I am a mariner of Odysseus with heart of fire but with mind ruthless and clear

Archive for August, 2010|Monthly archive page

Where are the Missing Neutron Galaxies of the Early Universe?

In astronomy on August 4, 2010 at 3:16 pm

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Ultradense cosmic cannonballs used to tear around the universe, punching through regular galaxies like a bullet through candyfloss, going their own way and heaven help whatever got in their way – and scientists don’t know where they are now.  Luckily this is cosmology, not cinema, or the answer would be “Right behind you!”

Because of the speed of light, staring into space is essentially looking back in time, and scientists have seen ultra-intense galaxies zipping around the first five billion years of existence.  Similar in principle to the intense density of neutron stars ( a collapsed star with a core so dense that a single spoonful would weigh 200 billion pounds) these galaxies were a thousand times denser than regular star-scatterings, packing as much mass as the Milky Way into 0.1% of the volume and far before regular galaxies had time to form.

Scientists suspect that these objects collapsed directly from vast clouds of proto-star material, unlike regular galaxies which form by multiple mergers of smaller galaxies.  But more important than where they came from is finding out where they went.  Three hundred billion stars isn’t the kind of thing you lose down the back of the sofa.

It’s unlikely they merged with other galaxies, since they’d punch through regular star collections like an armor-piercing round with only minimal effects on themselves, and collision with another ultra-dense galaxy would only create an even bigger wildly intense star selection.  Other processes which could hide them, such as building up a diffuse gas cloud or expanding due to stellar detonations, would seem to take longer than the universe has actually had so far.  Despite being awesome.

Space.  Every time we look there’s something cooler.

On the path to quantum computers: Ultra-strong interaction between light and matter realized

In Uncategorized on August 2, 2010 at 3:25 pm

July 30, 2010One more step on the path to quantum computers

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This is an impression of the interaction between a superconducting electrical circuit and a microwave photon. Credit: Dr. A. Marx, Technische Universitaet Muenchen

Researchers around the world are working on the development of quantum computers that will be vastly superior to present-day computers. Here, the strong coupling of quantum bits with light quanta plays a pivotal role. Professor Rudolf Gross, a physicist at the Technische Universitaet Muenchen, Germany, and his team of researchers have now realized an extremely strong interaction between light and matter that may represent a first step in this direction.

The interaction between matter and  represents one of the most fundamental processes in physics. Whether a car that heats up like an oven in the summer due to the absorption of light quanta or  that extract electricity from light or light-emitting diodes that convert electricity into light, we encounter the effects of these processes throughout our daily lives. Understanding the interactions between individual  – photons – and atoms is crucial for the development of a quantum computer.

Physicists from the Technische Universitaet Muenchen (TUM), the Walther-Meissner-Institute for Low Temperature Research of the Bavarian Academy of Sciences (WMI) and the Augsburg University have now, in collaboration with partners from Spain, realized an ultrastrong interaction between microwave photons and the atoms of a nano-structured circuit. The realized interaction is ten times stronger than levels previously achieved for such systems.

The simplest system for investigating the interactions between light and is a so-called cavity resonator with exactly one light particle and one atom captured inside (cavity quantum electrodynamics, cavity QED). Yet since the interaction is very weak, these experiments are very elaborate. A much stronger interaction can be obtained with nano-structured circuits in which metals like aluminum become superconducting at temperatures just above absolute zero (circuit QED). Properly configured, the billions of atoms in the merely nanometer thick conductors behave like a single artificial atom and obey the laws of quantum mechanics. In the simplest case, one obtains a system with two energy states, a so-called quantum bit or qubit.

Coupling these kinds of systems with microwave resonators has opened a rapidly growing new research domain in which the TUM Physics, the WMI and the cluster of excellence Nanosystems Initiative Munich (NIM) are leading the field. In contrast to cavity QED systems, the researchers can custom tailor the circuitry in many areas. 

One more step on the path to quantum computers

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This is an electron microscopical picture of the superconducting circuit (red: Aluminum-Qubit, grey: Niob-Resonator, green: Silicon substrate). Credit: Thomasz Niemczyk, Technische Universitaet Muenchen

To facilitate the measurements, Professor Gross and his team captured the photon in a special box, a resonator. This consists of a superconducting niobium conducting path that is configured with strongly reflective “mirrors” for microwaves at both ends. In this resonator, the artificial atom made of an aluminum circuit is positioned so that it can optimally interact with the photon. The researchers achieved the ultrastrong interactions by adding another superconducting component into their circuit, a so-called Josephson junction.

The measured interaction strength was up to twelve percent of the resonator frequency. This makes it ten times stronger than the effects previously measureable in circuit QED systems and thousands of times stronger than in a true cavity resonator. However, along with their success the researchers also created a new problem: Up to now, the Jaynes-Cummings theory developed in 1963 was able to describe all observed effects very well. Yet, it does not seem to apply to the domain of ultrastrong interactions. “The spectra look like those of a completely new kind of object,” says Professor Gross. “The coupling is so strong that the atom-photon pairs must be viewed as a new unit, a kind of molecule comprising one atom and one photon.

Experimental and theoretical physicists will need some time to examine this more closely. However, the new experimental inroads into this domain are already providing researchers with a whole array of new experimental options. The targeted manipulation of such atom-photon pairs could hold the key to quanta-based information processing, the so-called quantum computers that would be vastly superior to today’s computers
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Has Life Spread Virally Through the Universe?

In astronomy, evolution, extraterrestrial on August 2, 2010 at 3:05 pm

Life originated in a nebular cloud, over 10 billion years ago, but may have had multiple origins in multiple locations, including in galaxies older than the Milky Way according to Rudolf Schild of Harvard-Smithsonian Center for Astrophysics and Rhawn Joseph of the Brain Research Laboratory. Multiple origins, they believe, could account for the different domains of life: archae, bacteria, eukaryotes.

The first steps toward life may have been achieved when self-replicating nano-particles initially comprised of a mixture of carbon, calcium, oxygen, hydrogen, phosphorus, sugars, and other elements and gasses were combined and radiated, forming a nucleus around which a lipid-like permeable membrane was established, and within which DNA-bases were laddered together with phosphates and sugars; a process which may have taken billions of years.

DNA-based life, they propose, may be a “cosmic imperative” such that life can only achieve life upon acquiring a DNA genome. Alternatively, the “Universal Genetic Code” may have won out over inferior codes through natural selection. When the first microbe evolved, it immediately began multiplying and spreading throughout the cosmos via panspermia carried by solar winds, Bolide impact, comets, ejection of living planets prior to supernova which are then captured by a newly forming solar system, galactic collisions and following the exchange of stars between galaxies.

Bacteria, archae, and viruses, act as intergalactic genetic messengers, acquiring genes from and transferring genes to life forms dwelling on other planets. Viruses also serve as gene depositories, storing vast numbers of genes which may be transferred to archae and bacteria depending on cellular needs. The acquisition of these genes from the denizens of other worlds, enables prokaryotes and viruses to immediately adapt to the most extreme environments, including those that might be encountered on other planets.

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Whether the universe was created by a Big Bang Universe or an Eternal Infinite Universe, once life was established it began to evolve. Archae, bacteria, and viruses may have combined and mixed genes, fashioning the first multi-cellular eukaryote which continued to evolve. Initially, evolution on Earth-like planets was random and dictated by natural selection. Over time, increasingly complex and intelligent species evolved through natural selection whereas inferior competitors became extinct. However, their genes were copied by archae, bacteria, and viruses. If the first steps toward life in this galaxy began 13.6 billion years ago, then using Earth as an example, intelligent life might have evolved within this galaxy by 9 billion years ago. As life continued to spread throughout the cosmos, and as microbes and viruses were cast from world to world, genes continued to be exchanged via horizontal gene transfer and copies of genes coding for advanced and complex characteristics were acquired from and transferred to eukaryotes and highly evolved intelligent life.

Eventually descendants of these microbes, viruses, and their vast genetic libraries, fell to the new born Earth. The innumerable genes stored and maintained in the genomes of these viruses, coupled with prokaryote genes and those transferred to eurkaryotes, made it possible to biologically modify and terraform new Earth, and in so doing, some of these genes, now within the eurkaryote genome, were activated and expressed, replicating various species which had evolved on other worlds. Genes act on genes, and genes act on the environment and the altered environment activates and inhibits gene expression, thereby directly influencing the evolution of species.

On Earth, Schild and Joseph conclude, “the progression from simple cell to sentient intelligent being is due to the activation of viral, archae, and bacteria genes acquired from extra-terrestrial life and inserted into the Earthly eukaryote genome. What has been described as a random evolution is in fact the metamorphosis and replication of living creatures which long ago lived on other planets.”

Jason McManus via Journal of Cosmology