southern Christian Leadership Conference; the Student Nonviolent Coordination Committee (S.N.C.C.). We lived through The Cold War, the possibility of a conflict with Gog and Magog loomed in every ROTC and Sunday School class. Hal Lindsey's The Late, Great Planet Earth practically dripped with it.

M.A.D.: Mutual (or Mutually) Assured Destruction. When you've each reduced the planet to a crisp cinder, what victory does ANYONE left alive sanely claim?

The Doomsday Clock was meant to be figurative only. The Bulletin of Atomic Scientists have always used it to foster a continual public debate (when you debate, you cannot war) regarding the existentialism question Shakespeare through Hamlet posed:

To be, or not to be--that is the question:

Whether 'tis nobler in the mind to suffer

The slings and arrows of outrageous fortune

Or to take arms against a sea of troubles

And by opposing end them. To die, to sleep--

No more--and by a sleep to say we end

The heartache, and the thousand natural shocks

That flesh is heir to. 'Tis a consummation

Devoutly to be wished. To die, to sleep--

To sleep--perchance to dream: ay, there's the rub,

For in that sleep of death what dreams may come

When we have shuffled off this mortal coil,

Must give us pause. There's the respect

That makes calamity of so long life.

For who would bear the whips and scorns of time,

Th' oppressor's wrong, the proud man's contumely

The pangs of despised love, the law's delay,

The insolence of office, and the spurns

That patient merit of th' unworthy takes,

When he himself might his quietus make

With a bare bodkin? Who would fardels bear,

To grunt and sweat under a weary life,

But that the dread of something after death,

The undiscovered country, from whose bourn

No traveller returns, puzzles the will,

And makes us rather bear those ills we have

Than fly to others that we know not of?

Thus conscience does make cowards of us all,

And thus the native hue of resolution

Is sicklied o'er with the pale cast of thought,

And enterprise of great pitch and moment

With this regard their currents turn awry

And lose the name of action. -- Soft you now,

The fair Ophelia! -- Nymph, in thy orisons

Be all my sins remembered.

At least...it USED TO BE figurative, only.

The Bulletin: It is two and a half minutes to midnight
2017 Doomsday Clock Statement
Science and Security Board
Bulletin of the Atomic Scientists
Editor, John Mecklin

Read more…

A Need For Starships...

Posted by Reginald L. Goodwin on January 27, 2017 at 6:00am
Popular Mechanics (Discovery 1: 2001 - A Space Odyssey): What Would a Starship Actually Look Like?

Topics: NASA, Politics, Space Exploration, Star Trek

Star Trek was born in the 1960's during counter-culture demonstrations against the Vietnam War; for the Civil Rights Act (1964), Voting Rights Act (1965) and Fair Housing Act (1968). It was a decade of assassinations: Medgar Evers, Malcolm X, Martin Luther King and Robert F. Kennedy. It was an admittedly Pollyannaish futurism with fantastic technologies beyond the capabilities of our physics likely now and in the near future. From my perspective as an African American and a budding science nerd, it was a hope beyond the fear of nations annihilating each other, and that we'd stop fretting like paranoid, prehistoric Neanderthals over the magical powers of Melanin.

A recurring theme from old to new Trek is Native Americans. In Kirk's timeline, they were excavated from Earth by the aliens called the Preservers, resulting in temporary amnesia for James T and a stoned (the rocks kind) pregnant wife.

In the Next Generation, Picard met a tribe that left Terra on their own in the 22nd Century, using the fantastically impossible warp drive because we hadn't gotten to the Utopia of a United Federation of Planets. Ironically, they were again being asked to move, this time from a contested colonial planet between Federation and Cardassians.

Chakotay is described as a starfleet tactical officer, Maquis terrorist and Native American descendant: A renaissance man of sorts in the 24th Century. The Next Gen tie-in was his father died defending their home world on the same Cardassian outpost. As with a lot of Trek stories, his father would talk to him on vision quests in his often expressed Mayan spiritual traditions (i.e. no one ever really dies).

Boomers in the 22nd Century were people that lived most of their lives in space, many of them people of color as evidenced by Ensign Travis Mayweather.

Lastly, in the novel Federation, Zephram Cochrane‎ apparently released the plans for warp drive on the Internet: for the low price of $50,000 (which I assume covers radiation shielding) you too would go faster-than-light to (presciently) Alpha Centauri.

The Venn Diagram of the three previous examples I've given is a suggested departure, an Exodus from Mother Earth to a kind of Elysium without dying. The former Native Americans carried with them their culture and traditions as I'm sure Mayweather and his family carried theirs. Perhaps Roddenberry and subsequent writers were suggesting a social pressure for Earthlings to finally listen to their better angels, kind of a societal potty-training (embarrassment can be an effective motivator).

It occurred to me: what if we COULD voluntarily leave? At one-tenth the speed of light (0.10 c) would involve time dilation, so for every year on your starship several years (if not decades or centuries, depending on the destination) would pass on Earth. Whatever problems you experienced with say, discrimination and xenophobia (traffic tickets, or worse) would be consumed by considerable distance and time. What would be the reaction of "powers that be?" A backlash, perhaps? "Legal" blocks put in to keep humans planet-bound, preventing pilgrims to the stars on an "over-ground railroad?" It's hard to reinforce a hierarchical society of implicit bias and income inequality when The Untouchables (traditional and figurative) decide to leave the planetary caste system.

We are bound by our own terrestrial limits and tribal prejudices. We are stymied by our fears of the unknown; of "the other"; of facts that don't comport to our preconceived notions and beliefs. Lacking critical thinking and reasoning skills, we violently fight the unknown, the only outcome being the eventual destruction of that which is feared, or self-destruction by one's own fears.

Spaceflight is not trivial: radiation (as I've mentioned), lack of gravity causing muscle deterioration and mineral loss from bones; long-term weightlessness seems to result in nearsightedness in astronauts on the ISS. Not to mention: food, and bathrooms (delicately, someone's going to have to figure out how to have sex in less than 1 g). Near-miraculous technologies like 0.10 c propulsive acceleration, rotating habitats to simulate gravity and adequate radiation shielding have yet to be created. Such design breakthroughs require an environment a little less hostile to science and facts as I'm currently observing in the US.

The need for the overview effect on an extensive, massive scale, seeing ourselves teamed to survive even as close as Mars, or mining the asteroid belts. Space programs such as that of a starship or interplanetary engines requires cooperation across borders and economies; across cultures and religious differences. It's hard to war with the other when the same shared goal is surviving to the next day.

Currently, homophobia, racism, sexism, xenophobia (translate: fear, the bedrock of hierarchical, caste-based societies) and consumer driven, cronyism-rewarding technology is threatening the continued existence of the species.

A visible hope: I had meant to complete "Invisible Man" by Ralph Ellison last Friday during my fast from the inaugural festivities. My small stance seemed to have contributed an effect.

At a local restaurant, I was reading the book waiting for my meal in front of a gas-powered fireplace, decorated with the head of a buck, the portrait of a couple (likely, the owner-founders); a fireman's cap, a safety cap, waffle iron and snow shoes.

A gentleman was sitting with who appeared to me his father and son, three generations enjoying a late breakfast at Cracker Barrel. He noticed my book and it sparked a conversation: I found out he had read the book, loaned to him by his best friend. He raved about it, describing details from the first part of it only someone who had read it would know (specifically, New York fight clubs). At his friend's untimely death at 26, he found a photo of he and his friend in Prague inside the pages. He described his cherub, blonde son as a "miracle baby": he and his wife had tried to adopt 3 times unsuccessfully. His wife was finally pregnant, long enough for his mother to see his son's "bump." She died two months before he was born. I told him how old my adult sons were and to enjoy his. All this from a book I neglected to finish last week. I'm glad I didn't and appreciative of the human connection it fostered. I plan to complete it this week. The hard copy of "1984" is currently out-of-stock on Amazon. As apropos as it is, I recommend this and other classics as we grope through this current darkness.

Earth and Vulcan apparently survived their fictional world wars and flights of emotion and irrationality that led to them. An initial Exodus (Earthlings to Centauri; Vulcans to Romulus) pushed their fictional societies towards an overview enlightenment.

But things only happen perfectly in Star Trek, such that life may NOT imitate art.
Read more…

Flexible Ferroelectrics...

Posted by Reginald L. Goodwin on January 26, 2017 at 7:16am
A scanning electron microscopy image of flexible haloimidazole crystals, which were found to show both ferroelectric and piezoelectric properties. (Image by Seungbum Hong/Argonne National Laboratory.)

Topics: Condensed Matter Physics, Nanotechnology, Materials Science, Metamaterials, Solid State Physics

Until recently, “flexible ferroelectrics” could have been thought of as the same type of oxymoronic phrase. However, thanks to a new discovery by the U.S. Department of Energy’s (DOE) Argonne National Laboratory in collaboration with researchers at Northwestern University, scientists have pioneered a new class of materials with advanced functionalities that moves the idea from the realm of irony into reality.

Ferroelectrics are a useful type of material that is found in capacitors that are used in sensors, as well as computer memory and RFID cards. Their special properties originate from the fact that they contain charged regions polarized in a specific orientation, which can be controlled with an external electric field. But they’ve also had a big drawback as engineers try to use them in new inventions.

“Ferroelectric materials are known for being quite brittle, and so it has always been a big challenge to make them mechanically flexible,” said Argonne nanoscientist Seungbum Hong, who helped to lead the research. “Because ferroelectricity and this kind of flexibility are relatively rare properties to see on their own, to have both ferroelectricity and flexibility in this new material is basically unprecedented.”

Argonne National Laboratory: Flexible ferroelectrics bring two material worlds together

Read more…

Single File...

Posted by Reginald L. Goodwin on January 26, 2017 at 7:12am
Illustration of a sealed and empty single-walled carbon nanotube (top) and a nanotube filled with water.
(Courtesy: Xuedan Ma et al/Phys. Rev. Lett.)


Topics: Biology, Cancer, Carbon Nanotubes, Nanotechnology, Research


The optical properties of single-walled carbon nanotubes (SWCNTs) change when the tiny structures are filled with water. That is the conclusion of scientists in Belgium and the US, who attribute the change to a "quasi-phase transition" that occurs in the water – although the exact nature of the transition is unknown. The research points to a new technique for studying confined water molecules – which is crucial to various branches of science, but it is surprisingly difficult to do. The study could lead to better ways of delivering drugs in the body and even boost our understanding of quantum mechanics.

SWCNTs are hollow hair-like structures with walls that are one atom thick. Normally they are closed at both ends, but sometimes the ends can be open and Sofie Cambré of the University of Antwerp in Belgium and colleagues have previously shown that open SWCNTs rapidly fill with other molecules and hold on to them. Why this occurs is not well understood, but Cambré says "it seems the energy of a molecule inside a SWCNTs is much lower than when you have them separated."

SWCNTs are naturally fluorescent, and the colour of the fluorescent light shifts if the nanotube is filled. "You need dedicated equipment to really see these very small shifts", Cambré says. However, by measuring the shifts, researchers can potentially gain useful insights into the behaviour of confined molecules.

Physics World:
Quasi-phase transition spotted in water-filled carbon nanotubes, Tim Wogan

Read more…

Recipe For Time Crystals...

Posted by Reginald L. Goodwin on January 24, 2017 at 6:29am
Figure 1: Yao et al. [7] have developed a blueprint for creating a time crystal and a method for detecting it, which has been followed by two experimental groups [8, 9]. Quantum spins are subjected to imperfect spin-flip driving pulses and then allowed to interact with each other in the presence of strong random disorder in the local magnetic fields. The sequence repeats after a total time period T, but the spin system exhibits emergent oscillations with period 2T—the hallmark of a discrete quantum time crystal. [Credit: APS/Alan Stonebraker/Phil Richerme]


Topics: Computer Science, Quantum Computer, Quantum Mechanics, Theoretical Physics


A detailed theoretical recipe for making time crystals has been unveiled and swiftly implemented by two groups using vastly different experimental systems.

The story of time crystals—whose lowest-energy configurations are periodic in time rather than space—epitomizes the creative ideas, controversy, and vigorous discussion that lie at the core of the scientific process. Originally theorized by Frank Wilczek in 2012 [1] (see 15 October 2012 Viewpoint), time crystals were met with widespread attention, but also a healthy dose of skepticism [2]. This ignited a debate in the literature, culminating in a proof that time crystals cannot exist in thermal equilibrium, as originally imagined by Wilczek [3]. But the tale did not end there. It was later argued that time crystals might still be possible in periodically driven systems, which can never reach thermal equilibrium [4–6]. Three recent papers have now completed the story, one proposing a roadmap for creating a nonequilibrium time crystal in the lab [7], and two describing subsequent experimental demonstrations in systems of trapped ions [8] and spin impurities in diamond [9] (both posted on the physics arXiv preprint server).

Empty space exhibits continuous translation symmetry: nothing distinguishes one point from any other. Yet ordinary crystals break this symmetry because atoms are periodically arranged in specific locations and display long-range spatial correlations. Given that we live in four-dimensional spacetime, it is natural to wonder if an analogous process of crystallization and symmetry breaking can arise along the time dimension as well [1]. If it does, then any such time crystal should return back to its initial state at specific times, while spontaneously locking to an oscillation period that differs from that of any external time-dependent forces. Hence this definition excludes all known classical oscillatory systems such as waves or driven pendulums.

APS Physics Viewpoint: How to Create a Time Crystal, Phil Richerme
#P4TC: Time Crystals, October 13, 2016

Read more…

Ode to Buzz Lightyear...

Posted by Reginald L. Goodwin on January 23, 2017 at 9:50am
Artist's illustration of the New Horizons spacecraft flying by the Kuiper Belt object 2014 MU69 on Jan. 1, 2019 Credit: NASA/JHUAPL/SwRI/Alex Parker
Topics: NASA, Planetary Science, Pluto, Space Exploration, Spaceflight
To Pluto and beyond!
Nearly two years after its historic encounter with the dwarf planet Pluto, NASA's New Horizons spacecraft is getting ready for its next big adventure in the icy outskirts of the solar system.
Now, the spacecraft is on its way to a small, ancient object located about 1 billion miles (1.6 billion kilometers) beyond Pluto in the Kuiper Belt. This distant region surrounds the solar system and is filled with trillions of icy rocks that have yet to be explored. The new target was discovered by the Hubble Space Telescope in June 2014, and it was dubbed 2014 MU69.
A world of discoveries
It took the spacecraft about 16 months to beam back all of its data from the Pluto flyby, and planetary scientists have had a ball with that data.
"The New Horizons flyby of the Pluto system was completely successful, and now we've got all the data on the ground and we're putting a bow around it," Alan Stern, the New Horizons principal investigator at Southwest Research Institute, said in a Facebook Live event on Thursday (Jan. 19).
Thanks to New Horizons, scientists now have a global map of Pluto and the most detailed images yet of the dwarf planet's bizarre, mountainous landscape and icy volcanoes. Tall mountain ranges seen on Pluto also suggest recent geological activity on the dwarf planet's surface.
Space.com: Beyond Pluto: NASA's New Horizons Spacecraft Heads to Next AdventureHanneke Weitering, Staff Writer-Producer
Read more…

Things That Matter...

Posted by Reginald L. Goodwin on January 20, 2017 at 5:00am
A misquote via Tweet from ABC News, I explain it below. Source: Snopes.com

Topics: Commentary, Climate Change, Existentialism, Politics, Science

Though I attended an evening service by my church's Black History Group last Sunday, and I am attending a breakfast with my fraternity brothers today, Dr. Martin Luther King Jr. did NOT actually say the following (it's paraphrased):



"Our lives begin to end the day we become silent about things that matter."

It's a great quote, and obviously passed around quite a bit on social media - in ABC News' case, mainstream media. It's even attributed to him on Brainy Quote and Good Reads, but Snopes scores it a mixture and gives the full context of what he originally said and a fair synopsis of how it was contracted (see the excerpt below).

There are people that matter; things that matter (like the PLANET), such as we've experienced the third year of increasing temperatures likely to be followed by related storm activity in the form of hurricanes, flooding; tornadoes. There will of course be the associated property damage and loss of life. Scientific American also talks about it here. For a republic to STAND, we have to abide by a certain number of measurable data points of observation and experiment from reality to begin a conversation. We also have to learn the difference between scientific theory and a cliched expression.



An excerpt from his sermon after "Bloody Sunday" on the Edmund Pettus Bridge:

A man might be afraid his home will get bombed, or he's afraid that he will lose his job, or he's afraid that he will get shot, or beat down by state troopers, and he may go on and live until he's 80. He's just as dead at 36 as he would be at 80. The cessation of breathing in his life is merely the belated announcement of an earlier death of the spirit. He died...

A man dies when he refuses to stand up for that which is right. A man dies when he refuses to stand up for justice. A man dies when he refuses to take a stand for that which is true.

..."that which is true."

We are supposedly in a post-truth world, but I'm now sincerely doubting that. No mountainous mendacity; no stupendous obfuscation can convince a made-up human mind that has critical thinking faculties, wit and abiding curiosity. Such beings will always dig a little deeper. A news feed with actual sources can change many other minds, or at least point them in the right direction to ask further questions.

Despite the fact the quote in the photo above SOUNDS like something Dr. King might have said, I merely probed a little more and found the possible origins and history behind the paraphrase. It did not lessen my admiration for Dr. King in the slightest and what he accomplished for all of us in this nation, but it did give context, history and deeper meaning (and, I still like the quote).

May we all take a stand for "that which is true": actual, verifiable scientific FACTS, and face courageously the factions of trolls that will attempt to gaslight us all as a democratic republic away from them. They are our metaphorical fire hoses.

What is to be admired by Dr. Martin Luther King Jr. and Congressman John Lewis is those weren't just the words of a clever sermon: it might as well have been a police blotter, a report like so many others of so many bruised, battered, bitten and fire-hosed bodies that stood up with their backs straightened, and took blows for "that which is true," forcing our nation to live up to its own ideals... those which ultimately matter.

“The good thing about science is that it's true whether or not you believe in it.”

― Neil deGrasse Tyson

“The Seven Social Sins are:

Wealth without work.

Pleasure without conscience.

Knowledge without character.

Commerce without morality.

Science without humanity.

Worship without sacrifice.

Politics without principle.

From a sermon given by Frederick Lewis Donaldson in Westminster Abbey, London, on March 20, 1925.”
Read more…

Intrinsic Disorder...

Posted by Reginald L. Goodwin on January 19, 2017 at 7:55am
Ricardo Bessa for Quanta Magazine


Topics: Biology, Biochemistry, Biophysics, Research


Proteins work like rigid keys to activate cellular functions — or so everyone thought. Scientists are discovering a huge number of proteins that shape-shift to do their work, upending a century-old maxim of biology.

Structure equals function: If there’s one thing we all learned about proteins in high school biology, that would be it. According to the textbook story of the cell, a protein’s three-dimensional shape determines what it does — drive chemical reactions, pass signals up and down the cell’s information superhighway, or maybe hang molecular tags onto DNA. For more than a century, biologists have thought that the proteins carrying out these functions are like rigid cogs in the cell’s machinery.

Of course, exceptions would occasionally crop up. A scientist might bump into a protein that performed its functions perfectly well yet didn’t have rigid structures. Most researchers chalked these cases up to experimental error, or dismissed them as insignificant outliers.

More recently, however, biologists have begun paying attention to these shapeshifters. Their findings are tearing down the structure-function dogma.

Proteins are chains of strung-together amino acids, and recent studies estimate that up to half of the total amino acid sequence that makes up proteins in humans doesn’t fold into a distinct shape. (While some of the proteins that make up this total are unstructured from end to end, others contain long unstructured regions side-by-side with structured ones.) “Partly, people didn’t realize how big that number was, and that’s why they ignored it,” said Julie Forman-Kay, a biochemist at the Hospital for Sick Children and the University of Toronto. “And partly they just didn’t know what to think of it.”

This fluidity — dubbed “intrinsic disorder” — endows proteins with a set of superpowers that structured proteins don’t have. Folded proteins tend to bind to their targets firmly, like a key in a lock, at just one or two spots, but their more stretched-out wiggly cousins are like molecular Velcro, attaching lightly at multiple locations and releasing with ease. This quick-on-quick-off binding’s effect in the cell is huge: It allows intrinsically disordered proteins — or IDPs, for short — to receive and respond to a slew of molecular messages simultaneously or in rapid succession, essentially positioning them to serve as cellular messaging hubs, integrating these multiple signals and switching them on and off in response to changes in the cell’s environment and to keep cellular processes ticking along as they should.

Quanta Magazine: The Shape-Shifting Army Inside Your Cells
Alla Katsnelson

Read more…

Afrofuturist Artists Craft A Virtual World For Women Of Color

Posted by William Hayashi on January 19, 2017 at 4:10am

It was the summer of 2016 and molecular and cellular biologist/multidisciplinary artist Ashley Baccus-Clark was gifting herself a day of self-care. The police shootings of Alton Sterling and Philando Castile had left her, like so many black Americans, anguished and weary. She tried to ease her heartache by visiting Storm King, the 500-acre sculpture park in upstate New York where hulking man-made forms dwell among rolling green fields.

Click here for the full article

Read more…

Cosmic Mystery...

Posted by Reginald L. Goodwin on January 18, 2017 at 2:38pm
Figure 1: Both the LUX and PandaX-II experiments look for dark matter particles (Chi-Chi) by sensing their interaction with xenon atoms. The detector in each experiment consists of a large tank of ultrapure liquid xenon (dark purple) topped with xenon gas (light purple). An interaction produces two light signals, one from photons, S1, and another, S2, from electrons when they drift into the gas. The signals are detected by photomultiplier tubes at the top and bottom of the tank (yellow cylinders). [Credit: APS/Carin Cain]


Topics: Astronomy, Astrophysics, Cosmology, Dark Matter


Over 80 years ago astronomers and astrophysicists began to inventory the amount of matter in the Universe. In doing so, they stumbled into an incredible discovery: the motion of stars within galaxies, and of galaxies within galaxy clusters, could not be explained by the gravitational tug of visible matter alone [1]. So to rectify the situation, they suggested the presence of a large amount of invisible, or “dark,” matter. We now know that dark matter makes up 84% of the matter in the Universe [2], but its composition—the type of particle or particles it’s made from—remains a mystery. Researchers have pursued a myriad of theoretical candidates, but none of these “suspects” have been apprehended. The lack of detection has helped better define the parameters, such as masses and interaction strengths, that could characterize the particles. For the most compelling dark matter candidate, WIMPs, the viable parameter space has recently become smaller with the announcement in September 2016 by the PandaX-II Collaboration [3] and now by the Large Underground Xenon (LUX) Collaboration [4] that a search for the particles has come up empty.

Since physicists don’t know what dark matter is, they need a diverse portfolio of instruments and approaches to detect it. One technique is to try to make dark matter in an accelerator, such as the Large Hadron Collider at CERN, and then to look for its decay products with a particle detector. A second technique is to use instruments such as the Fermi Gamma-ray Space Telescope to observe dark matter interactions in and beyond our Galaxy. This approach is called “indirect detection” because what the telescope actually observes is the particles produced by a collision between dark matter particles. In the same way that forensic scientists rely on physical evidence to reverse-engineer a crime with no witnesses, scientists use the aftermath of these collisions to reconstruct the identities of the initial dark matter particles.

The third technique, and the one used in both the LUX and PandaX-II experiments, is known as “direct detection.” Here, a detector is constructed on Earth with a massive target to increase the odds of an interaction with the dark matter that exists in our Galaxy. In the case of LUX and PandaX-II, the dark matter particles leave behind traces of light that can be detected with sophisticated sensors. This is akin to having placed cameras at the scene of a crime, capturing the culprit in the act.

The heart of both LUX, located in South Dakota in the US, and PandaX-II, situated in Sichuan, China, is a time-projection chamber. This consists of a large tank of ultrapure liquid xenon—250 kg at LUX and 500 kg at PandaX-II—topped with xenon gas (Fig. 1). A particle (dark matter or ordinary matter) that enters the chamber and interacts with a xenon atom in the liquid generates photons (by scintillation) and electrons (by ionization). The photons produce a signal, S1, which is read by photomultiplier tubes located at the top and bottom of the tank. The electrons are instead coaxed into the gaseous portion of the detector by an electric field where they induce a second round of scintillation and a signal S2. The pattern of S1 and S2 signals is different when the xenon interacts with a dark matter particle than with an ordinary particle, which is what allows scientists to distinguish between two such events. To reduce the background signal from ordinary particles, both LUX and PandaX-II are buried underground to provide protection from cosmic rays. In addition, the use of ultrapure materials in the construction of the experiment cuts the background contributed by radioactive emissions.

APS Viewpoint: Dark Matter Still at Large
Jodi A. Cooley, Department of Physics, Southern Methodist University, 3215 Daniel Ave., Dallas, TX 75205, USA
January 11, 2017• Physics 10, 3

Read more…

Euler's Method...

Posted by Reginald L. Goodwin on January 17, 2017 at 9:30am
From Notes on Diffy Qs: Differential Equations for Engineers, by Jirí Lebl

"What if we want to find the value of the solution at some particular x? Or perhaps we want to produce a graph of the solution to inspect the behavior. In this section we will learn about the basics of numerical approximation of solutions.

The simplest method for approximating a solution is Euler’s method. It works as follows: We take x0 and compute the slope k = f (x0; y0). The slope is the change in y per unit change in x. We follow the line for an interval of length h on the x axis. Hence if y = y0 at x0, then we will say that y1 (the approximate value of y at x1 = x0 + h) will be y1 = y0 + hk. Rinse, repeat! That is, compute x2 and y2 using x1 and y1." See Notes on Diffy Qs above (under graphic)


 Topics: Differential Equations, Diversity in Science, Mathematics, Women in Science

Okay, this is the LAST time I'll talk about Hidden Figures (although I did order the book).

Not to spoil it for you, but Dr. Katherine Johnson (played by Taraji P. Henson) mentioned an "old method" of mathematics. What both the actress and NASA scientist referred to is something you're taught usually sophomore year in a STEM major. Euler's Method is named after Leonhard Euler, and it's used to numerically approximate differential equations, something in the movie and the embed below alludes to is now done by what we now know as computers (the laptop kind, not female mathematicians).

It is important to understand the steps, derivation and mathematics behind computer calculation. How do you KNOW it's right? I'm often challenged as to "when I ever use Calculus" at work. Most often they're right, I don't. There's a software package designed with the equations embed within them to literally SPIT out an answer. The program doesn't have imagination nor does it visualize an expected end result. "The answer" is the end of a calculation without any notion of its consequences if incorrect.

Part of its practicality is essentially how the study of mathematics and physics organizes one's thinking. I use systematic approaches to solving just about any problem in life. However in Hidden Figures, it was initially the NASA scientists and eventually Dr. Johnson knowing the mathematics and relying on human insight and intuition that averted catastrophe, not that it doesn't happen when launching humans on the top of essentially systematic staged bombs to achieve Earth orbit.

The old riddle "which came first: the chicken or the egg?" can easily be answered with regards to computers and humans. The Singularity will have a ways yet.

François Arago said of him (Euler) "He calculated just as men breathe, as eagles sustain themselves in the air" (Beckmann 1971, p. 143; Boyer 1968, p. 482). [1]

In a testament to Euler's proficiency in all branches of mathematics, the great French mathematician and celestial mechanic Laplace told his students, "Liesez Euler, Liesez Euler, c'est notre maître à tous" ("Read Euler, read Euler, he is our master in everything" (Beckmann 1971, p. 153). [2]

1, 2: Scienceworld.Wolfram.com: Euler
LA Times:
Meet the ‘Hidden Figures’ mathematician who helped send Americans into space, Amina Khan

Read more…

Squeezing Below The Quantum Limit...

Posted by Reginald L. Goodwin on January 16, 2017 at 10:37am




NIST researchers applied a special form of microwave light to cool a microscopic aluminum drum to an energy level below the generally accepted limit, to just one fifth of a single quantum of energy. Having a diameter of 20 micrometers and a thickness of 100 nanometers, the drum beat 10 million times per second while its range of motion fell to nearly zero.

Credit: Teufel/NIST

Topics: Metamaterials, Nanotechnology, Quantum Computer, Quantum Mechanics


Physicists at the National Institute of Standards and Technology (NIST) have cooled a mechanical object to a temperature lower than previously thought possible, below the so-called “quantum limit.”

The new NIST theory and experiments, described in the Jan. 12, 2017, issue of Nature, showed that a microscopic mechanical drum—a vibrating aluminum membrane—could be cooled to less than one-fifth of a single quantum, or packet of energy, lower than ordinarily predicted by quantum physics. The new technique theoretically could be used to cool objects to absolute zero, the temperature at which matter is devoid of nearly all energy and motion, NIST scientists said.

“The colder you can get the drum, the better it is for any application,” said NIST physicist John Teufel, who led the experiment. “Sensors would become more sensitive. You can store information longer. If you were using it in a quantum computer, then you would compute without distortion, and you would actually get the answer you want.”


 NIST Physicists ‘Squeeze’ Light to Cool Microscopic Drum Below Quantum Limit
Laura Ost
Read more…

I, Nerd...

Posted by Reginald L. Goodwin on January 13, 2017 at 7:00am
Image Source: see "most intimidating Captain" below, or StarTrek.com


Topics: Commentary, Diversity in Science, Science Fiction, Star Trek, STEM


I am a nerd. Those of us of African descent have taken the name "blerds."

During the 70's, being a nerd of color wasn't a family outing in the park. I recall getting bullied...a lot. The fact that I: never ate nor liked the smell of chitterlings; watched Star Trek, Mutual of Omaha's Wild Kingdom and The Undersea World of Jacques Cousteau didn't help much either. A distinct memory of my nose bloodied from getting shoved in my locker after 9th grade English class for reading a poem - a haiku (that WAS the assignment) and getting the F-bomb epithet while my assailants sprinted down the hall. I noted when as an undergraduate almost the entire school karate team - led by my Calculus instructor - consisted entirely of STEM majors, with the exception of one in Communications. Nerds tend to know from experience defensive skills are a PLUS.

I noticed Physics Today and its related media Inside Science commented on the sitcom The Big Bang Theory. I've watched a few episodes, though with the exception of passing interest I have understandably never been a big fan. I can recall seeing a scene (a "scene" mind you) with Dr. Neil deGrasse Tyson on YouTube. I recall seeing an episode (maybe two?) with actress Regina King as an HR rep that had to haul Sheldon and company into her office to "set them straight." She's listed as officially appearing in four.

The big nerd show of my day was Star Trek, and The Bang gives a lot of hat tips to it quite often in their dialogue. It was the blend of science and swashbuckling; you could study the cosmos faster-than-light (defying all laws of physics), do a flying sidekick (Kirk) or a Vulcan neck pinch (Spock). Note to Sheldon: kick, yes; pinch, no.

I specifically in many ways was enamored with Nichelle Nichols/Lieutenant Uhura. It was moving that Dr. Martin Luther King talked her into staying after her first season as a role model. I'm grateful that she stayed, because without the image others might not have tried majoring in STEM like Dr. Mae Jemison, Dr. Tyson, Dr. Ronald E. McNair (deceased from the Challenger Disaster).

Even in my fandom, I have listed a few of my observations and critiques (this starts with TOS and its recent variants):
  • Uhura was technically third in command of the Enterprise, though I don't recall an episode where she took "the comm" (command chair). She technically outranked Scottie who took command in the Captain's absence on several occasions.
  • With the exception of a vampire salt monster (The Man Trap) masquerading as a black male and speaking Swahili; her forced kiss with Captain Kirk (Plato's Stepchildren - not played then in racist southern markets) she never had a story arc with a love interest.
  • Dr. Richard Daystrom (William Marshall), a genius that apparently won the Nobel Prize in I'd assume Computer Science (as yet not seen up to now - we get Peace Prizes mostly) and something called the Zee-Magnees Prize in 2243 invented the talking personal computers with Majel Barrett's voice and attitude. He of course also conveniently went mad. He would become the archetype for Miles Dyson (Joe Morton) in Terminator 2: Judgment Day, the twist is he didn't go mad, his creation did when it reached the Singularity, and realized humans are generally pricks.
  • With Captain's Kirk (TOS), Picard (TNG), Janeway (VOY), and Archer (ENT) their respective series STARTED with them at the rank of Captain. Their previous experiences were referred to in passing commentary, and their records deemed impeccable and impressive.
  • Benjamin Sisko started Deep Space 9 at the rank of Commander, though he eventually promoted into Captain. He also started with "an attitude," seeing Picard was the reason his wife died in the Borg battle at Wolf 359. He also punched Q (not mad at him for that), but it did play into the stereotype of being hotheaded. He was also a reluctant single dad (see "attitude"). He made "most intimidating Captain" in a Trek poll.
  • In Star Trek: Discovery Michelle Yeoh, fresh off "Crouching Tiger, Hidden Dragon" will play a starfleet Captain. Following the Sisko formula, the leader of the Starship Discovery Sonequa Martin-Green will start her screen life as a Lieutenant Commander (and from Sisko level, demoted), so it seems a sister STILL has to work twice as hard to get ahead in the Utopian 23rd Century.

Don't get me wrong: I'm not saying Star Trek hasn't done a lot of things RIGHT. The old Motorola StarTek was a knockoff of the Trek communicator; comm badges in TNG became the model for Bluetooth devices everyone had in their ears (talking to themselves) until we piped it through our radios. Heck, we even have the makings with phone apps of a Universal Translator; automatic doors at the mall started out on Trek with two guys on either side of William Shatner opening and closing the door on queue before optical electronics (and there were in all variants bloopers). It's just that scripts are usually written in a vacuum, usually with a team of people you know, and dependent on that team's exposure to diversity and other cultures well, see the above bullets.

Since the 1960 presidential debates between John F. Kennedy and Richard M. Nixon, images have mattered. Like the Internet and social media, television changes our brains and perceptions of what is real and what is frankly true. Though I was not on the planet, many who watched the presidential debates thought the cooler, younger, non-sweaty and more photogenic Kennedy won the debate. For the "old school" radio listeners, Nixon won it. Technology has been skewing our perceptions ever since.

Part of the goal of working in STEM at any level is imagining yourself in the role doing it. Taraji P. Henson - I talked about her last week at the debut of Hidden Figures (GO see it) said reading the script for the movie "hurt her" because she would have liked to know of these women when she was growing up. Images matter to young people that have a visual media thrown at them now 24/7 through flat screens, laptops and mobile devices; they are "programmed" quite subtly in what is proper for them to aspire to. Trivia: Ms. Henson majored in Electrical Engineering at my Alma Mater before transferring to Howard and majoring in Drama. The rest as they say, is history. Maybe she has a valid point. For that, young people all need actors that look like themselves so they can start thinking it is possible. I hope, like her to facilitate that.

In the meantime:

Je suis noir (I am black).

I am nerd.

I will (as long as ambulatory) blog.
Read more…

Electron Puddle...

Posted by Reginald L. Goodwin on January 12, 2017 at 7:10am
In a new study, Argonne scientists have discovered a way to confine the behavior of electrons by using extremely high magnetic fields. (Image by Argonne National Laboratory.)


Topics: Electromagnetism, Materials Science


Olympic figure skaters and electrons have a lot in common. In figure skating competitions, the "free skate" segment gives the skater the flexibility to travel in whichever pattern he or she chooses around the rink. Similarly, in metals, electrons in outer orbitals can wander fairly freely.

However, when the magnetic field is increased dramatically, researchers have found that the motion of these electrons becomes much more tightly confined. Their behavior looks like figure skaters completing compulsory tight spins and jumps.

In a new study from the U.S. Department of Energy's (DOE's) Argonne National Laboratory, researchers used extremely high magnetic fields — equivalent to those found in the center of neutron stars — to alter electronic behavior. By observing the change in the behavior of these electrons, scientists may be able to gain an enriched understanding of material behavior.

"The rules of the game are changed when we apply a magnetic field of this intensity," said Argonne materials scientist Anand Bhattacharya, who led the research. "The nature of this new state that we see has been debated theoretically for over half a century, but experiments to measure its properties have been hard to come by."

Argonne National Laboratory:
Electrons "puddle" under high magnetic fields, study reveals, Jared Sagoff

Read more…

Fusion Breeding...

Posted by Reginald L. Goodwin on January 11, 2017 at 8:35pm
Image Source: Binus University Research Interest Group


Topics: Alternative Energy, Nuclear Fusion, Nuclear Physics, Nuclear Power

 Abstract

This article is an editorial, which makes the case that fusion breeding (that is using fusion neutrons to breed nuclear fuel for use in conventional nuclear reactors) is the best objective for the fusion program. To make the case, it reviews a great deal of plasma physics and fusion data. Fusion breeding could potentially play a key role in delivering large-scale sustainable carbon-free commercial power by mid-century. There is almost no chance that pure fusion can do that. The leading magnetic fusion concept, the tokamak, is subject to well-known constraints, which we have called conservative design rules, and review in this paper. These constraints will very likely prevent tokamaks from ever delivering economical pure fusion. Inertial fusion, in pure fusion mode, may ultimately be able to deliver commercial power, but the failure to date of the leading inertial fusion experiment, the National Ignition Campaign, shows that there are still large gaps in our understanding of laser fusion. Fusion breeding, based on either magnetic fusion or inertial fusion, greatly relaxes the requirements on the fusion reactor. It is also a much better fit to today’s and tomorrow’s nuclear infrastructure than is its competitor, fission breeding. This article also shows that the proposed fusion and fission infrastructure, ‘The Energy Park’, reviewed here, is sustainable, economically and environmentally sound, and poses little or no proliferation risk.

Introduction

The fusion program, both short term and long term, is in trouble, certainly in the United States, and likely worldwide. In addition to large cost overruns and failures to meet milestones, surely another reason is that pure fusion has almost no chance of meeting energy requirements on a time scale that anyone alive today can relate to. Hence the assertion of this article is that fusion breeding of conventional nuclear fuel is a likely way out of fusion’s current and future difficulties. Fusion breeding substantially reduces the requirements on the fusion reactor. It significantly reduces the necessary Q (fusion power divided by input power), wall loading, and availability fraction. The capital cost of a reactor, estimated based on ITER’s capital cost, is affordable for fusion breeding, but definitely is not for pure fusion. It is likely that fusion breeding can produce fuel at a reasonable cost by mid century. The entire fusion and fission infrastructure would be sustainable, economical, environmentally sound, and have little or no proliferation risk. This article’s mission then, is to hopefully convince a much larger portion of the fusion establishment to make this case. At the very least it hopes to broaden the discussion in the fusion community from where we are now, where one prestigious review committee after another insists that every existing project is absolutely vital, nothing can be changed; except give us more $$$. The inevitable result of this process is that one fusion project after another gets knocked off.



 RD Springer: Fusion Breeding for Mid-Century Sustainable Power, Wallace Manheimer

Read more…

Brexit and Exodus...

Posted by Reginald L. Goodwin on January 10, 2017 at 9:30am
Image Source: Wiki Gender

Topics: Existentialism, Politics, Science, Research

A survey of more than 1,000 UK-based university staff suggests that the country’s vote to leave the European Union could drive an academic exodus.

Forty-two per cent of lecturers and professors surveyed say they are more likely to consider leaving the UK higher-education sector as a result of the referendum outcome. The proportion was even greater (76%) among the non-UK EU citizens in the survey, commissioned by the University and College Union, which represents tens of thousands of academics and is based in London.

Many individual foreign researchers have said they feel less welcome in Britain after the Brexit vote, or that they now see better opportunities abroad. But the latest poll is one of the clearest indications of the widespread nature of this feeling in UK academia.


 Scientific American: Brexit May Spark British Brain Drain, Daniel Cressey
Read more…

Lucy and Psyche...

Posted by Reginald L. Goodwin on January 9, 2017 at 2:50pm
(Left) An artist’s conception of the Lucy spacecraft flying by the Trojan Eurybates – one of the six diverse and scientifically important Trojans to be studied. Trojans are fossils of planet formation and so will supply important clues to the earliest history of the solar system. (Right) Psyche, the first mission to the metal world 16 Psyche will map features, structure, composition, and magnetic field, and examine a landscape unlike anything explored before. Psyche will teach us about the hidden cores of the Earth, Mars, Mercury and Venus.
(Photo: SwRI and SSL/Peter Rubin)


Topics: Asteroids, NASA, Planetary Science, Space Exploration


NASA will embark on two missions it says could unlock secrets to how our solar system was formed.

The Lucy and Psyche missions — both robotic, unmanned endeavors controlled from Earth — will take us back to the time 10 million years after the sun was born.

Lucy will visit the Trojan asteroids of Jupiter when it launches in October 2021. Scientists suspect the asteroids, currently caught in the largest planet's 12-year orbit around the sun, may have existed in the beginnings of the solar system and before Jupiter's orbit.

Lucy's principal investigator Harold F. Levison claims the mission will yield other-worldly insight into our universe.

"Because the Trojans are remnants of the primordial material that formed the outer planets, they hold vital clues to deciphering the history of the solar system," he explained. "Lucy, like the human fossil for which it is named, will revolutionize the understanding of our origins."

But don't wait up, Lucy's first stop won't come until 2025 when it arrives at a main belt asteroid. It will examine the Trojans from 2027 to 2033.

USA Today: NASA asteroid missions to discover secrets of the universe, Sean Rossman

Read more…