pcdube2007: What's this

What is anything?


Quantum Encryption May Be HackableQuantum communication systems offer the promise of virtually unbreakable encryption. Unlike classical encryption, which is used to send secure data over networks today and whose security depends on the difficulty of solving mathematical problems like the factoring of large numbers, most quantum encryption schemes keep the encryption key separate from the data. This approach ensures that an eavesdropper with access only to the data could not decipher the key. However, researchers have recently demonstrated that even quantum encryption may be susceptible to hacking.Read more: http://www.laboratoryequipment.com/news/2013/05/quantum-encryption-may-be-hackable

Star Plays Dizzying Dance of Doom with Black Hole
Black holes are probably among the scariest things in the universe, with gravitational forces powerful enough to warp the fabric of spacetime itself. Red dwarfs, on the other hand, are amongst the smallest of stars, shining dimly in the darkness — not exactly the sort of pairing which you might expect to be make dancing partners.
All the same, that’s exactly the pairing you’ll find in a star system known as MAXI J1659-152. This system contains just such an odd couple, locked in a tight orbit where a red dwarf is speeding around it’s heavier companion at an astonishing two million kilometers per hour (1.2 million mph)! Read more.

Ask a grown-up: is there anything smaller than an atom?
Cern scientist Jon Butterworth answers eight-year-old Adam’s question

Yes, and we use them every day. Electrons are one of the things inside atoms and we are very used to seeing them move around when an electric current flows. They have been known about for more than 100 years.
We have something called the standard model of physics, which is a list of things that are not made of anything else – in other words, the smallest things we know of. That list includes quarks, gluons, electrons and neutrinos. Then there are the forces that join those things up: light is one of them. Light is carried by little particles called photons. And there is the Higgs boson particle, which we found last year, which is also smaller than an atom.
It does still boggle my mind. You know the maths of particle physics but while the maths is elegant and beautiful, it feels completely other to everyday life. When we built the Large Hadron Collider and actually saw the Higgs boson particle in action, it was amazing.

Black Hole’s Mystery ‘Wave’ Surprises Scientists

Astronomers studying an unusual black hole system have spotted a never-before-seen structure in the disk of matter encircling the system.
Swift J1357.2, an X-ray binary system that regularly emits outbursts of high energy, consists of a black hole slowly consuming its companion star. Matter from the doomed star falls into the accretion disk, which surrounds the black hole, feeding it dust and gas.

While observing the system, a team of scientists noticed an unusual vertical feature traveling through the material.

“It’s the first time we can resolve such [a] structure in an accretion disk, and it might be ubiquitous in X-ray binaries during the outburst state,” Jesus Corral-Santana, of the Astrophysical Institute of the Canary Islands in Spain, told SPACE.com by email.

A hidden structure
The black hole contained in Swift J1357.2 is one of the millions of stellar black holes that dot the Milky Way galaxy.

About three times as massive as the sun, the behemoth likely formed when a single star collapsed inward on itself. The resulting, city-sized body packed a great deal of mass into a tiny package, creating a strong gravitational pull on nearby dust and gas.

Located in the Virgo constellation, approximately 4,900 light-years from Earth, Swift J1357.2 also contains a small companion star, which has only a quarter the mass of the sun. This companion star orbits the pair’s center of mass every 2.8 hours, one of the shortest known orbital periods for such systems.

The black hole pulls material from the companion star into its accretion disk, occasionally emitting the X-ray bursts that enabled scientists to find this otherwise hard-to-spot system, researchers said.

Corral-Santana and his team took hundreds of optical images of the system using the Isaac Newton and the William Herschel Telescopes, both of which are in the Canary Islands. Studying the light produced by the accretion disk, the researchers noticed a periodic dimming in the system, sometimes occurring over the course of only a few seconds.

“Since the orbital period of the system is 2.8 hours, those dips cannot be produced by eclipses of the companion star. They are much faster,” Corral-Santana said. “Therefore, they must be produced by a hidden structure placed very close to the black hole, in the inner accretion disk.”

The new find can only been seen in the outer, optical portion of the accretion disk, not on the inside, where X-ray bursts originate. The X-ray emission, which shows no periodic variation, unlike its optical counterpart, indicated a vertical structure was hiding the black hole, Corral-Santana said.

Rather than appearing at a set, predictable time, the structure shows up over a steadily increasing period, indicating a wave-like movement through the accretion disk.

“It is a wave produced in the accretion disk, moving outward,” Corral-Santana said, “like the wave produced when a stone is dropped in calm water.”

The missing population
The wave-like feature also provides information about the orientation of the black hole.

Objects in space face Earth at a variety of angles, or inclinations. They can be seen edge-on, face-on or somewhere in between. Swift J1357.2 is the only one of 50 suspected similar black-hole systems found with an edge-on accretion disk — what scientists call a high inclination. However, astronomers think approximately 20 percent of these systems should provide such a perspective.

In order to see the wave-like structure in the accretion disk, scientists must have such an edge-on view of the disk, or one close to it. A view from a lower inclination, closer to face-on, would not reveal the sudden rises and falls in the total light coming from the system.

“Swift J1357.2 is the prototype of the hitherto missing population of high-inclination black holes in transient X-ray binaries,” Corral-Santana said.

Because Swift J1357.2 is the first such system to allow such an edge-on view, the presence of the vertical structure takes on an added significance. No signs of such structures appear in other similar systems, but that could result simply from their unfortunate angles. Such structures could in fact exist in other, previously discovered transient X-ray binary systems, hidden only by their observational angles.

The findings were published online today (Feb 28) in the journal Science.

image: This image is a simulation of the X-ray binary system Swift J1357.2-0933, a black hole and star system, in which the effect of a strange, vertical mystery structure are at their maximum.
credit: Gabriel Perez Diaz, Instituto de Astrofisica de Canarias (Servicio MultiMedia)

Illustrative picture of wave-particle duality , which shows how the same phenomenon can be perceived in two different ways.

Walt Whitman’s iconic poem “When I Heard the Learn’d Astronomer” adapted into comic form. Check out the inspiring full version at Zen Pencils.
In fact, check out all of the comics at Zen Pencils. They’re outstanding.


The many-worlds interpretation of quantum mechanics, which implies that all possible alternative histories and futures are real, by Henry Reich of MinutePhysics.


Quantum World in Conflict with Everyday ExperienceA team at the Univ. of Vienna, led by the Austrian physicist Anton Zeilinger, has now carried out an experiment with photons, in which they have closed an important loophole. The researchers have provided the most complete experimental proof that the quantum world is in conflict with our everyday experience. The results of this study appear this week in the renowned journal Nature.Read more: http://www.laboratoryequipment.com/news/2013/04/quantum-world-conflict-everyday-experience



One half of the humans are female, so one half of the scientists should be female.
- Bill Nye at the Storytelling of Science at ASU

(Source: kitten-little, via barelysarcasm)



If your favorite scientists throughout history were super-hip web start-ups, these would be their logos.

I would buy stock in that Feynman guy any day. He’s my dude. Check out the rest of the superb collection from Alan Betancourt.

(Source: jtotheizzoe)


Black Hole Firewall: Trouble On The Edge
Ever wondered what happens to things as they are consumed by the black hole, the left over matter of dead stars? For a time, it used to be okay to assume matter was destroyed once it entered into a black hole, spaghettified and all.. but it turned out that this couldn’t be further away from the truth. NewScientists Anil Ananthaswamy has a wonderful 3 page piece getting into full details of this history and what questions scientists are asking now. If you love black holes, this is a definite recommend. Although registration (completely free!) is required to view the whole article. It’s pretty insightful and accurately presents the problems currently being faced with how black holes do what they do:

“Paradoxes are good in physics,” reflects John Preskill. “They help to point the way towards important discoveries.” Quantum mechanics and Einstein’s theories of relativity offer plenty to choose from. There’s the cat that can be dead and alive at the same time. Or the Back to the Future-style time traveller who kills his own grandfather, rendering his own birth impossible. Or the twins who disagree on their age after one returns from a near light-speed trip to a neighbouring star. Each perplexing scenario forces us to examine the fine print of the problem, thereby advancing our understanding of the theory behind it. A case in point is Einstein, whose own theories came from trying to resolve the paradoxes of his time.
Image: Ring of fireSam Chivers
Now Preskill, a theoretical physicist at the California Institute of Technology in Pasadena, is scratching his head over the latest one to surface. Nicknamed the black hole firewall paradox, it comes about when you consider what happens to someone falling into a black hole.
With the nearest black hole more than 1000 light years away, the question is very much a theoretical one. Yet just by studying such a possibility, physicists are hoping to make a breakthrough in their efforts to combine general relativity and quantum mechanics into a theory of quantum gravity – one of the most intractable problems in physics today.
Black holes have long been fertile breeding grounds for paradoxes. Back in 1974, Stephen Hawking, along with Jacob Bekenstein of the Hebrew University in Jerusalem, Israel, famously showed that black holes are not entirely black. Instead, they radiate energy known as Hawking radiation comprising photons and other quantum particles – an agonisingly slow process that eventually causes the black hole to evaporate completely.
Hawking spotted a problem with this picture. The radiation seemed so random that he surmised it couldn’t carry any information about the stuff that had fallen in. So as the black hole evaporates, the information it holds must eventually disappear. Yet this is in direct conflict with a central tenet of quantum physics, which says that information cannot be destroyed. The black hole information paradox was born.
Over the decades, physicists have struggled with this paradox. Hawking thought that black holes destroyed information and the answer was to question quantum mechanics. Others disagreed. After all, Hawking’s idea came from his efforts to meld general relativity and quantum mechanics – a mathematical feat so elusive that he was forced to make approximations. Preskill even made a bet with Hawking that black holes don’t destroy information.
Several arguments suggest that Hawking was wrong. One of the most compelling comes from thinking about what happens as the evaporating black hole gets smaller and smaller. If information can’t escape or be destroyed, then more and more has to be stored in an ever-shrinking volume. But if this is the case, quantum theory says the probability for making a tiny black hole increases from virtually nothing to almost infinity wherever matter collides against matter. “You should have seen it at the Large Hadron Collider, you should have seen it at Fermilab, you should have seen it in tiny room-sized particle accelerators from the 1930s,” says Don Marolf, a theorist at the University of California in Santa Barbara (UCSB). “You should see it when you go and jump up and down on the grass.”
Obviously that hasn’t happened. The other possibility – that matter and the information it carries can leak out from a black hole – is unlikely. Any material that falls in would need to travel faster than light to escape the black hole’s fearsome gravity.
Perhaps, instead, the answer lies with the Hawking radiation itself. Maybe it isn’t so featureless. “A common reaction was that Hawking had simply been careless,” says Joseph Polchinski, also at UCSB. “It wasn’t that information was lost, it was that he hadn’t kept track of it enough.”
Yet all early efforts to do away with the paradox proved unsuccessful. “Hawking had identified a really deep problem,” says Polchinski.
As it happened, Hawking changed his mind in 2004, partly due to work by an Argentinian physicist called Juan Maldacena (see “Hawking’s change of heart”). Black holes don’t destroy information after all, he conceded. He honoured the bet he made with Preskill and presented him with an encyclopaedia of baseball, which Preskill likened to a black hole, because it was heavy and it took effort to get information out of it.
Into The Abyss..

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