Time and Eternity Alex Gould (GENS4010) There are at least three reasons why considering time, from both religious and scientific perspectives, may be non-trivial: 1. There may be scientific benefits to doing so; understanding the nature of time could provide insights into the natural world that might one day form the basis of discoveries in the field of space travel, for example. 2. An investigation into the nature of time could provide us with insights into the nature of creation, and consequently, into the nature of the creator. This would have significant consequences in our religious beliefs, which in turn would have social, psychological and potentially eternal ramifications. 3. Such consideration may assist in fulfilling our natural curiosity and drive to understand the nature of existence. The following analysis will consider various models of time, including cyclic and infinite, linear and spacetime. Through these models, issues such as the creation and direction of time, the reality of past and future, and the relationship between time and the mind will be addressed. The analysis will conclude with some applications of the models, including religious inferences and travel through time. Yes, Simba. But let me explain. When we die, our bodies become the grass. And the antelope eat the grass. And so we are all connected in the great circle of life. Mufasa, The Lion King, 1994 The circular model of time probably dates back to tribal societies in which cyclic patterns of nature were important to survival and central to tribal wisdom. Since then, cyclicity has played a part in Hindu, Chinese, Egyptian, Babylonian and Mayan cosmologies as well as being central to most ancient Greek and Roman philosophy (Davies, 1992; Dowden, 2004). The appeal of this model is that it is consistent with our experiences of paired concepts such as life and death, and yin and yang, as suggested in Ecclesiastes 3: 1bAnd a season for every activity under heaven: 2 a time to be born and a time to die, a time to plant and a time to uproot, 3 a time to kill and a time to heal, a time to tear down and a time to build, As an infinite-time model, in which time is infinite in duration, the model is also appealing in that it avoids some of the difficulties of linear models of time, such as the question of what happened before the dawn of time. While it is quite difficult to conceive of what might exist outside of time, one can readily conceive of a circular time system in which time has always been and now is. This is a double-edged sword, however. As Jason Dulle (2004) argues, “It is impossible to have an infinite amount of time before the present because the present would be the terminus of that infinite amount of preceding time.” By definition, infinity is without bound, so one cannot limit an infinite past with the present moment. If we accept this argument then time must have a beginning, and therefore it cannot be circular. In the beginning the Universe was created. This has made a lot of people very angry and been widely regarded as a bad move. Douglas Adams, The Restaurant at the End of the Universe, 1980 Rejecting circularity, Islamic and Christian theologians adopted the Jewish notion that time is linear with the universe created at a definite moment in the past (Dowden, 2004). This linear model of time remains dominant in science and philosophy today. Astronomers have calculated the age of the Universe as 13.7 billion years, at the onset of which they postulate the universe was in a state of zero size and infinite density (Dowden, 2004). Such a picture of the creation of space and time is inferred from the Big Bang theory, which draws on evidence to suggest that the universe is expanding, is layered with background radiation, and contains a larger proportion of hydrogen than can otherwise be explained; all of which suggest a time of great density and temperature (Lecture 5). This hypothesis, however, is prone to the obvious question: what happened before the beginning of time? While Augustine answers this trivially as, since time did not exist, God did not have time to do anything (Custance, 1977), the question can be restated as, what caused time to begin, and why? Einstein’s general relativity suggests that time and space are intrinsically connected, as spacetime (Davies, 1992). As the realm of science extends only as far as scientific observation may be applied, any opinion on the nature of existence beyond spacetime must necessarily be a theological one. The popular theological response to the above question is that the Big Bang was a result of a divine entity who is eternal in a timeless sense, in contrast to the infinite-time eternity of the circular model. This concept raises some questions. Firstly, it is difficult to conceive of how an entity can exist, but not exist in time, as this is a fundamental characteristic of existence as we understand it. It begs the question of the source of whatever realm of existence this entity resides in, with the ultimate answer being that something at some stage must have existed without cause. It is similarly challenging to conceive of how God might bring about the Big Bang from a state of existence outside time and hence outside causation as we understand it. Finally, it is unclear as to why such a being would create the universe. Traditional responses, that God is love, that God created the universe as a reflection of his power and glory, or perhaps that God was suffering from an existential crisis, involve our transferring human motivations onto a God who by definition is outside the spacetime that allows us our chemical concepts of meaning and desire. Brian Tee (2004) suggests that this dilemma might be resolved by assuming that God is a moral entity – as theological religions do. Given this assumption, God is compelled by His very nature to create our universe as the most ideal state of affairs. This response, however, merely transforms our problem into the question of why God is a moral entity, and how He came to be so. It seems we are obliged to accept the notion of something existing without prior cause, eternal in the timeless sense, and whose very nature implies the creation of time and space. As though a rose should shut and be a bud again John Keats, Eve of St Agnes An interesting question is why time appears to flow in the direction that it does. The equations of classical mechanics as well as those of the theory of relativity are time reversible. That is, they are solved just as adequately for –t as they are for +t. This interesting observation begs the question of why it is that time is not reversible. Stephen Hawking (1996) suggests three processes that describe the apparent flow of time: the thermodynamic; cosmological; and psychological arrows of time. The first of these stems from the second law of thermodynamics, which states that there is a tendency for disequilibriums in energy distribution to equalize, a process known as entropy. This can be seen in the cooling of a pan when it is taken off a hot stove or in air rushing out of a small hole in a tire. The second of these stems from the expansion of the universe which may be inferred from the Doppler Effect, where wavelengths of light lengthen as the source moves away from us, causing a red shift when measured. The third arrow is similar to the first, but applied to our perception of time, we remember the past but we do not remember the future, for example (Hawking, 1996). Will the universe one day cease to expand and instead contract? And in this case, would the thermodynamic arrow reverse as well, and time itself turn backwards? While such conjecture is outside the scope of this essay, it does raise the interesting question, “what happens if time comes to an end?” From a scientific perspective, it is suggested that ultimately the end of the universe will result in either ‘death by fire’ or ‘death by ice’, with the first option corresponding to a scenario in which the universe contracts, and the second in which it either stabilizes or continues to expand. In either case, the universe will eventually be uninhabitable, although the time until this situation arises is large enough to consider it trivial for human purposes. From a religious perspective, in Christianity, Zoroastrianism (an ancient Persian religion) and Islam, the universe is seen as incomplete or imperfect, but it is headed towards a final completion or perfection (Hooker, 1996). In Zoroastrianism and Islam, the universe will continue to exist after this point, in eternal equilibrium, in an infinite time sense. Christian perspectives on this issue are divided, with eternity being interpreted in both senses of the word. All that is clear is that at the end of time as we know it, judgment will occur: “the day of God's wrath, when his righteous judgment will be revealed.” (Romans, 2:5b) Reality is merely an illusion, albeit a very persistent one. Albert Einstein It is a known fact that a slideshow of images flashing up on the screen actually does make the installation progress bar on our computer screen move faster. Hallucinogenic drugs too can also distort our perception of time. But is time itself subjective? Relational theories of time imply that the apparent flow of time is really just an illusion – a product of our minds; that all that exists are real objects and their spatial relationships to other objects. This idea was raised by Leibniz, who argued that only the present ‘now’ exists. A similar idea from common sense is that we all share a common present; however, both these ideas have been challenged by Einstein’s theory of relativity and the time dilation effect. Time dilation describes a situation in which “the faster an object is moving, the slower time will be measured” (Cline, 2002). This effect has been confirmed in experiments such as the Hafele and Keating experiment of October 1971. Cesium atomic beam clocks were flown around the earth in different directions and the resulting time difference between these clocks and a stationary clock in the US Naval Laboratory was correctly predicted by the theory of relativity (Nave, 2003). Gravity can produce the same effect, for example, Pound and Rebka (Anon, 2004) were able to demonstrate a difference in time measured at the top and bottom of a 22m tower to 1% accuracy. Some have drawn from these results the implication that there is no universal present moment. One response is to argue that the experimentally verified existence of background radiation allows us to speak of a unique cosmic time (Follin, 2002). Einstein’s reaction was the conception of spacetime into what is known as the block universe, in which the universe can be considered as a single block of spacetime, with slices through the block representing moments of creation, and various entities differing as to which slice they perceive as being the ‘present’. This view, however, implies that the future may be fixed, where quantum mechanics reveals, that at the sub-atomic level, our universe, and hence the future, is inherently unpredictable (Al-Khalili, 2003). It is not surprising that this issue, as with most raised in this discussion, remains unresolved. As James Barr noted, the biblical view of time is a question for which the Bible affords little material. Other religions are similarly reticent when it comes to pronouncing a clear theory of the actual nature of time (Follin, 2002). Scientific views are generally theoretical, applying to situations beyond the scope of our humble Earthly existence, making it difficult to empirically verify conclusions. Let us now consider some applications of the models of time presented to real world problems. This is a dude who, 700 years ago, totally ravaged China, and who we were told, 2 hours ago, totally ravaged Ashman's Sporting Goods. Ted, Introducing Genghis Khan, Bill and Ted’s Excellent Adventure, 1989 A given model of time will influence one’s appreciation of the validity of time travel. If we ascribe to Leibniz, for example, we would have to accept that time travel is not possible; only a single ‘now’ exists and we would have to completely restructure the basic components of reality itself to artificially move ourselves into a different time. Under Einstein’s block universe model of time, however, time travel might be seen as more reasonable. The experimentally verifiable effect of time dilation discussed above suggests that forward time-travel may be theoretically possible. But backward time-travel would also merit further investigation should one ascribe to the block universe model. Such travel would require what is known in physics as a ‘closed time-like curve’ in spacetime, which resembles something of a four dimensional loop-the-loop on a rollercoaster ride (Al-Khalili, 2003). Other concepts of time, such as the timelessness of the Buddhist state of enlightenment or the interaction between time and timelessness in Trinitarian theology, might see time as inherently mutable, or even illusionary. In these situations too we might be inclined to believe that time travel is possible, though in this case it would be through an extension of the mind or soul. One of the main reasons why backward time travel is often dismissed in physics is captured in the Grandfather paradox, in which you travel back in time and kill your grandfather before he has met your grandmother, thus preventing your own birth. In this situation, you both exist and do not exist at the same time, an apparent paradox. If we assume the universe is non-contradictory, we can conclude time travel is impossible. Our sentiments toward time and eternity may also have religious implications. For example, if one is partial to a relativist or subjective model of time, one would be more inclined to believe Buddhist claims of achieving an enlightened state, beyond the constraints of time and space. Someone who believed firmly in an absolute model of time, whereby the entire universe is subject to a unique present moment, may perceive such claims as imprecise descriptions of a psychological state of mind, however. We have seen that the linear model of time poses the question of why time began, with the ultimate conclusion necessitating an eternal being beyond prior cause. Advocates of this view might be inclined toward selecting a theist religion such as Christianity or Islam. And if one was dissatisfied with the lingering presence of time within indoctrinated afterlife concepts, one could consider becoming a Deist. What then is time? If no one asks me, I know what it is. If I wish to explain it to him who asks, I do not know. Augustine, Book XI, Confessions This essay has explored some of the key issues in the arena of time, by way of an analysis of various models of time and their relationship to some mainstream religions and branches of scientific thought. While “thinking of the Earth as flat is mostly appropriate for everyday life” (Follin, 2002), it is important for us to be able to suspend our natural reaction with regards to time, and openly consider theories that challenge these responses, such as the possibility that something might exist without prior cause, that something may be eternal in either a timeless or an infinite-time sense, or that there may be more than one ‘present’ moment. While these ideas may seem strange to some, it is helpful to remember that the concept of a spherical Earth was once strange, too. It is important to be cautious of convincing oneself of an answer to a question just to manage the drive we feel to understand. An example of this search for conviction might be found in asking many atheists where the world comes from, and having received the response, “from the Big Bang”, enquiring as to what the Big Bang actually entails. Bearing in mind that our contemplations regarding time might have social, psychological and scientific ramifications puts a degree of responsibility on the thinker to, at times, accept the incommode of not always knowing the answers. Note: This article was adopted from a general education course assignment References: Al-Khalili, J., (2003) Time Travel: separating science fact from science fiction, IOP Publishing (www.iop.org/EJ/article/0031-9120/38/1/302/pe3102.pdf) Anon., (2004) Science Fair Projects Encyclopedia: Gravitational Redshift (http://www.all-science-fair-projects.com/science_fair_projects_encyclopedia/Gravitational_redshift) Cline, D., (2002) Math Definitions, LattieStone Ballistics (http://www.aeroballisticsonline.com/ballistics/mathdefinitions.html) Custance, A., (1977) Time and Eternity (http://custance.org/old/time/ch4.html) Davies, P., (1992) The Mind of God, Simon & Schuster Dowden, B., (2004) Time, The Internet Encyclopedia of Time (http://www.utm.edu/research/iep/t/time.htm) Dulle, J., (2004) Eternity is Not Forever: An Argument for Theism (http://www.apostolic.net/biblicalstudies/eternityforever.htm) Fagg, L., (1996) Sacred Indwelling and the Electromagnetic Undercurrent in Nature: A Physicist's Perspective, Zygon 37:2 Follin, M., (2002) What is the Relation of an Eternal God to a Temporal World, St John’s College, Nottingham Hawking, S., (1996) A Brief History of Time, Bantam (http://newton.physics.metu.edu.tr/~fizikt/html/hawking/h.html) Hooker, R., (1996) World Cultures General Glossary: Eschatology (http://www.wsu.edu:8080/~dee/GLOSSARY/ESCHA.HTM) Nave, C., (2003) Hyperphysics (http://hyperphysics.phy-astr.gsu.edu/hbase/relativ/airtim.html#c1) Tee, B., (2004) Forum Post, Philo Sophos •com (http://www.philosophos.com/knowledge_base/archives_9/philosophy_questions_927 .html)

CRICOS Provider Code: 00098G