The Anthropic Principle

 The Anthropic Principal is based upon the idea that the universe is based upon several fundamental constants of physics; these physical constants describe the way the Universe works.  But what has recently been recognized is that any minor variation in these constants would make life impossible.  The fact that these constants seem to finely tuned to permit life provides a strong indication that there was design behind them; they did not just fall into place out of chance.  John Wheeler, who first made this idea popular, stated, “A life-giving factor lies at the centre of the whole machinery and design of the world.”

 The idea that the universe was created for mankind has been a central point of philosophy in many cultures up until the recent past.  The notion that the natural world, including the cosmos, was created for man is the very bedrock of many world religions and world-views, including the Judaic, Greek, and Christian philosophies.  Teleology is the study of the evidence for overall design and purpose in nature.  It proposes the Universe was created for a purpose and did not randomly leap into existence.  Teleology has attracted the attention of many prominent philosophers and theologians such as Augustine, Maimonides, Aquinas, Newton, and Paley, all of whom devoted much of their life to this philosophical notion.

 It has only been comparatively recently, however, that there has been recognition that design may also apply to gross features of the universe.  In 1937, Paul Dirac noted that the number of baryons (protons plus neutrons) in the universe is almost exactly equal to the inverse square of the gravitational constant, and to the square of the age of the universe.  Dirac, later in 1961, noted that these relationships would imply a narrow age range of the universe during which time life could come forth.  Stars of the right type for sustaining planets capable of supporting life can only occur during a certain narrow age range for the universe.  Similarly, stars of the right type can only form within a narrow range of values for the gravitational constant.  It was this latter interesting fact that led for the search and documentation of other “coincidences” that must occur simultaneously for life to exist on earth.

a. The Gravitational Coupling Constant.  The force of gravity determines what stars are possible in the universe.  If the gravitational force were slightly stronger, star formation would proceed more efficiently and all stars would be more massive than our own.  These large stars are important in that they manufacture elements that are heavier than iron, and they along can disperse elements heavier than beryllium to the interstellar medium.  However, these stars also burn too rapidly ad too inconstantly to maintain life-supporting conditions on surrounding planets.  More stable and longer lived stars such as our sun are required for life.  On the other hand, if the gravitational constant were too weak, then all stars would be smaller than the sun.  Although such stars burn long enough and stable enough to maintain life-supporting planets, there would be no heavier elements formed for the building of rock planets upon which life could occur.

    b. The Strong Nuclear Force Coupling Constant.  This force holds together the particle sin the nucleus of an atom.  If the strong nuclear force were slightly weaker, then multi-proton nuclei could not form because they would just fly apart due to the repulsion from like charged protons.  Hydrogen would be the only element in the universe.  If on the other hand, the strong nuclear force were slightly greater, then nuclear particles would tend to bind together more frequently and more firmly.  Then hydrogen would be rare in the universe, and elements more massive than iron which are necessary for life that are produced from the fission of very heavy elements would be insufficient.  Either way, life becomes impossible.

    Similarly, if the strong nuclear force were only increased by 2 percent, then mean that protons would never form from quarks.  A similar decrease would mean that certain heavy elements essential for life would be unstable.

    c. The Weak Nuclear Force Coupling Constant.  The weak nuclear force affects the properties of leptons.  Leptons are a whole class of elementary particles (e.g., neutrinos, electrons, and photons) that do not participate in strong nuclear reactions; they are not contained within the nucleus.  The most familiar weak nuclear force is radioactivity; in particular, the beta decay reaction whereupon a neutron decays into a proton, an electron, and a neutrino.  The number of neutrons available as the universe first cooled after the big bang determines the amount of helium initially produced.  If the weak nuclear force coupling constant were slightly larger, then neutrons would decay more readily and would therefore be less available.  Therefore, little or no helium would be produced from the big bang, and then heavy elements sufficient for the construction of life would not be formed.  On the other hand, if the weak force were too small, then most of the available hydrogen would have been burned into helium during the initial explosion producing an over-abundance of heavier elements and again, life would not be possible.

    Another restriction is placed on the weak nuclear force since a certain amount of neutrinos must be formed when a supernova explodes to disperse the heavy elements formed in the outer layers of the star.  If the weak nuclear force were smaller, then too many neutrinos would be made and would not interact sufficiently with the outer layers of the star to sufficiently disperse its contents.  On the other hand, if the weak nuclear force were larger, then neutrinos would be trapped inside the star and again would be unavailable to disperse its outer layer sufficiently

    d. The Electromagnetic Coupling Constant.  This force binds electrons (a lepton) to protons (a baryon) in an atom.  The characteristics of the orbits of electrons about atomic nuclei determine what molecules can be formed as the atoms bind to each other.  If the electromagnetic coupling constant were slightly smaller, then few electrons would be held in their orbit about the proton.  If on the other hand, the electromagnetic force were too large, then a proton would not “share” its electrons with other protons in other atoms and molecules would not form.  Either way, the molecules necessary for life could not form.

    e. The Radio of Protons to Electrons.  During the first few seconds of the universe’s existence, there was a great destruction of anti-matter by matter; namely, anti-protons were destroyed by protons, and anti-electrons (positrons) were destroyed by electrons.  Amazingly, the number of electrons and protons that were left over after this destruction almost exactly equaled each other to better than one part in 10^37.  If this had not balanced out almost exactly, then there would have been a prevalence of either electrons (net negativity) or protons (net positivity) and electromagnetism would have so overwhelmed gravity as a force, that the formation of the current universe would not have been possible.

    f. The Radio of Electron to Proton Mass.  This particular ratio determines the characteristics of the orbit of the electron around the proton.  A proton is 1836 times more massive than an electron.  If the electron to proton mass were much larger or small, then the necessary molecules for life could not form and life would then be impossible.

    g. The Age of the Universe.  The age of the universe determines what kind of stars exist.  It took about 2 billion years for the first stars to form, and then another 10 billion years for supernovae to disperse enough heavy metals for our planets to form.  Another few billion years were then necessary for solar-type stars to form and then stabilize in order to support advanced life.  Therefore, if the universe were only a few billion years old, then there would not be enough heavy medals formed to produce planets such as the earth.  On the other hand, if the universe were much older, then there would no longer be solar-type stars in order to support life either.

    h. Expansion Rate of the Universe.  If the expansion rate of the universe were slower, then the whole universe would have collapsed back toward singularity again before any solar-type stars could develop and stabilize to support life.  On the other hand, if the expansion rate of the universe is too fast, then no galaxies or stars could have condensed from the original elements of the explosion.  Alan Guth has estimated that this expansion rate must be accurate to one part in 1055!

    i. The Entropy Level of the Universe.  This level affects the degree to which massive systems such as galaxies and stars condense.  The ratio of photons to baryons is an indication of the entropy level; our universe has a ratio of about a billion to one.  Therefore, there are about a billion photons for every baryon.  If the entropy level for the universe were slightly larger, then no galactic systems would form (and hence no stars).  The degree of entropy (tendency toward disorganization) would prohibit the entropy defying increased organization of galaxy or star formation.  If the entropy level were slightly smaller, then galactic systems that would form would not form stars.  Either way, the universe would be devoid of stars – and hence, life.

    j. The Mass of the Universe.  If the mass of the universe were slightly larger, then too much deuterium would form during the cooling of the big bang.  Deuterium is a powerful catalyst for subsequent nuclear reactions in stars; the extra deuterium would cause stars to burn too rapidly to sustain life on planets.  On the other hand, if the mass of the universe were slightly smaller, then no helium would have been generated during the cooling of the big bang.  Without helium, stars cannot produce heavy elements necessary for life.

    k. The Uniformity of the Universe.  The universe had to be created in a way so as to ensure considerable uniformity; otherwise, the universe would consist of a large number of black holes separated by empty space.  Such uniformity is thought to be consistent with a brief period of inflationary expansion near the time of the origin of the universe which spread the early matter evenly throughout.  On the other hand, if the universe were smoother, then the condensations necessary to form galaxies, stars, and then planets would never have come to exist either.  Thus, the uniformity of the Universe is precisely what is necessary to form the proper conditions for life.

    l. The Stability of the Proton.  Each proton contains three quarks.  Quarks themselves decay into antiquarks, pions, and positrons.  The decay process occurs on the average of only one proton per 1032 years.  If that decay rate of the proton were higher, then lethal doses of radiation would be produced and the consequences for higher, more complicated organisms (like man) would be catastrophic.  On the other hand, if the decay process were slower and protons less likely to decay, then less matter would have emerged from the first split second of the creation of the universe, and life would again be impossible.

    m. Fine Structure Constants.  These constants relate to each of the four fundamental forces: gravitational, strong nuclear, weak nuclear, and electromagnetic.  Fine coupling constants typically yield strict design constraints for the universe.

    n. Velocity of Light.  The velocity of light can be expressed as a function of any of the fundamental forces of physics, or even as a function of one of the fine structure constants.  Therefore, any significant change in the velocity of light would also affect all of these other constants which again would negate the possibility of life in the universe.

    o. Nuclear Energy Levels of 8Be, 12C, and 16O.  Atomic nuclei exist at strict energy levels.  A transition from one energy level to another occurs through the emission or the capture of a photon that possesses precisely the energy difference between the two nuclear energy levels.  8Be decays in just 10-15 second – it is very unstable.  Because it is so unstable, it slows down the fusion process.  If it were more stable, fusion of heavier elements would proceed so rapidly that catastrophic stellar explosions would occur.  On the other hand, if 8Be were even more unstable, then element production beyond 8Be would not occur and life again would be impossible.

    The next element to be considered, 12C, happens to have a nuclear energy level that is very slightly above the sum of the energy levels for 8Be and 4He.  Anything other than this precise energy level for 12C would mean there would be insufficient carbon production for life.

    Finally, 16O has just the right energy level to prevent all the carbon from turning into oxygen and to facilitate adequate production of 16O for life.

    In summary, the ground state nuclear energy levels for 4He, 8Be, 12C, and 16O could not be any higher or lower than they are with respect to each other to more than four percent without yielding a universe with insufficient oxygen or carbon for life to occur.

    Interestingly, Fred Hoyle, who discovered these remarkable “coincidences,” remarked that “a superintellect has monkeyed with physics, as well as with chemistry and biology.”

    p. Distance between Stars.  The distance between stars affects the orbits or planets – and even whether they can exist at all.  The average distance between stars in our region of the galaxy is about 30 trillion miles.  If this distance were slightly smaller, gravitational interaction among stars would destabilize planetary orbits.  On the other hand, if the distance between stars were too great, then there would be an insufficient concentration of heavy element debris thrown out by supernovae to produce the rocky planets that produce life forms.

    q. Rate of Luminosity Increase for Stars.  The luminosity of stars affects the surface temperature on planets orbiting those stars.  Small stars, like the sun, settle into stable burning once hydrogen fusion ignites within their core.  However, during this stable phase, stars undergo a very gradual increase in their luminosity.  This gradual increase in luminosity is perfect for the gradual introduction of life forms in a sequence from primitive to advanced, upon a planet.  Naturally, the start date for the introduction of life forms, and the rate of introduction of subsequent life forms are very critical upon the successful intelligent creatures.  If the rate of luminosity were slightly greater, then a run-away greenhouse effect would ensue.  However, if the rate of increase in stellar luminosity were slightly smaller, then a runaway freezing of the oceans and lakes would occur.  Either way, the planet’s temperature would become too hot or too cold for advanced life to generate.

This list is by no means complete, and yet it demonstrates why a growing number of astronomers and cosmologists agree in the possibility that the universe was not only divinely created, but also divinely designed.  American astronomer George Greenstein said,  “As we survey all the evidence, the though insistently arises that some supernatural agency – or, rather, Agency – must be involved.  Is it possible that suddenly, without intending to, we have stumbled upon scientific proof of the existence of a Supreme Being?  Was it God who stepped in and so providentially crafter the cosmos for our benefit?"

The Earth as a Fit Habitat for Life.  We are hearing much in recent months about the discovery of planets encircling distant stars.  Modern cosmology would predict that this would be the case; the same forces that shaped our own solar system to allow it to be able to support life, also have shaped other regions of our galaxy and the universe.  For example, we can look out into the universe and see many other spiral galaxies just like our own.  However, the major difference is that other spiral galaxies are now, of course, just like ours in all respect, and certainly other planetary systems are not just like ours either.  There must be many “chance” occurrences happen in order to make life suitable on these distant planets.  Without all these occurrences all happening together, then life would be impossible.

Most children are probably familiar with the calculations and arguments made by Scklovsky and Sagan, who claimed that 0.001 percent of all stars could have a planet capable of supporting advanced life.  This argument was made many years ago before it became obvious that such could not be the case.  Their calculations overestimated the range of permissible star types and the range of permissible planetary distances, in addition to ignoring many other factors that must be calculated into the equation.  These are some of those characteristics that need to be calculated, all of which are independent variables;

a. Number of stars in the planetary system.  If there are more than one star in the planetary system, then tidal interactions would so disrupt planetary orbits as to make them unstable and unfit for advanced life;  if less than one star then no hear would be produced for advanced life to occur.

b. Parent star birth date.  If more recent, then the star would not yet have reached stable burning phase; if less recent, then the star system would not have enough heavy elements to make earthen planets,

    c. Parent star age.  If older, then the luminosity of the star would change too quickly; if younger, then the luminosity of star would change too quickly {again}.

    d. Parent star distance from the center of its galaxy.  If farther, then the quantity of heavy elements would be insufficient for making rocky planets.  If closer, then stellar density and hence radiation would be too great.

    e. Parent star mass.  If greater, then the luminosity of the star would change too quickly, and the star would burn too rapidly; if lesser, the range of distances appropriate for life would be very narrow.  Tidal forces would disrupt the rotational period of a planet at “correct” distances for the planet would need to be quite close to the star.  Also, ultraviolet radiation would be inadequate for planets to make sugars and oxygen.

    f. Surface gravity.  It the gravity were stronger on a planet, then the atmosphere would retain too much methane and ammonia and life would be poisoned; if the gravity were weaker, then the planet’s atmosphere would lose too much water.

    g. Distance from parent star.  If the distance were farther, then the planet would be too cool for a stable water cycle; if the distance were shorter, then the planet would be too warm for a stable water cycle.

    h. Axial tilt.  If the axial tilt were greater, then surface temperature differences would be too great; if the axial tilt were smaller, then surface temperature differences would be too great.

    i. Rotation period.  If the rotation period were longer, then diurnal temperature differences would be too great; if the rotation period were shorter, then atmospheric wind velocities would be too great.

    j. Gravitational interaction with a moon.  If the gravitational interaction with a moon were greater, then the tidal effects on the moon, atmosphere, and rotaoin period would be too severe; however, if the gravitational interaction with a moon were less, then there would be climatic instabilities.

    k. Magnetic fields.  If the magnetic field around a planet were stronger, the electromagnetic storms would be too severe; however, the magnetic field around a planet were less strong, then there would be inadequate protection from stellar radiation.

    l. Thickness of planetary crust.  If the planetary crust thickness were thicker, then there would be too much oxygen transferred from the atmosphere to the crust; however, if the planetary crust thickness were thinner, then there would be increased volcanic and tectonic activity.

    m. Albedo (ratio of reflected light to total light falling upon a planet).  If the albedo of a planet were greater, then runaway ice ages would develop; however, if the albedo were less, then a runaway greenhouse effect would develop.

    n. Oxygen to nitrogen ratio in the atmosphere.  If this rate were larger, then advanced life functions would proceed too quickly; if this rate were smaller, then advanced life functions would proceed more slowly.

    o. Carbon dioxide and water vapor levels in the atmosphere.  If these levels were greater, then a runaway greenhouse effect would ensue; however, if these levels were less, then the greenhouse effect would be insufficient and an ice age might develop.

    p. Ozone level in the atmosphere.  If the ozone level were greater, then surface temperatures would be too low; however, if the ozone level were less, then surface temperatures would be too high and here would be too much radiation at the surface of the planet to support life.

    q. Atmospheric electric discharge rate.  If the atmospheric electric discharge rate were too high, then there would be too much destruction from fire; if the electric discharge rate were too small, then there would be too little nitrogen fixed in the atmosphere.

    r. Oxygen quantity in the atmosphere.  If the oxygen quantity in the atmosphere were greater, then plants and hydrocarbons would burn up too readily; alternatively, if the oxygen quantity in the atmosphere were less, then advanced animals would have too little oxygen to survive.

    s. Seismic activity.  If planetary seismic activity were greater, then too many life-forms would be destroyed; however, if seismic activity were less, then nutrients on ocean floors would not be recycled to the continents through tectonic uplift.

Many other potential similar relationships are currently being actively researched.  However, the twenty planetary characteristics listed above would be fulfilled in much fewer than a trillionth of a trillionth of a percent of all stars.  Considering that the universe only has about a trillion galaxies each of which averages one hundred billion stars, statistics argue that not even one planet would be expected by natural processes alone to harbor life.  Many astronomers such as Robert Rood and James Trefil, among others, are now deciding that given the above statistical probability, it is unlikely that life, especially intelligent life, exists anywhere else in the universe.