Multiplying universes: How many is the multiverse?

Multiplying universes: How many is the multiverse?

by Amanda Gefter

HOW many universes are there? Cosmologists Andrei Linde and Vitaly Vanchurin at Stanford University in California calculate that the number dwarfs the 10500 universes postulated in string theory, and raise the provocative notion that the answer may depend on the human brain.

The idea that there is more than one universe, each with its own laws of physics, arises out of several different theories, including string theory and cosmic inflation. This concept of a "multiverse" could explain a puzzling mystery - why dark energy, the furtive force that is accelerating the expansion of space, appears improbably fine-tuned for life. With a large number of universes, there is bound to be one that has a dark energy value like ours.

Calculating the probability of observing this value - and other features of the cosmos - depends on how many universes of various kinds populate the multiverse. String theory describes 10500 universes, but that just counts different vacuum states, which are like the blank canvases upon which universes are painted. The features of each canvas determine what the overall painting will look like - such as the laws of physics in that universe - but not the details.

Thanks to the randomness of quantum mechanics, two identical vacuum states can end up as very different universes. Small quantum fluctuations in the very early universe are stretched to astronomical scales by inflation, the period of faster-than-light expansion just after the big bang. These fluctuations lay down a gravitational blueprint that eventually determines the placement of stars and galaxies across the sky. Small differences in the form of these fluctuations can produce a universe in which the Milky Way is slightly bigger, or closer to its neighbours.


So just how many of these different universes can inflation's quantum fluctuations produce? According to Linde and Vanchurin, the total is about 101010,000,000 - that's a 10 raised to a number ending with 10 million zeros (arxiv.org/abs/0910.1589). Suddenly string theory's multiverse of 10500 universes is looking rather claustrophobic.

It might be, however, that this number is irrelevant, and that in a world ruled by quantum physics what matters is how many universes a single observer can distinguish. "Before quantum mechanics," says Linde, "we thought that 'reality' was a well-defined word." In classical physics, observers are irrelevant - we simply want to know how many universes exist.
It may not matter how many universes exist - just how many a single observer can tell apart

According to quantum physics, observers affect the systems they measure (see "Restricted view"). If observers are an integral part of the cosmic formula, then it may not matter how many universes exist - just how many a single observer can tell apart. If the observer is a person, that depends on how many bits of information the brain can process. "Based on the number of synapses in a typical brain, a human observer can register 1016," says Linde. That means humans can differentiate 101016 universes, which is much more manageable than the 101010,000,000 Linde and Vanchurin found to start with.

But does the human brain really play a role in making predictions in the multiverse? "This goes deep into philosophy," Linde says. "It's a slippery slope."


Cosmologist Alex Vilenkin of Tufts University in Boston is equally ambivalent. "It could be right that what is important is what an observer sees," he says. "But there might be things an observer doesn't see that are still there."

Restricted view

Quantum theory splits the world into two parts: the system under study and the rest of the world, which contains the observer. The system hovers in a ghostly state of near-existence made up of a host of possibilities until the observer makes a measurement - and so reduces this to a single reality.

Cosmology suffers from the paradox that no observer can be outside the universe - so the universe is doomed to spend eternity as nothing more than a vague possibility. The lesson of quantum cosmology is that we can't talk about the universe as a whole, but only what a given observer inside it might measure. Applying that lesson to the multiverse, Andrei Linde and Vitaly Vanchurin suggest that what matters is not the total number of possible universes, but the number of universes a single observer could distinguish.


If that observer is a human, the brain limits the amount of information they can register. But any observer - even an inanimate one such as a galaxy - is limited in the information it can store. These limitations in what observers can measure whittle down the number of universes that come into play in cosmological predictions. That means an observer might make a difference in explaining the value of things like dark energy.


World Science Festival 2009: Infinite Worlds, Part 3 of 6 from World Science Festival on Vimeo.

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Intention & Retrocausality

Cause and effect is pretty easy to understand. I pick up a remote control, press the power button and my TV turns on. Me pressing the power button is the cause, the TV turning on is the effect. We all learned about it in grade school.

But what if that were reversed? What if my TV turned on, and that caused me in the past to press the power button on the remote control? It goes against everything we think we know about the way the universe works, but that is the essence of the theory of retrocausality. The effect
creates the cause. It sounds like something straight out of the pages of science fiction, but many scientists today believe that retrocausality could be a real phenomenon.

From wikipedia: Retrocausality (also called retro-causation, backward causation and similar terms) is any of several hypothetical phenomena or processes that reverse causality, allowing an effect to occur before its cause.

According to Paul March from a Talk Polywell comment: Dr. Cramer's retrocausal experiment should be completed by the end of this year. And if verified it would buttress Dr. Woodward's M-E (Mach Effect) arguments and provide a path to finally merging GRT (General relativity) with QM (Quantum Mechanics).

A 36 page presentation from 2007: The UW Nonlocal Quantum Communication Experiment by John Cramer

Entanglement: The separated but “entangled” parts of the same quantum system can only be described by referencing the state of other part.
The possible outcomes of measurement M2 depend of the results of measurement M1, and vice versa. This is usually a consequence of conservation laws.


Nonlocality: This “connectedness” between the separated system parts is called quantum nonlocality. It should act even of the system parts are separated by light years. Einstein called this “spooky actions at a distance.”



Physicist York Dobyns explains retrocausality -- how human intentions affect the past; discusses Cal Tech Physicist Kip Thorne's theories of wormholes on the fabric of space and time; and touches upon some of the strange implications of our current understanding of quantum mechanics. Interview by Tom Munnecke at the American Association for the Advancement of Science at University of San Diego on June 23, 2006.


York Dobyns earned his PhD in physics at Princeton and is the Analytical Coordinator for the Princeton Engineering Anomalies Research (PEAR) program.
For more information, visit: http://www.princeton.edu/~pear/


A Brief History of Retrocausality Experiments: 35 years ago, Helmut Schmidt pioneered studies on the effects of human intention on random event generators (REGs) — machines which generate a string of qubits that can be imagined as a stream of coins flipping in the air. Using REG data which were prerecorded and unobserved, Schmidt showed that his subjects were able to influence selected heads or tails events which had occurred up to six days earlier. More recently, Brenda Dunne and Robert Jahn (PEAR) conducted close to 87,000 similar (and statistically significant) REG/RPK experiments. Elmar Grubers retrocausation experiments (PK Effects on Pre-Recorded Group Behaviour of Living Systems European Journal of Parapsychology, 3, 1980, 167-75) showed that conscious intention can seemingly influence the past activity of both animals and humans. In one of the human trials, the effect size was 0.74, which is over twenty-three times greater than the effect size of most prescription drugs (0.032). These studies — and numerous others involving everything from steel marbles to human skin conductance and heart rate — have shown the apparent effect that conscious intent has on altering events which have already occurred... Or, at least, events which have already occurred from our commonly held perspective.




Part 2: http://www.youtube.com/watch?v=bYOaQQUWk7s

Part 3: http://www.youtube.com/watch?v=AAUTs-1ukrY

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Origins of the Universe

At least our one "local" universe (quantum theory suggest an infinite number of them), the big bang theory is stil being debated. Sam neil hosts this doc with decent production value. worrrd.


Watch Programme 1: Star Stuff in Educational | View More Free Videos Online at Veoh.com
The multiverse (or meta-universe (metaverse)) is the hypothetical set of multiple possible universes (including our universe) that together comprise all of reality. The different universes within the multiverse are sometimes called parallel universes. The structure of the multiverse, the nature of each universe within it and the relationship between the various constituent universes, depend on the specific multiverse hypothesis considered.

and "are we alone"


Watch Programme 4: Are We Alone? in Educational | View More Free Videos Online at Veoh.com

quantum physics and consciousness

A commonly debated use of the term refers to quantum mechanics, where, if the outcome of an event has not been observed, it exists in a state of 'superposition', which is akin to being in all possible states at once. In the famous thought experiment known as Schrödinger's cat the cat is supposedly neither alive nor dead until observed. However, most quantum physicists, in resolving Schrödinger's seeming paradox, now understand that the acts of 'observation' and 'measurement' must also be defined in quantum terms before the question makes sense. From this point of view, there is no 'observer effect', only one vastly entangled quantum system. A significant minority still find the equations point to an observer; Wheeler, who probably worked more deeply on this subject than any physicist thus far, devised a graphic in which the universe was represented by a "U" with an eye on one end, turned around and viewing itself, to describe his understanding.


good video about the connection between perceived reality/matter and consciousness.



The Heisenberg uncertainty principle is also frequently confused with the "observer effect". The uncertainty principle actually describes how precisely we may measure the position and momentum of a particle at the same time — if we increase the precision in measuring one quantity, we are forced to lose precision in measuring the other. Thus, the uncertainty principle deals with measurement, and not observation. The idea that the Uncertainty Principle is caused by disturbance (and hence by observation) is not considered to be valid by some, although it was extant in the early years of quantum mechanics, and is often repeated in popular treatments.



There is a related issue in quantum mechanics relating to whether systems have pre-existing — prior to measurement, that is — properties corresponding to all measurements that could possibly be made on them. The assumption that they do is often referred to as "realism" in the literature, although it has been argued that the word "realism" is being used in a more restricted sense than philosophical realism[1]. A recent experiment in the realm of quantum physics has been quoted as meaning that we have to "say goodbye" to realism, although the author of the paper states only that "we would [..] have to give up certain intuitive features of realism" [2] [3]. These experiments demonstrate a puzzling relationship between the act of measurement and the system being measured, although it is clear from experiment that an "observer" consisting of a single electron is sufficient -- the observer need not be a conscious observer. Also, note that Bell's Theorem suggests strongly that the idea that the state of a system exists independently of its observer may be false.



Note that the special role given to observation (the claim that it affects the system being observed, regardless of the specific method used for observation) is a defining feature of the Copenhagen Interpretation of quantum mechanics. Other interpretations resolve the apparent paradoxes from experimental results in other ways. For instance, the Many-Worlds Interpretation posits the existence of multiple universes in which an observed system displays all possible states to all possible observers. In this model, observation of a system does not change the behavior of the system -- it simply answers the question of which universe(s) the observer(s) is(are) located in: In some universes the observer would observe one result from one state of the system, and in others the observer would observe a different result from a different state of the system.

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Created Quantum Creatures

Water bears, similar to the one pictured here, can survive in a vacuum and might be made to behave like quantum objects

Quantum weirdness could soon invade the living world, if a scheme to give a flu virus a strange double life comes off.

In quantum theory, a single object can be doing two different things at once. This so-called "superposition" is a delicate state, destroyed by any contact with the outside world. The largest objects that have been superposed so far are molecules. It is hard to put a much larger object such as a cat or human into a superposition because air molecules and photons are always bouncing off it.

But it might be possible with a small life form, according to Oriol Romero-Isart of the Max Planck Institute for Quantum Optics in Garching, Germany, and his colleagues. They hope to prove the concept with the flu virus, which exhibits some properties of life, because it can survive in a vacuum – solving the problem of pesky air molecules.

Laser hold

Their scheme would use two laser beams, whose light exerts a gentle force on matter. Where the two beams cross they form an "optical cavity" holding the virus in place.

By adjusting the frequency of the beams, the laser photons can be made to absorb the vibration energy of the trapped virus about its centre of mass until it is slowed to its lowest possible energy state. In this "ground state" the virus is ready to go into a superposition.

Sending a laser photon towards the trap should do the trick. Since a photon is a quantum entity it has more than one option open to it. Thus it will be both reflected and transmitted at the trap, putting it into a superposition.

By impinging on the virus, it forces it into a superposition of both its ground state and next vibrational energy state. Now the virus should be doing two different things at once – the equivalent of you simultaneously mowing the lawn and doing the shopping. "They have come up with a really neat experiment – inventive and I think feasible," says Peter Knight of Imperial College London.

Romero-Isart and his colleagues speculate that they could pull off the same feat with a tardigrade, or water bear, an animal less than a millimetre in size that can survive extreme temperatures and a vacuum for several days.

Big questions

Making a living thing do two things at once is more than a physicist's tour de force. It could answer fundamental questions about the nature of quantum theory.

Most physicists believe that the reason quantum behaviour manifests itself only in small things is that objects are difficult to isolate from their surroundings. But the prominent physicist Roger Penrose of the University of Oxford believes instead that there is a critical size, or mass, at which bodies cease to become quantum.

According to Knight, experiments of the kind proposed by Romero-Isart's team could finally offer a way to distinguish between the mainstream view and Penrose's.

Fractal Geometry / Electromagnetism / Golden Ratio

 (image of an actual snowflake)

Relativity's replacement announced by Dan Winter - "The Word 'Relativity' is obsolete to describe the relationship of mass to energy because that relationship (which allows charge to compress and thus be called MASS) is more precisely FRACTAL.

 Thus geometric self-similarity perfected (Golden Ratio) allows charge (energy) to compress (non destructively) and thus become MASS. Fractality (of charge) creates MASS , life force, and self-organization (because that is what permits implosion). That Fractal path permitting non-destructive charge compression simultaneously produces charge ACCLERATION -(recursion in velocity heterodynes) which is the only source of the phenomenon called GRAVITY. The rotation of energy which stores the inertia called mass - which is also our only definition of time - is always only held in place by the centripedal charge force (gravity) caused by fractal self-similarity - being the only way any wave system (time or space) emerges from chaos."

In mathematics and the arts, two quantities are in the golden ratio if the ratio of the sum of the quantities to the larger one equals the ratio of the larger one to the smaller. The golden ratio is an irrational mathematical constant, approximately 1.6180339887. Other names frequently used for the golden ratio are the golden section (Latin: sectio aurea) and golden mean. Other terms encountered include extreme and mean ratio, medial section, divine proportion, divine section (Latin: sectio divina), golden proportion, golden cut, golden number, and mean of Phidias. The golden ratio is often denoted by the Greek letter phi, usually lower case (φ).
The figure on the right illustrates the geometric relationship that defines this constant. Expressed algebraically:

The Uncertain Nature of Matter

Uncertain Principles
This BBC documentary explores the emergence of Heisenberg's Uncertainty Principle in the early 20th century, and how its implications shook up the scientific establishment of the day. Its detractors -- including Einstein -- wanted to believe that an underlying determinism and realism is foundational to the universe. Despite experiments attempting to disprove Heisenberg's work, the Uncertainty Principle prevailed and remains one of the fundamental concepts of quantum theory.

Quantum Physics Simplified

Quantum mechanics (QM) is a set of principles describing physical reality at the atomic level of matter (molecules and atoms) and the subatomic (electrons, protons, and even smaller particles). These descriptions include the simultaneous wave-like and particle-like behavior of both matter[1] and radiation[2] ("wave–particle duality"). In the quantum mechanics of a subatomic particle, one can never specify its state, such as its simultaneous location and velocity, with complete certainty (this is called the Heisenberg uncertainty principle — see its formula in the box to the right).

Certain systems, however, do exhibit quantum mechanical effects on a larger scale; superfluidity (the frictionless flow of a liquid at temperatures near absolute zero) is one well-known example. Quantum theory also provides accurate descriptions for many previously unexplained phenomena such as black body radiation and the stability of electron orbits. It has also given insight into the workings of many different biological systems, including smell receptors and protein structures.[3]
Even so, classical physics often can be a good approximation to results otherwise obtained by quantum physics, typically in circumstances with large numbers of particles (some questions remain open, however, in the field of quantum chaos).

The particle/wave experiment where the observer affects the outcome, done in cartoon form for knuckle heads.

Other Dimensional Life

Are there extra dimensions of space?

The Tevatron
At Fermilab’s Tevatron, physicists study such exotic phenomena as extra dimensions, paving the way for scientific discoveries.

The revolutionary concept of string theory is a bold realization of Einstein's dream of an ultimate explanation for everything from the tiniest quanta of particle physics to the cosmos itself. String theory unifies physics by producing all known forces and particles as

different vibrations of a single substance called superstrings. String theory brings quantum consistency to physics with an elegant mathematical construct that appears to be unique.

Do superstrings exist?

The strings themselves are probably too tiny to observe directly, but string theory makes a number of testable predictions. It implies supersymmetry and predicts seven undiscovered dimensions of space, dimensions that would give rise to much of the mysterious complexity of particle physics. Testing the validity of string theory requires searching for the extra dimensions and exploring their properties. How many are there? What are their shapes and sizes? How and why are they hidden? And what are the new particles associated with the extra dimensions?

to travel from one parallel universe to an adjacent one. A wormhole which connects (usually closed) universes is called a Schwarzschild wormhole. In string theory, a wormhole has been envisioned to

connect two D-branes, where the mouths are attached to the branes and are connected by a flux tube. If a brane is in fact a universe, this would make perfect sense. Also wormholes are believed to be a part of space-time foam. There are two main types of wormholes: Lorentzian wormholes and Euclidean wormholes.

..Lorentzian wormholes are a product of general relativity and semi-classical gravity, but Euclidean wormholes are studied in particle physics. Interestingly, traversable wormholes (a special kind of Lorentzian wormhole) could possibly allow a human to travel from one side of the wormhole to the other. It would certainly allow a cross transmission of EMF or other forms of pure energy.

..Lorentzian wormholes are not excluded within the framework of general relativity, but the physical plausibility of their existence has remained elusive. It is also unknown whether a theory of quantum gravity, merging general relativity with quantum mechanics, would still allow them, but I suspect they would. Most of the accepted solutions of general relativity which allow for traversable wormholes require the existence of exotic matter, a theoretical substance which would have to have a negative energy density. However, it has not been mathematically proven that this is an absolute requirement for traversable wormholes, nor has it been established that exotic matter cannot exist.

Exotic matter is a hypothetical concept of particle physics. It covers any material which violates one or more classical conditions or is not made of known baryonic particles. Such materials would possess qualities like negative mass or being repelled rather than attracted by gravity. The closest known real representative of exotic matter is a region of pseudo-negative pressure density produced by the Casimir effect. In physics, the Casimir effect and the Casimir-Polder force are physical forces arising from a quantized field. The typical example is of two uncharged metallic plates in a vacuum, placed a few micrometers apart, without any external electromagnetic field.

Scientists discuss what sort of life could be found in the eleventh dimension. With talk of world of lightning bolts, electricity, unstable atoms and more, this video from BBC show 'Parallel Universe' is full of mind-bending theories.

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The Elegant Universe

For most of us, or perhaps all of us, it's impossible to imagine a world consisting of more than three spatial dimensions. Are we correct when we intuit that such a world couldn't exist? Or is it that our brains are simply incapable of imagining additional dimensions—dimensions that may turn out to be as real as other things we can't detect?

String theorists are betting that extra dimensions do indeed exist; in fact, the equations that describe superstring theory require a universe with no fewer than 10 dimensions. But even physicists who spend all day thinking about extra spatial dimensions have a hard time describing what they might look like or how we apparently feeble-minded humans might approach an understanding of them. That's always been the case, and perhaps always will be

Watch The Elegant Universe Nova in Educational | View More Free Videos Online at Veoh.com

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Quantum Mechanics Lecture

Image via Wikipedia

Lecture 1 of Leonard Susskind's Modern Physics course concentrating on Quantum Mechanics. Recorded January 14, 2008 at Stanford University.

This Stanford Continuing Studies course is the second of a six-quarter sequence of classes exploring the essential theoretical foundations of modern physics. The topics covered in this course focus on quantum mechanics. Leonard Susskind is the Felix Bloch Professor of Physics at Stanford University.

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