Cloud Hosting

You may think of physics as a way to explain the behaviors of things like black holes, colliding particles, falling apples, and quantum computers. But a small group physicists today is working on a theory that doesnt just study individual phenomena; its an entirely new way to describe the universe itself. This theory might solve wide-ranging problems such as why biological evolution is possible and how abstract things like ideas and information seem to possess properties that are independent of any physical system. Its called constructor theory, but as fascinating as it is, theres one glaring problem: how to test it.

When I first learned of constructor theory, it seemed too bold to be true, said Abel Jansma, a graduate student in physics and genetics at the University of Edinburgh. The early papers covered life, thermodynamics, and information, which seemed to be too much groundwork for such a young theory. But maybe its natural to work through the theory in this way. As an outsider, its exciting to watch.

As a young physics researcher in the 2010s, Chiara Marletto had been interested in problems regarding biological processes. The laws of physics do not say anything about the possibility of lifeyet even a slight tweak of any of the constants of physics would render life as we know it impossible. So why is evolution by natural selection possible in the first place? No matter how long you stared at the equations of physics, it would never dawn on you that they allow for biological evolutionand yet, apparently, they do.

Marletto was dissatisfied by this paradox. She wanted to explain why the emergence and evolution of life is possible when the laws of physics contain no hints that it should be. She came across a 2013 paper written by Oxford physicist and quantum computing pioneer David Deutsch, in which he laid the foundation for constructor theory, the fundamental principle of which is: All other laws of physics are expressible entirely in terms of statements about which physical transformations are possible and which are impossible, and why.

Marletto said she suspected that constructor theory had a useful set of tools to address this problem of why evolution is possible despite the laws of physics not explicitly encoding the design of biological adaptations. Intrigued by the possibilities, Marletto soon shifted the focus of her PhD research to constructor theory.

While many theories are concerned with what does happen, constructor theory is about what can possibly happen. In the current paradigm of physics, one seeks to predict the trajectory of, say, a wandering comet, given its initial state and general relativitys equations of motion. Constructor theory, meanwhile, is more general and seeks to explain which trajectories of said comet are possible in principle. For instance, no trajectory in which the comets velocity exceeds the speed of light is possible, but trajectories in which its velocity remains below this limit are possible, provided that they are also consistent with the laws of relativity.

The prevailing theories of physics today can explain things as titanically violent as the collision of two black holes, but they struggle to explain how and why a tree exists. Because constructor theory is concerned with what can possibly happen, it can explain regularitiesany patterns that warrant explanationin domains that are inherently unpredictable, such as evolution.

Constructor theory can also capture properties of information, which do not depend on the physical system in which they exist: The same song lyrics can be sent over radio waves, conjured in ones mind, or written on a piece of paper, for example. The constructor theory of information also proposes new principles that explain which transformations of information are possible and impossible, and why.

The laws of thermodynamics, too, have been expressed exactly in constructor theory; previously, theyd only been stated as approximations that would only apply at certain scales. For example, in attempting to capture the Second Law of Thermodynamicsthat the entropy of isolated systems can never decrease over timesome models show that a physical system will reach eventual equilibrium (maximum entropy) because that is the most probable configuration of the system. But the scale at which these configurations are measured has traditionally been arbitrary. Would such models work for systems at the nanoscale, or for systems that are composed of merely one particle? By recasting the laws of thermodynamics in terms of possible and impossible transformations, rather than in terms of the time evolution of a physical system, constructor theory has expressed these laws in exact, scale-independent statements: It describes the Second Law of Thermodynamics as allowing some transformation from X to Y to be possible, but not its inversework can be entirely converted into heat, but heat can never be entirely converted into work without side effects.

Physics has come a long way since the days of the Scientific Revolution. In 1687, Isaac Newton proposed his universal physical theory in his magnum opus, Principia Mathematica. Newtons theory, called classical mechanics, was founded on his famous three laws of motion. Newtons theory implies that if one knows both the force acting on a system for some time interval as well as the systems initial velocity and position, then one could use classical mechanics equations of motion to predict the systems velocity and position at any subsequent moment in that time interval. In the first few decades of the 20th century, classical mechanics was shown to be wrong from two directions. Quantum mechanics overturned Newton in explaining the physics of the microscopic world. Einsteins general relativity superseded classical mechanics and deepened our understanding of gravity and the nature of mass, space, and time. Although the details differ between the three theoriesclassical mechanics, quantum mechanics, and general relativitythey are all nevertheless expressible in terms of initial conditions and dynamical laws of motion that allow one to predict the state of a systems trajectory across time. This general framework is known as the prevailing conception.

But there are many domains in which our best theories are simply not expressible in terms of the prevailing conception of initial conditions plus laws of motion. For instance, quantum computations laws are not fundamentally about what happens in a quantum system following some initial state but rather about what transformations of information are possible and impossible. The problem of whether or not a so-called universal quantum computera quantum computer that is capable of simulating any physical system to arbitrary accuracycan possibly be built is utterly foreign to the initial conditions plus laws of motion framework. Even in cosmology, the well-known problem of explaining the initial conditions of the universe is difficult in the prevailing conception: We can work backward to understand what happened in the moments after the Big Bang, but we have no explanation for why the universe was in its particular initial state rather than any other. Constructor theory, though, may be able to show that the initial conditions of our universeat the moment of the Big Bangcan be deduced from the theorys principles. If you only think of physics in terms of the prevailing conception, problems in quantum computation, biology, and the creation of the universe can seem impossible to solve.

The basic ingredients of constructor theory are the constructor, the input substrate, and the output substrate. The constructor is any object that is capable of causing a particular physical transformation and retains its ability to do so again. The input substrate is the physical system that is presented to the constructor, and the output substrate is the physical system that results from the constructors transformation of the input.

For a simple example of how constructor theory might describe a system, consider a smoothie blender. This device takes in ingredients such as milk, fruits, and sugar and outputs a drink in completed, homogenized form. The blender is a constructor, as it is capable of repeating this transformation again and again. The input substrate is the set of ingredients, and the output substrate is the smoothie.

A more cosmic example is our Sun. The Sun acts as a nuclear fusion reactor that takes hydrogen as its input substrate and converts it into helium and light as its output substrate. The Sun itself is the constructor, as it retains its ability to cause another such conversion.

In the prevailing conception, one might take the Suns initial state and run it through the appropriate algorithm, which would yield a prediction of the Suns ending once it has run out of fuel. In constructor theory, one instead expresses that the transformation of hydrogen into helium and light is possible. Once its known that the transformation from hydrogen to helium and light is possible, it follows that a constructor that can cause such a transformation is also possible.

Constructor theorys fundamental principle implies that all laws of physicsthose of general relativity, thermodynamics, quantum mechanics, and even informationcan be expressed as which physical transformations are possible in principle and which are not.

This setup is, perhaps counterintuitively, extremely general. It includes a chemical reaction in the presence of a catalyst: the chemical catalyst is the constructor, while the reactants are the input substrate and the products are the output substrate. The operation of a computer is also a kind of construction: the computer (and its program) is a constructor, and the informational input and output correspond to constructor theorys input substrate and output substrate. A heat engine is yet another kind of constructor, and so are all forms of self-reproducing life. Think of a bacterium with some genetic code. The cell along with its code are a kind of constructor whose output is an offspring cell with a copy of the parent cells genetic code.

Because explaining which transformations are possible and which are impossible never relies on the particular form that a constructor takes, it can be abstracted away, leaving statements about transformations as the main focus of constructor theory. This is already extremely advantageous, since, for instance, one could express which computer programs or simulations are realizable and which are not in principle, without having to worry about the details of the computer itself.

How could one show that the evolution of life, with all of its elegant adaptations and appearance of design, is compatible with the laws of physics, which seem to contain no design whatsoever? No amount of inspection of the equations of general relativity and quantum mechanics would result in a eureka momentthey show no hint of the possibility of life. Darwins theory of evolution by natural selection explains the appearance of design in the biosphere, but it fails to explain why such a process is possible in the first place.

Biological evolution is understood today as a process whereby genes propagate over generations by replicating themselves at the expense of rival, alternative genes called alleles. Furthermore, genes have evolved complex vehicles for themselves that they use to reproduce, such as cells and organisms, including you. The biologist Richard Dawkins is famous for, among other things, popularizing this view of evolution: Genes are the fundamental unit of natural selection, and they strive for immortality by copying themselves as strands of DNA, using temporary, protective vehicles to proliferate from generation to generation. Copying is imperfect, which results in genetic mutations and therefore variation in the ability of genes to spread in this great competition with their rivals. The environment of the genes is the arbiter that determines which genes are best able to spread and which are unfit to do soand therefore, is the source of natural selection.

With this replicator-vehicle logic in mind, one can state the problem more precisely: The laws of physics do not make explicit that the transformations required by evolution and by biological adaptations are possible. Given this, what properties must the laws of physics possess to allow for such a process that demands self-reproduction, the appearance of design, and natural selection?

Note that this question cannot be answered in the prevailing conception, which would force us to try to predict the emergence of life following, say, the initial conditions of the universe. Constructor theory allows us to reframe the problem and consider why and under what conditions life is possible. As Marletto put it in a 2014 paper: the prevailing conception could at most predict the exact number of goats that will (or will probably) appear on Earth given certain initial conditions. In constructor theory, one states instead whether goats are possible and why.

Marlettos paper, Constructor Theory of Life, was published just two years after Deutschs initial paper. In it, she shows that the evolution of life is compatible with laws of physics that themselves contain no design, provided that they allow for the embodiment of digital information (on Earth, this takes the form of DNA). She also shows that an accurate replicator, such as survivable genes, must use vehicles in order to evolve. In this sense, if constructor theory is true, then temporary vehicles are not merely a contingency of life on our planet but rather mandated by the laws of nature. One interesting prediction that bears on the search for extraterrestrial life is that wherever you find life in the universe, it will necessarily rely on replicators and vehicles. Of course, these may not be the DNA, cells, and organisms with which we are familiar, but replicators and vehicles will be present in some arrangement.

You can think of constructor theory as a theory about theories. By contrast, general relativity explains and predicts the motions of objects as they interact with each other and the arena of space-time. Such a theory can be called an object-level theory. Constructor theory, on the other hand, is a meta-level theoryits statements are laws about laws. So while general relativity mandates the behavior of all stars, both those weve observed and those that weve never seen, constructor theory mandates that all object-level theories, both current and future, conform to its meta-level laws, also called principles. With hindsight, we can see that scientists have already taken such principles seriously, even before the dawn of constructor theory. For example, physicists expect that all as-yet unknown physical theories will conform to the principle of conservation of energy.

General relativity can be tested by observing the motions of stars and galaxies; quantum mechanics can be tested in laboratories like the Large Hadron Collider. But since constructor theory principles do not make direct predictions about the motion of physical systems, how could one test them? Vlatko Vedral, Oxford physicist and professor of quantum information science, has been collaborating with Marletto to do exactly that, by imagining laboratory experiments in which quantum mechanical systems could interact with gravity.

One of the greatest outstanding problems in modern physics is that general relativity and quantum mechanics are incompatible with each othergeneral relativity does not explain the tiny motions and interactions of atoms, while quantum mechanics does not explain gravity nor its effects on massive objects. All sorts of proposals have been formulated that might unify the two pillars under a deeper theory that contains both of them, but these are notoriously difficult to test experimentally. However, one could go around directly testing such theories by instead considering the principles to which they should conform.

In 2014, Marletto and Deutsch published a paper outlining the constructor theory of information, in which they expressed quantities such as information, computation, measurement, and distinguishability in terms of possible and impossible transformations. Importantly, they also showed that all of the accepted features of quantum information follow from their proposed constructor theoretic principles. An information medium is a physical system in which information is substantiated, such as a computer or a brain. An observable is any physical quantity that can be measured. They defined a superinformation mediumas an information medium with at least two information observables whose union is not an information observable. For example, in quantum theory, one can measure exactly a particles velocity or its position, but never both simultaneously. Quantum information is an example of superinformation. But crucially, the constructor theoretic concept of superinformation is more general and is expected to hold for any theories that supersede quantum theory and general relativity as well.

In a working paper from March 2020, Marletto and Vedral showed that if the constructor theoretic principles of information are correct, then if two quantum systems, such as two masses, become entangled with each other via a third system, such as a gravitational field, then this third system must itself be quantum (one of their earlier publications on the problem can be found here). So, if one could construct an experiment in which a gravitational field can locally generate entanglement between, say, two qubits, then gravity must be non-classicalit would have two observables that cannot simultaneously be measured with the same precision, as is the case in quantum theory. If such an experiment were to show no entanglement between the qubits, then constructor theory would require an overhaul, or it may be outright false.

Should the experiment show entanglement between the two masses, all current attempts to unify general relativity and quantum mechanics that assume that gravity is classical would be ruled out.

There are three versions of how gravity could be made consistent with quantum physics, said Vedral. One of them is to have a fully quantum gravity. Theories that propose fully quantum gravity include loop quantum gravity, the idea that space is composed of loops of gravitational fields, and string theory, the idea that particles are made up of strings, which move through space and some of whose vibrations correspond to quantum mechanical particles that carry gravitational force.

These would be consistent with a positive outcome of our proposed experiment, said Vedral. The ones that would be refuted are the so-called semi-classical theories, such as whats called quantum theory in curved space-time. There is a whole range of these theories. All of them would be ruled outit would be inconsistent to think of space-time as classical if its really capable of producing entanglement between two massive particles.

Marletto and Vedrals proposed experiment, unfortunately, faces some major practical challenges.

I think our experiment is still five or six orders of magnitude away from current technological capabilities, said Vedral. One issue is that we need to eliminate any sources of noise, like induced electromagnetic interaction... The other issue is that its very hard to create a near-perfect vacuum. If you have a background bunch of molecules around objects that you want to entangle, even a single collision between one of the background molecules and one of the objects you wish to entangle, this could be detrimental and cause decoherence. The vacuum has to be so close to perfect as to guarantee that not a single atomic collision happens during the experiment.

Vedral came to constructor theory as an interested outsider, having focused primarily on issues of quantum information. He sometimes thinks about the so-called universal constructor, a theoretical device that is capable of performing all possible tasks that the laws of physics allow.

While we have models of the universal computermeaning ideas of how to make a computer that can simulate any physical systemwe have no such thing for the universal constructor. A breakthrough might be a set of axioms that capture what it means to be a universal constructor. This is a big open problem. What kind of machine would that be? This excites me a lot. Its a wide-open field. If I was a young researcher, I would jump on that now. It feels like the next revolution.

Samuel Kuypers, a physics graduate student at the University of Oxford who works in the field of quantum information, said that constructor theory has unequivocally achieved great successes already, such as grounding concepts of information in exact physical terms and rigorously explaining the difference between heat and work in thermodynamics, but it should be judged as an ongoing project with a set of aims and problems. Thinking of potential future achievements, Kuypers hopes that general relativity can be reformulated in constructor theoretic terms, which I think would be extremely fruitful for trying to unify general relativity and quantum mechanics.

Time will tell whether or not constructor theory is a revolution in the making. In the few years since its inception, only a handful of physicists, primarily at Oxford University, have been working on it. Constructor theory is of a different character than other speculative theories, like string theory. It is an entirely different way of thinking about the nature of reality, and its ambitions are perhaps even bolder than those of the more mainstream speculations. If constructor theory continues to solve problems, then physicists may come to adopt a revolutionary new worldview. They will think of reality not as a machine that behaves predictably according to laws of motion, but as a cosmic ocean full of resources capable of being transformed by an appropriate constructor. It would be a reality defined by possibility rather than destiny.

Logan Chipkin is a freelance writer in Philadelphia. His writing focuses on science, philosophy, economics, and history. Links to previous publications can be found at http://www.loganchipkin.com. Follow him on Twitter @ChipkinLogan.

Continue reading here:

A Meta-Theory of Physics Could Explain Life, the Universe, Computation, and More - Gizmodo

The expanding Universe, full of galaxies and the complex structure we observe today, arose from a ... [+] smaller, hotter, denser, more uniform state. But even that initial state had its origins, with cosmic inflation as the leading candidate for where that all came from.

Of all the questions humanity has ever pondered, perhaps the most profound is, where did all of this come from? For generations, we told one another tales of our own invention, and chose the narrative that sounded best to us. The idea that we could find the answers by examining the Universe itself was foreign until recently, when scientific measurements began to solve the puzzles that had stymied philosophers, theologians, and thinkers alike.

The 20th century brought us General Relativity, quantum physics, and the Big Bang, all accompanied by spectacular observational and experimental successes. These frameworks enabled us to make theoretical predictions that we then went out and tested, and they passed with flying colors while the alternatives fell away. But at least for the Big Bang it left some unexplained problems that required us to go farther. When we did, we found an uncomfortable conclusion that were still reckoning with today: any information about the beginning of the Universe is no longer contained within our observable cosmos. Heres the disconcerting story.

The stars and galaxies we see today didn't always exist, and the farther back we go, the closer to ... [+] an apparent singularity the Universe gets, as we go to hotter, denser, and more uniform states. However, there is a limit to that extrapolation, as going all the way back to a singularity creates puzzles we cannot answer.

In the 1920s, just under a century ago, our conception of the Universe changed forever as two sets of observations came together in perfect harmony. For the past few years, scientists led by Vesto Slipher had begun to measure spectral lines emission and absorption features of a variety of stars and nebulae. Because atoms are the same everywhere in the Universe, the electrons within them make the same transitions: they have the same absorption and emission spectra. But a few of these nebulae, the spirals and ellipticals in particular, had extremely large redshifts that corresponded to high recession speeds: faster than anything else in our galaxy.

Starting in 1923, Edwin Hubble and Milton Humason began measuring individual stars in these nebulae, determining the distances to them. They were far beyond our own Milky Way: millions of light-years away in most instances. When you combined the distance and redshift measurements together, it all pointed to one inescapable conclusion that was also theoretically supported by Einsteins General theory of Relativity: the Universe was expanding. The farther away a galaxy is, the faster it appears to recede from us.

The original 1929 observations of the Hubble expansion of the Universe, followed by subsequently ... [+] more detailed, but also uncertain, observations. Hubble's graph clearly shows the redshift-distance relation with superior data to his predecessors and competitors; the modern equivalents go much farther. Note that peculiar velocities always remain present, even at large distances, but that the general trend is what's important.

If the Universe is expanding today, that means that all of the following must be true.

Those are some remarkable and mind-bending facts, as they enable us to extrapolate whats going to happen to the Universe as time marches inexorably forwards. But the same laws of physics that tell us whats going to happen in the future can also tell us what happened in the past, and the Universe itself is no exception. If the Universe is expanding, cooling, and getting less dense today, that means it was smaller, hotter, and denser in the distant past.

While matter (both normal and dark) and radiation become less dense as the Universe expands owing to ... [+] its increasing volume, dark energy, and also the field energy during inflation, is a form of energy inherent to space itself. As new space gets created in the expanding Universe, the dark energy density remains constant.

The big idea of the Big Bang was to extrapolate this back as far as possible: to ever hotter, denser, and more uniform states as we go earlier and earlier. This led to a series of remarkable predictions, including that:

All four of these predictions have been observationally confirmed, with that leftover bath of radiation originally known as the primeval fireball and now called the cosmic microwave background discovered in the mid-1960s often referred to as the smoking gun of the Big Bang.

Arno Penzias and Bob Wilson at the location of the antenna in Holmdel, New Jersey, where the cosmic ... [+] microwave background was first identified. Although many sources can produce low-energy radiation backgrounds, the properties of the CMB confirm its cosmic origin.

You might think that this means that we can extrapolate the Big Bang all the way back, arbitrarily far into the past, until all the matter and energy in the Universe is concentrated into a single point. The Universe would reach infinitely high temperatures and densities, creating a physical condition known as a singularity: where the laws of physics as we know them give predictions that no longer make sense and cannot be valid anymore.

At last! After millennia of searching, we had it: an origin for the Universe! The Universe began with a Big Bang some finite time ago, corresponding to the birth of space and time, and that everything weve ever observed has been a product of that aftermath. For the first time, we had a scientific answer that truly indicated not only that the Universe had a beginning, but when that beginning occurred. In the words of Georges Lemaitre, the first person to put together the physics of the expanding Universe, it was a day without yesterday.

A visual history of the expanding Universe includes the hot, dense state known as the Big Bang and ... [+] the growth and formation of structure subsequently. The full suite of data, including the observations of the light elements and the cosmic microwave background, leaves only the Big Bang as a valid explanation for all we see. As the Universe expands, it also cools, enabling ions, neutral atoms, and eventually molecules, gas clouds, stars, and finally galaxies to form.

Only, there were a number of unresolved puzzles that the Big Bang posed, but presented no answers for.

Why did regions that were causally disconnected i.e., had no time to exchange information, even at the speed of light have the same temperatures as one another?

Why were the initial expansion rate of the Universe (which works to expand things) and the total amount of energy in the Universe (which gravitates and fights the expansion) perfectly balanced early on: to more than 50 decimal places?

And why, if we reached these ultra-high temperatures and densities early on, are there no leftover relic remnants from those times in our Universe today?

Throughout the 1970s, the top physicists and astrophysicists in the world worried about these problems, theorizing about possible answers to these puzzles. Then, in late 1979, a young theorist named Alan Guth had a spectacular realization that changed history.

In the top panel, our modern Universe has the same properties (including temperature) everywhere ... [+] because they originated from a region possessing the same properties. In the middle panel, the space that could have had any arbitrary curvature is inflated to the point where we cannot observe any curvature today, solving the flatness problem. And in the bottom panel, pre-existing high-energy relics are inflated away, providing a solution to the high-energy relic problem. This is how inflation solves the three great puzzles that the Big Bang cannot account for on its own.

The new theory was known as cosmic inflation, and postulated that perhaps the idea of the Big Bang was only a good extrapolation back to a certain point in time, where it was preceded (and set up) by this inflationary state. Instead of reaching arbitrary high temperatures, densities, and energies, inflation states that:

until inflation ends. When it ends, the energy that was inherent to space itself the energy thats the same everywhere, except for the quantum fluctuations imprinted atop it gets converted into matter and energy, resulting in a hot Big Bang.

The quantum fluctuations that occur during inflation get stretched across the Universe, and when ... [+] inflation ends, they become density fluctuations. This leads, over time, to the large-scale structure in the Universe today, as well as the fluctuations in temperature observed in the CMB. New predictions like these are essential for demonstrating the validity of a proposed fine-tuning mechanism.

Theoretically, this was a brilliant leap, because it offered a plausible physical explanation for the observed properties the Big Bang alone could not account for. Causally disconnected regions have the same temperature because they all arose from the same inflationary patch of space. The expansion rate and the energy density were perfectly balanced because inflation gave that same expansion rate and energy density to the Universe prior to the Big Bang. And there were no left over, high-energy remnants because the Universe only reached a finite temperature after inflation ended.

In fact, inflation also made a series of novel predictions that differed from that of the non-inflationary Big Bang, meaning we could go out and test this idea. As of today, in 2020, weve collected data that puts four of those predictions to the test:

The large, medium and small-scale fluctuations from the inflationary period of the early Universe ... [+] determine the hot and cold (underdense and overdense) spots in the Big Bang's leftover glow. These fluctuations, which get stretched across the Universe in inflation, should be of a slightly different magnitude on small scales versus large ones.

With data from satellites like COBE, WMAP, and Planck, weve tested all four, and only inflation (and not the non-inflationary hot Big Bang) yields predictions that are in line with what weve observed. But this means that the Big Bang wasnt the very beginning of everything; it was only the beginning of the Universe as were familiar with it. Prior to the hot Big Bang, there was a state known as cosmic inflation, that eventually ended and gave rise to the hot Big Bang, and we can observe the imprints of cosmic inflation on the Universe today.

But only for the last tiny, minuscule fraction of a second of inflation. Only, perhaps, for the final ~10-33 seconds of it (or so) can we observe the imprints that inflation left on our Universe. Its possible that inflation lasted for only that duration, or for far longer. Its possible that the inflationary state was eternal, or that it was transient, arising from something else. Its possible that the Universe did begin with a singularity, or arose as part of a cycle, or has always existed. But that information doesnt exist in our Universe. Inflation by its very nature erases whatever existed in the pre-inflationary Universe.

The quantum fluctuations that occur during inflation do indeed get stretched across the Universe, ... [+] but they also cause fluctuations in the total energy density. These field fluctuations cause density imperfections in the early Universe, which then lead to the temperature fluctuations we experience in the cosmic microwave background. The fluctuations, according to inflation, must be adiabatic in nature.

In many ways, inflation is like pressing the cosmic reset button. Whatever existed prior to the inflationary state, if anything, gets expanded away so rapidly and thoroughly that all were left with is empty, uniform space with the quantum fluctuations that inflation creates superimposed atop it. When inflation ends, only a tiny volume of that space somewhere between the size of a soccer ball and a city block will become our observable Universe. Everything else, including any of the information that would enable us to reconstruct what happened earlier in our Universes past, now lies forever beyond our reach.

Its one of the most remarkable achievements of science of all: that we can go back billions of years in time and understand when and how our Universe, as we know it, came to be this way. But like many adventures, revealing those answers has only raised more questions. The puzzles that have arisen this time, however, may truly never be solved. If that information is no longer present in our Universe, it will take a revolution to solve the greatest puzzle of all: where did all this come from?

Read the rest here:

How Physics Erases The Beginning Of The Universe - Forbes

Experiencing 2020 from the POV of a rational-minded person is exhausting and scary. It sometimes feels as though weve ended up in the worst timeline of a badly-scripted parallel universes story. While everyone has their own tried-and-true coping mechanisms, wed like to suggest a science-based remedy for the pandemic blues: read some wacky research papers.

Hear us out. You could spend your day thinking about things like the upcoming US presidential elections, COVID-19, global climate crisis, and other horrifying topics. You could. Or you could take some time off and read about head transplants, the birth of our future overlords, compelling evidence youre actually living inside a computer simulation run by your great-great-great-great grandkids, whatever the hell Quantum Darwinism is, and how a new class of calculus will brute force superintelligent AI into existence.

Science is awesome and these are the receipts. Whether youre a bonafide astrophysicist or a curious kid in grammar school, these papers will entertain and enlighten you. Youre probably already familiar with the concepts discussed in them, but after reading themyoull find that theres more to all of these topics than meets the eye.

[Read: How to read a scientific research paper]

What better place to begin than with the Dr. Sergio Canveros epic paper entitled The Gemini spinal cord fusion protocol: Reloaded? This paper starts with a bang and just gets more interesting as it goes:

Sir,

Cephalosomatic anastomosis (CSA), that is, the surgical transference of a healthy head on a surgically beheaded body under deep hypothermic conditions, as conceived by Robert White, hinges on the reconnection of the severed stumps of two heterologous spinal cords. On the occasion of the first CSA between primates in 1970, Dr White hewed to the view that a severed spinal cord could not be reconnected, thus leaving the animal paralyzed.

Canvero alleged he was going to perform a human head transplant back in 2017, in the time since hes faded off into relative obscurity and many publications that showed interest in his work have since deleted those references. Most reputable medical experts considered his efforts to be quackery, but Canvero spent a large portion of his career examining the possibilities.

[Read: Human head transplants and scientist wholl perform them]

He believes that the problem with connecting millions of damaged nerves together in order to properly transplant a human head can be solved through use of a common fusogen (sealant) comprised of polyethylene glycol (PEG). Why nobody else ever though to just glue one head onto another body well never know (perhaps it was because its obviously not going to work).

Still the paper is fun and the story behind it is cool too. Not too mention theres a certain prestige that comes with being the person in your peer group with the most knowledge of human head transplants. You never know how that could come in handy.

Theres no AI in Middle-Earth, though golems are probably related. But there is AI right here on planet COVID and, if you believe Elon Musk and the late Stephen Hawking, one day its going to become superintelligent and treat us like pets (if were lucky).

While theres a lot of theories on what we should do about that, there arent many believable origin stories for the future overlords. How we do go from autocorrect that cant figure out after all these years that were almost never trying to spell duck to machines that can subjugate and destroy us?

Honestly, Google and Amazon dont have any clearer a path towards artificial general intelligence (AGI) than James Cameron when he made the movie Terminator or Daniel J. Buehrer did when he wrote A Mathematical Framework for Superintelligent Machines.

Whats that? You havent read Buehrers work? Dont feel bad, we stumbled across it one day in all its glory on sheer accident.

[Read: One machine to rule them all: A master algorithm may emerge sooner than you think]

In this paper he writes:

We describe a class calculus that is expressive enough to describe and improve its own learning process. It can design and debug programs that satisfy given input/output constraints, based on its ontology of previously learned programs. It can improve its own model of the world by checking the actual results of the actions of its robotic activators.

For instance, it could check the black box of a car crash to determine if it was probably caused by electric failure, a stuck electronic gate, dark ice, or some other condition that it must add to its ontology in order to meet its sub-goal of preventing such crashes in the future.

In essence Buehrer is talking about creating a new class of calculus that, in its own execution, would be capable of mathematical consciousness through sheer brute force of interpreting its own sensory input. If it works like he describes it, we imagine this calculus would self-propagate. So just a dab will do you.

Were not sure if we believe this aggressive methodology towards superintelligence, but it sure does make for compelling reading and there arent many other people coming up novel avenues to AGI.

Einstein and just about everybody else involved in creating the atomic bomb spent a lot of time wondering about esoteric things like whether or not God plays dice with the universe. You dont have to think very hard to imagine why.

If youre also the type of person who spends a significant portion of their time creating something intended for mass destruction (perhaps you work at a social media company or Clearview AI), then you might find this 2009 paper called Quantum Darwinism interesting.

In it, physicist Wojciech Hubert Zurek lays out the ideas behind a decoherence-based view of classical reality.

[Read: Quantum Darwinism may finally answer the question of whether God plays dice or not]

Heres what the paper says:

The quantum principle of superposition implies that any combination of quantum states is also a legal state. This seems to be in conflict with everyday reality: States we encounter are localized. Classical objects can be either here or there, but never both here and there. Yet, the principle of superposition says that localization should be a rare exception and not a rule for quantum systems.

Zurke describes how quantum Darwinism the idea that were not really seeing reality but instead an echo or imprint of reality left behind as quantum states become decoherent and then fade back into quantum coherence explains away the supposed gap between the quantum and classical worlds.

Its a fascinating paper that lends perfectly to the esoteric does God even exist? discussion. Unlike most hard-science papers discussing quantum physics, it postulates a solid connection between the distinctly different worlds complete with an explanation that makes sense.

Theres a greater than zero chance that you live inside a computer simulation. Perhaps no scientific fact hits harder than Nick Bostroms tilemma supposition (which admittedly requires a little more context than is prudent for this article):

When Bostrom published his masterfully written Are you living in a computer simulation in 2003 it was a red letter day for armchair philosophers, aspiring futurologists, and fans of The Matrix, which had just been released a few years prior arguably The ThirteenthFloor(also released in 1999) is the more closely aligned film though.

[Read: Simulation theory and the scientific pursuit of God]

Just about all of us has had a silly conversation with a friend who says things like what if this is all a dream or what if it turns out were all in a coma aboard a space ship. But Nick Bostrom actually did the work to narrow down the idea to its brass tacks and present it in a jaw-droppingly simple way. By the time you finish this paper you should be questioning your reality.

Side note: if this is a simulation, whoever is in charge of the 2020 update is a real ass.

Ian Goodfellow. If youre into AI we just got your attention. And if you dont know who that is, I envy you because youre in for a real treat. Goodfellow, as MITs Martin Giles dubbed him, is the GANfather. Hes responsible for creating the general adverserial network or GAN.

GANs are a type of AI system that makes some of the most impressive deep learning feats possible. All those cool this _____ does not exist sites that show of AI-generated images are powered by GANs. DeepFakes are powerered by GANs and so are just about any other AI that purports to generate novel content meant to imitate human work.

If there were a Mount Rushmore for modern AI architects, Ian Goodfellow goes on that list. The reason hes on this list is because he was lead author of the team who wrote the original General Adverserial Nets paper back in 2014. Yoshua Bengino was also on that same team, so you probably get two Rushmore heads in one paper here. The papers very readable and, as far as feet-firmly-on-the-ground AI papers go, its quite a good read. It might not be the most fun paper on this list, but its the one youll learn the most from. If you want to understand AI, read GANs.

There are thousands of other great research papers out there so dont stop here. If youre really feeling sassy you can just go straight to Google Scholar and start searching for your own wacky research papers we suggest searching for multiverse, time travel, and Dyson spheres for starters.

Whats your favorite research paper? Is there one you keep going back to for inspiration and comfort when youre unsure what direction to take? Talk to @mrgreene1977 on Twitter.

Follow this link:

5 esoteric science papers to take your mind off the global hellscape - The Next Web

What if aliens showed up today? Not just any run-of-the-mill group of aliens either. We are talking about a group of highly intelligent creatures that have cracked all the mysteries our universe holds. These alleged aliens would know everything about the nature of reality. If they were to try to explain these ideas, do you think humans would be able to understand them? Better yet, would our leading ideas in science line up with what the aliens have to say? With our present-day understanding of the universe, how close would we be?

Most physicists would tell you that we are on the right path, but we still have some progress to make. In humanity's relentless pursuit to understand our reality, we have come up with testable and astoundingly accurate theories that explain events happening in an unimaginably small scale and an infinitely expansive universe. However, the current mathematical frameworks explaining the colossal and the minuscule do not agree with each other. For the past century, leading physicists have placed their hopes in the ever so elusive unified field theory or theory of everything (TOE). But, should they?

SEE ALSO: THE QUANTUM WORLD DOES NOT REALLY MAKE SENSE

In particle physics, a unified field theory, or grand unified theory, isan attempt to describe all fundamental forces and the relationships between elementary particles in terms of a single theoretical framework.

In the mid-19th century,James Clerk Maxwellformulated the first field theory in his theory ofelectromagnetism, which demonstrated the relationship between the forces of electricity and magnetism. Then, in the early 20th century,Albert Einsteindevelopedgeneral relativity, a field theory ofgravitation. Later, Einstein and others attempted to construct a unified field theory that incorporated both electromagnetism and gravity as different aspects of a single fundamental field.

Some researchers say that a unified theory is chasing a unicorn. Nevertheless, a vocal majority, including Einstein, believe it is possible to bridge the gap between the electromagnetic force, the strong and the weak nuclear forces, and gravity.

As the Cosmologist and particle physicistJohn Barrowof the University of Cambridge in the UK wrote, "Finding a theory of everything is quite conceivable. The laws of nature are rather few, they're simple and symmetrical, and there are only four fundamental forces." However, we are getting ahead of ourselves. You may be asking what exactly is a theory of everything?

The universe and everything in it are held together by four fundamental forces; the electromagnetic force, the strong and the weak nuclear force, and the gravity. The first three forces form the standard model of particle physics, which is the world of quantum mechanics in a nutshell. You are probably familiar with some aspects of the quantum world, like quantum entanglement and the uncertainty principle. Gravity is the black sheep of this family of forces, walking around like an unruly child, making things verydifficult for everyone.

The gravitational force explains the behavior of all things with mass or energy.In 1915, Albert Einstein proposed hisgeneral theory of relativity, which describes gravity not as aforce, but as a consequence of thecurvature of spacetimecaused by the uneven distribution of mass.

However, things (mostly math) fall apart when both quantum mechanics and relativity are applied together. A theory of everything would bring everything together, mathematically, and hopefully in a beautifully unified theory. However, this is immensely difficult. Although our understanding of physics has expanded since Einstein's contributions (i.e., strong and weak nuclear forces).

As the famed physicist once said to a student, "I want to know how God created this world. I'm not interested in this or that phenomenon, in the spectrum of this or that element. I want to know his thoughts; the rest are just details." So how much closer are we to knowing the mind of God? Well, it depends on who you ask. There are multiple candidates for a theory of everything, each with their own peculiarities, but each of them is equally mind-boggling. For this article, we will focus on the core ideas of these theories. Let's begin.

String theory is probably one of the strongest candidates on our list, as it is one of the most-explored potential theories of everything. You may have heard of it before in pop culture, or perhaps you have a friend who loves talking about it when drunk.

However, the world of string theory is a deep rabbit hole that can be a little brain-melting. String theory posits that particles are actually one-dimensional strings that vibrate at the very basic level.

According to String Theory, these strings vibrate at different levels determining particle types and properties, such as mass and charge. But, for this theory to work mathematically, extra spatial dimensions that cannot be experienced directly by humans need to be taken into the equation.

Though radical, the idea is an elegant approach to the conundrums mentioned above. However, there are multiple issues with string theory. We are going to focus on two big ones.

First and foremost, string theory is just that, "a theory," and theorists are having a hard time finding ways to properly test this idea, with some physicists going as far as to say that string theory is pseudoscience. This may change very soon. Leading physicists from institutions likeHarvard UniversityandStony Brook Universitybelieve the key to constructing a TOE over string theory revolves around the concept of inflation.

Inflation is thought to have played a major role in the Big Bang's earliest moments, explaining why the universe looks the way it does, and why it went through a phase of extreme expansion. If string theory can eventually be made to explain inflation, it may be one step closer to becoming the grand unified theory that we have been looking for all these years. However, this leads to our next issue.

At the moment, there are too many variants to the theory. Physicists have taken a shot at unifying multiple string theory ideas, creating a more general framework dubbed M-theory. However, M-theory just opens the doors to 10^ 500 universes. Some believe that this could be proof thatthere are multiple universes, or that the theory is untestable. String theory appears to have a long way to go before the scientific community can embrace it.

LQG or loop quantum gravity is currently one of string theory's biggest contesters for the title of "theory of everything". The general idea for loop quantum gravity is that space is not continuous but is broken up into tiny chunks or quantas: gravitational fields about 10^-35 meters across. These quantas of space are then connected by links to form the space that we experience. When these links get tangled into "braids" and "knots", they produce elementary particles. LQG has some bold claims, including describing how the universe may have formed after the collapse of a previous universe. Unlike string theory, LQG does not introduce extra dimensions and does not try to unify all forces. The theory could be used to explain some big real-world ideas and help clarifythe beginning of our universe.

However, most versions of loop quantum gravity struggle to incorporate gravity, and in fact, some don't even attempt to. Instead, they make an effort to quantize the gravitational field while it is kept separate from the other forces

This is the point on the list where things begin to get a bit weird, moving beyond mainstream science to more fringe areas of science or full-on thought experiments. Fotini Markopoulou and her colleagues at the Perimeter Institute for Theoretical Physics in Waterloo, Ontario, Canada aim to throw many universal assumptions out the window on their quest to find a theory of everything. Dubbed Quantum Graphity, Markopoulou believes that when the universe formed in the Big Bang, space did not exist as we know it.

According to this theory, the universe as we know it was once an abstract network of "nodes" of space. Each node was connected to one other. However, soon after the Big Bang, the universe collapsed, creating the principles that govern our reality today.

RESEARCHERS USE RICHARD FEYNMAN'S IDEAS TO DEVELOP A WORKING 'THEORY OF EVERYTHING'

One of the biggest issues with connecting gravity to the world of quantum mechanics is what happens to gravity on very small scales. Things get a little weird. The current models we have suggest that gravity is a very weak force. The same models would also have you believe that the closer two objects are to each other, the stronger the gravitational attraction between them. But this breaks down on the quantum level. Quantum Einstein gravity could be a potential explanation to this puzzle, and another candidate for a theory of everything. Proposed by Martin Reuter of the University of Mainz, Germany, this idea could open the doors to a quantum theory of gravity.

Garrett Lisi's paper "An Exceptionally Simple Theory of Everything" is controversial, elegant, and beautiful. According to the physicist's E8 theory, the 248-dimensional mathematical object above is the key to understanding the universe. The physicist and surfer's potential theory of everything can be summarized with an E8 Lie Group. Lisi created this structure by graphing the fundamental particles of a chart marking the electro-weak force, the hypercharge, and the charges in the Higgs field. After plotting all these particles on a 3D graph, this complex eight-dimensional mathematical pattern emerged with 248 points. Again, every single one of these dots are fundamental particles with different properties.

This is where things get interesting. There are a handful of particles on the diagram with specific properties that are "missing." This means that we can test and look for particles with these specific properties. Even more so, it is believed that these particles would correlate with gravity bridging our quantum and general relativity gap. Of course, this theory should be taken with a grain of salt, and even Lisi still believes the idea needs some work. However, he thinks it has a better chance of being a theory of everything than string theory. Shots fired.

As you have probably noticed, a lot of these theories float on the fringes of science. Even our most promising candidate string theory still struggles with finding practical ways of being tested. A grand unifying theory is based on the assumption that nature has an elegant, symmetrical mathematical solution to the principles that govern our reality. However, science shows us time and time again, that this is rarely the case. In an article for Nautilus, Sabine Hossenfelder, a Research Fellow at the Frankfurt Institute for Advanced Studies, the researcher stated that "This whole idea of a theory of everything is based on an unscientific premise."

"This is simply not a good strategy to develop scientific theories, and no, it is most certainly not standard methodology. Indeed, the opposite is the case. Relying on beauty in theory development has historically worked badly."

At times, the theory of everything seems to be as elusive as a shiny Pokemon and as mythical as a unicorn. Do you think one of the theories above will explain the nature of reality? Or do we still have a long way to go? What other ideas or approaches should we consider?

The rest is here:

Theory of Everything? One of These Theories Could Explain the Very Nature of Our Universe... Maybe - Interesting Engineering