[Paleopsych] Michio Kaku: Escape from the universe

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Escape from the universe
http://prospectmagazine.co.uk/printarticle.php?id=6701&category=138&issue=499&author=&AuthKey=6980b9de52579f3b22057c19594e76c9


    Issue 107 / February 2005
    Escape from the universe
    The universe is destined to end. Before it does, could an advanced
    civilisation escape via a "wormhole" into a parallel universe? The
    idea seems like science fiction, but it is consistent with the laws of
    physics and biology. Here's how to do it
    Michio Kaku
    The author is professor of theoretical physics at City University of
    New York. This article is adapted from his book "Parallel Worlds"
    (Allen Lane)
      _________________________________________________________________

    The universe is out of control, in a runaway acceleration. Eventually
    all intelligent life will face the final doomâthe big freeze. An
    advanced civilisation must embark on the ultimate journey: fleeing to
    a parallel universe.
    In Norse mythology, Ragnarokâthe fate of the godsâbegins when the
    earth is caught in the vice-like grip of a bone-chilling freeze. The
    heavens themselves freeze over, as the gods perish in great battles
    with evil serpents and murderous wolves. Eternal darkness settles over
    the bleak, frozen land as the sun and moon are both devoured. Odin,
    the father of all gods, finally falls to his death, and time itself
    comes to a halt.
    Does this ancient tale foretell our future? Ever since the work of
    Edwin Hubble in the 1920s, scientists have known that the universe is
    expanding, but most have believed that the expansion was slowing as
    the universe aged. In 1998, astronomers at the Lawrence Berkeley
    National Laboratory and the Australian National University calculated
    the expansion rate by studying dozens of powerful supernova explosions
    within distant galaxies, which can light up the entire universe. They
    could not believe their own data. Some unknown force was pushing the
    galaxies apart, causing the expansion of the universe to accelerate.
    Brian Schmidt, one of the group leaders, said, "I was still shaking my
    head, but we had checked everything⦠I was very reluctant to tell
    people, because I truly thought that we were going to get massacred."
    Physicists went scrambling back to their blackboards and realised that
    some "dark energy" of unknown origin, akin to Einstein's "cosmological
    constant," was acting as an anti-gravity force. Apparently, empty
    space itself contains enough repulsive dark energy to blow the
    universe apart. The more the universe expands, the more dark energy
    there is to make it expand even faster, leading to an exponential
    runaway mode.
    In 2003, this astonishing result was confirmed by the WMAP (Wilkinson
    microwave anisotropy probe) satellite. Orbiting at a million miles
    from earth, this satellite contains two telescopes capable of
    detecting the faint microwave radiation which bathes the universe. It
    is so sensitive that it is able to photograph in exquisite detail the
    afterglow of the microwave radiation left over from the big bang,
    which is still circulating the universe. The WMAP satellite, in
    effect, gave us "baby pictures" of the universe when it was a mere
    380,000 years old.
    The WMAP satellite settled the long-standing question of the age of
    the universe: it is officially 13.7bn years old (to within 1 per cent
    accuracy). But more remarkably, the data showed that dark energy is
    not a fluke, but makes up 73 per cent of the matter and energy of the
    entire universe. To deepen the mystery, the data showed that 23 per
    cent of the universe consists of "dark matter," a bizarre form of
    matter which is invisible but still has weight. Hydrogen and helium
    make up 4 per cent, while the higher elements, you and I included,
    make up just 0.03 per cent. Dark energy and most of dark matter do not
    consist of atoms, which means that, contrary to what the ancient
    Greeks believed and what is taught in every chemistry course, most of
    the universe is not made of atoms at all.
    As the universe expands, its energy content is diluted and
    temperatures eventually plunge to near absolute zero, where even atoms
    stop moving. One of the iron laws of physics is the second law of
    thermodynamics, which states that in the end everything runs down,
    that the total "entropy" (disorder or chaos) in the universe always
    increases. This means that iron rusts, our bodies age and crumble,
    empires fall, stars exhaust their nuclear fuel, and the universe
    itself will run down, as temperatures drop uniformly to near zero.
    Charles Darwin was referring to this law when he wrote: "Believing as
    I do that man in the distant future will be a far more perfect
    creature than he now is, it is an intolerable thought that he and all
    other sentient beings are doomed to complete annihilation after such
    long-continued slow progress." And one of the most depressing passages
    in the English language was written by Bertrand Russell, who described
    the "unyielding despair" he felt when contemplating the distant
    future: "No fire, no heroism, no intensity of thought or feeling, can
    preserve a life beyond the grave⦠all the labours of the ages, all
    the devotion, all the inspiration, all the noonday brightness of human
    genius, are destined to extinction in the vast death of the solar
    system; and the whole temple of man's achievement must inevitably be
    buried beneath the debris of a universe in ruins."
    Russell wrote this passage in an era before space travel, so the death
    of the sun does not seem so catastrophic todayâbut the death of the
    entire universe seems inescapable. So on some day in the far future,
    the last star will cease to shine, and the universe will be littered
    with nuclear debris, dead neutron stars and black holes. Intelligent
    civilisations, like homeless people in rags huddled next to dying
    campfires, will gather around the last flickering embers of black
    holes emitting a faint Hawking radiation.
    String theory to the rescue?
    Although thermodynamics and cosmology point to the eventual death of
    all lifeforms in the universe, there is still one loophole. It is a
    law of evolution that, when the environment changes radically, life
    must adapt, flee or die. The first alternative seems impossible. The
    last is undesirable. This leaves us with one choice: leave the
    universe.
    Although the concept of leaving our dying universe to enter another
    seems utterly mad, there is no law of physics forbidding entering a
    parallel universe. Einstein's general relativity theory allows for the
    existence of "wormholes" or gateways connecting parallel universes,
    sometimes called "Einstein-Rosen bridges." But it is still unknown
    whether quantum corrections make such a journey possible or not.
    Although once considered a preposterous idea, the concept of the
    "multiverse"âthat our universe coexists with an infinite number of
    parallel universesâhas recently generated much interest among
    physicists from several directions. First, the leading theory
    consistent with the WMAP data is the "inflationary" theory, proposed
    by Alan Guth of MIT in 1979. It postulates a turbo-charged expansion
    of the universe at the beginning of time. The inflationary universe
    idea neatly explains several stubborn cosmological mysteries,
    including the flatness and uniformity of the universe.
    But since physicists still do not know what drove this rapid
    inflationary process, there remains the chance that it could happen
    again, in an endless cycle. This is the chaotic inflationary idea of
    Andrei Linde of Stanford University, in which "parent universes" bud
    "baby universes" in a continuous, neverending cycle. Like soap bubbles
    which split into two smaller bubbles, universes can constantly sprout
    from other universes.
    But what caused the big bang and drove this inflation? The question
    remains unanswered. Since the big bang was so intense, we have to
    abandon Einstein's theory of general relativity, which forms the
    underlying framework for all of cosmology. Einstein's theory of
    gravity breaks down at the instant of the big bang, and hence cannot
    answer the deep philosophical and theological questions raised by this
    event. At these incredible temperatures, we must incorporate quantum
    theoryâthe other great theory to emerge in the 20th centuryâwhich
    governs the physics of the atom.
    Quantum theory and Einstein's relativity theory are opposites. The
    former governs the world of the very small, the peculiar subatomic
    realm of electrons and quarks. Relativity theory rules the world of
    the very largeâof black holes and expanding universes. Relativity,
    therefore, is not suited to explaining the instant of the big bang,
    where the universe was smaller than a subatomic particle. At this
    moment we would expect radiation effects to dominate over gravity, and
    hence we need a quantum description of gravity. Indeed, one of the
    greatest challenges facing physics is to unify these theories into a
    single, coherent theory of all the forces in the universe.
    Physicists today are groping for this "theory of everything." Many
    proposals have been made over the past half century, but all have been
    shown to be inconsistent or incomplete. So far, the leadingâin fact,
    the onlyâcandidate is string theory.
    The latest incarnation of string theory, M-theory, may answer a
    question which has dogged advocates of higher dimensions for a
    century: where are they? Smoke can expand and fill up an entire room
    without vanishing into hyperspace, so higher dimensions, if they exist
    at all, must be smaller than an atom. If higher-dimensional space were
    larger than an atom, then we should see atoms mysteriously drifting
    and disappearing into a higher dimension, which we do not see in the
    laboratory.
    In the older string picture, one had to "curl" or wrap up six of the
    ten original dimensions, leaving the four-dimensional universe of
    today. These unwanted dimensions were squeezed into a tiny ball
    (called a Calabi-Yau manifold) too small to be seen. But M-theory adds
    a new twist to this: some of these higher dimensions can be large, or
    even infinite, in size. Imagine two parallel sheets of paper. If an
    ant lived on each sheet, each would think that its sheet was the
    entire universe, unaware that there was another universe close by. In
    fact, the other universe would be invisible. Each ant would live out
    its life oblivious to the fact that another universe was only a few
    inches away. Similarly, our universe may be a membrane floating in
    11-dimensional hyperspace, while we remain oblivious of the parallel
    universes hovering nearby.
    One interesting version of M-theory cosmology is the "ekpyrotic" (from
    the Greek for "conflagration") universe, proposed by Paul Steinhardt,
    Burt Ovrut and Neil Turok. It assumes that our universe is a flat,
    infinite membrane floating in higher-dimensional space. But
    occasionally, gravity attracts a nearby membrane. These two parallel
    universes race towards each other until they collide, releasing a
    colossal amount of energy (the big splat). This explosion creates our
    known universe and sends the two parallel universes flying apart in
    hyperspace.
    Searching for higher dimensions
    The intense interest in higher dimensions generated by string theory
    has slowly spilled over into the world of experimental physics. Idle
    dinner-table chatter is being translated into multimillion-dollar
    physics experiments.
    At the University of Colorado in Denver, the first experiment was
    conducted to search for the presence of a parallel universe, perhaps
    only a millimetre away. Physicists searched for tiny deviations from
    Newton's inverse square law for gravity. The light from a candle is
    diluted as it spreads out, decreasing at the inverse square of the
    distance of separation. Similarly, according to Newton's law, gravity
    also spreads out over space and decreases in the same way. But in a
    four-dimensional universe, there is more room for light or gravity to
    spread out, so they decrease at the inverse cube of the distance.
    Hence, by searching for tiny deviations from the inverse square law,
    one may pick up the presence of the fourth dimension.
    Newton's inverse square law is so precise that it can guide our space
    probes throughout the solar system. But no one knows if it holds down
    to the millimetre level. At present, only null results have been found
    in these experiments. Other groups are searching for even smaller
    deviations. Physicists at Purdue University in Indiana are trying to
    test the law down to the atomic level, using nanotechnology.
    Other avenues are also being explored. In 2007, the large hadron
    collider (LHC), capable of blasting subatomic particles with a
    colossal energy of 14 trillion electron volts (10 trillion times the
    energy found in a typical chemical reaction) will be turned on outside
    Geneva. The world's largest atom smasher, this huge machine, 27km in
    circumference, straddling the French-Swiss border, will probe into
    places 10,000 times smaller than a proton. Physicists expect to find
    an entire zoo of new subatomic particles not seen since the big bang.
    Physicists predict that the LHC may create exotic particles like
    mini-black holes and supersymmetric particles, dubbed "sparticles,"
    which would provide indirect evidence for string theory. In string
    theory, every particle has a super-partner. The partner of the
    electron is the "selectron," the partner of the quark is the "squark,"
    and so on.
    Furthermore, around 2012, the space-based gravity wave detector Lisa
    (laser interferometer space antenna) will be sent into orbit. Lisa
    will be able to detect the gravitational shockwaves emitted less than
    a trillionth of a second after the big bang. It will consist of three
    satellites circling the sun, connected by laser beams, making a huge
    triangle in space 5m km on each side. Any gravitational wave which
    strikes Lisa will disturb the lasers, and this tiny distortion will be
    picked up by instruments, signalling the collision of two black holes
    or the big bang aftershock itself. Lisa is so sensitiveâit can measure
    distortions a tenth the diameter of an atomâthat it may be able to
    test many of the scenarios being proposed for the pre-big bang
    universe, including string theory.
    Steps to leave the universe
    Unfortunately, the energy necessary to manipulate these higher
    dimensions, rather than just observe them, is far beyond anything
    available to us in the foreseeable future: 10^19bn electron volts, or
    a quadrillion times the energy of the large hadron collider. To
    operate here one needs the technology of a super-advanced
    civilisation.
    In order to organise a discussion of advanced extraterrestrial
    civilisations, astrophysicists often use the classification of Type I,
    II and III civilisations introduced by Russian astrophysicist Nikolai
    Kardashev in the 1960s, who ranked them by their energy consumption.
    One might expect that a Type III civilisation, using the full power of
    its unimaginably vast galactic resources, would be able to evade the
    big freeze. The bodies of its citizens, for example, might be
    genetically altered and their organs replaced by computerised
    implants, representing a sophisticated merger of silicon and carbon
    technologies. But even these superhuman bodies would not survive the
    big freeze. This is because we define intelligence as the ability to
    process information. According to physics, all machines, whether they
    are computers, rockets, locomotives or steam engines, ultimately
    depend on extracting energy from temperature differences: steam
    engines, for example, work by extracting energy from boiling water.
    But information-processing, and hence intelligence, requires energy
    supplied by machines and motors, which will become impossible as
    temperature differences drop to zero. According to the laws of
    physics, in a uniformly cold universe where temperature differences do
    not exist, intelligence cannot survive.
    But since the big freeze is probably billions to trillions of years
    away, there is time for a Type III civilisation to plot the only
    strategy consistent with the laws of physics: leaving this universe.
    To do this, an advanced civilisation will first have to discover the
    laws of quantum gravity, which may or may not turn out to be string
    theory. These laws will be crucial in calculating several unknown
    factors, such as the stability of wormholes connecting us to a
    parallel universe, and how we will know what these parallel worlds
    will look like. Before leaping into the unknown, we have to know what
    is on the other side. But how do we make the leap? Here are some of
    the ways.
    Find a naturally occurring wormhole
    An advanced civilisation which has colonised the galaxy may have
    stumbled during its past explorations upon exotic, primordial
    left-overs from the big bang. The original expansion was so rapid and
    explosive that even tiny wormholes might have been stretched and blown
    up into macroscopic size. Wormholes, cosmic strings, negative matter,
    negative energy, false vacua and other exotic creatures of physics may
    be relics left over from creation.
    But if such naturally occurring gateways are not found, then the
    civilisation will have to take more complex and demanding steps.
    Send a probe through a black hole
    Black holes, we now realise, are plentiful; there is one lurking in
    the centre of our own milky way galaxy weighing about 3m solar masses.
    Probes sent through a black hole may settle some unsolved questions.
    In 1963, the mathematician Roy Kerr showed that a rapidly spinning
    black hole will not collapse into a dot, but rather into a rotating
    ring, which is kept from collapsing by centrifugal forces.
    All black holes are surrounded by an event horizon, or point of no
    return: passing through the event horizon is a one-way trip.
    Conceivably, two such black holes would be needed for a return trip.
    But to an advanced civilisation fleeing the big freeze, a one-way trip
    may be all that is required.
    What happens if one falls through the Kerr ring is a matter for
    debate. Some believe that the act of entering the wormhole will close
    it, making it unstable. And light falling into the black hole would be
    blue-shifted, giving rise to the possibility that one might be fried
    as one passed into a parallel universe. No one knows for sure, so
    experiments must be done. This controversy heated up last year when
    Stephen Hawking admitted that he had made a mistake 30 years ago in
    betting that black holes gobble up everything, including information.
    Perhaps the information is crushed forever by the black hole, or
    perhaps it passes into the parallel universe on the other side of the
    Kerr ring. Hawking's latest thinking is that information is not
    totally lost. But no one believes that the final word on this delicate
    question has been spoken.
    To gain further data on space-times which are stretched to breaking
    point, an advanced civilisation might create a black hole in slow
    motion. In 1939, Einstein analysed a rotating mass of stellar debris
    which was slowly collapsing under its own gravity. Although Einstein
    showed that this rotating mass would not collapse into a black hole,
    an advanced civilisation may duplicate this experiment in slow motion
    by collecting a swirling mass of neutron stars weighing less than
    about 3 solar masses and then gradually injecting extra stellar
    material into the mass, forcing it to undergo gravitational collapse.
    Instead of collapsing into a dot, it will collapse into a ring, and
    hence allow scientists to witness the formation of a Kerr black hole
    in slow motion.
    Create negative energy
    If Kerr rings prove to be too unstable or lethal, one might also
    contemplate opening up wormholes via negative matter/energy. In 1988,
    Kip Thorne and his colleagues at the California Institute of
    Technology showed that if one had enough negative matter or negative
    energy, one could use it to create a transversable wormholeâone in
    which you could pass freely back and forth between your lab and a
    distant point in space (and even time). Negative matter/energy would
    be sufficient to keep the throat of the wormhole open for travel.
    Unfortunately, no one has ever seen negative matter. In principle, it
    should weigh less than nothing and fall up, rather than down. If it
    existed when the earth was created, it would have been repelled by the
    earth's gravity and drifted off into space.
    Negative energy, however, has been seen in the laboratory in the form
    of the Casimir effect. Normally, the force between two uncharged
    parallel plates should be zero. But if quantum fluctuations outside
    the plates are greater than the fluctuations between the plates, a net
    compression force will be created. The fluctuations pushing the plates
    from the outside are larger than the fluctuations pushing out from
    within the plates, so these uncharged plates are attracted to each
    other.
    This was first predicted in 1948 and measured in 1958. However, the
    Casimir energy is tinyâproportional to the inverse fourth power of the
    separation of the plates. To make use of the Casimir effect would
    require advanced technology to squeeze these parallel plates to very
    small separations. If one were to reshape these parallel plates into a
    sphere with a double lining, and use vast amounts of energy to press
    these spherical plates together, enough negative energy might be
    generated for the interior of the sphere to separate from the rest of
    the universe.
    Another source of negative energy is laser beams. Pulses of laser
    energy contain "squeezed states," which contain negative as well as
    positive energy. The problem is separating the negative from the
    positive energy within the beam. Although this is theoretically
    possible, it is exceedingly difficult. If a sophisticated civilisation
    could do this, then powerful laser beams might generate enough
    negative energy for the sphere to peel from our universe.
    Even black holes have negative energy surrounding them, near their
    event horizons. In principle, this may yield vast quantities of
    negative energy. However, the technical problems of extracting
    negative energy so close to a black hole are extremely tricky.
    Create a baby universe
    According to inflation, just a few ounces of matter might suffice to
    create a baby universe. This is because the positive energy of matter
    cancels out the negative energy of gravity. If the universe is closed,
    then they cancel out exactly. In some sense, the universe may be a
    free lunch, as Guth has emphasised. Strange as it may seem, it
    requires no net energy to create an entire universe. Baby universes
    are in principle created naturally when a certain region of space-time
    becomes unstable and enters a state called the "false vacuum," which
    destabilises the fabric of space-time. An advanced civilisation might
    do this deliberately by concentrating energy in a single region. This
    would require either compressing matter to a density of 10^80g/cm3, or
    heating it to 10^29 degrees kelvin.
    To create the fantastic conditions necessary to open up a wormhole
    with negative energy or to create a false vacuum with positive energy,
    one might need a "cosmic atom-smasher." Physicists are attempting to
    build "table-top" accelerators that can, in principle, attain billions
    of electron volts on a kitchen table. They have used powerful laser
    beams to attain an energy acceleration of 200bn electron volts per
    metre, a new record. Progress is rapid, with the energy growing by a
    factor of ten every five years. Although technical problems still
    prevent a true table-top accelerator, an advanced civilisation has
    billions of years to perfect these and other devices.
    To reach the Planck energy (10^28eV) with this laser technology would
    require an atom-smasher ten light years long, beyond the nearest star,
    which would be well within the technological capabilities of a Type
    III civilisation. Since the vacuum of empty space is better than any
    vacuum attainable on the earth, the beam of subatomic particles may
    not need light years of tubing to contain it; it could be fired in
    empty space. Power stations would have to be placed along the path in
    order to pump laser energy into the beam, and also to focus it.
    Another possibility would be to bend the path into a circle so that it
    fits within the solar system. Gigantic magnets could be placed on
    asteroids to bend and focus the beam in a circular path around the
    sun. The magnetic field necessary to bend the beam would be so huge
    that the surge of power through the coils might melt them, meaning
    that they could only be used once. After the beam had passed, the
    melted coils would have to be discarded and replaced in time for the
    next pass.
    Build a laser implosion machine
    In principle, it might be possible to create laser beams of limitless
    power; the only constraints are the stability of the lasing material
    and the energy of the power source. In the lab, terawatt (trillion
    watt) lasers are now common, and petawatt (quadrillion watt) lasers
    are slowly becoming possible (in comparison, a commercial nuclear
    power plant generates only a billion watts of continuous power). One
    can even envisage an X-ray laser powered by the output of a hydrogen
    bomb, which would carry unimaginable power in its beam. At the
    Lawrence Livermore National Laboratory, a battery of lasers is fired
    radially on a small pellet of lithium deuteride, the active ingredient
    of a hydrogen bomb, in order to tame the power of thermonuclear
    fusion.
    An advanced civilisation might create huge laser stations on the
    asteroids and then fire millions of laser beams on to a single point,
    creating vast temperatures and pressures unimaginable today.
    Send a nanobot to recreate civilisation
    If the wormholes created in the previous steps are too small, too
    unstable, or the radiation effects too intense, then perhaps we could
    send only atom-sized particles through a wormhole. In this case, this
    civilisation may embark upon the ultimate solution: passing an
    atomic-sized "seed" through the wormhole capable of regenerating the
    civilisation on the other side. This process is commonly found in
    nature. The seed of an oak tree, for example, is compact, rugged and
    designed to survive a long journey and live off the land. It also
    contains all the genetic information needed to regenerate the tree.
    An advanced civilisation might want to send enough information through
    the wormhole to create a "nanobot," a self-replicating atomic-sized
    machine, built with nanotechnology. It would be able to travel at near
    the speed of light because it would be only the size of a molecule. It
    would land on a barren moon, and then use the raw materials to create
    a chemical factory which could create millions of copies of itself. A
    horde of these robots would then travel to other moons in other solar
    systems and create new chemical factories. This whole process would be
    repeated over and over again, making millions upon millions of copies
    of the original robot. Starting from a single robot, there will be a
    sphere of trillions of such robot probes expanding at near the speed
    of light, colonising the entire galaxy.
    (This was the basis of the movie 2001, probably the most
    scientifically accurate fictional depiction of an encounter with an
    extraterrestrial lifeform. Instead of meeting aliens in a flying
    saucer or the USS Enterprise, the most realistic possibility is that
    we will make contact with a robot probe left on a moon from a passing
    Type III civilisation. This was outlined by scientists in the opening
    minutes of the film, but Stanley Kubrick cut the interviews from the
    final edit.)
    Next, these robot probes would create huge biotechnology laboratories.
    The DNA sequences of the probes' creators would have been carefully
    recorded, and the robots would have been designed to inject this
    information into incubators, which would then clone the entire
    species. An advanced civilisation may also code the personalities and
    memories of its inhabitants and inject this into the clones, enabling
    the entire race to be reincarnated.
    Although seemingly fantastic, this scenario is consistent with the
    known laws of physics and biology, and is within the capabilities of a
    Type III civilisation. There is nothing in the rules of science to
    prevent the regeneration of an advanced civilisation from the
    molecular level. For a dying civilisation trapped in a freezing
    universe, this may be the last hope.