At the turn of the 20th century, when noted German mathematician and philosopher Gottlob Frege had undertaken the monumental task of trying to put the science of mathematics upon firm foundations, soon after he had finished his book Grundgesetze der Arithmetik he received from Bertrand Russell a letter dated June 16, 1900, with a logical paradox that essentially shook the very foundations upon which his book was built. In a rather courageous reply to Russell, Frege wrote the following:
“Your discovery of the contradiction caused me the greatest surprise and, I would almost say, consternation, since it has shaken the basis on which I intended to build arithmetic. It is all the more serious since, with the loss of my Rule V, not only the foundations of my arithmetic, but also the sole possible foundations of arithmetic, seem to vanish.”
But when Russell himself tried to put mathematics upon solid foundations and rid it from inconsistencies once and for all with the book Principia Mathematica written in collaboration with Alfred North Whitehead, a massive effort that practically consumed him, he himself was struck hard when logician Kurt Gödel announced the discovery of his famous incompleteness theorem that asserted, among other things, that the consistency of mathematics cannot be proven, and thus Russell would never be able to achieve what he started out to do in his program.
The title of the book Principia Mathematica was without a doubt inspired by the title that Sir Isaac Newton gave to his own book, Principia, a book that sought to lay down upon solid grounds the foundations of the science of mechanics that had just been discovered by him. Yet, the philosophical foundations of Newton’s book were also demolished (among them the concept of an “absolute” universal time, and the concept of “action at a distance”) when Albert Einstein announced the theory of general relativity to the world.
This book has been written with the author keenly aware of cases such as the ones cited above. What seems to be an almost absolute truth to many for a brief period of time may end up being dismantled at its very core by the announcement of some new discovery or a new idea that had not occurred previously to anybody. The history of science itself is filled with many fiascoes and disappointments, although we may not hear from them since science relishes in its triumphs but tries to forget promptly its failures and its non-heroes, sending them to oblivion as quickly as possible. Both the author and the reader of this book must keep an open mind and must be fully prepared at all times to face whatever new realities the future may bring, and we owe it to ourselves and to the children of the future to accept and confront with full resolution all those changes that destiny may have in store for us. As we will soon see, already some of those changes may be on their way.
Thanks to more powerful tools for probing deep into the corners of the Universe itself such as the Hubble Space Telescope, the Compton Gamma Ray Observatory, the Rossi X-Ray Timing Explorer and the ROSAT X-ray Telescope, new data is being gathered at this very moment that is shaking some commonly accepted beliefs, data which demands new explanations at a moment when science is hard pressed to come up with acceptable answers. And even newer tools have just been put into operation or are on their way to us, such as the following:
- The Laser Interferometer Gravitational-Wave Observatory (LIGO).
- The Very Large Telescope (VLT) array, already partly in operation.
- The Chandra X-ray observatory. Launched: July 1999.
- The X-Ray Multimirror Mission (XMM). Launch date: 2000.
- The Microwave Anisotropy Probe. Launch date: 2000.
- The Astro-E. Launch date: 2000.
- The Gravity Probe B. Launch date: 2000.
- INTEGRAL (International Gamma-Ray Astrophysics Laboratory). Launch date: 2001.
- GLAST (Gamma-Ray Large Area Space Telescope). Launch date: 2005.
- The Space Interferometer Mission (SIM). Launch date: 2005.
- The European microwave anisotropy probe Planck. Launch date: 2007.
- Constellation X. Launch date: 2007
- The Next Generation Space Telescope. Launch date: 2007.
Just to give the reader an idea of the sensitivity in some of the instruments that are being deployed, the Laser Interferometer Gravitational-Wave Observatory LIGO facilities (located near Livingston, Louisiana, and Richland, Washington) will be able to detect the forces produced by minute gravitational waves (predicted by the general theory of relativity) by moving mirrors as little as one-billionth the diameter of a hydrogen atom. Besides the above tools, there are other important projects at the design stage, among which we can cite ARISE (Advanced Radio Interferometry between Space and Earth), LISA (Laser Interferometry Space Array), OWL (Orbiting Wide-Angle Light Collection), XEUS (X-ray mission for Evolving Universe Spectroscopy), that together with the Sloan Digital Sky Survey and NASA’s Origins program will no doubt bring more surprises, making life even harder for many theoretical scientists and cosmologists around the world.
At the time this is being written, the following issues are creating shock waves in the scientific communities:
- The existence of planetary systems besides our own, with worlds in orbit around a normal sun like star, now called exoplanets, once thought to be just a possibility, has now been confirmed both through indirect means and by direct visual observation, raising the probabilities for life to develop somewhere else besides our own planet.
- A growing body of evidence which seems to indicate that, within the confines of the solar system but outside of Earth itself, there are sufficient conditions capable for sustaining life; plus the discovery of what appear to be fossil remains from primitive life forms that may have flourished once on Mars.
- The expansion of the Universe, which was assumed to be proceeding at a uniform pace, perhaps even slowing down, according to Hubble’s law, is instead accelerating.
- The cosmological constant which Einstein called his “greatest mistake” is actually being resurrected in an attempt to reconcile theory with the facts that are now coming to light.
- There is now a strong suspicion that the Universe is permeated with some yet unknown form of gravitational energy, dubbed dark energy, that repels rather instead of attracting.
- The discovery that a small particle abundant everywhere in the cosmos, the neutrino [the neutrino, a term which stands for "the tiny neutral one", is an elementary subatomic particle whose existence was first proposed in 1930 by the Austrian physicist Wolfgang Pauli in order to satisfy some conservation laws], until recently thought to have no mass, has now been determined to have a small mass.
The discovery of a planet in orbit about a star of the type commonly known as pulsars, by observing not the planet itself but the minute gravitational effects produced by the planet as it orbits around the pulsar, was first reported back in 1992 by A. Wolszczan and D. A. Frail. Three years later, on October 6th 1995, a team led by Michel Mayor and Didier Queloz of the Geneva Observatory in Switzerland, again using indirect means, reported the discovery of the first planet orbiting a star much like our own Sun, a Jupiter-sized planet nicknamed 51 Pegasi B. Another team of American astronomers led by Geoffrey Marcy and Paul Butler working at the W. M. Keck Observatory in Hawaii by using a revolutionary new technique later confirmed this discovery. In 1996, Marcy and Butler announced the discovery of a planet orbiting the sunlike star Upsilon Andromedae, again by indirect means, studying changes in the star’s velocity, and by mid-April 1999 they had found two more planets orbiting the same star Upsilon Andromedae, thus confirming the existence of the first multiplanet solar system besides our own. Also by April 1999, the list of planets orbiting sun like stars had grown to a total of 20 worlds. But even more recently, on November 7th 1999, the first direct visual confirmation of the existence of another planet outside the Solar system was accomplished by Gregory W. Henry of the University of Tennessee and his colleagues, by focusing their telescopes on star HD 209458 located about 150 light-years away from the Pegasus constellation, and with subsequent measurements it was further determined that the brightness of the star should decrease about 1.7% every 3.523 days as the planet completes a full orbit around the star and partially blocks for a brief period of time the light on its way to Earth which comes from the star. There is already a widening list of target stars in the quest for planets like our own that may be out there, and to this purpose NASA came up with its Terrestrial Planet Finder (TPF) plan, consisting of an array of orbiting small telescopes mounted on a fixed structure or on separated spacecraft floating in precision formation simulating a much larger and powerful telescope (for the time being, this plan is shelved due to budgetary constraints). The European Space Agency also has its own similar plan for the detection of extrasolar terrestrial planets called Darwin. As this last name implies, the ultimate objective is not merely the discovery of more Earth-like planets beyond our solar system, but the actual discovery of what we call life. Thus, the question no longer is whether there can be other solar systems besides our own with several planets orbiting a sun like star, but whether any of the planets already detected or about to be detected have the necessary conditions to sustain some form of living organisms. If another “big blue marble” were to be found out there during the coming years –and we must be open minded for the possibility this may happen during our lifetimes-, this would undoubtedly have major consequences in many of the beliefs we have long cherished, and would dethrone us forever from the privileged place we have given ourselves in the Universe. It has already been made quite clear that, given the right initial conditions, life will emerge sooner or later, and there is no reason to expect the long lasting effect of those initial conditions to have been confined on this small speck of the Universe we call planet Earth just to fulfill our own egotistical purposes.
Raising the stakes for the possibility of extraterrestrial life, on August 7th 1996 people around the globe woke up to stunning news that were being printed and broadcast throughout all sorts of news media. In New York, a person opening up his daily issue of The New York Times would have stumbled upon the following front-page story:
“Clues in Meteorite Seem to Show Signs of Life on Mars Long Ago: Startling Find of Organic Molecules from Space.
Scientists studying a meteorite that fell to Earth from Mars have identified organic compounds and certain minerals that they conclude ‘are evidence for primitive life on early Mars’ … The discovery of the first organic molecules ever seen in a Martian rock is being hailed as startling and compelling evidence that at least microbial life existed on Mars long ago, when the planet was warmer and wetter. The molecules found in the rock, which left Mars some 15 millions years ago, are being described as the fossil trace of past biological activity … In a statement issued yesterday, as unofficial word of the discovery spread, Daniel S. Goldin, the NASA administrator, confirmed that scientists had made ‘a startling discovery that points to the possibility that a primitive form of microscopic life may have existed on Mars more than three billion years ago’ … A detailed description of the research, conducted at the Johnson Space Center in Houston, is to be given at a news conference at 1 P.M. today at the National Aeronautics and Space Administration in Washington. The journal Science is publishing a full report on the work in its August 16 issue.”
The above news story is referring to a 1.9 kilograms meteorite of Martian origin found here on Earth in Antarctica, designated ALH84001 and thought to have been dislodged from the Martian surface by a powerful impact from another celestial body, most likely a comet. Together with eleven other meteorites identified also as being of Martian origin, this meteorite was found to have the highest concentration of carbonates. The high carbonate content supports the hypothesis that water once flowed on Mars. But it is not the high carbonate content that created a shock on those who studied the meteorite. It was the detection of polycyclic aromatic hydrocarbons (PAHs) that stunned them. One explanation for the presence of these organic molecules in the meteorite was that they could have originated from material delivered to Mars by the comet that struck the planet. But another equally valid explanation is that the PAHs appeared as precursors of primitive life on Mars, keeping in mind that here on Earth some PAHs are the products of biological activity. Either way, we are talking about the residues of primitive extraterrestrial life. Even though the integrity of the Martian rock has come into question because it has shown signs of contamination (in January 16th 1998, two studies published in the journal Science reported such material contamination; one study indicating the presence of small amounts of amino acids similar to those found in Antarctica where the meteorite was discovered, and the other study finding the presence of high levels of carbon 14 which is another indicator of terrestrial contamination), the PAHs themselves remain largely undisputed. It is, of course, possible that a comet that impacted Earth long ago could have propelled debris from Earth carrying primitive living organisms that somehow managed to survive the trip from Earth to Mars, and thrive there while conditions allowed (there seem to be little doubts that water once flowed abundantly on the Martian surface). But this hypothesis has few supporters on the grounds that it would have been extremely difficult for any microscopic living organism to have survived the extreme temperatures it would have encountered while making the trip from Earth to Mars when it was being carried along by a hot comet (by the same token, what we got from Mars in the ALH84001 rock appear to be fossil remains, not living Martian organisms that could have in turn given rise to life on Earth).
Besides the possibility that once there may have been life on Mars, life that left its imprint on the Martian meteorite, there is also the possibility that there may be extraterrestrial life right now in another part of the solar system. We are talking about Europa, a satellite (moon) of Jupiter. It is now a confirmed fact thanks to the Hubble Space Telescope and the Galileo spacecraft launched from Earth in October 1989 that Europa holds more water than all the oceans here on Earth, and most of it is probably liquid water. It is believed that the tidal forces of Jupiter’s gravity generate enough heat to keep the water beneath its surface ice crust from freezing. Europa has also been found to contain organic compounds. As if all this was not enough, it was reported on the February 23rd 1995 issue of Nature that Doyle Hall of Johns Hopkins University and others had found evidence -by using the Hubble Space Telescope- of a thin atmosphere of oxygen on Europa, making it the first moon in the solar system that has been found to contain molecular oxygen in its atmosphere. Therefore, Europa has all the essential ingredients to support life as we know it, and few scientists would be completely surprised if a space probe launched to Europa would convey the news that indeed some form of life has been able to develop there. At the very least, Europa right now appears to have all of the necessary ingredients to support small organisms from Earth if such organisms were to be sent as “seeds” for future life. As a matter of fact, Francis Crick, one of the co-discoverers of the DNA double-helix, has proposed this issue as a very viable possibility, as we can see from his book Life Itself: Its Origin and Nature:
“Bacteria may be extremely simple when compared to organisms like ourselves, but as self-reproducing chemical factories they are not only compact and robust, but chemically very versatile … For all these reasons, then, microorganisms, and especially those that can live without oxygen, are the obvious creatures to send to another planet, provided one’s aim is to get life started there rather than to deliver a fully formed higher organism having some chance of survival. This is why (Leslie) Orgel and I suggested them as the most likely cargo for the unmanned spaceship we postulated for Direct Panspermia.”
However, taking a step such as this one assumes that earlier probes sent to the planet chosen to receive the “seeds” of life has absolutely no life forms of its own. Otherwise, such a “gift” from us could very well be taken to be an extraterrestrial alien invasion directed against any life form that may be developing there, an alien invasion coming from Earth!
Not surprisingly, there is an enormous interest in the international scientific communities in the launching of probes to Mars and Europa. Any confirmation of the suspicions many scientists now have could have a major consequence in the way we view ourselves in the Universe, and most likely it could change the course of History just as the “Enlightenment” period after the Middle Ages and the discovery of America by Christopher Columbus did in what now seems to be a long time ago.
More recently, Saturn’s moon Enceladus became the hottest new place to look for life in the chilly outer solar system. According to a news release by the NASA Jet Propulsion laboratory (July 29, 2005), the Cassini spacecraft found a huge cloud of water vapor over the moon’s south pole, and warm fractures where evaporating ice probably supplies the vapor cloud. Thus, this moon, which ought to be cold and dead, instead displays evidence for active ice volcanism.
On a separate front, on a special report entitled “Revolution in Cosmology” that was published in Scientific American on January 1999, we read the following introduction to the report:
“At a conference last May entitled ‘The Missing Energy in the Universe’, cosmologists took a vote. Did they believe recent observations of distant exploding stars, which implied –in defiance of all expectations- that the universe is growing at an even faster rate? Although astronomers have known since the 1920s that the universe is enlarging in size, pushing galaxies even farther apart, they have always assumed that this expansion is mellowing out as gravity exerts its force of restraint. If in fact the growth is accelerating, the universe must be filled with some unknown form of matter or energy whose gravity repels rather than attracts. Hitherto unseen energy is, well, a repulsive thought for physicists. And yet of the 60 researchers present for the vote, 40 said they accepted the new findings … Astronomers had suspected for more than a decade that all was not well in the halls of modern cosmology. When observers totted up the ordinary matter in the universe, it fell short of the amount needed to slow the cosmic expansion as predicted by the theory of inflation, an elegant explanation of the earliest stages of the big bang. Until now, the evidence against the theory has never been strong enough to overcome its advantages. But today even the theorists accept that something is amiss. At the very least the expansion is not decelerating as rapidly as once thought. Either scientists must reconcile themselves to kooky energy, or they must modify or abandon inflation.”
In one of the articles in this report under the heading “Surveying Space-Time with Supernovae”, Craig Hogan, Robert Kirshner and Nicholas Suntzeff cite the observational evidence for the above and add:
“The big surprise is that the supernovae we see are fainter than predicted for a nearly empty universe (which has maximum energy curvature). Taken at face value, our observations appear to require that expansion is actually accelerating with time. A universe composed only of normal matter cannot grow in this fashion, because its gravity is always attractive. Yet according to Einstein’s theory, the expansion can speed up if an exotic form of energy fills empty space everywhere. This strange ‘vacuum energy’ is embodied in Einstein’s equations as the so-called cosmological constant. Unlike ordinary forms of mass and energy, the vacuum energy adds gravity that is repulsive and can drive the universe apart at ever increasing speeds. Once we admit this extraordinary possibility, we can explain our observations perfectly, even assuming the flat geometry beloved of theorists … Evidence for a strange form of energy imparting a repulsive gravitational force is the most interesting result we could have hoped for, yet it is so astonishing that we and others remain suitably skeptical.”
All of the above conclusions came as the result of what appears to be a major discovery: in examining the light arriving at Earth from very distant supernovas, measuring how quickly those distant supernovas are receding from Earth and gauging the distances to Earth (and thus the differences over time in the rate of the Universe’s expansion), it was found that the oldest, farthest supernovas which were expected to be receding from Earth at a slower rate because of gravity were 10% to 15% farther away from where they were supposed to be, and thus it was determined that the Universe is currently expanding at a rate about 15% faster than when the Universe was half as old as it is today.
As early as February 27th 1998, an international team of astronomers called the High-z Supernova Search team that was led by Brian Schmidt of Mount Stromlo and Siding Spring Observatory in Australia had arrived at the conclusion that there was an unknown force in the Universe acting against the force of gravity, basing their beliefs on the evidence that the Universe is expanding at an accelerating rate. Just a few years before, the common assumption was that the gravitational pull of matter in the Universe was slowing down because of the expansion of the Universe, but with the finding that the expansion of the Universe is not just moving at a steady pace but is indeed accelerating this implies the existence of another unknown force which is acting to push the Universe apart, a force that repels matter instead of attracting it. In another article entitled “Cosmological Antigravity” that also appeared on the above Scientific American special report, Lawrence M. Krauss writes:
“Together all these results suggest that the (cosmological) constant contributes between 40 and 70 percent of the energy needed to make the universe flat. Despite the preponderance of evidence, it is worth remembering the old saw that an astronomical theory whose predictions agree with all observations is probably wrong, if only because some of the measurements or some of the predictions are likely to be erroneous. Nevertheless, theorists are already scrambling to understand what 20 years ago would have been unthinkable: a cosmological constant greater than zero yet much smaller than current quantum theories predict. Some feat of fine-tuning must subtract virtual-particle energies to123 decimal places but leave the 124th untouched –a precision seen nowhere else in nature … One direction, explored recently by Steven Weinberg of the University of Texas at Austin and his colleagues, invokes the last resort of cosmologists, the anthropic principle. If the observed universe is merely one of an infinity of disconnected universes –each of which might have slightly different constants of nature, as suggested by some incarnations of inflationary theory combined with emerging ideas of quantum gravity- then physicists can hope to estimate the magnitude of the cosmological constant by asking in which universes intelligent life is likely to evolve. Weinberg and others have arrived at a result that is compatible with the apparent magnitude of the cosmological constant … How will cosmologists know for certain whether they have to reconcile themselves to this theoretically perplexing universe? New measurements of the microwave background, the continued analysis of distant supernovae and measurements of gravitational lensing of distant quasars should be able to pin down the cosmological constant over the next few years. One thing is already certain. The standard cosmology of the 1980s, postulating a flat universe dominated by matter, is dead. The universe is either open or filled with an energy of unknown origin. Although I believe the evidence points in favor of the latter, either scenario will require a dramatic new understanding of physics.”
If we draw a “cosmological constant” (which we shall denote with the Greek letter lambda Λ) into the picture, Einstein’s basic tensor equation for general relativity becomes as follows:
G + Λ = 8πT
The reason Einstein found it necessary to include this “cosmological constant” into his equation for general relativity was because at the time the commonly held belief was that our Universe was a static Universe. In a static unchanging Universe, gravity will begin to pull everything together (planets, stars, galaxies, comets, nebulas, everything), and sooner or later there will be a “big crunch”, so a static Universe cannot remain stable for long, not unless there is some kind of repulsive force which will counteract the pull of gravity with just the precise amount of repulsion being exerted in the opposite direction, in which case the Universe would remain stable forever (or almost “forever”) thanks to such a very delicate balancing act between gravity and the mysterious repulsive form of energy.
However, when astronomy through the work of Edwin Hubble proved beyond any reasonable doubt that the Universe, far from being static, was in fact very dynamic and in the process of a continuing expansion, Einstein realized the he himself could have predicted a dynamic Universe if only he had not introduced that cosmological constant into his basic equation (and it would have been one of his most dramatic predictions!) At this point, he decided to do away with the cosmological constant altogether, in effect setting:
Λ = 0
and wasted no time at all in calling the cosmological constant “his greatest mistake”.
Yet, with the most recent data that is being obtained with extremely powerful probes into the cosmos, with mounting evidence that not only is the Universe expanding but also the rate of expansion itself is accelerating, theoretical astrophysics may be on the verge of facing one of its most serious crises. At present, the only possible way in which theory can be reconciled with mounting facts is to assume that the cosmological constant is not zero. But this admission, which perhaps would have shocked Einstein, brings with it a wealth of new problems that so far defy solution. For if the cosmological constant is not zero, and the rate of expansion of the Universe is accelerating, what then is the source for this negative energy responsible for the acceleration? Why was it never detected before? Could it have anything to do with the mysterious “dark matter” whose existence has been postulated by astronomers also to reconcile theory with facts? Are there other forms of elementary particles out there that have not yet been detected or produced in the high-energy accelerators here on Earth, particles that could perhaps be used as fuel for interplanetary exploration? For if a source of negative energy can be found in our current theoretical models (or perhaps in a yet-to-be discovered new theoretical model that would radically modify physics as we now know it), the impact could be more far-reaching than many of us can imagine, for we may be talking here about the possibility of true antigravity, the very stuff that has the potential of catapulting Man beyond the solar system and launch him into a whole new era of interplanetary space exploration, rendering all of our chemically propelled rockets obsolete and making all of our state-of-the-art means of transportation seem like a joke. And this is not science fiction. These are cold facts.
As gratifying as the above possibility may sound, not everyone is completely happy at this prospect. Theoretical physicists will find it extremely difficult to fit such a concept within the framework of Einstein’s theory of relativity. The topic of antigravity is so worrisome to many of them that even the “Bible of General Relativity”, the 1973 edition of the book Gravitation by Charles Misner, Kip Thorne and John Archibald Wheeler, long used as the standard training source for theoretical physicists working their ways towards their doctoral degrees in Physics around the world, makes no reference to the possibility of antigravity altogether, a topic that is considered anathema in the book. As a matter of fact, the word itself does not even appear in the book. To get information and opinions about this topic in the past decades it was necessary to resort to less formal literature, such as the book The Relativity Explosion by Martin Gardner, where we can read:
“In 1957 Philip Morrison and Thomas Gold conjectured that antiparticles may have negative gravitational mass. If so, any gravitational force acting upon them would cause them to accelerate in a negative direction. An antiapple made of antimatter would have flown up in the sky instead of falling on Newton’s nose. The conjecture is attractive because, if true, it would explain the absence of antimatter in our galaxy. Any antimatter produced in the past, in the vicinity of the galaxy, would long ago have been projected outward. Whether antiparticles have negative gravitational mass has not yet been unequivocally determined, but if it is found that they do, relativity theory will be in serious trouble.”
For men who have dedicated their entire lives to uphold a scientific theory such as the theory of relativity, the possibility that their “philosopher’s stone” will be cracked in pieces is certainly something most of them are not willing to accept quite easily. But perhaps their worries are exaggerated. The theory of relativity has too much experimental evidence in its favor to be brushed aside and swept under the rug. It is plausible that just by manipulating the cosmological constant Λ the new facts will still be able to fit into the theory. If not, it is possible that any new theory will somehow incorporate the theory of relativity into its framework, so instead of replacing the theory of relativity it will expand it into something even more complete, perhaps into quantum gravity, perhaps into the unified field theory that Einstein so desperately sought but was unable to accomplish within his lifetime. Or, in the final analysis, it is just possible that the new astronomical data could turn out to be wrong, in which case many theoretical physicists could make a sigh of relief adding William Shakespeare’s phrase “All’s well that ends well”. However, they should keep in mind something that Albert Einstein himself said regarding his theory of relativity:
“But I do not doubt that the day will come when that description (in reference to the theory of relativity), too, will have to yield to another one, for reasons which at present we do not yet surmise.”
Another article appearing in the same January 1999 issue of Scientific American entitled “Inflation in a Low-Density Universe”, Martine A. Bucher and David N. Spergel add the following:
“The laws of physics generally describe how a physical system develops from some initial state. But any theory that explains how the universe began must involve a radically different kind of law, one that explains the initial state itself. If normal laws are the road maps telling you how to get from A to B, the new laws must justify why you started at A to begin with. Many creative possibilities have been proposed … In 1983 James B. Hartle of the University of California at Santa Barbara and Stephen Hawking of the University of Cambridge applied quantum mechanics to the universe as a whole, producing a cosmic wave function analogous to the wave function for atoms and elementary particles. The wave function determines the initial conditions of the universe. According to this approach, the usual distinction between future and past breaks down in the very early universe; the time direction takes on the properties of a spatial direction. Just as there is no edge to space, there is no identifiable beginning to time … Unfortunately, it may be very difficult (though perhaps not impossible) for astronomers to test any of these ideas. Inflation erases almost all observational signatures of what preceded it. Many physicists suspect that a fuller explanation of the preinflationary universe –and the origin of the physical laws themselves- will have to await a truly fundamental theory of physics, perhaps string theory.”
As if all of the above was not enough, there was yet another development from which theoretical physics has not yet recovered, a development that reaches from within the confines of the atom to the outer reaches of the cosmos itself: the discovery that the particle we call the neutrino appears to have a mass. This discovery was accomplished by a team of scientists led by Yoji Totsuka of the Kamioka Neutrino Observatory located in Kamioka, Japan; and was announced to the world on June 1998 at the Neutrino ’98 conference on neutrino research held in Takayama, Japan. The tool used for the discovery, the Super-Kamiokande, a 12.5 million gallons (47 million liters) tank of purified water located about 2,000 feet (600 meters) underground, is essentially a giant underground neutrino detector, carefully shielded from the outside to block noise that might give false readings. The finding that the neutrino does indeed have a mass was made indirectly using the fact that neutrinos, thought to exist in three types, according to quantum mechanics theories can oscillate between two of those types provided there is a difference in mass between those two types, which means that at least one of the types had to have a mass that was not zero if any oscillations were to be observed. The oscillations were indeed detected. Although the experiment did not determine the magnitude of the mass of the neutrino, it did suggest that the mass might be about one-500,000th the mass of an electron.
To many theoretical physicists and cosmologists, the discovery that the neutrino does indeed have a mass could not have come at a worst time. It was once thought that the “dark matter”, the “missing mass” in the Universe needed to halt the expansion of the Universe and maintain galaxies bounded as they are today could perhaps be explained if the neutrino was found to possess a mass, taking into account the enormous amounts of neutrinos thought to be out there filling the vastness of space. Indeed, a few years before it would have come as most welcome news. But now with the discovery that the expansion of the Universe is not slowing down but instead appears to be accelerating, the delicate balancing act provided by current cosmological models is being undone at its foundations.
The issues discussed above are not something into which we are jumping in of our own liking. We are being driven willy-nilly by the experimental data, and a higher level of reality is forcing the facts upon us, whether we like it or not.
Ancient astronomers believed that the Sun, the Moon and the heavens revolved around us. They were wrong. Astronomers believed during the early 20th century that the Milky Way galaxy, our galaxy, was the entire Universe, and they were also wrong, and near the end of the century we now know that the Universe is made up of at least a hundred billion galaxies, a number that is constantly being revised upwards. Tempting, as it may be, to mock at the beliefs of those who came before us, it would be wise to imagine ourselves in the uncomfortable position of being the laughing stock of the generations yet to come during the third millennium. And nobody knows yet who will have the last laugh.
