Part 10 (2/2)

In fact, there is one theory that states that dark alaxy,in a parallel universe As in H G Wells's novel The Invisible Man, a person would become invisible if he floated just above us in the fourth diine two parallel sheets of paper, with so on one sheet, just above the other

In the saht be an ordinary galaxy hovering above us in another alaxy, since gravity can ooze its way between universes, but the other galaxy would be invisible to us because light alaxy would have gravity but would be invisible, which fits the description of dark ht consist of the next vibration of the superstring Everything we see around us, such as ato but the lowest vibration of the superstring Dark her set of vibrations) To be sure, most of these parallel universes are probably dead ones, consisting of a foras of subatomic particles, such as electrons and neutrinos In these universes the proton ht be unstable, so all matter as we knoould slowly decay and dissolve Co of atoms and molecules, probably would not be possible in ht be just the opposite, with co we can conceive of Instead of just one type of atoht have a dazzling array of other types of stable ht also collide, creating cosmic fireworks Some physicists at Princeton believe that perhaps our universe started out as two gigantic o The shock waves from that cataclysmic collision created our universe, they believe Ree idea are explored they apparentlythe Earth (This is called the ”Big Splat” theory) The theory of the multiverse has one fact in its favor When we analyze the constants of nature, we find that they are ”tuned” very precisely to allow for life If we increase the strength of the nuclear force, then the stars burn out too quickly to give rise to life If we decrease the strength of the nuclear force, then stars never ignite at all and life cannot exist If we increase the force of gravity, then our universe dies quickly in a Big Crunch If we decrease the strength of gravity, then the universe expands rapidly into a Big Freeze In fact, there are scores of ”accidents” involving the constants of nature that allow for life Apparently, our universe lives in a ”Goldilocks zone” of many parameters, all of which are ”fine-tuned” to allow for life So either we are left with the conclusion that there is a God of soht” to allow for life, or there are billions of parallel universes, many of them dead As Freeman Dyson has said, ”The universe seee University has written that this fine tuning is, in fact, convincing evidence for the multiverse There are five physical constants (such as the strength of the various forces) that are fine-tuned to allow for life, and he believes that there are also an infinite number of universes in which the constants of nature are not compatible with life

This is the so-called ”anthropic principle” The weak version simply states that our universe is fine-tuned to allow for life (because we are here toversion says that perhaps our existence was a by-product of design or purpose Most cosree to the weak version of the anthropic principle, but there is considerable debate over whether the anthropic principle is a new principle of science that could lead to new discoveries and results, or whether it is simply a statement of the obvious

QUANTUM THEORY

In addition to higher dimensions and the multiverse, there is yet another type of parallel universe, one that gave Einstein headaches and one that continues to bedevil physicists today This is the quantum universe predicted by ordinary quantum mechanics The paradoxes within quantum physics seem so intractable that nobel laureate Richard Feyn that no one really understands the quantuh the quantum theory is the most successful theory ever proposed by the human mind (often accurate to within one part in 10 billion), it is built on a sand of chance, luck, and probabilities Unlike Newtonian theory, which gave definite, hard answers to the ive only probabilities The wonders of the e, such as lasers, the Internet, computers, TV, cell phones, radar, microwave ovens, and so forth, are all based on the shi+fting sands of probabilities

The sharpest exaer's cat” problem (formulated by one of the founders of the quantum theory, who paradoxically proposed the problem in order to sainst this interpretation of his theory, stating, ”If one has to stick to this da ever been involved in this thing”

The Schrodinger's cat paradox is as follows: a cat is placed in a sealed box Inside a gun is pointed at the cat (and the trigger is then connected to a Geiger counter next to a piece of uraniuer counter and then the gun and the cat is killed The uranium atom can either decay or not The cat is either dead or alive This is just common sense

But in the quantum theory, we don't know for sure if the uraniu the wave function of a decayed atom with the wave function of an intact atom But this means that, in order to describe the cat, we have to add the two states of the cat So the cat is neither dead nor alive It is represented as the sum of a dead cat and a live cat!

As Feynman once wrote, quantum mechanics ”describes nature as absurd frorees with experiment So I hope you can accept nature as She is-absurd”

To Einstein and Schrodinger, this was preposterous Einstein believed in ”objective reality,” a commonsense, Newtonian viehich objects existed in definite states, not as the sum of many possible states And yet this bizarre interpretation lies at the heart of modern civilization Without it modern electronics (and the very atoms of our body) would cease to exist (In our ordinary world we sonant” But in the quantum world, it's even worse We exist sinant, pregnant, a child, an elderly woer, a career woman, etc) There are several ways to resolve this sticky paradox The founders of the quantuen School, which said that once you open the box, you make a measurement and can determine if the cat is dead or alive The wave function has ”collapsed” into a single state and co only particles This means that the cat now enters a definite state (either dead or alive) and is no longer described by a wave function

Thus there is an invisible barrier separating the bizarre world of the atom and theis described by waves of probability, in which atoer the wave at so the particle at that point But for large objects these waves have collapsed and objects exist in definite states, and hence couests would come to Einstein's house, he would point to the moon and ask, ”Does the moon exist because a en School iously adhere to the original Copenhagen School, but many research physicists have abandoned it We now have nanotechnology and can manipulate individual atoms, so atoms that dart in and out of existence can bethe microscopic and macroscopic world There is a continuum

At present there is no consensus on how to resolve this issue, which strikes at the very heart of modern physics At conferences, many theories heatedly compete with others One minority point of view is that therethe universe Objects spring into being when measures Hence there must be cos which state we are in Soued that this proves the existence of God or soner wrote, ”It was not possible to formulate the laws [of the quantum theory] in a fully consistent ithout reference to consciousness” In fact, he even expressed an interest in the Vedanta philosophy of Hinduis consciousness) Another viewpoint on the paradox is the ”h Everett in 1957, which states that the universe simply splits in half, with a live cat in one half and a dead cat in the other Thisof parallel universes each time a quantum event occurs Any universe that can exist, does The more bizarre the universe, the less likely it is, but nonetheless these universes exist This means there is a parallel world in which the nazis won World War II, or a world where the Spanish Ar in Spanish In other words, the wave function never collapses It si off into countless universes

As MIT physicist Alan Guth has said, ”There is a universe where Elvis is still alive, and Al Gore is President” nobel laureate Frank Wilczek says, ”We are haunted by the awareness that infinitelyout their parallel lives and that everyinto existence and take up our aining in popularity a called ”decoherence” This theory states that all these parallel universes are possibilities, but our wave function has decohered froer vibrates in unison with theer interacts with the room you coexist simultaneously with the wave function of dinosaurs, aliens, pirates, unicorns, all of the firer ”in tune” with the, this is like tuning into a radio station in your living roonals from scores of radio stations from around the country and the world But your radio tunes into only one station It has ”decohered” fro notes that the ”many worlds” idea is ”a miserable idea, except for all the other ideas”) So does there exist the wave function of an evil Federation of Planets that plunders weaker planets and slaughters its enemies? Perhaps, but if so, we have decohered froh Everett discussed his ”many worlds” theory with other physicists, he received puzzled or indifferent reactions One physicist, Bryce DeWitt of the University of Texas, objected to the theory because ”I just can't feel myself split” But this, Everett said, is similar to the way Galileo answered his critics who said that they could not feel the Earth(Eventually DeWitt on over to Everett's side and beca proponent of the theory) For decades the ”uished in obscurity It was simply too fantastic to be true John Wheeler, Everett's adviser at Princeton, finally concluded that there was too e” associated with the theory But one reason that Everett's theory is suddenly in vogue right now is because physicists are atte to apply the quantu quantized: the universe itself Applying the uncertainty principle to the entire universe naturally leads to a y” at first seems like a contradiction in terms: the quantum theory refers to the infinitesiy refers to the entire universe But consider this: at the instant of the big bang, the universe was rees that electrons must be quantized; that is, they are described by a probabilistic wave equation (the Dirac equation) and can exist in parallel states Hence if electrons must be quantized, and if the universe was once smaller than an electron, then the universe must also exist in parallel states-a theory that naturally leads to a ”en interpretation of Niels Bohr, however, encounters probleen interpretation, although it is taught in every PhD-level quantu an observation and collapsing the wave function The observation process is absolutely essential in defining the macroscopic world But how can one be ”outside” the universe while observing the entire universe? If a wave function describes the universe, then how can an ”outside” observer collapse the wave function of the universe? In fact, some see the inability to observe the universe froen interpretation

In the ”many worlds” approach the solution to this problem is simple: the universe simply exists in many parallel states, all defined by a master wave function, called the ”wave function of the universe” In quantuy the universe started out as a quantum fluctuation of the vacuum, that is, as a tiny bubble in the space-time foa bang and then i Crunch afterward That is e never see the in and out of the vacuu with baby universes popping in and out of existence, but on a scale that is too small to detect with our instruments But for some reason, one of the bubbles in the space-ti Crunch, but kept on expanding This is our universe According to Alan Guth, this means that the entire universe is a free lunch

In quantuue of the Schrodinger equation, which governs the wave function of electrons and atoms They use the DeWitt-Wheeler equation, which acts on the ”wave function of the universe” Usually the Schrodinger wave function is defined at every point in space and ti an electron at that point in space and time But the ”wave function of the universe” is defined over all possible universes If the wave function of the universe happens to be large when defined for a specific universe, it ood chance that the universe will be in that particular state

Hawking has been pushi+ng this point of view Our universe, he clai other universes The wave function of the universe is large for our universe and is nearly zero for most other universes Thus there is a small but finite probability that other universes can exist in the , in fact, tries to derive inflation in this way In this picture a universe that inflates is simply more likely than a universe that does not, and hence our universe has inflated

The theory that our universe caht seem to be totally untestable, but it is consistent with several simple observations First,that the total aes in our universe comes out to exactly zero, at least to within experiranted that in outer space gravity is the doative charges cancel out precisely If there was the slightest ies on the Earth, it ravitational force that holds the Earth together One simple way to explain why there is this balance between positive and negative charges is to assu” has zero charge

Second, our universe has zero spin Although for years Kurt Godel tried to show that the universe was spinning by adding up the spins of the various galaxies, astronomers today believe that the total spin of the universe is zero The phenomenon would be easily explained if the universe ca” has zero spin

Third, our universe's co would help to explain why the total y content of the universe is so sy of ravity, the two seeeneral relativity, if the universe is closed and finite, then the total ay in the universe should be exactly zero (If our universe is open and infinite, this does not have to be true, but inflationary theory does seey in our universe is remarkably small) CONTACT BETWEEN UNIVERSES?

This leaves open so questions: If physicists can't rule out the possibility of several types of parallel universes, would it be possible to make contact with thes from other universes have visited us?

Contact with other quantuhly unlikely The reason that we have decohered from these other universes is that our ato environment Each time a collision occurs, the wave function of that atom appears to ”collapse” a bit; that is, the number of parallel universes decreases Each collision narrows the number of possibilities The suives the illusion that the atoms of our body are totally collapsed in a definite state The ”objective reality” of Einstein is an illusion created by the fact that we have sointo others, each ti the nu at an out-of-focus ih a camera This would correspond to theseems fuzzy and indefinite But each tiets sharper and sharper This corresponds to trillions of tiny collisions with neighboring atoms, each of which reduces the number of possible universes In this e smoothly make the transition from the fuzzy microworld to thewith another quantum universe similar to ours is not zero, but it decreases rapidly with the number of atoms in your body Since there are trillions upon trillions of atoms in your body, the chance that you will interact with another universe consisting of dinosaurs or aliens is infinitesimally ser than the lifetime of the universe for such an event to happen

So contact with a quantum parallel universe cannot be ruled out, but it would be an exceedingly rare event since we have decohered froy, we encounter a different type of parallel universe: a multiverse of universes that coexist with each other, like soap bubbles floating in a bubble bath Contact with another universe in the multiverse is a different question It would undoubtedly be a difficult feat, but one that ht be possible for a Type III civilization

As we discussed before, the energy necessary to open a hole in space or to nify the space-tiy, where all known physics breaks down space and tiy, and this opens the possibility of leaving our universe (assu that other universes exist and we are not killed in the process)

This is not a purely acadeent life in the universe will one day have to confront the end of the universe Ultimately, the theory of the ent life in our universe Recent data fro the Earth confir rate One day weFreeze Eventually, the entire universe will go black; all the stars in the heavens will blink out and the universe will consist of dead stars, neutron stars, and black holes Even the very atoe to near absolute zero,life impossible

As the universe approaches that point, an advanced civilization facing the ulti the ultis the choice would be to freeze to death or leave The laws of physics are a death warrant for all intelligent life, but there is an escape clause in those laws

Such a civilization would have to harness the power of huge atoe as a solar systele point in order to attain the fabled Planck energy It is possible that doing so would be sufficient to open up a worateway to another universe A Type III civilization y at their disposal to open a wor our dying universe and starting over again

A BABY UNIVERSE IN THE LABORATORY?

As far-fetched as some of these ideas appear, they have been seriously considered by physicists For exaot started, we have to analyze the conditions that inal explosion In other words, we have to ask: how do you make a baby universe in the laboratory? Andrei Linde of Stanford University, one of the cocreators of the inflationary universe idea, says that if we can create baby universes, then ” more sophisticated than just the creator of the universe”

The idea is not new Years ago when physicists calculated the energy necessary to ignite the big bang ”people immediately started to wonder ould happen if you put lots of energy in one space in the lab-shot lots of cannons together Could you concentrate enough energy to set off a h energy at a single point all you would get would be a collapse of space-ti more But in 1981 Alan Guth of MIT and Linde proposed the ”inflationary universe” theory, which has since generated enor to this idea, the big bang started off with a turbocharged expansion, much faster than previously believed (The inflationary universe idea solved y, such as why the universe should be so uniforht sky to the opposite side, we see a uniforh tiions to be in contact The answer to this puzzle, according to the inflationary universe theory, is that a tiny piece of space-time that was relatively uniform blew up to become the entire visible universe) In order to ju of time there were tiny bubbles of space-time, one of which inflated enormously to become the universe of today

In one swoop the inflationary universe theory answered a host of cosical questions Moreover, it is consistent with all the data pouring in today from outer space from the WMAP and COBE satellites It is, in fact, unquestionably the leading candidate for a theory of the big bang

Yet the inflationary universe theory raises a series of e questions Why did this bubble start to inflate? What turned off the expansion, resulting in the present-day universe? If inflation happened once, could it happen again? Ironically, although the inflation scenario is the leading theory in cos is known about what set the inflation into ing questions, in 1987 Alan Guth and Edward Fahri of MIT asked another hypothetical question: how ht an advanced civilization inflate its own universe? They believed that if they could answer this question, they ht be able to answer the deeper question of why the universe inflated to begin with

They found that if you concentrated enough energy at a single point, tiny bubbles of space-time would form spontaneously But if the bubbles were too small, they would disappear back into the space-tih could they expand into an entire universe

On the outside the birth of this new universe would not look like much, perhaps no more than the detonation of a 500-kiloton nuclear bomb It would appear as if a s a small nuclear explosion But inside the bubble an entirely new universe ht expand out Think of a soap bubble that splits or buds a s a baby soap bubble The tiny soap bubble ht expand rapidly into an entirely new soap bubble Likewise, inside the universe you would see an enormous explosion of space-time and the creation of an entire universe

Since 1987 many theories have been proposed to see if the introduction of energy can e bubble expand into an entire universe The most commonly accepted theory is that a new particle, called the ”inflaton,” destabilized space-ti these bubbles to form and expand

The latest controversy erupted in 2006 when physicists began to look seriously at a new proposal to ignite a baby universe with a le north or south pole-have never been seen, it is believed that they doinal early universe They are so massive that they are extremely hard to create in the laboratory, but precisely because they are so y into a nite a baby universe into expanding into a real universe

Why would physicists want to create a universe? Linde says, ”In this perspective, each of us can beco to create a new universe: ultimately, to escape the eventual death of our universe

THE EVOLUTION OF UNIVERSES?