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.
[This New Scientist article is only available to subscribers so it has been presented here in its entirety.]
SUBATOMIC particles have broken the universe’s fundamental speed limit, or so it was reported last week. The speed of light is the ultimate limit on travel in the universe, and the basis for Einstein’s special theory of relativity, so if the finding stands up to scrutiny, does it spell the end for physics as we know it? The reality is less simplistic and far more interesting.
"People were saying this means Einstein is wrong," says physicist Heinrich Päs of the Technical University of Dortmund in Germany. "But that’s not really correct."
Instead, the result could be the first evidence for a reality built out of extra dimensions. Future historians of science may regard it not as the moment we abandoned Einstein and broke physics, but rather as the point at which our view of space vastly expanded, from three dimensions to four, or more.
"This may be a physics revolution," says Thomas Weiler at Vanderbilt University in Nashville, Tennessee, who has devised theories built on extra dimensions. "The famous words ‘paradigm shift’ are used too often and tritely, but they might be relevant."
The subatomic particles - neutrinos - seem to have zipped faster than light from CERN, near Geneva, Switzerland, to the OPERA detector at the Gran Sasso lab near L’Aquila, Italy. It’s a conceptually simple result: neutrinos making the 730-kilometre journey arrived 60 nanoseconds earlier than they would have if they were travelling at light speed. And it relies on three seemingly simple measurements, says Dario Autiero of the Institute of Nuclear Physics in Lyon, France, a member of the OPERA collaboration: the distance between the labs, the time the neutrinos left CERN, and the time they arrived at Gran Sasso.
But actually measuring those times and distances to the accuracy needed to detect nanosecond differences is no easy task. The OPERA collaboration spent three years chasing down every source of error they could imagine (see illustration) before Autiero made the result public in a seminar at CERN on 23 September.
Physicists grilled Autiero for an hour after his talk to ensure the team had considered details like the curvature of the Earth, the tidal effects of the moon and the general relativistic effects of having two clocks at different heights (gravity slows time so a clock closer to Earth’s surface runs a tiny bit slower).
They were impressed. “I want to congratulate you on this extremely beautiful experiment,” said Nobel laureate Samuel Ting of the Massachusetts Institute of Technology after Autiero’s talk. “The experiment is very carefully done, and the systematic error carefully checked.”
Most physicists still expect some sort of experimental error to crop up and explain the anomaly, mainly because it contravenes the incredibly successful law of special relativity which holds that the speed of light is a constant that no object can exceed. The theory also leads to the famous equation E = mc2.
Hotly anticipated are results from other neutrino detectors, including T2K in Japan and MINOS at Fermilab in Illinois, which will run similar experiments and confirm the results or rule them out (see “Fermilab stops hunting Higgs, starts neutrino quest”).
In 2007, the MINOS experiment searched for faster-than-light neutrinos but didn’t see anything statistically significant. The team plans to reanalyse its data and upgrade the detector’s stopwatch. “These are the kind of things that we have to follow through, and make sure that our prejudices don’t get in the way of discovering something truly fantastic,” says Stephen Parke of Fermilab.
In the meantime, suggests Sandip Pakvasa of the University of Hawaii, let’s suppose the OPERA result is real. If the experiment is tested and replicated and the only explanation is faster-than-light neutrinos, is E = mc2 done for?
Not necessarily. In 2006, Pakvasa, Päs and Weiler came up with a model that allows certain particles to break the cosmic speed limit while leaving special relativity intact. “One can, if not rescue Einstein, at least leave him valid,” Weiler says.
The trick is to send neutrinos on a shortcut through a fourth, thus-far-unobserved dimension of space, reducing the distance they have to travel. Then the neutrinos wouldn’t have to outstrip light to reach their destination in the observed time.
In such a universe, the particles and forces we are familiar with are anchored to a four-dimensional membrane, or “brane”, with three dimensions of space and one of time. Crucially, the brane floats in a higher dimensional space-time called the bulk, which we are normally completely oblivious to.
The fantastic success of special relativity up to now, plus other cosmological observations, have led physicists to think that the brane might be flat, like a sheet of paper. Quantum fluctuations could make it ripple and roll like the surface of the ocean, Weiler says. Then, if neutrinos can break free of the brane, they might get from one point on it to another by dashing through the bulk, like a flying fish taking a shortcut between the waves (see illustration).
This model is attractive because it offers a way out of one of the biggest theoretical problems posed by the OPERA result: busting the apparent speed limit set by neutrinos detected pouring from a supernova in 1987.
As stars explode in a supernova, most of their energy streams out as neutrinos. These particles hardly ever interact with matter. That means they should escape the star almost immediately, while photons of light will take about 3 hours. In 1987, trillions of neutrinos arrived at Earth 3 hours before the dying star’s light caught up. If the neutrinos were travelling as fast as those going from CERN to OPERA, they should have arrived in 1982.
OPERA’s neutrinos were about 1000 times as energetic as the supernova’s neutrinos, though. And Pakvasa and colleagues’ model calls for neutrinos with a specific energy that makes them prefer tunnelling through the bulk to travelling along the brane. If that energy is around 20 gigaelectronvolts - and the team don’t yet know that it is - “then you expect large effects in the OPERA region, and small effects at the supernova energies,” Pakvasa says. He and Päs are meeting next week to work out the details.
The flying fish shortcut isn’t available to all particles. In the language of string theory, a mathematical model some physicists hope will lead to a comprehensive “theory of everything”, most particles are represented by tiny vibrating strings whose ends are permanently stuck to the brane. One of the only exceptions is the theoretical "sterile neutrino", represented by a closed loop of string. These are also the only type of neutrino thought capable of escaping the brane.
Neutrinos are known to switch back and forth between their three observed types (electron, muon and tau neutrinos), and OPERA was originally designed to detect these shifts. In Pakvasa’s model, the muon neutrinos produced at CERN could have transformed to sterile neutrinos mid-flight, made a short hop through the bulk, and then switched back to muon before reappearing on the brane.
So if OPERA’s results hold up, they could provide support for the existence of sterile neutrinos, extra dimensions and perhaps string theory. Such theories could also explain why gravity is so weak compared with the other fundamental forces. The theoretical particles that mediate gravity, known as gravitons, may also be closed loops of string that leak off into the bulk. “If, in the end, nobody sees anything wrong and other people reproduce OPERA’s results, then I think it’s evidence for string theory, in that string theory is what makes extra dimensions credible in the first place,” Weiler says.
Meanwhile, alternative theories are likely to abound. Weiler expects papers to appear in a matter of days or weeks.
Even if relativity is pushed aside, Einstein has worked so well for so long that he will never really go away. At worst, relativity will turn out to work for most of the universe but not all, just as Newton’s mechanics work until things get extremely large or small. “The fact that Einstein has worked for 106 years means he’ll always be there, either as the right answer or a low-energy effective theory,” Weiler says.
(via New Scientist)
Related reading » Neutrinos: Everything you need to know
An ambitious experiment to make a glass sphere exist in two places at once could provide the most sensitive test of quantum theory yet. The experiment will place a sphere containing millions of atoms – making it larger than many viruses – into a superposition of states in different places, say researchers in Europe.
Physicists have questioned whether large objects can follow quantum laws ever since Erwin Schrödinger’s thought-experiment suggested a cat could exist in a superposition of being both alive and dead.
The idea is to zap a glass sphere 40 nanometres in diameter with a laser while it is inside a small cavity. This should force the sphere to bounce from one side of the cavity to the other. But since the light is quantum in nature, so too will be the position of the sphere. This forces it into a quantum superposition.
The experiment will have to be carried out in high vacuum and at extremely low temperatures so that the sphere is not disturbed by thermal noise or air molecules, says lead author Oriol Romero-Isart from the Max Planck Institute of Quantum Optics in Garching, Germany.
Last year Aaron O’Connell and colleagues at the University of California, Santa Barbara, demonstrated that it should be possible to create superpositions in a 60-micrometre-long metal strip. However, the physical separation associated with the two different states of the strip was only 1 femtometre, about the width of the nucleus of an atom.
The new experiment, in contrast, would put the glass sphere in two entirely distinct places at once, with no overlap. “In our proposal the centre of mass is put into a superposition of spatial locations separated by a distance larger than the size of the object,” Romero-Isart says.
Atom interferometer experiments have previously achieved good separation, putting fullerene and other molecules containing up to a few hundred atoms into distinct superposition states, but the new scheme will do this with truly macroscopic objects.
This will be particularly valuable in providing tests for quantum mechanics, the researchers say. Observing the behaviour of such very large objects obeying quantum laws offers our best hope of finding ways in which quantum theory breaks down.
The Romero-Isart experiment would take us “substantially beyond the current state of the art”, says Anthony Leggett of the University of Illinois at Urbana-Champaign. “Neither the fullerene experiments nor that of O’Connell and his team are able to test well-developed competitors to quantum mechanics.”
Journal reference: Physical Review Letters, DOI: 10.1103/PhysRevLett.107.020405
The topic of “life after death” raises disreputable connotations of past-life regression and haunted houses, but there are a large number of people in the world who believe in some form of persistence of the individual soul after life ends. Clearly this is an important question, one of the most important ones we can possibly think of in terms of relevance to human life. If science has something to say about, we should all be interested in hearing.
Adam Frank thinks that science has nothing to say about it. He advocates being “firmly agnostic” on the question. (His coblogger Alva Noë resolutely disagrees.) I have an enormous respect for Adam; he’s a smart guy and a careful thinker. When we disagree it’s with the kind of respectful dialogue that should be a model for disagreeing with non-crazy people. But here he couldn’t be more wrong.
Adam claims that there “simply is no controlled, experimental[ly] verifiable information” regarding life after death. By these standards, there is no controlled, experimentally verifiable information regarding whether the Moon is made of green cheese. Sure, we can take spectra of light reflecting from the Moon, and even send astronauts up there and bring samples back for analysis. But that’s only scratching the surface, as it were. What if the Moon is almost all green cheese, but is covered with a layer of dust a few meters thick? Can you really say that you know this isn’t true? Until you have actually every single cubic centimeter of the Moon’s interior, you don’t really have experimentally verifiable information, do you? So maybe agnosticism on the green-cheese issue is warranted. (Come up with all the information we actually do have about the Moon; I promise you I can fit it into the green-cheese hypothesis.)
Obviously this is completely crazy. Our conviction that green cheese makes up a negligible fraction of the Moon’s interior comes not from direct observation, but from the gross incompatibility of that idea with other things we think we know. Given what we do understand about rocks and planets and dairy products and the Solar System, it’s absurd to imagine that the Moon is made of green cheese. We know better.
We also know better for life after death, although people are much more reluctant to admit it. Admittedly, “direct” evidence one way or the other is hard to come by — all we have are a few legends and sketchy claims from unreliable witnesses with near-death experiences, plus a bucketload of wishful thinking. But surely it’s okay to take account of indirect evidence — namely, compatibility of the idea that some form of our individual soul survives death with other things we know about how the world works.
Claims that some form of consciousness persists after our bodies die and decay into their constituent atoms face one huge, insuperable obstacle: the laws of physics underlying everyday life are completely understood, and there’s no way within those laws to allow for the information stored in our brains to persist after we die. If you claim that some form of soul persists beyond death, what particles is that soul made of? What forces are holding it together? How does it interact with ordinary matter?
Everything we know about quantum field theory (QFT) says that there aren’t any sensible answers to these questions. Of course, everything we know about quantum field theory could be wrong. Also, the Moon could be made of green cheese.
Among advocates for life after death, nobody even tries to sit down and do the hard work of explaining how the basic physics of atoms and electrons would have to be altered in order for this to be true. If we tried, the fundamental absurdity of the task would quickly become evident.
Even if you don’t believe that human beings are “simply” collections of atoms evolving and interacting according to rules laid down in the Standard Model of particle physics, most people would grudgingly admit that atoms are part of who we are. If it’s really nothing but atoms and the known forces, there is clearly no way for the soul to survive death. Believing in life after death, to put it mildly, requires physics beyond the Standard Model. Most importantly, we need some way for that “new physics” to interact with the atoms that we do have.
Very roughly speaking, when most people think about an immaterial soul that persists after death, they have in mind some sort of blob of spirit energy that takes up residence near our brain, and drives around our body like a soccer mom driving an SUV. The questions are these: what form does that spirit energy take, and how does it interact with our ordinary atoms? Not only is new physics required, but dramatically new physics. Within QFT, there can’t be a new collection of “spirit particles” and “spirit forces” that interact with our regular atoms, because we would have detected them in existing experiments. Ockham’s razor is not on your side here, since you have to posit a completely new realm of reality obeying very different rules than the ones we know.
But let’s say you do that. How is the spirit energy supposed to interact with us? Here is the equation that tells us how electrons behave in the everyday world:
Don’t worry about the details; it’s the fact that the equation exists that matters, not its particular form. It’s the Dirac equation — the two terms on the left are roughly the velocity of the electron and its inertia — coupled to electromagnetism and gravity, the two terms on the right.
As far as every experiment ever done is concerned, this equation is the correct description of how electrons behave at everyday energies. It’s not a complete description; we haven’t included the weak nuclear force, or couplings to hypothetical particles like the Higgs boson. But that’s okay, since those are only important at high energies and/or short distances, very far from the regime of relevance to the human brain.
If you believe in an immaterial soul that interacts with our bodies, you need to believe that this equation is not right, even at everyday energies. There needs to be a new term (at minimum) on the right, representing how the soul interacts with electrons. (If that term doesn’t exist, electrons will just go on their way as if there weren’t any soul at all, and then what’s the point?) So any respectable scientist who took this idea seriously would be asking — what form does that interaction take? Is it local in spacetime? Does the soul respect gauge invariance and Lorentz invariance? Does the soul have a Hamiltonian? Do the interactions preserve unitarity and conservation of information?
Nobody ever asks these questions out loud, possibly because of how silly they sound. Once you start asking them, the choice you are faced with becomes clear: either overthrow everything we think we have learned about modern physics, or distrust the stew of religious accounts/unreliable testimony/wishful thinking that makes people believe in the possibility of life after death. It’s not a difficult decision, as scientific theory-choice goes.
We don’t choose theories in a vacuum. We are allowed — indeed, required — to ask how claims about how the world works fit in with other things we know about how the world works. I’ve been talking here like a particle physicist, but there’s an analogous line of reasoning that would come from evolutionary biology. Presumably amino acids and proteins don’t have souls that persist after death. What about viruses or bacteria? Where upon the chain of evolution from our monocellular ancestors to today did organisms stop being described purely as atoms interacting through gravity and electromagnetism, and develop an immaterial immortal soul?
There’s no reason to be agnostic about ideas that are dramatically incompatible with everything we know about modern science. Once we get over any reluctance to face reality on this issue, we can get down to the much more interesting questions of how human beings and consciousness really work.
The concept of time as a way to measure the duration of events is not only deeply intuitive, it also plays an important role in our mathematical descriptions of physical systems. For instance, we define an object’s speed as its displacement per a given time. But some researchers theorize that this Newtonian idea of time as an absolute quantity that flows on its own, along with the idea that time is the fourth dimension of spacetime, are incorrect. They propose to replace these concepts of time with a view that corresponds more accurately to the physical world: time as a measure of the numerical order of change.
In two recent papers (one published and one to be published) in Physics Essays, Amrit Sorli, Davide Fiscaletti, and Dusan Klinar from the Scientific Research Centre Bistra in Ptuj, Slovenia, have described in more detail what this means.
No time dimension
They begin by explaining how we usually assume that time is an absolute physical quantity that plays the role of the independent variable (time, t, is often the x-axis on graphs that show the evolution of a physical system). But, as they note, we never really measure t. What we do measure is an object’s frequency, speed, etc. In other words, what experimentally exists are the motion of an object and the tick of a clock, and we compare the object’s motion to the tick of a clock to measure the object’s frequency, speed, etc. By itself, t has only a mathematical value, and no primary physical existence.
This view doesn’t mean that time does not exist, but that time has more to do with space than with the idea of an absolute time. So while 4D spacetime is usually considered to consist of three dimensions of space and one dimension of time, the researchers’ view suggests that it’s more correct to imagine spacetime as four dimensions of space. In other words, as they say, the universe is “timeless.”
“Minkowski space is not 3D + T, it is 4D,” the scientists write in their most recent paper. “The point of view which considers time to be a physical entity in which material changes occur is here replaced with a more convenient view of time being merely the numerical order of material change. This view corresponds better to the physical world and has more explanatory power in describing immediate physical phenomena: gravity, electrostatic interaction, information transfer by EPR experiment are physical phenomena carried directly by the space in which physical phenomena occur.”
As the scientists added, the roots of this idea come from Einstein himself.
“Einstein said, ‘Time has no independent existence apart from the order of events by which we measure it,’” Sorli told PhysOrg.com. “Time is exactly the order of events: this is my conclusion.”
In the future, the scientists plan to investigate the possibility that quantum space has three dimensions of space, as Sorli explained.
“The idea of time being the fourth dimension of space did not bring much progress in physics and is in contradiction with the formalism of special relativity,” he said. “We are now developing a formalism of 3D quantum space based on Planck work. It seems that the universe is 3D from the macro to the micro level to the Planck volume, which per formalism is 3D. In this 3D space there is no ‘length contraction,’ there is no ‘time dilation.’ What really exists is that the velocity of material change is ‘relative’ in the Einstein sense.”
Numerical order in space
The researchers give an example of this concept of time by imagining a photon that is moving between two points in space. The distance between these two points is composed of Planck distances, each of which is the smallest distance that the photon can move. (The fundamental unit of this motion is Planck time.) When the photon moves a Planck distance, it is moving exclusively in space and not in absolute time, the researchers explain. The photon can be thought of as moving from point 1 to point 2, and its position at point 1 is “before” its position at point 2 in the sense that the number 1 comes before the number 2 in the numerical order. Numerical order is not equivalent to temporal order, i.e., the number 1 does not exist before the number 2 in time, only numerically.
As the researchers explain, without using time as the fourth dimension of spacetime, the physical world can be described more accurately. As physicist Enrico Prati noted in a recent study, Hamiltonian dynamics (equations in classical mechanics) is robustly well-defined without the concept of absolute time. Other scientists have pointed out that the mathematical model of spacetime does not correspond to physical reality, and propose that a timeless “state space” provides a more accurate framework.
The scientists also investigated the falsifiability of the two notions of time. The concept of time as the fourth dimension of space - as a fundamental physical entity in which an experiment occurs - can be falsified by an experiment in which time does not exist, according to the scientists. An example of an experiment in which time is not present as a fundamental entity is the Coulomb experiment; mathematically, this experiment takes place only in space. On the other hand, in the concept of time as a numerical order of change taking place in space, space is the fundamental physical entity in which a given experiment occurs. Although this concept could be falsified by an experiment in which time (measured by clocks) is not the numerical order of material change, such an experiment is not yet known.
“Newton theory on absolute time is not falsifiable, you cannot prove it or disprove it, you have to believe in it,” Sorli said. “The theory of time as the fourth dimension of space is falsifiable and in our last article we prove there are strong indications that it might be wrong. On the basis of experimental data, time is what we measure with clocks: with clocks we measure the numerical order of material change, i.e., motion in space.”
How it makes sense
In addition to providing a more accurate description of the nature of physical reality, the concept of time as a numerical order of change can also resolve Zeno’s paradox of Achilles and the Tortoise. In this paradox, the faster Achilles gives the Tortoise a head start in the race. But although Achilles can run 10 times faster than the Tortoise, he can never surpass the Tortoise because, for every distance unit that Achilles runs, the Tortoise also runs 1/10 that distance. So whenever Achilles reaches a point where the Tortoise has been, the Tortoise has also moved slightly ahead. Although the conclusion that Achilles can never surpass the Tortoise is obviously false, there are many different proposed explanations for why the argument is flawed.
Here, the researchers explain that the paradox can be resolved by redefining velocity, so that the velocity of both runners is derived from the numerical order of their motion, rather than their displacement and direction in time. From this perspective, Achilles and the Tortoise move through space only, and Achilles can surpass Tortoise in space, though not in absolute time.
The researchers also briefly examine how this new view of time fits with how we intuitively perceive time. Many neurological studies have confirmed that we do have a sense of past, present, and future. This evidence has led to the proposal that the brain represents time with an internal “clock” that emits neural ticks (the “pacemaker-accumulator” model). However, some recent studies have challenged this traditional view, and suggest that the brain represents time in a spatially distributed way, by detecting the activation of different neural populations. Although we perceive events as occurring in the past, present, or future, these concepts may just be part of a psychological frame in which we experience material changes in space.
Finally, the researchers explain that this view of time does not look encouraging for time travelers.
“In our view, time travel into the past and future are not possible,” Sorli said. “One can travel in space only, and time is a numerical order of his motion.”
Amrit Sorli, Davide Fiscaletti, and Dusan Klinar. “Replacing time with numerical order of material change resolves Zeno problems of motion.” Physics Essays, 24, 1 (2011). DOI: 10.4006/1.3525416
Amrit Sorli, Dusan Klinar, and Davide Fiscaletti. “New Insights into the Special Theory of Relativity.” Physics Essays 24, 2 (2011). To be published.
© 2010 PhysOrg.com
In 1935, the physicist Erwin Schrödinger proposed a thought experiment in which a live cat was placed in a sealed box together with a mechanism that could be triggered by a quantum event — the decay of a subatomic particle that had a certain probability of happening — that would kill the cat when it occurred. According to quantum theory, subatomic particles can be in a condition of superposition — in other words, the particle can be in two states at once, until observed. Thus, the killing mechanism in the box could be both triggered and not triggered. So, Schrödinger wondered: Could the cat be both alive and dead at the same time?
For some thinkers, including Einstein, this was obviously impossible, areductio ad absurdum. But for others, it was clear that quantum physics points to just this possibility. To explain such theoretical high strangeness, many theories have since emerged, including the possibility of parallel universes.
But Schrödinger’s cat has today emerged from its box, and is dead-and-alive and well and smiling uncannily at us, like another cat from Cheshire, from every point of our macro-reality. We are clearly now passing through an extraordinary moment of the revelation of quantum superposition in our phenomenal plane.
Quantum undecidability reigns in most people’s minds about whether we are headed for planetary apocalypse or the dawn of a golden age. Some see that it is obvious that modern life is unsustainable ecologically, and can list all the plagues that are coming at us right now, which require not just four horsemen, but a stampeding army of wraith-riders bringing death and destruction as karmic blowback to our morally degraded world. But others are living in glorious optimism, in a sunny world of high technology that will soon solve all our planet’s problems, and even lead to a singularity in which human intellect merges with far more powerful artificial intelligence in a cyborg utopia of limitless longevity for titanium-based life forms sharing a virtual matrix of unified consciousness. Still others find the cyborg future a horrid dystopian vision, and instead share a different sort of optimism, seeing a future of transcendent beings in light bodies, re-dreaming the world through mystic psycho-technology, in a unified field of divine love. Can all these visions be simultaneously true? Quantum theory says yes (and simultaneously of course, no).
If indeed what we are witnessing is quantum superposition writ large, then many people will be experiencing this as terrifying fragmentation. It is producing anxiety and even psychosis in some, and at the same time, ecstatic mystical awakening in others. In fact, some people are in superposed states of enlightenment and psychic meltdown in the same instant. There was a time when we needed to take LSD, magic mushrooms, or ayahuasca to experience such feelings and throw open the doors of multidimensional perception. But now, it is happening unbidden to more and more of us.
A comedienne some years ago delivered a wonderful line: Reality is a crutch for people who can’t handle drugs. But things have now changed. The crutch is being removed. Reality itself is a drug that is wearing off. None of our stories hold together any more. The opposites are crashing into one another. Time is yielding to simultaneity. Sense and nonsense interpenetrate.
Of course, religion has always affirmed quantum superposition. What is Christ except the symbol of the superposition of man and God? The Buddhists say that samsara is in superposition with nirvana. Form is superposed with emptiness. The Advaitins assert that that the world of multiplicity is superposed with the Absolute. Duality is nonduality. The ego mind is in superposition with the mind of God, body-consciousness with the Buddha-nature.
Schrödinger’s monstrous cat has been loosed upon our world. We had better prepare ourselves for its approach. It is marking its territory everywhere. It is rubbing against our legs. We are already in quantum entanglement with its tail. Soon it will jump into our lap. Already we can’t tell if we are coming or going, if we are at alpha or omega. You look into the mirror and see the back of your head. You look in someone’s eyes and realize you are gazing at yourself. You look out the window and see a déjà view. “You know something’s happening here, but you don’t know what it is.” The cat has disappeared yet somehow it is beginning to speak through your mouth. You are becoming the cat’s meow.
But this magical moment in which the quantum wave is de-collapsing will not last. We are returning to the initial conditions of transfinite quantum potentiality, as the cosmic wave massively superposes new possibilities upon every undecidable superposition, burgeoning into a blur of becoming.
Return, t’shuvah in the Kabbalistic tradition, enables tikkun — the repair of the world. But full repair cannot be achieved unless we surrender to the Absolute beyond all possible conditions. As Islam rightly insists, there is no god but God. We must stop our worship of the ego, our sin of making idols out of money, physical beauty, power, or other mere mirage-like manifestations of the Absolute, and return all our attention and love one-pointedly to the Source. For optimal results in this tango of entanglement, the cosmic dance of Shakti and Shiva, we must humbly pay our homage to Emptiness. We must de-cathect our demonic and catabolic desires, de-focus our fixations, and junk our juvenile jouissance. Only then can we avoid being overwhelmed by the deadly fallout of our malpractice of creative consciousness.
This is the moment not only of superposition, but of super-consciousness. If we awaken to the hidden power we have been given, and use it with integrity, then this bardo state will birth a paradise; otherwise, what is to ensue will be unbearable. And the ultimate option is now also open: Supreme Liberation from this hall of mirrors, in union with the Absolute.
Conventional entanglement links particles across space. Now physicists say a similar effect links particles through time.
Entanglement is the strange quantum phenomenon in which two or more particles become so deeply linked that they share the same existence.
That leads to some counterintuitive effects, in particular, when two entangled particles become widely separated. When that happens, a measurement on one immediately influences the other, regardless of the distance between them. This “spooky-action-at-a-distance” has profound implications about the nature of reality but a clear understanding of it still eludes physicists.
Today, they have something else to puzzle over. Jay Olson and Timothy Ralph at the University of Queensland in Australia say they’ve discovered a new type of entanglement that extends, not through space, but through time.
They begin by thinking about a simplified universe consisting of one dimension of space and one of time.
It’s easy to plot this universe on a plane with the x-axis corresponding to a spatial dimension and the y-axis corresponding to time.
If you imagine the present as the origin of this graph, then the future (ie the space you can reach at subluminal speeds) forms a wedge that is symmetric about the y-axis. Your past (ie the space you could have arrived from at subluminal speeds) is a mirror image of this wedge reflected in the x-axis.
When two particles are present, both sitting on the x-axis, their wedges will overlap in the future and in the past. This has a simple meaning: these particles could have interacted in the past and could do so again in the future, but only in the areas of overlap.
Conventional entanglement cuts across this world, quite literally. It acts along the the x-axis, linking particles instantly in time and in defiance of the boundaries to these wedges.
What Olson and Ralph show is that entanglement can just as easily work along the y-axis too. In other words, entanglement is so deeply enmeshed in the universe that a measurement in the past has an automatic influence on the future.
That may sound like a truism. Isn’t this is how the universe works, I hear you say. But this isn’t ordinary cause and effect; there are some interesting subtleties to this phenomenon.
To see how, imagine an experiment that Ralph and Olson describe in which a qubit is sent into the future. The idea is that a detector acts on a qubit and then generates a classical message describing how this particle can be detected. Then, at some point in the future, another detector at the same position in space, receives this message and carries out the required measurement, thereby reconstructing the qubit.
But there’s a twist. Olson and Ralph show that the detection of the qubit in the future must be symmetric in time with its creation in the past. “If the past detector was active at a quarter to 12:00, then the future detector must wait to become active at precisely a quarter past 12:00 in order to achieve entanglement,” they say. For that reason, they call this process “teleportation in time”.
But how is this different from ordinary existence? After all, we’re all time travellers, moving into the future at the same rate. What’s special about Olson and Ralph’s route?
The answer is that Olson and Ralph’s teleportation provides a shortcut into the future. What they’re saying is that it’s possible to travel into the future without being present during the time in between.
That’s a fascinating scenario that immediately raises many questions. One of the first that springs to mind is what advantage might we get from this process. Might it be possible, for example, to make short-lived particles live longer by teleporting them into the future?
That isn’t clear. Neither is it clear exactly how such an experiment might be done although. Presumably, it wouldn’t be very different to the type of teleportation that is done in labs all over the world today, as a matter of routine (in fact Olson and Ralph say that timelike entangelment is interchangeable with the spacelike version).
That means it’s only a matter of time before somebody tries it. We’ll be watching!
Ref: arxiv.org/abs/1101.2565: Extraction Of Timelike Entanglement From The Quantum Vacuum
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.
I quite enjoyed the documentary. If you guys haven’t seen “Parallel Universes" check it out. :)
BBC documentary featuring Michio Kaku about quantum physics, higher dimensional mathematics, supergravity, hyperspace, string theory, m theory and parallel worlds.
Everything you are about to hear is true, at least in this Universe it is. For almost a hundred years science has been haunted by a dark secret: that there might be mysterious hidden worlds beyond our human senses. Mystics had long claimed there were such places. They were, they said, full of ghosts and spirits. The last thing science wanted was to be associated with such superstition, but ever since the 1920s physicists have been trying to make sense of an uncomfortable discovery. When they tried to pinpoint the exact location of atomic particles like electrons they found it was utterly impossible. They had no single location.
When one studies the properties of atoms one found that the reality is far stranger than anybody would have invented in the form of fiction. Particles really do have the possibility of, in some sense, being in more than one place at one time.
The only explanation which anyone could come up with is that the particles don’t just exist in our Universe. They flit into existence in other universes, too and there are an infinite number of these parallel universes, all of them slightly different…
Scientists have for some years been able to ‘teleport’ quantum states from one place to another. Now Seth Lloyd and his MIT team say that, using the same principles and a further strange quantum effect known as ‘postselection’, it should be possible to do the same backwards in time. Lloyd told the Technology Review: “It is possible for particles (and, in principle, people) to tunnel from the future to the past.”
Postselection is a vital part of the nascent science of quantum computing. In traditional computing, if a user needs to determine which set of variables in an equation leads to the answer being true, the computer must try every combination until it hits upon one that works. In quantum computing, due to the weird parallel behaviour of subatomic particles, it seems to be possible to simplify the procedure by running all possible variations simultaneously, and selecting only the combinations that make the answer true.
Professor Lloyd and his team say that, by combining teleportation and postselection, it would be possible to carry out the quantum teleportation effect in reverse; that is, to decide after the teleportation what the quantum state must have been before it. This works as postselection allows you to dictate which quantum states can be teleported, limiting what state it can have been in before the teleportation. The state of the particle post-teleportation has therefore, in effect, travelled back in time.
Dr Richard Low, a quantum computing scientist from the University of Bristol, says: “You could think of it as postselection affecting the history of the particle, sending the state back in time.”
Unlike previous theories of teleportation, this apparently avoids the “grandfather paradox” - or, to Back to the Future fans, the Marty McFly problem. If you go back and change time, and accidentally end up killing your own grandparent, you create a paradox - you will not be born, so you cannot go back and affect time. Even with subatomic particles, this is still a problem: upon travelling back in time, the particle could somehow destroy its earlier self or move it, thus preventing it from travelling.
However, because of the probabilistic nature of quantum mechanics, Prof Lloyd’s method seems to avoid this. Anything caused by the time travel must have had a finite probability of happening anyway, so paradoxical impossibilities are out.
Further, this time travel method does not involve bending spacetime, unlike other proposed systems. At the moment, the only conditions known that would bend spacetime sufficiently exist in black holes, which would be impractical at best.
It is a controversial theory, to say the least. Some physicists claim that the apparently impossible things implied by postselection prove that it cannot work, which would destroy Prof Lloyd’s theory before it got off the ground.
The theory is unlikely to lead to DeLorean time machines or anything remotely similar. Instead, Prof Lloyd and his team hope that it can advance our understanding of physics: “Our hope is that this theory may prove useful in formulating a quantum theory of gravity,” he says.
Prof Lloyd’s paper, The quantum mechanics of time travel through post-selected teleportation, is published in arxiv.org - Quantum Physics.
Chaos is everywhere in the natural world, present in the coiling of smoke rings, the fronds of ferns, and the beating of our hearts. But at the level of quantum physics, chaos as we now define it is unquantifiable.