Monday, 27 May 2019

A Quantum Revolution Is Coming


uncaptioned
credits: DEPOSITPHOTOS

AI & Big DataJayshree Pandya is Founder of Risk Group & Host of Risk Roundup.
Quantum physics, the study of the universe on an atomic scale, gives us a reference model to understand the human ecosystem in the discrete individual unit. It helps us understand how individual human behavior impacts collective systems and the security of humanity.
Metaphorically, we can see this in how a particle can act both like a particle or a wave. The concept of entanglement is at the core of much of applied quantum physics. The commonly understood definition of entanglement says that particles can be generated to have a distinct reliance on each other, despite any three-dimensional or 4-dimensional distance between the particles. What this definition and understanding imply is that even if two or more particles are physically detached with no traditional or measurable linkages, what happens to one still has a quantifiable effect on the other.
Now, individuals and entities across NGIOA are part of an entangled global system. Since the ability to generate and manipulate pairs of entangled particles is at the foundation of many quantum technologies, it is important to understand and evaluate how the principles of quantum physics translate to the survival and security of humanity.
If an individual human is seen as a single atom, is our behavior guided by deterministic laws? How does individual human behavior impact the collective human species? How is an individual representative of how collective systems, whether they be economic to security-based systems, operate?
Acknowledging this emerging reality, Risk Group initiated a much-needed discussion on Strategic Impact of Quantum Physics on Financial Industry with Joseph Firmage, Founder & Chairman at National Working Group on New Physics based in the United States, on Risk Roundup.

Quantum physics, the study of the universe on an atomic scale, gives us a reference model to understand the human ecosystem in the discrete individual unit. It helps us understand how individual human behavior impacts collective systems and the security of humanity.
Metaphorically, we can see this in how a particle can act both like a particle or a wave. The concept of entanglement is at the core of much of applied quantum physics. The commonly understood definition of entanglement says that particles can be generated to have a distinct reliance on each other, despite any three-dimensional or 4-dimensional distance between the particles. What this definition and understanding imply is that even if two or more particles are physically detached with no traditional or measurable linkages, what happens to one still has a quantifiable effect on the other.
Now, individuals and entities across NGIOA are part of an entangled global system. Since the ability to generate and manipulate pairs of entangled particles is at the foundation of many quantum technologies, it is important to understand and evaluate how the principles of quantum physics translate to the survival and security of humanity.
If an individual human is seen as a single atom, is our behavior guided by deterministic laws? How does individual human behavior impact the collective human species? How is an individual representative of how collective systems, whether they be economic to security-based systems, operate?
Acknowledging this emerging reality, Risk Group initiated a much-needed discussion on Strategic Impact of Quantum Physics on Financial Industry with Joseph Firmage, Founder & Chairman at National Working Group on New Physics based in the United States, on Risk Roundup.

source and credits: forbes

Thursday, 16 May 2019

What made our universe what it is today: A Mumbai-based cosmologist finds out

Snehal Fernandes · 06-May-2019
A multinational team of astronomers, led by a Mumbai-based scientist, has solved a long-standing cosmic puzzle: How many years after the Big Bang did the universe achieve conditions that determined and eventually led to the universe we see around us today? The seven-member team, including 35-year-old theoretical physicist Girish Kulkarni from the Tata Institute of Fundamental Research (TIFR), Mumbai, found that the universe finished heating up 12.7 billion years ago by a process called reionisation that occurred due to light from young stars formed in the first galaxies. That’s 1.1 billion years after Big Bang. The paper was published in the April issue of the Monthly Notices of the Royal Astronomical Society, London. “Reionisation led to the universe we see around us,” said Dr Kulkarni, the paper’s lead author. “Without reionisation, the universe would be dark and cold with temperatures close to absolute zero (–273.15 degrees Celsius). The universe would not be hot as is today. There would be no galaxies or solar systems, and humans would not exist.”
Previous studies had suggested that reionisation occurred much earlier, within one billion years of the Big Bang, the accepted theoretical birth of our universe 13.8 billion years ago.
The ‘reionisation epoch’ is the period of time when ultraviolet light from the first galaxies ionised the gas in deep space, transforming the universe from a neutral to an ionised state in which it remains today. Simply put, ionisation is when an atom or a molecule acquires a negative or positive charge by gaining or losing electrons. An atom thus formed is called an ion. This takes places in combination with other chemical changes. In a neutral state, an atom will have an equal number of protons (positively-charged sub-atomic particles) and negatively-charged electrons.


Researchers said understanding the thermal evolution of the universe since the Big Bang fills a gap in our understanding of the universe’s history. The study findings will also aid future experiments such as the 10-nation Square Kilometre Array (SKA) of which India is a member and which aims to detect neutral hydrogen from the early universe to uncover as-yet-unseen epochs of cosmic evolution.
“Late reionisation is also good news for future experiments that aim to detect the neutral hydrogen which is important to uncover cosmic evolution from the early universe,” Kulkarni said. “The later the reionisation, the easier it will be for experiments such as SKA to succeed.”
Knowing the accurate time of reionisation is important, said researchers, to better understand the formation and characteristics of the first galaxies.
“The findings are very significant,” said George Becker, professor at the department of physics and astronomy, University of California, Riverside, who was not involved in the study and whose research interests include cosmic reionisation. “The authors have shown, for the first time, that reionisation, one of the most significant events in the universe, may have lasted far longer than previously thought. When reionisation occurred carries implications for the properties of the first galaxies.”
Fifty million years after the Big Bang, the universe – mostly made of gas at temperatures a few degrees above absolute zero – was dark, and devoid of bright stars and galaxies. During reionisation, the universe transitioned out of these cosmic dark ages and is today filled with hot and ionised hydrogen gas at a temperature of around 10,000 degrees Celsius.
Hydrogen gas dims light from distant galaxies much like streetlights are dimmed by fog on a winter morning. By observing this dimming of a special type of bright galaxies called quasars, astronomers can study conditions in the early universe.
In the last few years, observations of this specific dimming pattern suggested that this fogginess of the universe varies significantly from one part of the universe to another, but the reason behind these variations was unknown.
To find the cause behind these variations, Kulkarni and his team used state-of-the art computer simulations of intergalactic gas and radiation performed on supercomputers based at universities of Cambridge, Durham and Paris. “We found that variations in fogginess result from large regions full of cold hydrogen gas present in the universe when it was just 1.1 billion years old. This enabled us to pinpoint when reionisation ended,” said Kulkarni, department of theoretical physics, TIFR. “This is how today, 13.8 billion years after the Big Bang, the universe is bathed in light from stars in a variety of galaxies, and the gas is a thousand times hotter.”
Researchers said that the study opens up the way to observe an era in the universe’s past that has not yet been seen byastronomers, and also solves the puzzle of why the universe is so different today as compared to when it was formed.
Professor Abraham Loeb, chair of department of astronomy, and Frank B. Baird Jr. Professor of Science at Harvard University, who was not involved with the study, said the research findings are “important” and “explains consistently several independent observations of the infant universe”.


“The paper demonstrates that the process of reionisation completed about a billion years after the Big Bang, when the universe was 7% of its current age,” said Loeb. “Computer simulations show consistency with measurement of the large variations in the islands of neutral hydrogen as probed through the Lyman-alpha absorption of quasar light, and measurements of the column of free electrons inferred from scattering of the cosmic microwave background.”

Sunday, 12 May 2019

How To Enhance Your Problem-Solving Ability in Physics


Knowing how to solve physics problems is a process that can be learned.

May, 11th 2019

Albert Einstein once said: “The formulation of the problem is often more essential than its solution ... 

How To Enhance Your Problem-Solving Ability in Physics
credits:deposit photos
Former Apple CEO Steve Jobs said, "When you start looking at a problem and it seems really simple, you don’t really understand the complexity of the problem. Then you get into the problem, and you see that it’s really complicated, and you come up with all these convoluted solutions. That’s sort of the middle, and that’s where most people stop… But the really great person will keep on going and find the key, the underlying principle of the problem — and come up with an elegant, really beautiful solution that works."
Solving problems, whether in physics or other disciplines, can be learned. Rafis Abazov on the TopUniversities website promotes the IDEAL methodology for his students: Identify, Define, Examine, Act and Look.
1. Identify the problem - identify the nature of the problem by visualizing the physical situation, and translating the written information in the problem into mathematical variables. Draw a diagram showing the objects, and their motions or interactions. For example, an interaction can be two objects connected by a rope.
2. Define the main elements of the problem - on the diagram, label all the known and unknown information. This allows you to translate between verbal, visual, and mathematical modes and their concrete manifestations of words, pictures, and equations. Be sure to include each item's associated units, this will help you identify what is being solved for.
3. Examine possible solutions - once the physical situation has been visualized and diagrammed, and the numerical information has been extracted from the problem statement, students can either use their background knowledge of physics and physics formulae or else they can seek out that information in class notes, instructional packets, textbooks or online resources.


It sometimes helps to work backward by saying, "I want the answer to Z, but if I knew Y, I could find Z, and if I knew X ... and so forth until you get back to something you are given in the original problem statement.

4. Act on resolving the problem - this often includes working through previous problems that are similar, and observing the solution process. Then, the known information is substituted into the identified formulae to solve for the unknown quantity. Always solve symbolically first before putting in the actual quantities. This allows you to make sure your answer makes sense in the physical world.
5. Look for lessons to be learned - by evaluating the solution process, you can formulate the lessons you've learned so that the next problem-solving project will be more effective.

A Solution in a Dream

Sometimes, other hands are at work in the solving of problems. Take chemist August Kekule's solution to the structure of the benzene molecule, and hence the structure of all aromatic compounds. After long struggling with the problem, Kekule took a nap. He dreamed of a snake that was swallowing its own tail, and he awoke with the realization that the shape of the benzene molecule was a ring.

Tuesday, 7 May 2019

Quantum computing with graphene plasmons


Quantum computing with graphene plasmons
Schematic of a graphene-based two-photon gate. Credit: University of Vienna, created by Thomas Rögelsperger
A novel material that consists of a single sheet of carbon atoms could lead to new designs for optical quantum computers. Physicists from the University of Vienna and the Institute of Photonic Sciences in Barcelona have shown that tailored graphene structures enable single photons to interact with each other. The proposed new architecture for quantum computer is published in the recent issue of npj Quantum Information.
Photons barely interact with the environment, making them a leading candidate for storing and transmitting  information. This same feature makes it especially difficult to manipulate information that is encoded in photons. In order to build a photonic quantum computer, one  must change the state of a second. Such a device is called a quantum logic gate, and millions of  will be needed to build a quantum computer. One way to achieve this is to use a so-called '' wherein two photons interact within the material. Unfortunately, standard nonlinear materials are far too inefficient to build a quantum logic gate.
It was recently realized that nonlinear interactions can be greatly enhanced by using plasmons. In a , light is bound to electrons on the surface of the material. These electrons can then help the photons to interact much more strongly. However, plasmons in standard materials decay before the needed quantum effects can take place.
In their new work, the team of scientists led by Prof. Philip Walther at the University of Vienna propose to create plasmons in graphene. This 2-D material discovered barely a decade ago consists of a single layer of carbon atoms arranged in a honeycomb structure, and, since its discovery, it has not stopped surprising us. For this particular purpose, the peculiar configuration of the electrons in graphene leads to both an extremely strong nonlinear interaction and plasmons that live for an exceptionally long time.
Quantum computing with graphene plasmons
Schematic of a graphene-based two-photon gate. Credit: University of Vienna, created by Thomas Rögelsperger
In their proposed graphene quantum logic gate, the scientists show that if single plasmons are created in nanoribbons made out of graphene, two plasmons in different nanoribbons can interact through their electric fields. Provided that each plasmon stays in its ribbon multiple  can be applied to the plasmons which is required for quantum computation. "We have shown that the strong nonlinear interaction in graphene makes it impossible for two plasmons to hop into the same ribbon," says Irati Alonso Calafell, first author of the study.
Their proposed scheme makes use of several unique properties of graphene, each of which has been observed individually. The team in Vienna is currently performing experimental measurements on a similar -based system to confirm the feasibility of their gate with current technology. Since the gate is naturally small, and operates at room temperature it should readily lend itself to being scaled up, as is required for many quantum technologies.
source and credits: phys.org
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