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The leap from our universe to another is theoretically possible, say physicists. And the technology to test the idea is available today
The idea that our universe is embedded in a broader multidimensional space has captured the imagination of scientists and the general population alike.
This notion is not entirely science fiction. According to some theories, our cosmos may exist in parallel with other universes in other sets of dimensions. Cosmologists call these universes braneworlds. And among that many prospects that this raises is the idea that things from our Universe might somehow end up in another.
A couple of years ago, Michael Sarrazin at the University of Namur in Belgium and a few others showed how matter might make the leap in the presence of large magnetic potentials. That provided a theoretical basis for real matter swapping.
Today, Sarrazin and a few pals say that our galaxy might produce a magnetic potential large enough to make this happen for real. If so, we ought to be able to observe matter leaping back and forth between universes in the lab. In fact, such observations might already have been made in certain experiments.
The experiments in question involve trapping ultracold neutrons in bottles at places like the Institut Laue Langevin in Grenoble, France, and the Saint Petersburg Institute of Nuclear Physics. Ultracold neutrons move so slowly that it is possible to trap them using ‘bottles’ made of magnetic fields, ordinary matter and even gravity.
One reason to do this is to measure how quickly the neutrons decay by beta emission. So physicists measure the rate at which the neutrons hit the bottle walls and how quickly this drops.
There are two processes at work here: the rate of neutron decay and the rate at which neutrons escape from the bottle. So in the case of an ideal bottle, the rate of decay should be equal to the beta decay rate. But the bottles are not ideal so the rate of decay is always faster.
That leaves open the possibility that there might be a third process at work: that some of the extra decay might be the result of neutrons jumping from our universe to another.
So Sarrazin and co have used the measured decay rates to place an upper limit on how often this can happen.
Their conclusion is that the probability of a neutron jumping ship is smaller than about one in a million.
That doesn’t really say anything about whether matter swapping actually takes place. Only that if it does, it doesn’t happen very often.
However, Sarrazzin and co also say it should be straightforward to take better data that places stricter limits.
According to their theoretical work, a change in the gravitational potential should also influence the rate of matter swapping. So one idea is to carry out a neutron trapping experiment that lasts for a year or more, allowing the Earth to complete at least one orbit of the Sun.
In that time, the gravitational potential changes in a way that should influence the rate of matter swapping. Indeed, there ought to be an annual cycle. “If one can detect such a modulation it would be a strong indication that matter swapping really occurs,” they say.
That would be one of the biggest and most controversial discoveries in modern physics and one that is possible with technologies available today.
Anyone got an old neutron bottle lying around and a bit of spare time on their hands?
Ref: arxiv.org/abs/1201.3949: Experimental Limits On Neutron Disappearance Into Another Braneworld
(via Technology Review)
The wavefunction is a real physical object after all, say researchers.
At the heart of the weirdness for which the field of quantum mechanics is famous is the wavefunction, a powerful but mysterious entity that is used to determine the probabilities that quantum particles will have certain properties. Now, a preprint posted online on 14 November1 reopens the question of what the wavefunction represents — with an answer that could rock quantum theory to its core. Whereas many physicists have generally interpreted the wavefunction as a statistical tool that reflects our ignorance of the particles being measured, the authors of the latest paper argue that, instead, it is physically real.
At the heart of the experiment is one of the weirdest, and most important, tenets of quantum mechanics: the principle that empty space is anything but. Quantum theory predicts that a vacuum is actually a writhing foam of particles flitting in and out of existence.
This is the kind of news I love waking up to.
Recent discoveries require us to rethink our understanding of history. “The histories of the universe,” said renowned physicist Stephen Hawking “depend on what is being measured, contrary to the usual idea that the universe has an objective observer-independent history.”
Is it possible we live and die in a world of illusions? Physics tells us that objects exist in a suspended state until observed, when they collapse in to just one outcome. Paradoxically, whether events happened in the past may not be determined until sometime in your future — and may even depend on actions that you haven’t taken yet.
In 2002, scientists carried out an amazing experiment, which showed that particles of light “photons” knew — in advance −- what their distant twins would do in the future. They tested the communication between pairs of photons — whether to be either a wave or a particle. Researchers stretched the distance one of the photons had to take to reach its detector, so that the other photon would hit its own detector first. The photons taking this path already finished their journeys -− they either collapse into a particle or don’t before their twin encounters a scrambling device. Somehow, the particles acted on this information before it happened, and across distances instantaneously as if there was no space or time between them. They decided not to become particles before their twin ever encountered the scrambler. It doesn’t matter how we set up the experiment. Our mind and its knowledge is the only thing that determines how they behave. Experiments consistently confirm these observer-dependent effects.
More recently (Science 315, 966, 2007), scientists in France shot photons into an apparatus, and showed that what they did could retroactively change something that had already happened. As the photons passed a fork in the apparatus, they had to decide whether to behave like particles or waves when they hit a beam splitter. Later on - well after the photons passed the fork - the experimenter could randomly switch a second beam splitter on and off. It turns out that what the observer decided at that point, determined what the particle actually did at the fork in the past. At that moment, the experimenter chose his history.
Of course, we live in the same world. Particles have a range of possible states, and it’s not until observed that they take on properties. So until the present is determined, how can there be a past? According to visionary physicist John Wheeler (who coined the word “black hole”), “The quantum principle shows that there is a sense in which what an observer will do in the future defines what happens in the past.” Part of the past is locked in when you observe things and the “probability waves collapse.” But there’s still uncertainty, for instance, as to what’s underneath your feet. If you dig a hole, there’s a probability you’ll find a boulder. Say you hit a boulder, the glacial movements of the past that account for the rock being in exactly that spot will change as described in the Science experiment.
But what about dinosaur fossils? Fossils are really no different than anything else in nature. For instance, the carbon atoms in your body are “fossils” created in the heart of exploding supernova stars. Bottom line: reality begins and ends with the observer. “We are participators,” Wheeler said “in bringing about something of the universe in the distant past.” Before his death, he stated that when observing light from a quasar, we set up a quantum observation on an enormously large scale. It means, he said, the measurements made on the light now, determines the path it took billions of years ago.
Like the light from Wheeler’s quasar, historical events such as who killed JFK, might also depend on events that haven’t occurred yet. There’s enough uncertainty that it could be one person in one set of circumstances, or another person in another. Although JFK was assassinated, you only possess fragments of information about the event. But as you investigate, you collapse more and more reality. According to biocentrism, space and time are relative to the individual observer - we each carry them around like turtles with shells.
History is a biological phenomenon − it’s the logic of what you, the animal observer experiences. You have multiple possible futures, each with a different history like in the Science experiment. Consider the JFK example: say two gunmen shot at JFK, and there was an equal chance one or the other killed him. This would be a situation much like the famous Schrödinger’s cat experiment, in which the cat is both alive and dead − both possibilities exist until you open the box and investigate.
"We must re-think all that we have ever learned about the past, human evolution and the nature of reality, if we are ever to find our true place in the cosmos," says Constance Hilliard, a historian of science at UNT. Choices you haven’t made yet might determine which of your childhood friends are still alive, or whether your dog got hit by a car yesterday. In fact, you might even collapse realities that determine whether Noah’s Ark sank. "The universe," said John Haldane, "is not only queerer than we suppose, but queerer than we can suppose.”
— Robert Lanza
Through the Wormhole - Season 2, Episode 1: Is There Life After Death
[Full-Length] Original Air Date—8 June 2011
"In the premiere episode of the second season, Morgan Freeman dives deep into this provocative question that has mystified humans since the beginning of time. Modern physics and neuroscience are venturing into this once hallowed ground, and radically changing our ideas of life after death. Freeman serves as host to this polarized debate, where scientists and spiritualist attempt to define ‘what is consciousness,’ while cutting edge quantum mechanics could provide the answer to what happens when we die."
Love. this. show.
One of the central planks of quantum mechanics was called into question in a new take on the classic two-slit experiment.
One of the central notions in quantum mechanics is that light and matter can behave as both particle and wave. The principle of “complementarity” has always been understood to prevent the observation of both behaviours simultaneously. However, new research published in Science on 2 June, suggests that physicists at the University of Toronto and Griffith University in Brisbane have for the first time observed both behaviours at the same time.
In Thomas Young’s 19th century “two-slit experiment”, light is passed through two tiny holes and is then viewed on a screen. The two beams interfere with each other, forming a diffraction pattern, as if the light were made of waves. If one of the slits is blocked, the light can be seen as a single beam on the screen, as if light were made of particles. The two-slit experiment shows that, depending on how it’s measured, a photon will act like either a particle or a wave, but never both.
Aephraim Steinberg of the University of Toronto and Sacha Kocsis of Griffith recreated this experiment, easily observing the interference pattern indicative of the wave nature of light. But significantly, they were also able measure the path of the particles of light.
Science reporter, Adrian Cho elaborates on the importance of their new research:
"For decades, [the] experiment has served as physicists’ canonical example of the uncertainty principle: the law of nature that says you can’t know both where a subatomic particle is and how fast it is moving, and thus can’t trace its trajectory. But now physicists have tweaked that classic experiment to show that they can follow the average path taken by many particles."
Steinberg and his team allowed photons to pass through a calcite crystal which gave each photon a small deviation in its path. By measuring the light patterns on a camera, the team was able to deduce what paths the photons had taken. They clearly saw the interference pattern which infers the wave nature of light, but surprisingly they also could see from which slits the photons had come from, a telltale sign of the particle nature of light.
Marlan Scully, a quantum physicist at Texas University, commented:
"It’s a beautiful series of measurements by an excellent group, the likes of which I’ve not seen before.",
"This paper is probably the first that has really put this weak measurement idea into a real experimental realisation." He said that the work would - inevitably - raise philosophical issues as well. "The exact way to think about what they’re doing will be researched for some time, and the weak measurement concept itself will be a matter of controversy"
Professor Steinberg commented, “I feel like we’re starting to pull back a veil on what nature really is”.
(via Particle Decelerator)
COULD the structure of space and time be sketched out inside a cousin of plain old pencil lead? The atomic grid of graphene may mimic a lattice underlying reality, two physicists have claimed, an idea that could explain the curious spin of the electron. Graphene is an atom-thick layer of carbon in a hexagonal formation. Depending on its position in this grid, an electron can adopt either of two quantum states - a property called pseudospin which is mathematically akin to the intrinsic spin of an electron. Most physicists do not think it is true spin, but Chris Regan at the University of California, Los Angeles, disagrees. He cites work with carbon nanotubes (rolled up sheets of graphene) in the late 1990s, in which electrons were found to be reluctant to bounce back off these obstacles. Regan and his colleague Matthew Mecklenburg say this can be explained if a tricky change in spin is required to reverse direction. Their quantum model of graphene backs that up. The spin arises from the way electrons hop between atoms in graphene’s lattice, says Regan. So how about the electron’s intrinsic spin? It cannot be a rotation in the ordinary sense, as electrons are point particles with no radius and no innards. Instead, like pseudospin, it might come from a lattice pattern in space-time itself, says Regan. This echoes some attempts to unify quantum mechanics with gravity in which space-time is built out of tiny pieces or fundamental networks (Physical Review Letters, vol 106, p 116803). Sergei Sharapov of the National Academy of Sciences of Ukraine in Kiev says that the work provides an interesting angle on how electrons and other particles acquire spin, but he is doubtful how far the analogy can be pushed. Regan admits that moving from the flatland world of graphene to higher-dimensional space is tricky. “It will be interesting to see if there are other lattices that give emergent spin,” he says. via NewScientist
COULD the structure of space and time be sketched out inside a cousin of plain old pencil lead? The atomic grid of graphene may mimic a lattice underlying reality, two physicists have claimed, an idea that could explain the curious spin of the electron.
Graphene is an atom-thick layer of carbon in a hexagonal formation. Depending on its position in this grid, an electron can adopt either of two quantum states - a property called pseudospin which is mathematically akin to the intrinsic spin of an electron.
Most physicists do not think it is true spin, but Chris Regan at the University of California, Los Angeles, disagrees. He cites work with carbon nanotubes (rolled up sheets of graphene) in the late 1990s, in which electrons were found to be reluctant to bounce back off these obstacles. Regan and his colleague Matthew Mecklenburg say this can be explained if a tricky change in spin is required to reverse direction. Their quantum model of graphene backs that up. The spin arises from the way electrons hop between atoms in graphene’s lattice, says Regan.
So how about the electron’s intrinsic spin? It cannot be a rotation in the ordinary sense, as electrons are point particles with no radius and no innards. Instead, like pseudospin, it might come from a lattice pattern in space-time itself, says Regan. This echoes some attempts to unify quantum mechanics with gravity in which space-time is built out of tiny pieces or fundamental networks (Physical Review Letters, vol 106, p 116803).
Sergei Sharapov of the National Academy of Sciences of Ukraine in Kiev says that the work provides an interesting angle on how electrons and other particles acquire spin, but he is doubtful how far the analogy can be pushed. Regan admits that moving from the flatland world of graphene to higher-dimensional space is tricky. “It will be interesting to see if there are other lattices that give emergent spin,” he says.
Until this year, all human-made objects have moved according to the laws of classical mechanics. Back in March, however, a group of researchers designed a gadget that moves in ways that can only be described by quantum mechanics — the set of rules that governs the behavior of tiny things like molecules, atoms, and subatomic particles. In recognition of the conceptual ground their experiment breaks, the ingenuity behind it and its many potential applications, Science has called this discovery the most significant scientific advance of 2010.
Physicists Andrew Cleland and John Martinis from the University of California at Santa Barbara and their colleagues designed the machine—a tiny metal paddle of semiconductor, visible to the naked eye—and coaxed it into dancing with a quantum groove. First, they cooled the paddle until it reached its “ground state,” or the lowest energy state permitted by the laws of quantum mechanics (a goal long-sought by physicists). Then they raised the widget’s energy by a single quantum to produce a purely quantum-mechanical state of motion. They even managed to put the gadget in both states at once, so that it literally vibrated a little and a lot at the same time—a bizarre phenomenon allowed by the weird rules of quantum mechanics.
Science and its publisher, AAAS, the nonprofit science society, have recognized this first quantum machine as the 2010 Breakthrough of the Year. They have also compiled nine other important scientific accomplishments from this past year into a top ten list, appearing in a special news feature in the journal’s 17 December 2010 issue. Additionally, Science news writers and editors have chosen to spotlight 10 “Insights of the Decade” that have transformed the landscape of science in the 21st Century.
"This year’s Breakthrough of the Year represents the first time that scientists have demonstrated quantum effects in the motion of a human-made object," said Adrian Cho, a news writer for Science. “On a conceptual level that’s cool because it extends quantum mechanics into a whole new realm. On a practical level, it opens up a variety of possibilities ranging from new experiments that meld quantum control over light, electrical currents and motion to, perhaps someday, tests of the bounds of quantum mechanics and our sense of reality.”
The quantum machine proves that the principles of quantum mechanics can apply to the motion of macroscopic objects, as well as atomic and subatomic particles. It provides the key first step toward gaining complete control over an object’s vibrations at the quantum level. Such control over the motion of an engineered device should allow scientists to manipulate those minuscule movements, much as they now control electrical currents and particles of light. In turn, that capability may lead to new devices to control the quantum states of light, ultra-sensitive force detectors and, ultimately, investigations into the bounds of quantum mechanics and our sense of reality. (This last grand goal might be achieved by trying to put a macroscopic object in a state in which it’s literally in two slightly different places at the same time—an experiment that might reveal precisely why something as big as a human can’t be in two places at the same time.)
"Mind you, physicists still haven’t achieved a two-places-at-once state with a tiny object like this one," said Cho. "But now that they have reached the simplest state of quantum motion, it seems a whole lot more obtainable—more like a matter of ‘when’ than ‘if.’"
Science’s list of the nine other groundbreaking achievements from 2010 follows:
Synthetic Biology: In a defining moment for biology and biotechnology, researchers built a synthetic genome and used it to transform the identity of a bacterium. The genome replaced the bacterium’s DNA so that it produced a new set of proteins—an achievement that prompted a Congressional hearing on synthetic biology. In the future, researchers envision synthetic genomes that are custom-built to generate biofuels, pharmaceuticals or other useful chemicals.
Neandertal Genome: Researchers sequenced the Neandertal genome from the bones of three female Neandertals who lived in Croatia sometime between 38,000 and 44,000 years ago. New methods of sequencing degraded fragments of DNA allowed scientists to make the first direct comparisons between the modern human genome and that of our Neandertal ancestors.
HIV Prophylaxis: Two HIV prevention trials of different, novel strategies reported unequivocal success: A vaginal gel that contains the anti-HIV drug tenofovir reduced HIV infections in women by 39 percent and an oral pre-exposure prophylaxis led to 43.8 fewer HIV infections in a group of men and transgender women who have sex with men.
Exome Sequencing/Rare Disease Genes: By sequencing just the exons of a genome, or the tiny portion that actually codes for proteins, researchers who study rare inherited diseases caused by a single, flawed gene were able to identify specific mutations underlying at least a dozen diseases.
Molecular Dynamics Simulations: Simulating the gyrations that proteins make as they fold has been a combinatorial nightmare. Now, researchers have harnessed the power of one of the world’s most powerful computers to track the motions of atoms in a small, folding protein for a length of time 100 times longer than any previous efforts.
Quantum Simulator: To describe what they see in the lab, physicists cook up theories based on equations. Those equations can be fiendishly hard to solve. This year, though, researchers found a short-cut by making quantum simulators—artificial crystals in which spots of laser light play the role of ions and atoms trapped in the light stand in for electrons. The devices provide quick answers to theoretical problems in condensed matter physics and they might eventually help solve mysteries such as superconductivity.
Next-Generation Genomics: Faster and cheaper sequencing technologies are enabling very large-scale studies of both ancient and modern DNA. The 1,000 Genomes Project, for example, has already identified much of the genome variation that makes us uniquely human—and other projects in the works are set to reveal much more of the genome’s function.
RNA Reprogramming: Reprogramming cells—turning back their developmental clocks to make them behave like unspecialized “stem cells” in an embryo—has become a standard lab technique for studying diseases and development. This year, researchers found a way to do it using synthetic RNA. Compared with previous methods, the new technique is twice as fast, 100 times as efficient and potentially safer for therapeutic use.
The Return of the Rat: Mice rule the world of laboratory animals, but for many purposes researchers would rather use rats. Rats are easier to work with and anatomically more similar to human beings; their big drawback is that methods used to make “knockout mice”—animals tailored for research by having specific genes precisely disabled—don’t work for rats. A flurry of research this year, however, promises to bring “knockout rats” to labs in a big way.
Finally, to celebrate the end of the current decade, Science news reporters and editors have taken a step back from their weekly reporting to take a broader look at 10 of the scientific insights that have changed the face of science since the dawn of the new millennium. A list of these 10 “Insights of the Decade” follows.
The Dark Genome: Genes used to get all the glory. Now, however, researchers recognize that these protein-coding regions of the genome account for just 1.5 percent of the whole. The rest of the genome, including small coding and non-coding RNAs—previously written off as “junk”—is proving to be just as important as the genes.
Precision Cosmology: Over the past decade, researchers have deduced a very precise recipe for the content of the universe, which consists of ordinary matter, dark matter and dark energy; as well as instructions for putting it all together. These advances have transformed cosmology into a precision science with a standard theory that now leaves very little wiggle room for other ideas.
Ancient Biomolecules: The realization that “biomolecules” like ancient DNA and collagen can survive for tens of thousands of years and provide important information about long-dead plants, animals and humans has provided a boon for paleontology. Analysis of these tiny time machines can now reveal anatomical adaptations that skeletal evidence simply can’t provide, such as the color of a dinosaur’s feathers or how woolly mammoths withstood the cold.
Water on Mars: Half a dozen missions to Mars over the past decade have provided clear evidence that the Red Planet once harbored enough water—either on it or just inside it—to alter rock formations and, possibly, sustain life. This Martian water was probably present around the time that life was beginning to appear on Earth, but there is still enough moisture on Mars today to encourage scientists seeking living, breathing microbes.
Reprogramming Cells: During the past decade, the notion that development is a one-way street has been turned on its head. Now, researchers have figured out how to “reprogram” fully developed cells into so-called pluripotent cells that regain their potential to become any type of cell in the body. This technique has already been used to make cell lines from patients with rare diseases, but ultimately, scientists hope to grow genetically matched replacement cells, tissues and organs.
The Microbiome: A major shift in the way we view the microbes and viruses that call the human body home has led researchers to the concept of the microbiome—or the collective genomes of the host and the other creatures that live on or inside it. Since 90 percent of the cells in our bodies are actually microbial, scientists are beginning to understand how significantly microbial genes can affect how much energy we absorb from our foods and how our immune systems respond to infections.
Exoplanets: In the year 2000, researchers were aware of just 26 planets outside our solar system. By 2010, that number had jumped to 502—and still counting. With emerging technologies, astronomers expect to find abundant Earth-like planets in the universe. But for now, the sizes and orbits of larger planets already discovered are revolutionizing scientists’ understanding of how planetary systems form and evolve.
Inflammation: Not long ago, inflammation was known as the simple sidekick to our healing machinery, briefly setting in to help immune cells rebuild tissue damage caused by trauma or infection. Today, however, researchers believe that inflammation is also a driving force behind the chronic diseases that will eventually kill nearly all of us, including cancer, Alzheimer’s disease, atherosclerosis, diabetes and obesity.
Metamaterials: By synthesizing materials with unconventional and tunable optical properties, physicists and engineers have pioneered new ways to guide and manipulate light, creating lenses that defy the fundamental limits on resolution. They’ve even begun constructing “cloaks” that can make an object invisible.
Climate Change: Over the past decade, researchers have solidified some fundamental facts surrounding global climate change: The world is warming, humans are behind the warming and the natural processes of the Earth are not likely to slow that warming. But, the next 10 years will determine how scientists and policymakers proceed with this vital information.
More information: http://www.sciencemag.org/special/insights2010/
AN IDENTICAL copy of you is also reading this story. This twin is the same in every way, living on an Earth and in a universe that looks exactly like our own. And there may be an infinite number of them. Such doppelgängers could be a natural consequence of our present conception of the universe. Now, some physicists say they could pose a serious problem for quantum mechanics. But a possible fix may also be in sight, and it could help tie abstract quantum concepts to concrete physical causes.
In the uncertain, fuzzy world of quantum mechanics, particles do not have fixed properties until they are observed. Instead, objects that obey quantum rules exist in a “superposition” of all their possible states simultaneously. Schrödinger’s famous cat, for example, is both alive and dead until we take a peek inside the booby-trapped box in which it has been placed.
Because the probability that the cat will be found alive is based on a quantum event - the decay of a radioactive substance within the box - it can be calculated using a principle called the Born rule. The rule is used to transform the vague “wave function” of a quantum state, which is essentially a mixture of all possible outcomes, into concrete probabilities of particular observations (in this case, the cat being alive or dead). But this staple of quantum mechanics fails when it is applied to the universe at large, says Don Page at the University of Alberta in Edmonton, Canada.
At issue is the possibility that there could be a multiplicity of copies of any particular experiment floating about the universe, just as there could be a multiplicity of yous. There could even be an infinite number of them if, as is thought, the early universe underwent a period of exponential growth, called inflation. Although this period ended very soon after the big bang in our observable region of space, inflation may have continued elsewhere, giving rise to a “multiverse”, an infinite space containing infinite copies of our Earth. “In an infinite universe, every possible thing would happen, and it would happen an infinite number of times,” says cosmologist Alex Vilenkin of Tufts University in Medford, Massachusetts.
The Casimir Effect: One of the measurable forces inside quantum vacuums that makes the idea of magnetoelectric quantum wheels plausible.