... newer stories
Mittwoch, 6. April 2011
Rechnen mit 14 Quantenbits
klauslange,00:12h
Einen neuen Weltrekord mit einem Register aus verschränkten Quantenbits haben Forscher aufgestellt, wie scinexx berichtet: hier.
Zitat:
Weltrekord: 14 Quantenbits
Die Physiker um Blatt halten seit 2005 den Rekord für die Anzahl von verschränkten Quantenbits, die in einem Experiment realisiert wurden. Bis heute ist es niemand anderem gelungen, acht Teilchen auf kontrollierte Art und Weise zu verschränken und damit ein „Quantenbyte“ zu erzeugen.
Nun haben die Innsbrucker Wissenschaftler diesen Rekord noch einmal beinahe verdoppelt. In einer Ionenfalle haben sie 14 Kalziumatome gefangen, die sie, einem Quantenprozessor gleich, mit Laserlicht manipulieren. Interne Zustände jedes Atoms bilden dabei einzelne Quantenbits, zusammen entsteht ein Quantenregister mit 14 Recheneinheiten. Dieses bildet das Herzstück eines zukünftigen Quantencomputers.
Die Innsbrucker Physiker stellten aber auch fest, dass bei ihnen die Störungsempfindlichkeit nicht wie meist angenommen linear sondern mit der Anzahl der Teilchen quadratisch zunimmt. Werden mehrere Teilchen verschränkt, steigt die Empfindlichkeit deshalb stark an. „Dies wird als Superdekohärenz bezeichnet“, sagt Monz. „In der Quanteninformation wurde dieses Phänomen bisher kaum wahrgenommen.“ Es hat nicht nur für den Bau von Quantencomputern Bedeutung, sondern auch bei der Konstruktion sehr genauer Atomuhren oder für Quantensimulationen.
Zitat:
Weltrekord: 14 Quantenbits
Die Physiker um Blatt halten seit 2005 den Rekord für die Anzahl von verschränkten Quantenbits, die in einem Experiment realisiert wurden. Bis heute ist es niemand anderem gelungen, acht Teilchen auf kontrollierte Art und Weise zu verschränken und damit ein „Quantenbyte“ zu erzeugen.
Nun haben die Innsbrucker Wissenschaftler diesen Rekord noch einmal beinahe verdoppelt. In einer Ionenfalle haben sie 14 Kalziumatome gefangen, die sie, einem Quantenprozessor gleich, mit Laserlicht manipulieren. Interne Zustände jedes Atoms bilden dabei einzelne Quantenbits, zusammen entsteht ein Quantenregister mit 14 Recheneinheiten. Dieses bildet das Herzstück eines zukünftigen Quantencomputers.
Die Innsbrucker Physiker stellten aber auch fest, dass bei ihnen die Störungsempfindlichkeit nicht wie meist angenommen linear sondern mit der Anzahl der Teilchen quadratisch zunimmt. Werden mehrere Teilchen verschränkt, steigt die Empfindlichkeit deshalb stark an. „Dies wird als Superdekohärenz bezeichnet“, sagt Monz. „In der Quanteninformation wurde dieses Phänomen bisher kaum wahrgenommen.“ Es hat nicht nur für den Bau von Quantencomputern Bedeutung, sondern auch bei der Konstruktion sehr genauer Atomuhren oder für Quantensimulationen.
... link (0 Kommentare) ... comment
Dienstag, 5. April 2011
Sechsten Symmetrietyp gefunden?
klauslange,00:10h
Davon berichtet zumindest science daily: hier.
Zitat:
Before the publication of this paper, scientists and engineers had five different types of symmetries to use as tools for understanding the structures of materials whose building blocks are arranged in fairly regular patterns. Four types of symmetries had been known for thousands of years -- called rotation, inversion, rotation inversion, and translation -- and a fifth type -- called time reversal -- had been discovered about 60 years ago. Now, Gopalan and Litvin have added a new, sixth, type, called rotation reversal. As a result, the number of known ways in which the components of such crystalline materials can be combined in symmetrical ways has multiplied from no more than 1,651 before to more than 17,800 now. "We mathematically combined the new rotation-reversal symmetry with the previous five symmetries and now we know that symmetrical groups can form in crystalline materials in a much larger number of ways," said Daniel B. Litvin, distinguished professor of physics, who coauthored the study with Venkatraman Gopalan, professor of materials science and engineering.
The new rotation-reversal symmetry enriches the mathematical language that researchers use to describe a crystalline material's structure and to predict its properties. "Rotation reversal is an absolutely new approach that is different in that it acts on a static component of the material's structure, not on the whole structure all at once," Litvin said. "It is important to look at symmetries in materials because symmetry dictates all natural laws in our physical universe."
The most simple type of symmetry -- rotation symmetry -- is obvious, for example, when a square shape is rotated around its center point: the square shows its symmetrical character by looking exactly the same at four points during the rotation: at 90 degrees, 180 degrees, 270 degrees, and 360 degrees. Gopalan and Litvin say their new rotation-reversal symmetry is obvious, as well, if you know where to look.
The "eureka moment" of the discovery occurred when Gopalan recognized that the simple concept of reversing the direction of a spiral-shaped structure from clockwise to counterclockwise opens the door to a distinctly new type of symmetry. Just as a square shape has the quality of rotation symmetry even when it is not being rotated, Gopalan realized that a spiral shape has the quality of rotation-reversal symmetry even when it is not being physically forced to rotate in the reverse direction. Their further work with this rotation-reversal concept revealed many more structural symmetries than previously had been recognized in materials containing various types of directionally oriented structures. Many important biological molecules, for example, are said to be either "right handed" or "left handed," including DNA, sugars, and proteins.
"We found that rotation-reversal symmetry also exists in paired structures where the partner components lean toward each other, then away from each other in paired patterns symmetrically throughout a material," Gopalan said. These "tilting octahedral" structures are common in a wide variety of crystalline materials, where all the component structures are tightly interconnected by networks of shared atoms. The researchers say it is possible that components of materials with rotation-reversal symmetry could be engineered to function as on/off switches for a variety of novel applications.
The now-much-larger number of possible symmetry groups also is expected to be useful in identifying materials with unusual combinations of properties. "For example, the goal in developing a ferroelectric ferromagnet is to have a material in which the electrical dipoles and the magnetic moments coexist and are coupled in the same material -- that is, a material that allows electrical control of magnetism -- which would be very useful to have in computers," Gopalan said. The addition of rotation-reversal symmetry to the materials-science toolbox may help researchers to identify and search for structures in materials that could have strong ferroelectric and ferromagnetic properties.
Zitat:
Before the publication of this paper, scientists and engineers had five different types of symmetries to use as tools for understanding the structures of materials whose building blocks are arranged in fairly regular patterns. Four types of symmetries had been known for thousands of years -- called rotation, inversion, rotation inversion, and translation -- and a fifth type -- called time reversal -- had been discovered about 60 years ago. Now, Gopalan and Litvin have added a new, sixth, type, called rotation reversal. As a result, the number of known ways in which the components of such crystalline materials can be combined in symmetrical ways has multiplied from no more than 1,651 before to more than 17,800 now. "We mathematically combined the new rotation-reversal symmetry with the previous five symmetries and now we know that symmetrical groups can form in crystalline materials in a much larger number of ways," said Daniel B. Litvin, distinguished professor of physics, who coauthored the study with Venkatraman Gopalan, professor of materials science and engineering.
The new rotation-reversal symmetry enriches the mathematical language that researchers use to describe a crystalline material's structure and to predict its properties. "Rotation reversal is an absolutely new approach that is different in that it acts on a static component of the material's structure, not on the whole structure all at once," Litvin said. "It is important to look at symmetries in materials because symmetry dictates all natural laws in our physical universe."
The most simple type of symmetry -- rotation symmetry -- is obvious, for example, when a square shape is rotated around its center point: the square shows its symmetrical character by looking exactly the same at four points during the rotation: at 90 degrees, 180 degrees, 270 degrees, and 360 degrees. Gopalan and Litvin say their new rotation-reversal symmetry is obvious, as well, if you know where to look.
The "eureka moment" of the discovery occurred when Gopalan recognized that the simple concept of reversing the direction of a spiral-shaped structure from clockwise to counterclockwise opens the door to a distinctly new type of symmetry. Just as a square shape has the quality of rotation symmetry even when it is not being rotated, Gopalan realized that a spiral shape has the quality of rotation-reversal symmetry even when it is not being physically forced to rotate in the reverse direction. Their further work with this rotation-reversal concept revealed many more structural symmetries than previously had been recognized in materials containing various types of directionally oriented structures. Many important biological molecules, for example, are said to be either "right handed" or "left handed," including DNA, sugars, and proteins.
"We found that rotation-reversal symmetry also exists in paired structures where the partner components lean toward each other, then away from each other in paired patterns symmetrically throughout a material," Gopalan said. These "tilting octahedral" structures are common in a wide variety of crystalline materials, where all the component structures are tightly interconnected by networks of shared atoms. The researchers say it is possible that components of materials with rotation-reversal symmetry could be engineered to function as on/off switches for a variety of novel applications.
The now-much-larger number of possible symmetry groups also is expected to be useful in identifying materials with unusual combinations of properties. "For example, the goal in developing a ferroelectric ferromagnet is to have a material in which the electrical dipoles and the magnetic moments coexist and are coupled in the same material -- that is, a material that allows electrical control of magnetism -- which would be very useful to have in computers," Gopalan said. The addition of rotation-reversal symmetry to the materials-science toolbox may help researchers to identify and search for structures in materials that could have strong ferroelectric and ferromagnetic properties.
... link (0 Kommentare) ... comment
Sonntag, 3. April 2011
Sensationelle Papstaussage im neuen Buch
klauslange,22:21h
Am 31.März beendete ich die Lektüre des neuen Papstbuches zu Jesus von Nazareth - Band II -. Darin macht Benedikt XVI. eine sensationelle Aussage, die sich genau mit dem beschäftigt und stützt, was auch Michael König in seinem Urwort - Buch herausstellt.
Damit dies niemand für einen Aprilscherz hält, habe ich bis heute mit meiner Vorankündigung gewartet:
Ich werde demnächst im Blog 'Evolution und Schöpfung' ausführlich auf diese Passage eingehen und deren wissenschaftliche Bedeutung im Lichte der Urwort - Theorie erörtern.
Dazu braucht es aber eine gewisse Zeit, daher heute nur ersteinmal diese Vorwarnung.
Übrigens hat m.W. bis heute diese gefundene Passage noch niemand herausgestellt. Ich denke, um ihren sensationellen Gehalt erkennen zu können, muss man Michael Königs Buch verinnerlicht haben. Leider scheint es mir so, dass die Schnittmenge der Leser von König und der Leser vom neuen Papstbuch recht gering ist. Später mehr dazu: Stay tuned...!
Damit dies niemand für einen Aprilscherz hält, habe ich bis heute mit meiner Vorankündigung gewartet:
Ich werde demnächst im Blog 'Evolution und Schöpfung' ausführlich auf diese Passage eingehen und deren wissenschaftliche Bedeutung im Lichte der Urwort - Theorie erörtern.
Dazu braucht es aber eine gewisse Zeit, daher heute nur ersteinmal diese Vorwarnung.
Übrigens hat m.W. bis heute diese gefundene Passage noch niemand herausgestellt. Ich denke, um ihren sensationellen Gehalt erkennen zu können, muss man Michael Königs Buch verinnerlicht haben. Leider scheint es mir so, dass die Schnittmenge der Leser von König und der Leser vom neuen Papstbuch recht gering ist. Später mehr dazu: Stay tuned...!
... link (3 Kommentare) ... comment
Samstag, 2. April 2011
Ausführliches Interview mit Dr. Michael König
klauslange,18:19h
... link (0 Kommentare) ... comment
Largest Black Holes
klauslange,17:44h
... link (0 Kommentare) ... comment
Donnerstag, 31. März 2011
'Survival of the fittest' nicht allgemeingültig
klauslange,00:34h
Eine der Hauptlehrsätze der darwinschen Evolution ist jener vom Überleben der Bestangepassten in einer gegebenen Umgebung. In 'Nature' wurde nun ein Artikel veröffentlicht, dass diese Behauptung eindrücklich anhand von Bakterienkulturen zu widerlegen in der Lage ist: Evolution: Not Only the Fittest Survive
Zitat:
Conventional wisdom has it that for any given niche there should be a best species, the fittest, that will eventually dominate to exclude all others.
This is the principle of survival of the fittest. Ecologists often call this idea the `competitive exclusion principle' and it predicts that complex environments are needed to support complex, diverse populations.
Professor Robert Beardmore, from the University of Exeter, said: "Microbiologists have tested this principle by constructing very simple environments in the lab to see what happens after hundreds of generations of bacterial evolution, about 3,000 years in human terms. It had been believed that the genome of only the fittest bacteria would be left, but that wasn't their finding. The experiments generated lots of unexpected genetic diversity."
This test tube biodiversity proved controversial when first observed and had been explained away with claims that insufficient time had been allowed to pass for a clear winner to emerge.
The new research shows the experiments were not anomalies.
Professor Laurence Hurst, of the University of Bath, said: "Key to the new understanding is the realization that the amount of energy organisms squeeze out of their food depends on how much food they have. Give them abundant food and they use it inefficiently. When we combine this with the notion that organisms with different food-utilizing strategies are also affected in different ways by genetic mutations, then we discover a new principle, one in which both the fit and the unfit coexist indefinitely."
Dr Ivana Gudelj, also from the University of Exeter, said: "The fit use food well but they aren't resilient to mutations, whereas the less efficient, unfit consumers are maintained by their resilience to mutation. If there's a low mutation rate, survival of the fittest rules, but if not, lots of diversity can be maintained.
"Rather nicely, the numbers needed for the principle to work accord with those enigmatic experiments on bacteria. Their mutation rate seems to be high enough for both fit and unfit to be maintained."
Zitat:
Conventional wisdom has it that for any given niche there should be a best species, the fittest, that will eventually dominate to exclude all others.
This is the principle of survival of the fittest. Ecologists often call this idea the `competitive exclusion principle' and it predicts that complex environments are needed to support complex, diverse populations.
Professor Robert Beardmore, from the University of Exeter, said: "Microbiologists have tested this principle by constructing very simple environments in the lab to see what happens after hundreds of generations of bacterial evolution, about 3,000 years in human terms. It had been believed that the genome of only the fittest bacteria would be left, but that wasn't their finding. The experiments generated lots of unexpected genetic diversity."
This test tube biodiversity proved controversial when first observed and had been explained away with claims that insufficient time had been allowed to pass for a clear winner to emerge.
The new research shows the experiments were not anomalies.
Professor Laurence Hurst, of the University of Bath, said: "Key to the new understanding is the realization that the amount of energy organisms squeeze out of their food depends on how much food they have. Give them abundant food and they use it inefficiently. When we combine this with the notion that organisms with different food-utilizing strategies are also affected in different ways by genetic mutations, then we discover a new principle, one in which both the fit and the unfit coexist indefinitely."
Dr Ivana Gudelj, also from the University of Exeter, said: "The fit use food well but they aren't resilient to mutations, whereas the less efficient, unfit consumers are maintained by their resilience to mutation. If there's a low mutation rate, survival of the fittest rules, but if not, lots of diversity can be maintained.
"Rather nicely, the numbers needed for the principle to work accord with those enigmatic experiments on bacteria. Their mutation rate seems to be high enough for both fit and unfit to be maintained."
... link (0 Kommentare) ... comment
Samstag, 26. März 2011
Neues zur Riemann-Vermutung?
klauslange,20:09h
Nein, um eine neue Ankündigung für einen Beweis der Riemann-Vermutung kann ich nicht liefern, aber eine interessante Meldung zeigt eine neue Art dieses Problem anzugehen.
Die Meldung hier.
Die Meldung hier.
... link (0 Kommentare) ... comment
Mittwoch, 23. März 2011
Journal of Cosmology: Cyber Attacke auf Hoovers Paper
klauslange,23:37h
Eine sehr aufschlussreiche Erklärung hat das JoC zur Entdeckung von Hoover bzgl. Alien-Mikroben in Meteoriten abgegeben. Das Paper kann nicht mehr verlinkt werden, da es per Cyber Attacke sabotiert wird. So werden eben missliebige Meinungen und Forschungsergebnisse bekämpft:
The Hoover Paper and Figures Are Under Cyber Attack
"Robots" have linked to the Hoover Article and the Figures which are being downloaded so often our bandwidth capacity is continually being exceeded, which has put the Journal of Cosmology website repeatedly at risk for being shut down.
We regret we are temporarily unable to host the Hoover article and figures because of this ongoing cyber attack.
The Hoover paper, commentaries, and related chapters also detailing evidence of alien extraterrestrial life, have been bound in an inexpensive book "The Discovery of Alien ExtraTerrestrial life" , and which includes Hoover's discovery and landmark paper, and the discoveries of other independent scientists.
The Hoover Paper and Figures Are Under Cyber Attack
"Robots" have linked to the Hoover Article and the Figures which are being downloaded so often our bandwidth capacity is continually being exceeded, which has put the Journal of Cosmology website repeatedly at risk for being shut down.
We regret we are temporarily unable to host the Hoover article and figures because of this ongoing cyber attack.
The Hoover paper, commentaries, and related chapters also detailing evidence of alien extraterrestrial life, have been bound in an inexpensive book "The Discovery of Alien ExtraTerrestrial life" , and which includes Hoover's discovery and landmark paper, and the discoveries of other independent scientists.
... link (0 Kommentare) ... comment
... older stories