Jack Grealish – Favourite moment of my career

first_imgJack Grealish scored in Aston Villa’s 4-2 win against Birmingham on Sunday and described the goal as the best moment of his career.Aston Villa were trailing at home to Birmingham by the 28th minute, but a quick double in the 37th and 39th minute saw the hosts lead 2-1 going into halftime, and Grealish found the net with a header for the second goal.“Ever since I was a little kid at school, these were the games I dreamed of playing in and I am lucky enough to play in it,” Grealish told Sky Sports.Aston Villa explains why they spent so much money on players Manuel R. Medina – September 6, 2019 According to Aston Villa’s chief executive, the team needed to spend £144.5 million on 12 players in order to stay competitive.“But to score just brings it to another level and it is probably the favorite moment of my career so far.“I do not even think I have scored a header in my life, but Albert [Adomah] put a great ball in at the back stick and I could not miss really. When it went in I was over the moon.”last_img read more

Our Universe A Quantum Loop

first_img Explore further The best of both worlds: How to solve real problems on modern quantum computers The universe, says Ashtekar, acts in much the same way. The pre-universe collapses-in on itself. However, a new kind of repulsive force comes into play because of the quantum properties of the geometry itself. “No matter how heavy, how much mass,” says Ashtekar, “this repulsive force still wins out. When the universe reached a point of high Planck density, [named after Max Planck, the founder of quantum mechanics] the repulsive force bounced it out.” Ashtekar’s team created the first detailed calculations that show classical behavior in the universe before the epoch of the Big Bang. “This is the time when quantum physics and relativity must be combined, and at this point the new physics causes a Big Bounce. And we find the equations that tell us that before this Big Bounce, there was a classical universe.”While different scenarios abound as to what is on the other side of the Big Bang, no one had definitively predicted a classical universe. “The fact that there is a classical universe on the other side of the bounce, rather than a sort of quantum foam in which the space-time geometry fizzles out, was so surprising to us that we had to run more tests for several months to make sure it wasn’t a fluke. And the result was robust.”Ashtekar does admit one limitation to the equations on which this idea is based: “We start by assuming that the universe is homogeneous and isotropic. It is an approximation done in cosmology, even though we know that the universe is not exactly like that. So the question is how to make the model more and more realistic. And this is an ongoing work.”“All of this offers a solution to long-standing problems,” says Ashtekar. “We can show that spacetime was classical before the Big Bounce, and became classical again surprisingly close to after the bounce. We showed that there is no quantum foam on the other side, but that there is a classical branch connected by quantum geometry. And the coherence of these results shows that quantum geometry effects play a crucial role in understanding the true nature of the Big Bang.”Ashtekar also adds that this work, as he and his colleagues continue to probe the Big Bounce and work toward overcoming the limitations of their equations and models, will contribute to better understanding quantum gravity, and developing a more complete theory. “Our work has some essential features of a theory of quantum gravity,” he says. “It gives us confidence in our underlying ideas.”By Miranda Marquit, Copyright 2006 PhysOrg.com Citation: Our Universe: A Quantum Loop (2006, April 25) retrieved 18 August 2019 from https://phys.org/news/2006-04-universe-quantum-loop.html Ashtekar’s team from Pennsylvania State University’s Institute for Gravitational Physics and Geometry published a Letter in Physical Review Letters on April 12th, detailing what was found, and shedding a little more light on what actually happened at the time the universe began expanding.“The idea of a bounce has been around for a while,” Ashtekar explains to PhysOrg.com, “and it has been looked at in many contexts. One of them is String Theory.” He continues: “The pre-Big Bang cosmology considered the idea that a branch of the universe existed before the Big Bang, and in the Ekpyrotic scenario, a `brane’ collides with another `brane,’ causing a bounce.”What makes the PSU explanation different, says Ashtekar, is the fact that while it was assumed that there might possibly be something before the Big Bang, a systematic determination of what that might have been was missing. Additionally, “one never had systematic equations that are determinate, leading from the pre- to post-Big Bang branches of the universe.”Ashtekar and his colleagues use Einstein’s quantum equations from Loop Quantum Gravity (LQG), an approach to the unification of general relativity and quantum physics. LQG does not presuppose the existence of a space-time continuum. Ashtekar and his fellow team members find that quite likely there is a classical universe, one that looks and behaves pretty much like our currently universe, on the other side of the Big Bang, which he describes as more of a Big Bounce. In these classical universes, spacetime is a continuum and Einstein’s theory of general relativity is mostly accurate. But between these two classical universes, Ashtekar says, is a point at which general relativity doesn’t apply. “We know that on the quantum level the theory of general relativity breaks down,” he explains, “and this quantum bridge, which lasts for such a small period of `time,’ connects the two branches of the universe.”Using the collapse of stars as an example, Ashtekar explains how the pre-Big Bang universe retracted and became smaller until it bounced out and began expanding again in what we recognize as our universe: “Stars like our sun are in equilibrium. There is a radiation that push outward against gravity, which tries to collapse. When the star runs out of fuel, the radiation reduces, and there is nothing to stop the collapse. For stars with three times the mass of our sun or less, when it gets to a certain point, the neutrons repulse each other and they become neutron stars or pulsars.” He pauses and then continues to explain that in larger stars, stars with more than three times the mass of our sun, the crushing gravity causes the star to continue its collapse, becoming a black hole. “The forces of nature, which we understand well, just aren’t enough to stop that collapse.” “There are two classical branches of the universe connected by a quantum bridge. This connects the former collapse with the current expansion.” While Abhay Ashtekar and his colleagues, Tomasz Pawlowski and Parampreet Singh, may not have come with a completely new theory, what they have done is create a systematic way, through quantum equations, to look back in time to the birth of our current universe. This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.last_img

Researchers demonstrate entanglement of two quantum bits inside of a semiconductor

first_img This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. Citation: Researchers demonstrate entanglement of two quantum bits inside of a semiconductor (2012, April 13) retrieved 18 August 2019 from https://phys.org/news/2012-04-entanglement-quantum-bits-semiconductor.html Large scale qubit generation for quantum computing © 2012 Phys.Org Explore further (Phys.org) — Research into quantum bits (qubits) for use in a quantum computer has become tied to entanglement, the still mysterious phenomenon whereby subatomic particles exist in an entangled state such that any change to one happens simultaneously to the other, without communication or the passage of time. The reason entanglement of qubits is so important to the future of a quantum computer is because they are able to represent both a “1” and “0” state at the same time and because actions that cause a change in one entangled particle also cause the same change in its partner, theoretically allowing for processing speeds to increase exponentially when adding more entangled qubits. Thus far though, attempts to create entangled particles inside of a semiconductor material have been difficult to measure, and thus verify, due to their short lives. Journal information: Science Now however, a small group of researchers from Harvard University has succeeded in entangling two quantum bits inside of a semiconductor and holding on to them long enough for them to be measured. They describe how they achieved this feat in their paper published in the journal Science.In essence the team overcame the inherent instability of entangled pairs by adding a second electron to the qubits in the semiconducting material which would allow them to be defined by their spin states; doing so they write, added a second level of immunity from decoherence, where the qubit reverts to either a “0” or a “1” after a very short period of time. To cause the actual entanglement, all that was needed was an electrical charge. To make sure that what they thought was happening inside the material truly was, they measured the sample using state tomography.This experiment shows that creating entangled pairs inside of a material such as the semiconductor used, is no more difficult than doing so with such techniques as manipulating calcium atoms in a laser ion trap, the trick though has been to get them to hold their state long enough to be measured, and that’s what this team has achieved. It also demonstrates a process that the team says could be scaled up, a very important element in building a quantum computer. But this of course, just a first step towards building a quantum computer because entangled pairs of qubits would need to be lined up some distance apart from one another to allow for the construction of circuits. Thus far the team has entangled qubits just a few hundred nanometers apart, the goal is to reach at least a micron. More information: Demonstration of Entanglement of Electrostatically Coupled Singlet-Triplet Qubits, Science 13 April 2012: Vol. 336 no. 6078 pp. 202-205. DOI: 10.1126/science.1217692ABSTRACTQuantum computers have the potential to solve certain problems faster than classical computers. To exploit their power, it is necessary to perform interqubit operations and generate entangled states. Spin qubits are a promising candidate for implementing a quantum processor because of their potential for scalability and miniaturization. However, their weak interactions with the environment, which lead to their long coherence times, make interqubit operations challenging. We performed a controlled two-qubit operation between singlet-triplet qubits using a dynamically decoupled sequence that maintains the two-qubit coupling while decoupling each qubit from its fluctuating environment. Using state tomography, we measured the full density matrix of the system and determined the concurrence and the fidelity of the generated state, providing proof of entanglement.last_img read more

Ready for Microsofts Vista

first_imgNovember 1, 2006 4 min read Microsoft’s Vista promises to be the next big thing in Windows computing–literally. Will your PC be PC enough for Vista when it drops a few weeks from now? If not, AMD and Intel might be able to brighten your holidays. They’ve begun shipping a new generation of more powerful dual-core processors, forcing bone-deep price cuts on “old” dual-cores and Pentium-class chips.Just about any new computer will run Vista Starter or Basic now. Less clear is how much PC you’ll need to make the most of the new Windows. It depends on how graphical you want to be. Will you run the 3-D Aero “glass” interface? Make VoIP calls? Create a video blog? Watch TV on your PC? The extra vroom needed might still fit your budget.The long run-up to Vista has been hard on people who sell PCs–but great for people who buy them. Sales have languished for most of the year with a corresponding buildup in chip inventories and softening in prices. Intel and AMD finally began slashing 40 percent or more off first-generation dual-core prices last quarter to make room for a new dual-core generation.Competition being what it is, most of those savings get passed on to PC buyers as a mix of lower prices and hardware improvements. As recent corporate earning releases show, PC sellers have been giving away margin until it hurts.But lucky for Microsoft, hardware companies are playing through the pain. It starts with Intel and AMD, who can’t seem to stop one-upping each other with ever-faster and cooler chips. Intel’s new Core 2 Duo family forces deep price cuts in first-generation Core Duos that haven’t even had time to lose that new-chip smell. And the long-running Pentium line? That’s over. AMD’s new AM2 platform has a less dramatic debut–primarily, bringing DDR2 and other memory innovations to the midrange Athlon 64 X2 and top-of-the-line Athlon 64 FX-62. State of ReadinessAt first glance, Vista’s hardware requirements don’t sound that onerous–an 800MHz CPU for basic versions, a 1GHz engine for the Aero interface. Vendors haven’t sold PCs that slow in years, although millions are still out there, doing their jobs faithfully every day. But it’s not enough just to run Windows. You also need enough PC for bigger, better software versions–starting with Microsoft Office.It’s odd that clock speed is emphasized, because memory is much more important. Figure on a full gigabyte of system memory to be “Vista Ready” for Aero–and better make that DDR2 memory. Also, choose a processor with as much cache memory behind as wide a front-side bus as you can afford. Get at least 1MB of L2 cache–2MB would be better–and 4MB would put snap in your apps. And pick a graphics adapter with at least 128MB dedicated video memory.The impact can be seen in recent performance tests where Intel’s second-generation Core 2 Duo processor did 40 percent more work running at 2.66GHz than a first-generation dual core did at 3.6GHz. Either of the twin engines in Core 2 Duo can tap the full 4MB of cache they share as needed, but each first-generation dual-core engine is limited to 2MB. Core 2 Duo’s engines also benefit from a one-third wider front-side bus to memory and other efficiencies in Intel’s new Core microarchitecture.But these improvements sure complicate shopping. You can depend on vendors to label which Windows XP systems they’re selling today are Vista Ready or Vista Capable. But to get the most for your money, you may need to weigh two or three different options in each of the memory categories.PC vendors have been blowing out last-generation models and filling their price points with new, more powerful configurations up and down the product line. For example, at this writing, Dell’s cheapest Core 2 Duo model was packed with 1GB DDR2, 4MB L2, a 1066MHz FSB and nVidia Geforce video with 256MB. Price: $1,600–including a 20-inch flat panel!There’s just a lot more PC under the average price tag now. And Vista? Not a problem–at least, not for new PCs.Mike Hogan is Entrepreneur’s technology editor. Free Webinar | Sept 5: Tips and Tools for Making Progress Toward Important Goalscenter_img Attend this free webinar and learn how you can maximize efficiency while getting the most critical things done right. This story appears in the November 2006 issue of Entrepreneur. Subscribe » Register Now »last_img read more