Brainy Quote of the Day

Tuesday, August 30, 2016

Quantum Supersolution Techniques...

Figure 1

(a) Two photonic wave functions on the image plane, each coming from a point source. X1 and X2 are the point-source positions, θ1 is the centroid, θ2 is the separation, and σ is the width of the point-spread function. (b) If photon counting is performed on the image plane, the statistics are Poisson with a mean intensity proportional to Λ(x)=[|ψ1(x)|2+|ψ2(x)|2]/2 .
Topics: Modern Physics, Particle Physics, Quantum Mechanics

Rayleigh’s criterion for resolving two incoherent point sources has been the most influential measure of optical imaging resolution for over a century. In the context of statistical image processing, violation of the criterion is especially detrimental to the estimation of the separation between the sources, and modern far-field superresolution techniques rely on suppressing the emission of close sources to enhance the localization precision. Using quantum optics, quantum metrology, and statistical analysis, here we show that, even if two close incoherent sources emit simultaneously, measurements with linear optics and photon counting can estimate their separation from the far field almost as precisely as conventional methods do for isolated sources, rendering Rayleigh’s criterion irrelevant to the problem. Our results demonstrate that superresolution can be achieved not only for fluorophores but also for stars.

APS Physics: Quantum Theory of Superresolution for Two Incoherent Optical Point Sources
Mankei Tsang, Ranjith Nair, and Xiao-Ming Lu
Phys. Rev. X 6, 031033 – Published 29 August 2016

Monday, August 29, 2016

Jupiter's Extended Family...

Comparing Jupiter with Jupiter-like planets that orbit other stars can teach us about those distant worlds, and reveal new insights about our own solar system's formation and evolution. (Illustration)
Credits: NASA/JPL-Caltech
Topics: Astronomy, Astrophysics, Exoplanets, NASA, Planetary Science, Space Exploration

Our galaxy is home to a bewildering variety of Jupiter-like worlds: hot ones, cold ones, giant versions of our own giant, pint-sized pretenders only half as big around.

Astronomers say that in our galaxy alone, a billion or more such Jupiter-like worlds could be orbiting stars other than our sun. And we can use them to gain a better understanding of our solar system and our galactic environment, including the prospects for finding life.

It turns out the inverse is also true -- we can turn our instruments and probes to our own backyard, and view Jupiter as if it were an exoplanet to learn more about those far-off worlds. The best-ever chance to do this is now, with Juno, a NASA probe the size of a basketball court, which arrived at Jupiter in July to begin a series of long, looping orbits around our solar system's largest planet. Juno is expected to capture the most detailed images of the gas giant ever seen. And with a suite of science instruments, Juno will plumb the secrets beneath Jupiter's roiling atmosphere.

It will be a very long time, if ever, before scientists who study exoplanets -- planets orbiting other stars -- get the chance to watch an interstellar probe coast into orbit around an exo-Jupiter, dozens or hundreds of light-years away. But if they ever do, it's a safe bet the scene will summon echoes of Juno.

NASA: Jupiter's Extended Family? A Billion or More

Friday, August 26, 2016

ET and Xenophobia...

Image Source: Simon Kneebone – cartoonist and illustrator
Topics: Astrophysics, Cosmology, SETI, Space Exploration, Star Trek

Xenophobia is something we experience among ourselves from others with five fingers, five toes; slight differences in frames and shades of Melanin. We've never encountered - as far as we know - an intelligence beyond our world similar to us due to the laws of physics, chemistry and biology but distinctly: alien.

Whatever we as a species ascribe to as deity for example, MUST by design favor our particular human tribe. We create echo chambers to reinforce our own confirmation-bias about ourselves, in the modern vernacular "creating our own realities." Any news outside this special nurturing bubble is usually opposed with breathtaking, sometimes violent cognitive dissonance to maintain this special nurturing cocoon.

What exactly WILL we do when some species a little older, surviving its own M.A.D. ideology answers our calls in the dark? Our history - both current and documented - doesn't bode well towards a rational or civilized response.

The short-lived Star Trek: Enterprise seemed to be hitting its stride with the episodes Demons and Terra Prime before its cancellation; our current clamor for nationalism and purity makes them both quite prescient. Enterprise showed a humanity at the cusp of establishing a United Federation of Planets. They initially instead showed old prejudices, and our disdain for being put out of our self-appointed special place in the universe, post surviving Trek's fictional human extinction-level events of World War III and war with the Xindi. Before the imagined utopias of Kirk or Picard and the current xenophobia displayed among our own species, we likely still have some growing to do.

We are at a stage in our evolution where we do not yet know if we will ever communicate with intelligent beings that have evolved on other planets, yet we are intelligent and curious enough to wonder about this. We find ourselves wondering about this at the very beginning of a long era in which stellar luminosity warms many planets, and by our best models, continues to provide equally good opportunities for intelligent life to evolve. By simple Bayesian reasoning, if, as we believe, intelligent life forms have the same propensity to evolve later on other planets as we had to evolve on ours, it follows that they will likely not pass through a similar wondering stage in their evolution. This suggests that the future holds some kind of interstellar communication that will serve to inform newly evolved intelligent life forms that they are not alone before they become curious.

Physics arXiv: Odds for an enlightened rather than barren future, David Haussler

Thursday, August 25, 2016

Horror Vacui...

James O'Brien for Quanta Magazine
Topics: Cosmology, History, Modern Physics, Richard Feynman

Horror vacui: "nature abhors a vacuum." (attributed to Aristotle)

Richard Feynman looked tired when he wandered into my office. It was the end of a long, exhausting day in Santa Barbara, sometime around 1982. Events had included a seminar that was also a performance, lunchtime grilling by eager postdocs, and lively discussions with senior researchers. The life of a celebrated physicist is always intense. But our visitor still wanted to talk physics. We had a couple of hours to fill before dinner.

I described to Feynman what I thought were exciting if speculative new ideas such as fractional spin and anyons. Feynman was unimpressed, saying: “Wilczek, you should work on something real.” (Anyons are real, but that’s a topic for another post.)

Looking to break the awkward silence that followed, I asked Feynman the most disturbing question in physics, then as now: “There’s something else I’ve been thinking a lot about: Why doesn’t empty space weigh anything?”

Feynman, normally as quick and lively as they come, went silent. It was the only time I’ve ever seen him look wistful. Finally he said dreamily, “I once thought I had that one figured out. It was beautiful.” And then, excited, he began an explanation that crescendoed in a near shout: “The reason space doesn’t weigh anything, I thought, is because there’s nothing there!”

Vacuum, in modern usage, is what you get when you remove everything that you can, whether practically or in principle. We say a region of space “realizes vacuum” if it is free of all the different kinds of particles and radiation we know about (including, for this purpose, dark matter — which we know about in a general way, though not in detail). Alternatively, vacuum is the state of minimum energy.

Intergalactic space is a good approximation to a vacuum.

Void, on the other hand, is a theoretical idealization. It means nothingness: space without independent properties, whose only role, we might say, is to keep everything from happening in the same place. Void gives particles addresses, nothing more.

Aristotle famously claimed that “Nature abhors a vacuum,” but I’m pretty sure a more correct translation would be “Nature abhors a void.” Isaac Newton appeared to agree when he wrote:

...that one Body may act upon another at a Distance thro’ a Vacuum, without the Mediation of any thing else, by and through which their Action and Force may be conveyed from one to another, is to me so great an Absurdity, that I believe no Man who has in philosophical Matters a competent Faculty of thinking, can ever fall into it.

But in Newton’s masterpiece, the Principia, the players are bodies that exert forces on one another. Space, the stage, is an empty receptacle. It has no life of its own. In Newtonian physics, vacuum is a void.

Quanta Magazine: How Feynman Diagrams Almost Saved Space, Frank Wilczek

Wednesday, August 24, 2016

Zika and Louisiana...

Zika Mosquito - Internet Search
Topics: Biology, Climate Change, Global Warming, Research

I recorded something on my DVR titled "Global Weirding," which I think is far more descriptive of the phenomena. "Warming" tends to imply extreme heat like the Sahara Desert ALL the time. It's more like what you've grown comfortable expecting...don't. Sensational blockbusters like "The Day After Tomorrow" don't help in our impatient point-and-click attention-deficit patience either. Instead of a sudden dystopian disaster, it should be thought of as a slow but steady train wreck.

Aerosol threats have been expected from our changing climate. This new threat is currently growing and concerning for many, like me that have relatives in harms way on the Gulf Coast and Florida. Thankfully, our stalwart, "science-friendly" representatives are on the case, tying battling related birth defects to eliminating abortion. Infants will be safely born on the Gulf Coast (as Latin America grapples with their own previous conservative views and legal prohibitions) sadly, with smaller heads and shortened lifespans. It is an oxymoron; a contradiction in terms and "values."

One of the top U.S. public health officials on Sunday warned that the mosquito-borne Zika virus could extend its reach across the U.S. Gulf Coast after officials last week confirmed it as active in the popular tourist destination of Miami Beach.

The possibility of transmission in Gulf States such as Louisiana and Texas will likely fuel concerns that the virus, which has been shown to cause the severe birth defect known as microcephaly, could spread across the continental United States, even though officials have played down such an outcome.

Concern has mounted since confirmation that Zika has expanded into a second region of the tourist hub of Miami-Dade County in Florida. Miami's Wynwood arts neighborhood last month became the site of the first locally transmitted cases of Zika in the continental United States.

"It would not be surprising we would see additional cases perhaps in other Gulf Coast states," Dr. Anthony Fauci, director of the allergy and infectious diseases unit of the National Institutes of Health (NIH), said in an interview on Sunday morning with ABC News.

Scientific American:
Zika Poised for Possible Spread across U.S. Gulf, Chris Prentice

Tuesday, August 23, 2016

Super-Sized Molecules...

APS/Alan Stonebraker
Distant partners. In this sketch, two cesium atoms in high Rydberg states form a weakly bound molecule about 1 micrometer across, comparable to the size of typical bacteria.
Topics: Atomic Physics, Particle Physics, Quantum Computer, Rydberg Atom

Strongly bound diatomic molecules such as H2 or O2 are less than a nanometer across. Surprisingly, scientists have been able to create two-atom molecules more than a thousand times larger by using exotic atoms that attract one another only very weakly. Now, a pair of physicists have calculated what makes these “macrodimers” stable, and they have verified their predictions by creating micrometer-sized molecules containing two cesium atoms. The macrodimers could have applications in quantum computing.

Interest in these macromolecules stems from the challenges they pose to conventional understanding of molecules and bonds. More than a decade ago, physicists predicted that molecules with interatomic distances as large as 1 micrometer might be created by using a pair of atoms in so-called Rydberg states. These are atoms in which a single outer-shell electron has been excited to a high quantum state so that it orbits far away from the nucleus. Although Rydberg atoms are unstable, they can live as long as tens of microseconds, and experimenters have succeeded in creating macrodimers from them, confirming their existence indirectly by destroying them and detecting specific spectroscopic signatures [1].

APS Focus: Giant Molecule Made from Two Atoms, Mark Buchanan

Monday, August 22, 2016

Neutrinos, Matter and Antimatter...

Olena Shmahalo/Quanta Magazine
As neutrinos and antineutrinos change flavors they may illuminate the differences between matter and antimatter.
Topics: Atomic Physics, Neutrinos, Particle Physics, Quantum Mechanics

(July 28, 2016) - In the same underground observatory in Japan where, 18 years ago, neutrinos were first seen oscillating from one “flavor” to another — a landmark discovery that earned two physicists the 2015 Nobel Prize — a tiny anomaly has begun to surface in the neutrinos’ oscillations that could herald an answer to one of the biggest mysteries in physics: why matter dominates over antimatter in the universe.

The anomaly, detected by the T2K experiment, is not yet pronounced enough to be sure of, but it and the findings of two related experiments “are all pointing in the same direction,” said Hirohisa Tanaka of the University of Toronto, a member of the T2K team who presented the result to a packed audience in London earlier this month.

“A full proof will take more time,” said Werner Rodejohann, a neutrino specialist at the Max Planck Institute for Nuclear Physics in Heidelberg who was not involved in the experiments, “but my and many others’ feeling is that there is something real here.”

The long-standing puzzle to be solved is why we and everything we see is matter-made. More to the point, why does anything — matter or antimatter — exist at all? The reigning laws of particle physics, known as the Standard Model, treat matter and antimatter nearly equivalently, respecting (with one known exception) so-called charge-parity, or “CP,” symmetry: For every particle decay that produces, say, a negatively charged electron, the mirror-image decay yielding a positively charged antielectron occurs at the same rate. But this cannot be the whole story. If equal amounts of matter and antimatter were produced during the Big Bang, equal amounts should have existed shortly thereafter. And since matter and antimatter annihilate upon contact, such a situation would have led to the wholesale destruction of both, resulting in an empty cosmos.

Quanta Magazine: Neutrinos Hint of Matter-Antimatter Rift, Natalie Wolchover