However, space and time are relative according to the theories of Special and General Relativity which were developed by Einstein. A time period which is two hours long with respect to an observer may be one and a half hours or three hours long with respect to another observer. Let us suppose that two events are happening in different places (say New York and Istanbul) but simultenously with respect to an observer who is in between. The same events, however, will not be simultenous with respect to an observer who is in motion. If the observer moves towards the event happening on his right, that is, he diverges from the one on his left, then he will perceive the one on his right as happening earlier than the one on his left. Contrariwise, if he moves towards his left, that is, diverges from his right, then he will perceive the one on his left as happening earlier than the one on his right. Distances in space are thus relative and varying with respect to observers' positions.
Matter has a certain amount of influence over time and space according to Einstein's General Theory of Relativity (which he described as the theory he most enjoyed). Proportional to its mass, an object may cause changes in the geometry of space or in the acceleration of time. The curvature of space, for instance, is infinite near a black hole, which is regarded as a highly dense substance. Time is, however, constant and does not accelerate. This theory, with such peculiar outcomes, is mathematically perfect and coincides with observations conducted until now. Whether the universe is finite or infinite depends on the density of the material it contains, according to this theory.
Einstein's theories, though they seem flawless, cannot explain how the universe started all by itself. All laws of physics lose their validity at the time of the Big Bang (the explosion at the creation of the universe) and all the questions relevant to that moment and its precedents remain unanswered. How come the Big Explosion happened? How did it happen? What was there before the explosion? We need to rely on quantum physics in order to answer these questions or at least to deal with their paradoxes and be able to say something about the formation of the universe.
Newton's clock model or the deterministic model (that everything is realized in strict accordance with certain rules) is still influential in Einstein's theories, whereas quantum physics (which explains the activities of atomic and subatomic particles) is a more revolutionary approach to matter, actively engaging the observer in processes and tying events to probabilities. It seems that developing consistent theories about the beginning of the universe may only be achieved by using quantum physics, which might also have something to say about the macrocosm. However, the issue of how the theory of relativity and quantum physics can be reconciled is not yet solved. Here, it seems that the theory of multiple or parallel universes may be an alternative solution, and hence, many issues have been hitherto paradoxical and unsolvable are now being explained within a rational and logical frame of reference.
What are multiple universes?
In the Many Universes Interpretation (MUI) developed by physicists like Everett in the 1950s, the paradoxes caused by quantum physics in our modes of thinking are being eliminated and the issue of how the universe functions is being reviewed by an all-new approach. A parallel universe is a realm that carries features identical to those of ours and comprises space, time, matter, galaxies, stars and human beings all identical to those of ours. It can even be said that these two universes are sharing the very same space and that they are positioned to coexist. The substances in these parallel universes are interrelated according to the laws of quantum physics. That is, there are a great many universes like ours. You may, for instance, be taking a walk in a forest in a parallel universe while you are reading this article in this one.
Alternative histories can help us to understand parallel universes. How would the world have been shaped if the Ottoman sultan Mehmet II, who conquered Istanbul, had also succeeded in conquering Rome? Or, what would be happening now if Hitler had won World War II? Each of these probabilities has been realized in a parallel universe. Any world which is imaginably different and any history which is conceivably alternative is present and available somewhere out there. We can understand these multiple universes when we also consider our preferences. A person who chose to study medicine, for instance, would later become a medical doctor. If he or she had chosen biology, they might later have become a research scientist. Or, a man who chose to marry a woman merely due to her physical beauty but did not have a happy family life with her might have enjoyed a happy family life if he had married a pious woman who was his social equal and compatible with him. Thus, different universes, that is, differing probabilities become available according to our preferences.
Parallel universes are often a theme in science fiction novels and films. In the popular television serial Star Trek, for instance, during a routine beaming up process from a planet to their starship "Enterprise," Captain Kirk and his crew suddenly and accidentally find themselves in an ionized gas cloud. They find themselves inside an "Enterprise" that is almost identical to but surprisingly different from their own Enterprise. But, interestingly, the Mr. Spock in the new "Enterprise," is an extremely cruel person. In fact, all of the crew are cruel in this alternative starship. Meanwhile, the cruel Captain Kirk and his cruel crew have been beamed up to the other (good) "Enterprise" and these bad men have been imprisoned by the good Mr. Spock there. Both Mr. Spocks understand, after a short while, what the problem is. The Enterprise, due to an ionized gas storm, has been directed to a parallel universe in which an identical "Enterprise" and its identical crew exists. The duplication is almost perfect except that good is bad and vice versa. Had the ion storm not formed a space-time interconnection, the two (parallel) universes would have never become aware of one another. The good and bad versions of the parallel Captain Kirks have replaced each other; while the bad Captain Kirk is being held prisoner inside the good Enterprise, the good Captain Kirk has found himself inside the bad "Enterprise" and soon noticed that he can covertly correct some errors without being noticed and by acting as if he was one of the bad character.
In the television series The Twilight Zone a woman meets her (parallel) double while waiting at the bus stop. Her double has apparently left her own universe and entered this one. This double wants to replace her and succeeds in doing this. The genuine woman is meanwhile sectioned to a mental hospital.
In the story "August 2002, Night Meeting" from The Mars Chronicles, a terrestrial person named Thomas Gomez who has settled on the planet Mars happens to meet a parallel universe there. He hears an elderly man as he is about to depart after taking gasoline for his vehicle: "You may return to your world if you will not accept Mars as it is. Everything is different here: soil, air, canals, aborigines (though I have not yet seen any of them, but heard their voices) and watches. Even my watch functions peculiarly and even the time is different here."
Thomas then meets a Martian with gold-color eyes being carried by a machine that looks like a preying mantis peculiarly painted in bluish-green colors and greets him. The Martian greets Thomas in his own language. But neither understands the other. The Martian approaches and touches him, but Thomas does not feel him. They somehow start speaking the same language. As they try to shake hands, each one's hand passes through the other's as if they did not have hands at all. They can see each other, but cannot touch each other. They realize that they are in intersecting parallel universes. Each can sense his own body, but sees the other one as a ghost. They try to understand why they cannot touch each other while their universes mutually counter-influence. But they cannot find the answer. As he looks at his environment, the Martian sees a beautiful city full of marvelous things, while Thomas sees only desolate, unpopulated, ancient urban ruins. He shouts at the Martian, "All of these canals are empty!" The Martian replies,"The canals are full of violet-colored flowers." They finally understand that what they are experiencing is something related to time. However, they cannot discern who is in the past and who is in the future. Each of them thinks that his own world is the real one and the other one's is a realm of fancy.
Such peculiar-sounding tales contain some reality in the light of new physics.
New Physics: How do we know multiple universes exist?
One of the best explanations of quantum physics is the "double slit" experiment. In this experiment, a coherent light source which is emitting particles (photons and electrons for instance) illuminates a thin plate with two parallel slits cut in it, and the light passing through the slits strikes a screen behind them. When both slits of the thin plate are open, an interference pattern of alternating bright and dark bands is observed on the screen. However, a periodic pattern does not result as the pattern that forms when one slit is blocked is directed over the pattern that forms when the other slit is blocked. Or, when a measuring is conducted in order to determine the slit through which a particle has passed, the particle is behaving as if it is certainly passing through one of the slits, but this is distorting the pattern.
We can deduce, from this experiment, that the tendency of the particle changes when either one or both slits are open. Quantum physics explains this peculiar incident as the mutually-influencing of the probability of particle's passing through one slit with the probability of the same particle's passing through the other slit. That is, the particle, though being a single one, is behaving as if it is passing through both slits. The only logical way of developing a reasonable postulate is to consider that the particle passes through one slit in one world (i.e., universe) and through the other one in another world. So, these are the parallel universes which we have been trying to explain since the beginning. When the particle hits the screen, these universes unite again and become a single universe.
Another striking example which discloses the existence of parallel universes is the "thought experience" known as "Schrödinger's cat." The Austrian physicist Schrödinger devised this clever thought experiment: A cat sits in a steel chamber with a flask that contains a poisonous substance. There is also a small amount of a radioactive substance with a 50 % probability of decaying and thereby triggering a mechanism which will smash the flask, release the poison and so kill the cat. On the other hand there is also the 50 % probability that the radioactive substance will not decay, the poison will not be released and the cat will not die. Now, according to quantum physics, the cat will be 50% dead and 50% alive, that is, there is a superposition of states (the cat is both dead and alive) until the sealed chamber is opened and the cat observed. Naturally, such a thing is against logic and incomprehensible. The multiple universes (multiverse) model, however, explains this complicated situation more easily by saying that the cat is alive in one universe and dead in another.
Black holes and cosmology
Black holes, which came to the attention of science because of Einstein's General Theory of Relativity, are space-time structures that absorb everything including light. They form as a result of the collapse of stars which are three to four times bigger than the sun and which have fully consumed their energy. The structures of space and time become distorted due to the terrifying magnitude of a black hole's gravity as it is approached. Some physicists argue that black holes are passages between parallel universes and we would find ourselves in another universe if we could pass through one.
Belief in the existence of such a great number of universes also sheds light on cosmology, the science dealing with the creation of the universe and its structure. Possibly the most vital of the subjects that cosmology rarely touches on is the fact that the structure and composition of the universe are so delicately devised that it enables living species and conscious creatures to exist and survive in it. Only a single one among the many possible universes has been selected and made inhabitable for living and conscious species. If the universe had had rather different characteristics, these species would not have been able to live in it. The gravitational energy in the universe, for instance, is almost identical with the expansion energy of the Big Bang, and very delicate balances are observable in the constants of the laws of physics. By thorough observation, we can deduce that everything has been devised and prepared for our existence.
The multiple universes (multiverse) theory asserts that all possible universes exist. According to this assertion, there are universes in which no conscious species exist. The reason why we perceive that everything has been devised in this way in our universe is because we believe that we cannot survive in another one which is not devised with the delicate balances that enable the survival of living species. In fact, all this reminds us that there may exist unseen realms and worlds different than ours. The existence of beings like angels and jinns which cannot be observed by worldly eyes and the fact that the believers are those who believe in the unseen are mentioned in the Holy Qur'an. The existence of people like Khidhr who lived in realms of life different than ours, various prophetic miracles, saintly powers and the true prophetic dreams (ru'ya-i sadiqah) that give true prophesies all inform us that there are other realms beyond the visible one. Thanks to the new physics, the life in the grave, the life in the realm of barzakh (the intermediary life between the mundane and eternal worlds), the dimensions of paradise and of hell and their levels which we cannot explain in concrete terms, the realms in which we will either be punished or rewarded at existential co-ordinates beyond our imagination all seem more easily comprehensible today.
In fact, the principles of faith such as fate, death, the hereafter, the resurrection and doomsday do not need support from the cold and positivistic viewpoints of the physics with which we are familiar today. However, the fact that the idea of parallel universes was initially used in science-fiction works and only later dealt with in quantum physics might lead us to an important conclusion: We are witnessing today that many events which we could hardly imagine in the past (for instance, saving audio-visual recordings in huge computers and later presenting them as witnesses) are becoming quite common and ordinarily achievable in the real world. Likewise, the possibility that all our deeds which we perform throughout our lifetime might be saved by recorders in unknown metaphysical universes has become more easily acceptable and comprehensible. Today's imaginings might be the realities of one day in the future. Everything conceivable or inconceivable to us may be possible, for the One who created things is God, Who is Omnipotent and All-Knowing. Additionally, as He has informed us about all these phenomena in His Divine Revelation the Qur'an, of which even not a single word has been changed, we do not feel the least doubt. We shall experience how smoothly our souls transcend from this realm to another (as if passing from one room to another) when death knocks on our door one day. Certainly, we should never forget that the ease or difficulty of these experiences and the sights that we shall encounter in other realms will all depend on and be created out of our deeds in this mundane life. And, as we say "all praise and thanks be to God" in return for an apple that we eat here, we will witness, only when we face the reality, how this gratitude of ours will turn out to be a heavenly reward (a tree or a palace) in a different universe.
Salih Adem studied Biophysics at the University of Illinois at Urbana-Champaign until 2001 and philosophy at the University of Maryland at College Park until 2004. Adem is now freelance writer on physics and philosophy.