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I'm not sure if this is the correct stackexchange site for this question.
I've been reading this article on Vice Motherboard There's Growing Evidence That the Universe Is Connected by Giant Structures which while admittedly simplified for simpler folk like me put me wondering:
Is it at all possible that when we look out in to the distant universe in one direction, we are seeing the same galaxies and stars at a different point in time than if we look out in another direction? Could this occur if the distant body is moving laterally at a fast enough velocity relative to our position, or if the shape of the universe itself loops around?
Or is this not a proper interpretation of current theories of cosmology?
Could this occur if the distant body is moving laterally at a fast enough velocity relative to our position
Nope. I mean if the universe is flat it doesnt matter how fast the object goes you cannot see it twice in the sky.
or if the shape of the universe itself loops around?
Yes. If the universe has a positive curvature. When we look at the sky, we can see the same object in two opposite directions.
In our universe this is not possible since if the universe is positively curved then the radius of curvature is much larger then the size of the observable universe. So its highly unlikely that we will see the same object in two different positions in the sky.
In principle, the universe could be geometrically flat (as the evidence indicates) and still "wrap around" as you describe. In the old game Asteroids, when you went off one edge of the screen, you came back in the opposite edge. That is the topology of a torus, but geometrically the screen is flat. There is no mathematical reason the universe could not be like this in its three spatial dimensions. The book The Shape of Space by Jeffrey Weeks discusses this possibility.
I think most cosmologists consider this so unlikely that it's not worth investigating, but I believe some people have reviewed existing data to see if there are statistical patterns in galaxy distribution that would indicate this kind of "closed manifold" structure. They didn't find anything.
So it looks like the answer is No - all the galaxies we see are different.
What Is Time? A Simple Explanation
Time is familiar to everyone, yet it's hard to define and understand. Science, philosophy, religion, and the arts have different definitions of time, but the system of measuring it is relatively consistent.
Clocks are based on seconds, minutes, and hours. While the basis for these units has changed throughout history, they trace their roots back to ancient Sumeria. The modern international unit of time, the second, is defined by the electronic transition of the cesium atom. But what, exactly, is time?
Will We Ever Find Dark Matter in the Universe?
T he science of cosmology has had a spectacular run. Over the past few decades, cosmologists have carried out measurements and observations that have enabled us to reconstruct our universe&rsquos past in incredible detail. We can now say with great confidence that we understand how and why our universe evolved over the vast majority of its history. From this perspective, our universe looks more comprehensible than ever before.
And yet, not all is understood. Despite our considerable efforts, there remain essential facets of our universe that we simply do not know how to explain. Perhaps the most famous of these mysteries is that of dark matter. Modern measurements have determined the amount of matter in our universe to very high degree of precision, and it is much more than exists in the form of atoms. After decades of debate, we are now confident that most &ndash about 84 percent &ndash of our universe&rsquos matter does not consist of atoms or of any other known substances, but of something else that does not appreciably radiate, reflect, or absorb light. For lack of a better name, we call this mysterious stuff dark matter. But naming something is very different from understanding it.
A decade ago, many cosmologists &ndash including me &ndash thought we had a pretty good idea of what the dark matter likely consisted of. The arguments we made were predicated on how we thought this substance was formed during the first fractions of a second after the Big Bang. The quantity of dark matter particles produced in the early universe that then survived the conditions of the Big Bang, we calculated, should depend on how much those particles interact with themselves as well as with ordinary forms of matter. Based on our calculations, we were led to think that the dark matter must interact through what is known as the weak nuclear force, or through some other unknown force that is roughly as powerful. We called such particles WIMPs &ndash weakly interacting massive particles &ndash and they were our best guess for dark matter&rsquos identity.
If the dark matter is indeed made up of WIMPs, then it should be possible to conduct experiments that could directly detect and measure individual particles of this substance. With this goal in mind, a small army of physicists began to build ultra-sensitive dark matter detectors, deploying them in deep underground laboratories where they would be protected from the most distracting kinds of cosmic radiation. At the time, the odds seemed quite good that this approach would succeed. In fact, I made a bet in 2005 that dark matter particles would be discovered within a decade. I lost that bet. From a technological perspective, these experiments performed beautifully. Yet no signals appeared. Adding insult to injury, the Large Hadron Collider also began its operation during this time, finding no signs of dark matter. From these experiments, we learned that the dark matter is far more elusive than we had once imagined.
Our failure to detect particles of dark matter has had a palpable effect on the scientific community. Although it remains the case that a discovery could still plausibly lie right around the corner, most of us studying dark matter today will acknowledge that many of our favorite dark matter candidates should have been detected by now. This has driven the field to redirect its efforts toward new and sometimes very different ideas, ushering in an explosion of theoretical work related to dark matter and its nature.
One newly popular idea is that the dark matter might not be alone, but instead could be one of several kinds of particles that constitute what is known as a &ldquohidden sector.&rdquo The particles that make up such a hidden sector could interact among each other, but almost never with any of the known forms of matter, explaining why they have been so difficult to detect in underground experiments or to produce at the Large Hadron Collider. The particles that make up a hidden sector could have evolved and interacted in the early universe in any number of potentially complex ways, even experiencing forces that we have never witnessed. Particle physicists have proposed many theories in which the interactions between multiple kinds of hidden matter can lead to the viable production of dark matter in the early universe. In fact, it&rsquos been quite easy for particle physicists to come up with viable hidden sector theories that behave in this way.
Another possibility has less to do with the dark matter itself, and more to do with the space that it occupied during the first fractions of a second after the Big Bang. When we use the equations of general relativity to calculate how fast space should expand, we take into account all of the known forms of matter and energy, including all of the kinds of particles that we have observed at the Large Hadron Collider. But it&rsquos entirely plausible that other forms of matter were present in the early universe that we don&rsquot know about yet. If this was the case, then our universe may have expanded quite differently from how we currently envision. And if the early universe expanded either faster or slower than we currently expect, this would change how the dark matter particles interacted during this era, as well as how much of this substance would have survived these critical moments.
The range of possibilities for how our universe may have expanded and evolved during its first second is enormous. Unknown forms of matter and energy may have increased the rate of expansion, but it&rsquos possible that far stranger things occurred during these first moments as well. Perhaps our universe experienced a brief and sudden burst of expansion, or underwent a dramatic phase transition at some point during its first second. Alternatively, there may have been a population of particles that decayed, heating our universe and altering its evolution. The possibilities abound. Such events could have dramatically impacted how the dark matter was formed and interacted during our universe&rsquos first moments. If we were to learn one day that such an event really did take place, this would almost certainly change our expectations about the nature of dark matter and the kinds of experiments that we would need to carry out in order to detect it. It might even explain why the dark matter has remained so elusive for so long.
The remarkable progress of underground dark matter detectors and the Large Hadron Collider has thrown the field of cosmology into a state of major disruption. Dark matter, it seems, is quite different from what most of us had once thought. The stubborn elusiveness of dark matter has forced us to abandon many of our favorite theories and to consider some radically new ideas about this substance and the conditions under which it was formed in the first instants after the Big Bang.
By striving to discover the nature of dark matter, we hope not only to identify the particles that make up most of the matter in our universe, but also to learn about the earliest moments of our universe&rsquos history. In this sense, dark matter provides us with a window into the Big Bang. I have no doubt that these earliest moments hold incredible secrets but our universe holds its secrets closely. It is up to us to coax those secrets from its grip, transforming them from mystery into discovery.
If the Big Bang originated from a point, how is it that we see the universe grow younger when we look at it from many different points around the globe? Shouldn't we expect to see the universe simply "cut off" at the line marking where the universe still hasn't had time to expand into?
Something never quite made sense about this because if to originated from a super dense point shouldn't the origin if the universe actually be a point we would have to aim at in order to view the universe near the origin?
I'm a layman, although I frequent r/askscience so I've picked up on a few common pitfalls.
What you've heard is a simplification. The thing is, the explanation of a super dense point is an easy way of expressing how densely packed matter was in the early stage of the Universe, but the Universe itself was still as infinite as it is today. It was never concentrated into a single point, it was just very very dense.
The "explosion" or the big bang then refers to the rapid expansion of space itself, which is still happening today albeit at a far slower pace. This expansion of space happens everywhere.
As such, there isn't a center, and there never was.
The image of the big bang as an explosion is very misleading. The universe didn't originate at a point, with stuff flying away from the center. The expansion happened everywhere in an approximately homogeneous universe. Consequently, there is no "cut off" beyond which there is emptiness.
Essentially, this is part of how we know the universe expanded faster than the speed of light. Since the speed of light in vacuum is a constant, finite speed, the further away we look the older the light is. The limit to this is we can't see images if the light as been reabsorbed or scattered. So, the cosmic microwave background radiation is the oldest we can see. That's when the universe was cool enough for neutral hydrogen to form, and became transparent.
The second piece has to due with the universe being isotropic. Cosmic microwave background radiation was emitted in all directions, which is why we can see it in all directions. Since it's hard to think in more than four dimensions, picture blowing up a balloon with dots on it. Without any air, the dots all blend together. As you blow it up, they separate. If you imagine each dot emitting light radially at the instant the dots separate, traveling along the skin of the balloon, any particular dot would receive it from all directions until enough time passed that you could "see" the entire balloon. Because of inflation, that hasn't happened in the real universe yet.
Could different views of the universe simply be different points in time? - Astronomy
Suppose an extraterrestrial, who lacked a religion but possessed what most of us call rational capacity, were to visit earth. She might be quite puzzled by the fact that millions of people believe in God--that is, they believe that somebody or something called "God" exists and is very important--but she would be hard pressed to determine exactly what they mean by "God." Her quest would not be made easier if she possessed an historical sense. A little inquiry reveals that God has been described in hundreds, if not thousands, of ways, enough to confuse anybody. Here are a few of them: Supreme Being, Perfect Being, Life Eternal, The Supreme Good, The Way, The Truth, The Light, The Glorious One, The Incorruptible, Father of All, Mother of All, Creator, Ruler of the Universe, Lord, Allknowing, Allmighty, The Unmoved Mover, Providence, Fortune, Shepherd of His Flock, and a Friend in Time of Need.
What does all this confusion and the puzzlement of this extraterrestrial have to do with us? Not very much if we are secure inside the cocoon of an isolated village where there is only one church and only a short list of approved descriptions of God. But few of us are so lucky--or is it unlucky? In any case, many of us are in a situation not wholly unlike that of our extraterrestrial. Either we have never had, or we had once but have since lost, a faith which was secure only because we were unaware of alternatives. We are aware of a variety of religions and God-descriptions, and this very awareness makes our being-religious at least a little bit problematic.
Philosophical reflection on what is meant by the term "God" and whether such a God exists tries to use rational methods to clarify this problematic situation. Defining "rational" is almost as difficult as defining God, but I offer in Part I of this paper some groundrules which suggest some limits to rational inquiry on our subject. The remainder of the essay discusses philosophical conceptions of God which try, with different degrees of success, to meet conditions like those laid down in my rules. The essay takes no stand on whether one can rationally prove that God exists. It takes up a prior question--possible definitions of God only if we are confident that an idea of God is coherent can we reasonably ask whether a being conforming to that idea exists.
Part I: Some Guidelines for the Discussion
The following rules are not presented dogmatically: once you see what they rule out or allow in, you might wish to reject one or another of them. It would then be incumbent upon you to say what rule you would put in its place.
No. 1. The Compatibility Rule. Thou shalt not attribute to God incompatible properties.
This rule is required in order that the discussion of God remain a rational discussion. This rule would exclude the possibility that God is both the father of Jesus and Jesus himself if "father" is used in the biological sense of "male parent." It also excludes the possibility that both of the following are true together: (1) God's will is eternally fixed and (2) He actually makes up His mind at a particular point in time, say, after someone petitions Him in prayer.
No. 2. The Contemporary Knowledge (CK) Rule. Thou shalt make an effort not to describe God in such a way that the existence of such a God would conflict with the cautious conclusions of contemporary scientific and historical investigators.
Whereas the Compatibility Rule is designed to keep the discussion rational in the sense that logical inconsistencies are eliminated, the CK Rule is designed to keep it rational by taking seriously the collective human experience represented by communities of experts now mostly centered in universities where free inquiry takes place.
The CK Rule--as applied today--would tend to exclude claims like "God created the Sun to move around the earth" or "God placed a complicated system of dead animal skeletons (what we call fossils) in the earth to see if scientists could resist the temptation to develop a (false) evolutionary theory."
We should be especially wary of misapplying this rule. It would be a misapplication to assume that a view maintained by a small minority of contemporary scientists or historians counts as contemporary knowledge. (I would even say that a live theological option might conflict with a majority view among scientists or historians, so long as a significant minority of qualified researchers still had doubts.)
The following argument would also be a misapplication of the CK Rule: "Contemporary scientific knowledge does not provide substantial support to claim C about God therefore C must be considered false." Scientific research investigates the physical aspects of reality. Theology makes claims about aspects of reality sometimes rather distant from these physical aspects. So we should not expect science to provide decisive support for one and only one theology.
Incidentally, none of these rules are designed to prohibit anyone from formulating any description of God whatsoever. We have to formulate even the zaniest ideas before we can refine or correct them. The rules are designed to guide us in the evaluation of competing possible descriptions of God once these are "on the table."
No. 3. The Anti-Idolatry Rule. Thou shalt not mistake the symbol for what is symbolized.
If, for example, God is the power from which all life comes, it will not do to represent this power as, say, a young animal (a calf), then to represent this again in a graven image (for example, a golden calf), and then to think of the graven image as if the image were the power from which all life comes. If this is at all an accurate account of what is reported in Exodus, then the Israelites who worshipped the golden calf broke Rule No. 3. Something similar occurs when one has overzealous reverence for the allmighty dollar or the American flag.
The founders of most of the world's great religions reject idolatry. We are being quite traditional if we accept rule No. 3.
This rule might also be called the Anti-Fetishism Rule. A fetish is a visible object which is attributed more power than it has or more significance than it merits, all things considered.
No. 4. The Anti-Blasphemy Rule. Thou shalt not describe the divinity in such a way that people who accepted that description of Him (or Her or It) might be inclined to do something obviously immoral or to behave consistently in such a way that their moral growth might be prevented.
The effect of this rule is to build an ethical component into any rationally permissible theology. The rule would exclude, I suspect, a description of God as one who delights in the torture of nonbelievers or in the military conquest of one national group by another. I call this rule the "anti-blasphemy rule" on the assumption that if one describes God as encouraging people to become worse individuals, one is describing an evil God, and to do that is, in effect, to blame God for one's own bad traits. (This is not quite the usual sense of the word "blasphemy," but it is closely related to the word's original meaning.)
No. 5. The Heritage Rule. We should describe the divinity, so far as possible, in ways which show our acceptance of our cultural heritage.
The word "our" here in this rule needs to be taken broadly. The Rule does not justify an exclusive focus on the religion of one's biological ancestors. Even on that ground, of course, we would be justified in studying pagan religions (since we all have pagans among our ancestors). Our heritage is a pluralistic heritage. With many South Asian immigrants, the U.S. is getting more pluralistic every day. Moreover, we are all the children of one planet that means that even if we were raised Christians, our religious heritage also includes Judaism, Islam and Buddhism at the least.
This rule affirms the importance of past wisdom. We cannot escape the past by wishing it away. Besides, the past is a reservoir of great insights. If we are to benefit from them, we must not reject them by blanket condemnations simply because some people who claimed in the past to agree with them performed great crimes.
It is important not to take this rule as cancelling out any of the other rules. If my ancestors believed a doctrine full of literal contradictions, this is no justification for my believing them. If my ancestors worshipped golden calves, this is no justification for my worshipping them. If my ancestors' religion called for human sacrifices, it doesn't follow that I ought to try to perform them now. What the Heritage Rule demands is that we sift our religious traditions not only for their literal insights but also for the wisdom expressed in parables and poetry and other nonexplicit ways of communicating.
Part II: Traditional Philosophical View I
The first philosophical notion of divinity to be considered here is the conception of God employed by theologians of the Middle Ages. For a thousand years or more, God was described in terms derived from ancient Greek philosophy. Indeed, in Philosophy of Religion courses, God is still usually described in these terms. God was said to be an unmoved mover, eternal, all-knowing and transcendent. "Transcendent" here means existing beyond the physical universe, independent of it and outside of space and time. Transcendence is contrasted with immanance an immanent deity is somehow bound up with the physical universe and would not exist without it. We'll consider an immanent conception later.
The classical descriptions of God seem to be based on carrying something like the following thinking process to its so-called logical conclusion. Observe a child. It has little ability to remember or anticipate. A teenager will have better memory and better ability to anticipate and to plan. The normal adult will surpass the teenager in these respects. And a king of a great kingdom will be superior even to the normal adult. He will have at his disposal a network of spies liberally sprinkled throughout the opposition groups and a coterie of historians and wise men. His spies will give him ability to anticipate, his historians will tell him about past experience and his wise men will help him put it all together.
Thus, as the power of the adult surpasses that of the child, so the power of the king surpasses that of the normal adult. As we shift from the child to the king, we move from someone who has little knowledge of past and future to someone who has, comparatively, great knowledge of both. Traditional theologians merely extend this reasoning. There is, they say, a perfect mind whose knowledge of past and future is total. They will even draw a picture for us. Draw a straight line across the page. Mark the beginning as the first day of Creation, mark the end as the Day of Judgment. Somewhere in the line (probably closer to the end than to the beginning), mark "now." This represents time from Creation to the Last Day. We can take this line in all at once, just by standing back from the page. Well, then, that is the way God is said to see the whole history of universe, "all at once."
On this description, God must be beyond the universe and outside of time, just as we must be beyond the line in order to "take it in all at once." The term "eternity," in the strict sense, refers to being entirely outside of time it also includes not being subject to change, for only things in time can change. Note that "eternity" does not mean "lasting through all time." (The label for what lasts through all time is "everlasting.") Presumably, if an all-powerful God willed it, He could make some material object last through all time, but it would not then be eternal in the way God is thought to be eternal.
Any such God will be utterly unchanging. He knows everthing, past, present and future--He is never surprised.
This traditional view of God also usually involves the following doctrines. (Let's call the fuller view that includes them all Traditional View I.)
(1) God is an omnipotent creator: Everything that occurs is part of his plan. He creates the universe from nothing. While a sculptor or architect creates something from preexisting matter, God creates the matter as well as the form.
(2) God is perfect and good. This is another reason why He is not subject to change. (Any change would be for the worse.) As a result, God cannot be affected by anything outside Himself.
(3) God's creation is good and perfect. This is what you would expect if God is perfect and omnipotent.
(4) God Himself is pure mind. The traditional view tends to regard possession of a body as a sign of imperfection after all, creatures with bodies are subject to disease, suffering, sexual temptation, excessive desire for material possessions, etc. Since God is perfect, they reasoned, God must be bodiless.
Part III: Puzzles Associated with the Traditional View I
The view of God as all-knowing and eternal causes certain difficult questions to arise.
(A) If God knows all, then does He not know the future, and if the future can be known, is it not fixed? If the future is fixed, then how can we mortals make free choices? If we cannot make free choices, does it not follow that nobody is responsible for her actions? How then is moral evaluation possible?
(B) Another puzzle arises from the addition of the philosophical interpretation of "creator" to the notion of God as all-knower. God's will is then understood as the source of all being. That would include the being of our actions (when we perform them). In a way, God would seem to be also the source of our failures to act (for, on this view, do we not fail to act just when He wills not to give being to the acts we should have done?) But if God is the source of our actions and our failures to act, how can they really be our actions? Once again, moral responsibility seems to be impossible.
(C) A third puzzle arises from the fact that adherents of the Traditional View I also often considered themselves Christians or Jews or Moslems, and prayer is important in these religions. These philosophers understood God as free from any influence whatsoever from outside forces. Now, if prayer is a form of communication (which seems plausible) and communication affects the being with whom one communicates (which also seems plausible), then how can one pray to God?
(D) A fourth puzzle has to do with the reality of evil. A good and omnipotent God would make nothing bad. The traditional philosophical view holds that, in some sense at least, God makes everything. It would seem to follow, then, that everything must be good. What about evil, then--"natural evils" such as diseases, earthquakes, and deformed births or "moral evils" such as lies, thefts, murders, and briberies? Are these merely apparent evils, and not real evils at all?
Can the puzzles be solved? We are about to consider some proposed solutions. Most of them involve revising Traditional View I on one or more main point. Another possibility, which defenders of the Traditional View may wish to consider, is that all the puzzles involve faulty reasoning at some point or other. If you think so, your task is to show where the error is.
Part IV: Revision of Traditional View--Traditional View II
Some people who are attracted in many ways to the view of God identified above as Traditional View I attempt to avoid some of the puzzles by taking more seriously what seems to them to be implicit especially in the Old Testament narrative of God's relation to the human beings He created. This view, which we may call Traditional View II, does not necessarily deny God's omniscience, but it does deny that He plans everything down to the last detail, especially where human actions are concerned.
That is, Traditional View II holds that God is able to (and indeed did) create beings, distinct from Himself, who are able to make free and responsible choices. These beings include some embodied beings, such as humans. Therefore, once human beings are on the scene and external nature (ultimately controlled by God) permits them to function, God does not control literally everything they do, and thus He does not control everything that occurs.
This view immediately dissolves Puzzle B for God, on this view, is no longer the complete cause of our actions or failures to act. It may well be that we are responsible for them.
Puzzle D, to the extent that it concerns moral evil, is also dissolved. If God is not the complete cause of moral evil (since it is up to us and not to Him that moral evil enters the world), then the presence of moral evil is no argument against the goodness of God.
Defenders of Traditional View I may respond that to take this approach is to deny God's omnipotence. But Traditonal View II can develop the following interesting response: Suppose God had a choice, to create a purely machinelike universe entirely under His control or to create a universe such as we say the present one is, with embodied free beings distinct from Himself. Which is a richer world? Certainly the latter. Which is a better world? Certainly the latter. If God created the machinelike world, He would not have created the better world. Assuming God's goodness (as holders of Traditional View I do), the only explanation for His failure to create the better world would be that His power is limited. It seems that it is not us, but you, who believe in a relatively weak God. When we say that He created free human beings, we are celebrating His power, not His relative weakness.
We have not shown that Traditional View II can dissolve Puzzles A and C or Puzzle D insofar as it concerns the reality of natural evil. I leave it to class members who are attracted to View II to work at that task.
Part V: Augustine's View
In some ways, the theology of Augustine (354-430 AD), the first major and perhaps the most influential Christian philosopher combined features of the two preceding views. Augustine makes a distinction in time between the period after Creation before Adam ate of the Tree of Knowledge (thus sinning) and the period after his sin. Human beings had been created able to sin or not to sin that is, they originally had free will.
But when Adam sinned, his sin permanently disfigured or corrupted human nature. All of Adam's descendents inherit this corrupt human nature. Now, left to our own devices, and relying upon our human nature such as it now is, we are unable not to sin. Our will cannot free itself from bondage to sin through any effort of its own. Nor can we do anything to earn release from this bondage, wretched creatures that we are. However, through no merit of our own, God may bestow His grace upon us. If He does, we may avoid sinning, but if He does not--if we are left to what human nature now offers us--we shall certainly sin.
Incidentally, Augustine does not think that the people who have not received God's grace and, therefore, cannot avoid sinning as a result of inherited Original Sin, have any excuses. They still deserve punishment for their sins.
Some commentators have understandably said that Augustine's theology attributes free will to human nature prior to the Fall only to deny that it has free will ever since. Many of the Puzzles that arise for Traditional View I seem to arise for the Augustinian View as well.
A Final Observation on the Traditional View of God
Before we turn to alternate views, let us consider a final challenge to the traditional philosophical view: Perhaps the analogy on which it seems to be based extrapolates or extends the concept of mind and knowledge beyond all reasonable bounds. A critic might say that the analogy between the king and the eternal mind breaks down because for all his knowledge and hired wisdom, the king is still a prisoner of time. He must make sense of his information in the here and now. He must do so from his own point of view. The critic claims that all knowledge, whether it be that of a child, a normal adult, an historian, a king or a wise man, is inevitably bound up with the perspective of the knower. It is an occurrence, at a particular time and place, on the basis of limited, never complete, information. If the critic is correct, then the so-called "perspective of eternity" which God is alleged to have is not a perspective at all, because it lacks this limitation. If knowledge always includes dependence upon a perspective, then eternal knowledge is a contradiction in terms.
Even if this is so, it is a noteworthy fact that the idea of an all-seeing God has had important, salutary effects in Western thought. For one thing, divine knowledge is one way of describing the impartiality towards which morally sensitive people strive without being able fully to attain it. By trying to see social and moral relations a bit more as an all-seeing God might see them, we are encouraged to treat those outside our immediate circle of acquaintances more fairly and to take into better account the long-term consequences of our individual and collective actions.
Part VI: Charles Hartshorne's Panentheist View
If the puzzles associated with the traditional conception of God cannot somehow be removed, the traditional view will clash with the Compatibility Principle, whose main point is to rule out inconsistent beliefs. Some philosophers of religion believe that most of these puzzles are insoluble, and so they have sought a different conception of God that can avoid the puzzles. One of the most important contemporary philosophers to try this approach is Charles Hartshorne.
You might be attracted to Hartshorne's view if you find that the idea of a mind existing completely independent of a body makes no sense to you. For Hartshorne, God is both immanent and transcendent. That is to say, God's divine mind is present in the physical universe as a whole but also transcends or surpasses it. Hartshorne's view is that the universe is in God, or as it is sometimes called, "panentheism" (from Greek pan (all) + en (in) + theos (god)).
How does God's mind inhabit the universe? Perhaps an analogy to the way a life principle works in our bodies will help. Suppose all the cells, fluids, etc. from a living human body were first detached from one another and gathered in a heap somewhere. This heap would contain exactly the materials which were found earlier in the living human body. What, then, made the difference? Clearly, the difference was the way in which the component cells, fluids, etc. were put together into a dynamic unity. Let's call this extra thing the "structure" of the whole. It's important to realize that in living beings this structure is rule-governed and in human beings this structure (which makes us what we are) is partly intelligent. There's no question here of the structure's existing without the parts--if this structure is the human life principle, it is not going to survive the death of the body. (At least this is Hartshorne's view.)
For Hartshorne, God's mind is the structure and principle governing the whole physical universe. Since Hartshorne does not believe that the universe can have an end, he also believes that the universe and God have always existed.)
But Hartshorne's God also has a transcendent aspect. His mind transcends the material universe and is not entirely bound by it.
Hartshorne's God has a peculiar kind of qualified omniscience. God's mind perfectly knows what is happening and has happened. It knows all about the present and the past. But, contrary to what both versions of the Traditional View hold, God does not know all about the future.
Hartshorne rejects complete divine knowledge of the future for two connected reasons:
(1) The future is not yet entirely determined, according to him so how could anyone have complete knowledge of it?
(2) God's mind is not the ultimate source of all decisions: beings other than God, such as you and I, make choices independent of God's plans. (If we couldn't do this, Hartshorne believes, our actions would not be free and we would never be responsible for them.) Now, if God does not entirely make the future, He cannot be entirely sure what it will be.
Because his God is not entirely omniscient, Hartshorne's view is not subject to puzzle (A) concerning omniscience and moral responsibility. Nor is it subject to puzzle (B) concerning omnipotent creation and moral responsibility. Hartshorne's God is not omnipotent. Since human beings at least are free centers of choice partly independent of God's plans and designs, some things we do are beyond His power to force or prevent. He is therefore not as powerful a deity as some people might think they can conceive.
Hartshorne would nevertheless say that his God is the most powerful being really conceivable. If we try to conceive one more powerful, he would claim, we end up with something like the traditional philosophical view. This traditional view produces the puzzles we discussed (and which Hartshorne believes it cannot solve). Therefore, on his view, the traditional view is ultimately incoherent.
Hartshorne's view does not seem to be subject to the puzzle (D) concerning evil and the goodness of God. If some things that happen are not the result of His will, there's no contradiction in admitting that some things are imperfect or evil. One does not have to say that things which seem bad are only apparently so, or are only so from our imperfect point of view.
Far from holding that we do not influence God, Hartshorne claims that we influence Him in a very important way. Since He is omniscient about the past, but not about the future, He will learn what we have done when we have done it (but not, at least not in detail, before). Therefore our deeds are, as it were, etched in His memory. In fact, this is our immortality according to Hartshorne: we don't survive death as individuals, but our good and bad deeds are preserved forever in divine memory. They are not forgotten.)
Hartshorne is influenced by the scientific notion that nature operates according to general principles or laws. Thus he does not claim that God may temporarily abolish a natural law so that somebody may perform a miracle, only to reinstate the natural law afterwards. But the laws of nature now in effect are not the only laws that nature might have another set of natural laws might also be coherent. Hartshorne believes that God, whose mind is the ultimate guarantee of the coherence of nature, might change the natural laws if He thought that He could improve the cosmos that way. (Note how Hartshorne's belief in God corresponds to an optimism about the future of the cosmos.)
It might be objected that since Hartshorne's God is partially embodied in physical matter, there is a good chance that he is materially if not morally corruptible, and that possibility would not fit well with common conceptions of divine perfection. The dominant philosophical conception avoids this problem when it holds that God is incorruptible because He is immaterial, bodiless. But a defender of Hartshorne's view might argue that a partially immanent God can be incorruptible too. Beings are corruptible generally because they are subject to influences from outside. Individuals do not seduce themselves with money or sexual favors--these are influences coming from others. But nothing is outside of Hartshorne's God for the whole physical universe, including our bodies, is His body.
Part VII: The Stoic View of the Supreme Being
The traditional philosophical views of God flourished in the Middle Ages and are still defended by many thinkers today. The panentheist view discussed in the preceding section had ancient and medieval ancestors but received its most thoughtful formulation in the twentieth century. A third view, the ancient Stoic view, has few contemporary adherents, but is of interest to us for three reasons:
(1) It is another view concerning a divine supreme being to which rational people have been attracted (2) its similarities and differences with the other views can illuminate them and (3) it competed in ancient Greece and Rome with the atomist philosophy of Epicurus, which was a modified version of the atomist philosophy of Democritus.
So many features of the Stoic view are adopted either by the traditional transcendent view or by Hartshorne's immanent view that a chart setting out the similarities and differences can help us quickly grasp the nature of the Stoic view. Although the Stoics were, strictly speaking, polytheists and pagans, one god, the ruler of the universe, has a special place in Stoic philosophy.
The Stoic view of the supreme being is like the traditional view in the following respects:
(1) The Stoic supreme being is omniscient regarding past and future.
(2) The Stoic supreme being is the omnipotent planner/designer of everything that happens.
(3) The Stoic supreme being is absolutely good. Whatever happens happens for a good reason.
(4) The Stoic supreme being wills that we should obey moral principles.
The Stoic supreme being is unlike God in what I have called the traditional view:
(1) The Stoic supreme being is not the only deity, since there are also lesser divinities.
(2) The Stoic supreme being is immanent, not transcendent.
(3) The Stoic supreme being (or divine reason) is a "body."
Unlike Epicurus and Lucretius and many more recent thinkers, the Stoics believed that two bodies could occupy the same place at the same time. (Think how two liquids, for example, water and milk, appear to pervade each other when they are mixed.)
A widespread idea among the ancient philosophers of nature was that nature is made of four material stuffs or elements: earth, water, air and fire. According to the Stoics, two of these four "bodies" (air and fire) were active powers, and two of them (earth and water) were passive. The active powers were responsible for the lawfulness of nature in general, the cohesion of material objects from stones to living organisms, and the activity of active beings generally.
Among the active powers, fire was identified with intelligence. The Stoics described the supreme being as "an intelligent fire" pervading and controlling all things.
(3) The Stoics denied that there is a beginning and an ending point in time (like Hartshorne) nevertheless they agreed that time is finite (like what I have been calling the traditional view). How? Time is cyclical. Each cycle is of a fixed length and every cycle exactly repeats the previous one.
Why did they believe that time is finite (if they could not imagine an absolutely first moment in time)? Only finite things can be well-crafted. The universe is well-crafted. So it is finite. Cyclical time is a way of retaining finiteness without a beginning or end.
* * * The views discussed in this essay do not by any means exhaust the possibilities. For a twentieth-century immanent view of divinity which is compatible with what modern science tells us about the natural universe, see An Introduction to Pantheism. This website also contains an essay on the classical Greek polytheist ideas of the divine. See Homer's Gods, Plato's Gods.
Stephen Hawking's Final Book Says There's 'No Possibility' of God in Our Universe
From his desk at Cambridge University and beyond, Stephen Hawking sent his mind spiraling into the deepest depths of black holes, radiating across the endless cosmos and swirling back billions of years to witness time's first breath. He viewed creation as a scientist, and when he was called to discuss creation's biggest puzzles — Where do we come from? What is our purpose? Are we alone? — he answered as a scientist, often to the chagrin of religious critics.
In Stephen Hawking's final book "Brief Answers to Big Questions," published Tuesday (Oct. 16) by Bantam Books, the professor begins a series of 10 intergalactic essays by addressing life's oldest and most religiously fraught question of all: Is there a God? [Big Bang to Civilization: 10 Amazing Origin Events]
Hawking's answer — compiled from decades of prior interviews, essays and speeches with the help of his family, colleagues and the Steven Hawking Estate — should come as no surprise to readers who have followed his work, er, religiously.
"I think the universe was spontaneously created out of nothing, according to the laws of science," Hawking, who died in March, wrote. "If you accept, as I do, that the laws of nature are fixed, then it doesn't take long to ask: What role is there for God?"
In life, Hawking was a vocal champion of the Big Bang theory — the idea that the universe began by exploding suddenly out of an ultradense singularity smaller than an atom. From this speck emerged all the matter, energy and empty space that the universe would ever contain, and all that raw material evolved into the cosmos we perceive today by following a strict set of scientific laws. To Hawking and many like-minded scientists, the combined laws of gravity, relativity, quantum physics and a few other rules could explain everything that ever happened or ever will happen in our known universe.
"If you like, you can say the laws are the work of God, but that is more a definition of God than a proof of his existence," Hawking wrote.
With the universe running on a scientifically guided autopilot, the only role for an all-powerful deity might be setting the initial conditions of the universe so that those laws could take shape — a divine creator who caused the Big Bang to bang, then stepped back to behold His work.
"Did God create the quantum laws that allowed the Big Bang to occur?" Hawking wrote. "I have no desire to offend anyone of faith, but I think science has a more compelling explanation than a divine creator."
Hawking's explanation begins with quantum mechanics, which explains how subatomic particles behave. In quantum studies, it's common to see subatomic particles like protons and electrons seemingly appear out of nowhere, stick around for a while and then disappear again to a completely different location. Because the universe was once the size of a subatomic particle itself, it's plausible that it behaved similarly during the Big Bang, Hawking wrote.
"The universe itself, in all its mind-boggling vastness and complexity, could simply have popped into existence without violating the known laws of nature," he wrote.
That still doesn't explain away the possibility that God created that proton-size singularity, then flipped the quantum- mechanical switch that allowed it to pop. But Hawking says science has an explanation here, too. To illustrate, he points to the physics of black holes — collapsed stars that are so dense, nothing, including light, can escape their pull.
Black holes, like the universe before the Big Bang, condense into a singularity. In this ultra-packed point of mass, gravity is so strong that it distorts time as well as light and space. Simply put, in the depths of a black hole, time does not exist.
Because the universe also began as a singularity, time itself could not have existed before the Big Bang. Hawking's answer, then, to what happened before the Big Bang is, "there was no time before the Big Bang."
"We have finally found something that doesn&rsquot have a cause, because there was no time for a cause to exist in," Hawking wrote. "For me this means that there is no possibility of a creator, because there is no time for a creator to have existed in."
This argument will do little to persuade theistic believers, but that was never Hawking's intent. As a scientist with a near-religious devotion to understanding the cosmos, Hawking sought to "know the mind of God" by learning everything he could about the self-sufficient universe around us. While his view of the universe might render a divine creator and the laws of nature incompatible, it still leaves ample space for faith, hope, wonder and, especially, gratitude.
"We have this one life to appreciate the grand design of the universe," Hawking concludes the first chapter of his final book, "and for that I am extremely grateful."
How to Get There?
But what we want to know is: could you ever get to another space-time?
That depends. The American theoretical physicist and string theorist extraordinaire Brian Greene, of Columbia University, argues that the plausibility of multiversal travel—conceding that parallel universes really do exist—hinges on which multiverse concept you subscribe to. If you are an advocate of a multiple big bang multiverse, then that would mean that leaving our universe to travel to another would be just as impossible as travelling back to the time before the big bang that resulted in our universe even happened.
Now, if you believe a quantum physics-dominated notion of parallel universes, then there’s no need to travel to other universes, because you are already inhabiting multiple alternate universes (though not necessarily all of them). Can’t decide which dress to wear? No matter—you’ve worn them both, in two separate parallel universes.
Meanwhile, theoretical physicist Michio Kaku believes that our universe will end up in a “big freeze,” and that technology can one day allow us to travel between universes.
Neil deGrasse Tyson, on the other hand, says that if you come from a universe with higher dimensions, then it could be as easy to move between dimensions as stepping from one room to another. And in string theory—one of the leading contenders in bridging the seemingly insuperable gulf sundering quantum mechanics and general relativity—the assumption is that we actually have far more dimensions in this universe than we previously thought and that we just fail to detect them because they are actually very small, curled up in the infinitely minute, trans-subatomic realms beyond the reach of our instruments.
But how can we prove (or disprove) any of these arguments without gaining first-hand experience of it? Much as many aspects of our universe still remain elusive to us, it’s currently impossible to acquire any proof to confirm which of these hypotheses is right. But while we don’t have the means to definitively prove whether alternate universes do exist, and whether we could traverse borders to move from one to another, it’s highly unlikely that a topic as stimulating as this will disappear anytime soon, either in science fiction or in real-life science.
Meanwhile, physicists are at it. Watch this brief video of physicists going head to head with each other on string theory, Math, and potentially embarrassing alien encounters.
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Time Travel and The Multiverse – Many Worlds: Many Timelines
Time travel has enchanted and intrigued us since the earliest days of fiction, when authors such as H. G. Wells, Samuel Madden, Charles Dickens and Enrique Gaspar y Rimbau stretched and challenged our imaginations with images and tales of men and women who invented amazing machines and devices that could take them back in time, or forward into the future. But because of the restrictions of light speed, and the paradoxes of going back to the past without damaging the future timeline, and a host of other obstacles and challenges, we, in fact, have remained stuck in the present.
Our scientific knowledge and technological achievement has yet to catch up to the limitless dreams of our imaginations. But perhaps just because we have yet to achieve time travel in our universe, in our particular point along the cosmic arrow of time, doesn’t mean it isn’t achievable…and maybe the key is the universe itself. Are we limiting ourselves to our understanding only of the laws and possibilities of our universe, and leaving out of the equation other realities, other universes, with other laws and forces, paradoxes and limitation, possibilities and potentialities, far beyond our own?
In 2011, quantum physicists at the University of California at Santa Barbara, led by Andrew Cleland and John Martinis, designed a “quantum machine,” as they call it, that might one day lead to proof of time travel and parallel universes. Their machine, a tiny little teleporter barely visible to the naked eye, involves making a tiny metal paddle cool to its ground state, the lowest energy state permissible by the laws of quantum mechanics, and then raising it’s energy slowly by a single quantum to produce a purely quantum state of motion. And, they even were able to put the device in both states at once, so it vibrated both slowly and quickly at the same time, in another sort of Schrodinger’s Cat state of superposition. They posited that we can only see one of these potential states at once, and upon the act of observation, the state then splits into additional universes. Perhaps, there is a plethora of multiple or parallel universes all around us, but we cannot see them.
Wormholes could also be another possibility for teleportation, as physicist Max Tegmark suggested while attending a panel in January of 2008 at MIT to discuss the science behind the movie “Jumper” starring Hayden Christiansen, about a man who can teleport all over the world at will. Tegmark was asked about the science behind the science fiction, and remarked that a wormhole was one possible way of getting something quickly across space-time. However, after admitting that wormholes do appear to be theoretically possible, Tegmark commented that the actual trip would be rather grueling because of the instability of the wormhole. “It could collapse into a black hole, which would be kind of a bummer.”
Many scientists look to the possible existence of other levels of reality, or other universes, as a way to make time travel work outside of the restrictions of light speed and paradoxes. Imagine another universe alongside our own where the laws of physics are so completely different, that what is impossible here is mundane and trivial there. Multiple worlds, even, where each is different from the other, or perhaps an infinite number of universes where many would be exactly like our own. Hey, you might even exist in some of them just the way you are right now. In others, you might be rich, famous, handsome or even a cockroach! In fact, perhaps you might even be invisible in one of them!
But we are getting away with ourselves here, and when the talk turns to the multiverse and other similar concepts, it’s easy to start dreaming of science fiction worlds with every possible kind of life and all sorts of amazing machines and devices…and time travelers passing effortlessly back and forth between the past, present and future as if it were nothing more than a visit to a few Saturday morning garage sales.
Parallel universes have long been a mainstay of science fiction films and stories. Parallel universes can exist individually, or grouped together as the “multiverse,” and offer the possibility of a totally different reality in which someone, or something, can exist, or hop back and forth between. The laws of nature may be different in one parallel universe as they are in another, and in respect to time travel, would provide multiple versions of the future in which someone could exist, or not exist at all. Light speed limitations may not exist in a parallel universe, and the paradoxes that keep us from traveling back in time would be null and void if we could jump into a different historical timeline.
Two great fictional examples of a parallel universe would be “Alice’s Adventures in Wonderland,” written by English author Charles Lutwidge Dodgson under the pseudonym Lewis Carroll, and C.S. Lewis’s “The Chronicles of Narnia,” both of which involve some sort of portal or wormhole, such as a rabbit hole or a large piece of furniture, through which a person can enter into another realm.
Theoretically, parallel universes may be the result of a single random quantum event that branches off into an alternative universe. This is the “Many Worlds Interpretation” or MWI, of quantum mechanics, originally formulated by physicist Hugh Everett in 1957, and posits that each time a different choice is made at the quantum scale, a universe arises to accommodate that choice, thus creating infinite new worlds popping up all the time. These new worlds are being constantly created, and could cause problems for a potential time traveler. Physicist David Deutsch wrote in “Quantum mechanics near closed timelike curves” for the 1991 Physical Review, that if time travel to the past were indeed possible, the many worlds scenario would result in a time traveler ending up in a different branch of history than the one he departed from. Deutsch, of Oxford University, is a highly respected proponent of quantum theory, and suggests quantum theory does not forbid time travel, but rather sidesteps it, referring to the traveler’s ability to go into another universe, a parallel universe, and avoid the paradox limitations.
Deutsch’s idea of parallel universes, the multiverse, or “shadow universes” was described in his interview with the Guardian UK in June of 2010 (“David Deutsch’s Multiverse Carries Us Beyond the Realm of Imagination”) as being “co-incident with, somehow contiguous with, and weakly interacting with, this one. It is a composite, a layer cake, a palimpsest of universes very similar but not quite identical to each other.” The number of these shadow universes could be enormous, and Deutsch points to photon experiments that suggest possibly a trillion of them or more. He also suggests that future-directed time travel will essentially only require efficient rockets, and is on the “moderately distant but confidently foreseeable technological horizon.” When it comes to past travel, the multiverse might save a time traveler from the pesky Grandfather paradox. He uses an example of a writer who wants to go back in time with a copy of Shakespeare’s Complete Works and help the bard complete Hamlet. It can happen, but in the multiverse view, “the traveler has not come from the future of that copy of Shakespeare.”
Another off shoot of the MWI is the Many-Minds Interpretation, which extends the MWI by positing that the branching off of worlds occurs in the mind of the individual observer, introduced in 1995 by theoretical physicist H. Dieter Zeh, Professor Emeritus of the University of Heidelberg and the discoverer of decoherence. The Many-Minds Interpretation was widely criticized and somewhat ignored, mainly because of issues involving the theory that the mind can supervene on the physical as the mind has its own “trans-temporal identity.” The mind may select one identity as its own non-random “reality,” yet the universe as a whole remains unaffected, which presents additional problems when dealing with different observers ending up with the same measured realities. The actual process by which the mind of the observer would select the single, measured state is not explained by the MMI.
Alternate timelines, each with their own forward arrow of time and their own history, may exist then, allowing time travelers to jump into another version of history and override those pesky paradoxes. Imagine being able to jump into a timeline where you do get your dream of marrying your high school sweetheart, but, finding out she’s an evil tramp as soon as you say “I do,” you could jump back into your original historical timeline, where you didn’t marry her and instead ended up three years later marrying her sister, your true soul mate, and lived happily ever after.
Noted theoretical physicist Michio Kaku, author of “Parallel Worlds” and “Hyperspace,” writes in his newest book, “Physics of the Impossible: A Scientific Exploration Into the World of Phasers, Force Fields, Teleportation and Time Travel” of three ways around the paradoxes of time travel. The first is that you simply repeat past history and fulfill the past, and that everything you do once you are back in time was meant to happen anyway, a sort of destiny. This opinion is also mirrored in the views of famed physicist and superstring theory proponent Brian Greene, author of “The Fabric of the Cosmos: Space, Time and the Texture of Reality” and “The Elegant Universe: Superstrings, Hidden Dimensions and the Quest for the Ultimate Theory.” Greene writes that outside of the quantum world, in the classical science of the grander scale, we exist static and unchanging at various locations in what he calls the “space-time loaf” of block we call space-time. These moments are unchangeable and fixed. Using a wormhole, if one were to indeed go back in time to a certain point, or date, one would find that there is only one version of that date, and that your presence back in time would simply be a part of the original version of that moment. That moment has one incarnation, though. “By passing through the wormhole today and going back to that earlier time you would be fulfilling your ironclad destiny to appear at that earlier moment.” He points to the wormhole time machine itself as the culprit, with one opening or the other passing through time more slowly than the other end, but each opening is still going forward in time. Thus, there will also be a limit as to how far back in time you could travel in the first place.
The second of Kaku’s paths around the paradoxes involves having some free will to change the past, but within limits, so that you could go back and try to kill your grandfather, but something would prevent you from doing so. The gun might lock up, or you might drop it and shoot your foot instead and end up in the hospital. No matter what, you would somehow be prevented from knocking off your Grandpappy.
The third involves the universe splitting into two universes to accommodate the time traveler. His example offers someone going back in time to kill their parents, and in one time line the people look like your parents, but are different because you exist in a different timeline.
The many worlds approach could solve all the paradoxes in two ways. First, if we imagine the time line of our universe as a line drawn on a board, then we can draw another line to represent the universe that branches off from the first.
When you go back into the river of time, the river forks into two rivers, and one time line becomes two time lines, and so on, and so on. Say you planned to kill your own father. You go back in time and you do the dirty deed. If the river of time does indeed have many forks, this would not be a problem. “You’ve just killed somebody else’s father. In that timeline, you don’t exist, but you exist because you jumped the stream,” Kaku writes.
This idea would also solve another thorn in the side of physicists when discussing time travel: the radiation effects of entering a wormhole, which would no doubt destroy any time traveler, and also end up in a loop, the feedback of which would become so strong it would destroy the wormhole. “If the radiation goes into the time machine, and is sent into the past, it then enters a new universe it cannot reenter the time machine again, and again, and again.” Kaku points out that the main problems involving time travel and wormholes specifically center on the issues of the physics of the event horizon, as in the stability of the wormhole, the deadly radiation and the wormhole closing once it was entered. Solve those issues and really time travel might be a piece of cake!
Well, not a piece of cake, but all physicists agree that once they come up with a Theory of Everything that unites the four universal forces of electromagnetism, gravity and the strong and weak nuclear forces and formulate a complete theory of gravity and space-time, then time travel might be as close as finding a wormhole big enough, stable enough and open enough to get a time machine through. Not to mention the sheer amount of energy necessary to do this, which might require harnessing the power and energy of a neutron star, or finding that elusive exotic matter scientists are looking for, or a good source of negative energy, and we are far from doing any of these things.
Oh, then there is the problem of creating the machine. And let’s not forget finding or creating a wormhole that could handle it! An interesting problem was brought up by physicist and cosmologist Paul Davies, author of “About Time: Einstein’s Unfinished Revolution” and other books. In an interview with Discovery.com called “Is Time Travel Possible?” he discussed wormholes as time machines and potential time travel tourists from the future, but with the caveat that “theoretically, it would take more than 100 years to create a 100-year time difference between the two ends of a wormhole, so there’s no way that our descendants could come back and tell us we’re wrong about this.” So, it’s all about timing, then…pun intended.
The multiverse is the most widely mentioned theoretical “time travel paradox killer,” because it involves more than just one parallel universe, thus allowing for an increasingly possible world where the laws of physics are just right for time travel. If we can get from here to there, that is.
There may be a massive number of other universes out there, possibly even an infinite number, or maybe just twenty or seventy. While our astronomical observations cannot at this time detect them, it is most definitely a theoretical possibility that many cosmologists and physicists are considering. These universes may or may not be like ours. In fact, they may or may not even have the same laws of physics or distribution of matter, or even number of spatial and temporal dimensions. Some will undoubtedly be “dead” and others will have life forms that we cannot recognize or even imagine. Others still may have duplicates of us living their own separate lives and timelines. Maybe, Big Bangs are going on constantly, 24/7/365 all the while creating new universes.
The multiverse theory is not new, especially for readers of science fiction and fantasy, where other worlds beyond ours is a given. The actual term was coined in the year 1895 by psychologist and philosopher William James, and is now a mainstay of theoretical and quantum physics, as well as a part of our religious beliefs, mythological stories, and spiritual/New Age thought. The multiverse has been equated with everything from the Kingdom of Heaven of the Judeo-Christian bible to the Akashic Field or Hall of Records or various planes of existence of more metaphysical and spiritual thought, to the multiple timelines and dimensions of more paranormal and anomalous concepts.
Cosmologist Max Tegmark took the multiverse theory to the next level by creating a classification level for potential other worlds:
LEVEL ONE: Domains beyond our cosmological horizon – the least controversial type, what lies beyond the vantage point, yet likely has the same laws/constants, just with possibly different initial conditions than our own.
LEVEL TWO: Universes with different physical laws/constants, other post inflation bubbles, far more diverse than Level Ones, these bubbles also vary in initial conditions as well as other seemingly immutable aspects of nature.
LEVEL THREE: Quantum universes/Many Worlds Interpretation – exist alongside us on the quantum level where the random quantum processes cause the universe to branch into multiple copies, one copy for each possible outcome.
LEVEL FOUR: Ultimate Ensemble – Other mathematical structures, where ALL potential alternate realities can exist, anything and everything is possible in terms of location, cosmological properties, quantum states, and physical laws and constants. These exist outside of space-time.
Each level of multiverse has its own characteristics that separate it from the other levels, and for our purposes, the focus for time travel would be on those we humans could exist in, and possible travel between. One of the ways Tegmark himself differentiated the levels was by stating that in Level One, our doppelgängers could live somewhere else in three-dimensional space, but in Level Three they would live on another quantum branch in an infinite-dimensional Hilbert space, yet as the Many Worlds Interpretation states, likely not be able to interact once the split into another branch occurs. Those found in Level Two might be like “bubble universes” that have different physical laws and constants, and each new bubble is created by splits that occur when spontaneous symmetry breaks occur in Level Three.
Tegmark describes these levels in detail in his book “Universe or Multiverse,” and states that the key question isn’t so much whether there is a multiverse, but rather how many levels it has. He admits that nature may have tricked us into thinking that our vantage point was the extent of reality, a fixed view of the world around us. “Einstein taught us that space is not merely a boring static void, but a dynamic entity that can stretch (the expanding universe), vibrate (gravitational waves), and curve (gravity).”
Many scientists refer to the multiverse as more of a “pocket universe” concept, indicating different regions in space-time that are unobservable, but still a part of our one Universe. Inflationary cosmology does state that these pocket universes can be self-contained, with different laws of physics, different particles and forces and possibly even different dimensions.
Even the popular string theory allows for potentially trillions of possible universes, each one compatible with relativity and quantum theory. Michio Kaku states in “Physics of the Impossible” that “Normally communication between these universes is impossible. The atoms of our body are like flies trapped on flypaper. We can move freely about in three dimensions along our membrane universe, but we cannot leap off the universe into hyperspace, because we are glued onto our universe.” Gravity, however, can freely float into the spaces between universes. Kaku also points to one theory where dark matter, which is an invisible form of matter surrounding our galaxy, might actually be “normal” matter in another universe.
But the question remains, can we travel back and forth between these different worlds with different laws and arrows of time? Again, theoretically, it would require a shortcut through space and time…like a wormhole…and a means of safely getting through that wormhole should it be stable and traversable. So even though the multiverse theory takes care of some of the paradoxes by offering up alternate timelines and histories in which one can both go back to the past and kill their grandfather (while not killing him at the same time), it appears as though there is still no realistic way of actually doing that.
The multiverse also allows for alternate futures as well, and for multiple, alternate versions of “you” to exist in any number of historical timelines with different outcomes depending on the choices you make in each baby bubble universe. In an article titled “Riddles of the Multiverse” for PBS.org’s August 2011 Nova series, University of Southern California Professor of Physics and Astronomy Clifford Johnson was asked straight out about whether or not the multiverse could ever be “visited” by humans. His response was that we must first work out the physics of these other universes, in order to determine when and whether it makes sense to “cross over from one to the other.” He did admit that it is possible that the stuff we are made of, the matter and forces that make us and hold us together, may not allow us to ever leave our four-dimensional universe and go to another. Imagine doing so and well, coming undone!
So for now, it seems, we just don’t yet have the brainpower and technology to leap and jump between worlds, to cross timelines and experience as many pasts, presents and futures as we would like. That knowledge and technology may exist, though…out there…somewhere in time.
Reprinted, with permission of the publisher, from “This Book Is From the Future: A Journey Through Portals, Relativity, Wormholes and Other Adventures in Time Travel,” © 2012 Marie D. Jones and Larry Flaxman. Published by New Page Books a division of Career Press, Pompton Plains, NJ. 800-227-3371. All rights reserved.
1. Introduction: philosophical questions about space and time
In the context of interpreting Kant&rsquos views concerning space and time, a number of philosophical questions are relevant. Kant himself provides a litany of these questions in his so-called Inaugural Dissertation of 1770, a text in which he broke with his previous broadly &ldquoLeibnizian&rdquo views from the pre-critical period (Hatfield 2006, 72-6). He writes:
In this one pithy sentence, we find a list of many important early modern questions concerning space. Is space &ldquoreal,&rdquo or is it &ldquoideal&rdquo in some sense? Is it a substance in its own right, a property of some substance, or perhaps neither? Is it somehow dependent on the relations among objects, or independent of those relations? What is the relationship between space and the mind? And finally, how do these various issues intersect with one another?
The passage from the Inaugural Dissertation hints at five distinct questions or issues concerning space and time. First, there is the question of the ontology of space and time considered within the framework of what Kant would regard as the dogmatic metaphysics of the seventeenth century. This framework might suggest that if space and time are to exist, or to characterize the physical world, they must be considered either substances in their own right, or else properties of some substance. Neither option seems particularly attractive. Space and time seem distinct from substances because they are causally inert, causally inaccessible&mdashtheir aspects or properties cannot be altered by interacting with any other substance&mdashand imperceptible. Since they are often regarded as infinite, moreover, some thinkers have doubted that they could be substances, as God is often thought of as the sole infinite substance (Descartes may have conceived of space as &ldquoindefinite&rdquo for this reason). However, it is also difficult to think of space and time as properties of any substance, for then they would presumably be dependent on that substance for their existence. If we regard them as dependent on any contingent substance, it seems that we would be committed to the idea that space and time could fail to exist, or could disappear, depending on the happenings of that contingent substance. One might think instead that space and time depend on the one necessary substance, but this obviously raises a host of other issues. To think of space and time as properties of God is potentially to regard God as spatiotemporal, which is verboten from the point of view of many seventeenth-century thinkers (Janiak 2008, chapter five).
A second topic arises if we consider the ontology of space and time independently from the substance-property metaphysical framework, viz. by considering the relationship of space and time to physical objects. Following Newton&rsquos discussion in the first (1687) edition of the Scholium in the Principia, the modern debate concerning space&rsquos ontology has been centered on two overarching conceptions: absolutism (now sometimes called &ldquosubstantivalism,&rdquo although that label raises certain issues), the view that space and time exist independently of all possible objects and object relations, or perhaps the view that space-time points exist and relationalism, the view that space and time depend for their existence on possible objects and relations, or perhaps the view that space-time points do not exist (DiSalle 2006).
Leaving aside questions about ontology, there is a distinct&mdashor at least potentially distinct&mdashissue regarding space and time: what is the origin of our representation of space and of time? This third issue arises from the sense in the early modern period that our idea or representation of space and time must somehow be importantly distinct from our idea or representation of ordinary physical objects. Many believed that space and time are causally inert and therefore imperceptible&mdashhow then are we are able to represent space and time at all? Few are willing to deny that we have a representation, not merely of spatial and of temporal objects, but also of space and time themselves, so there is a genuine puzzle lurking here.
The fourth topic follows on the heels of the third: what is the content of our idea or representation of space and time? From Kant&rsquos point of view, the content of a representation might provide us with a guide as to its possible origin. Alternatively, we might be able to consider the origin of a representation as providing us with a clue as to what its content might be. In the case of space, there may be reason to think that the content of our representation must somehow reflect what we know about space from Euclidean geometry.
The fifth and final topic is closely connected with the third and fourth, and indeed, connects all four previous topics with one another: what is the relationship between space and time, on the one hand, and the human mind, on the other? This question obviously cries out for clarification. Part of what this question might mean can be characterized by the third and fourth questions above: if we think of the mind as representing space and time in a certain way, then perhaps this is part of our understanding of the mind&rsquos relationship with space and time themselves. But within the context of Kant&rsquos work, there is, at least prima facie, another issue lurking here&mdashare space and time somehow dependent upon the mind for their existence? It may be that some kind of dependence is suggested by the origin&mdashor by the content&mdashof our representation of space and time (or perhaps by these two jointly). But Kant also seems to think that a view recognizing the dependence of space and time on the mind might offer advantages in addressing the ontological problems mentioned above.
Each of these five philosophical issues concerning space and time is relevant for understanding Kant&rsquos views. As we will see below, part of the difficulty in interpreting Kant arises from the fact that he evidently transforms various aspects of the early modern debates concerning space and time through the perspective presented in the first Critique (Allison 2004, 120-1). Within the context of the first issue raised above, the view that space and time are real may mean that space and time are substances in their own right, rather than merely properties yet within the context of the absolutism-relationalism debate, if space and time are real, they exist independently of all objects and relations. But Kant uses the terms real and ideal to express views concerning the relation between space and time and the mind, leaving aside any views concerning objects and relations. This entry aims to clarify matters by separating these various considerations.
Could different views of the universe simply be different points in time? - Astronomy
The first speculations about the possibility of the Sun being the center of the cosmos and the Earth being one of the planets going around it go back to the third century BCE. In his Sand-Reckoner , Archimedes (d. 212 BCE), discusses how to express very large numbers. As an example he chooses the question as to how many grains of sand there are in the cosmos. And in order to make the problem more difficult, he chooses not the geocentric cosmos generally accepted at the time, but the heliocentric cosmos proposed by Aristarchus of Samos (ca. 310-230 BCE), which would have to be many times larger because of the lack of observable stellar parallax. We know, therefore, that already in Hellenistic times thinkers were at least toying with this notion, and because of its mention in Archimedes's book Aristarchus's speculation was well-known in Europe beginning in the High Middle Ages but not seriously entertained until Copernicus.
European learning was based on the Greek sources that had been passed down, and cosmological and astronomical thought were based on Aristotle and Ptolemy. Aristotle's cosmology of a central Earth surrounded by concentric spherical shells carrying the planets and fixed stars was the basis of European thought from the 12th century CE onward. Technical astronomy, also geocentric, was based on the constructions of excentric circles and epicycles codified in Ptolemy's Almagest (2d. century CE).
In the fifteenth century, the reform of European astronomy was begun by the astronomer/humanist Georg Peurbach (1423-1461) and his student Johannes Regiomontanus (1436-1476). Their efforts (like those of their colleagues in other fields) were concentrated on ridding astronomical texts, especially Ptolemy's, from errors by going back to the original Greek texts and providing deeper insight into the thoughts of the original authors. With their new textbook and a guide to the Almagest , Peurbach and Regiomontanus raised the level of theoretical astronomy in Europe.
Several problems were facing astronomers at the beginning of the sixteenth century. First, the tables (by means of which to predict astronomical events such as eclipses and conjunctions) were deemed not to be sufficiently accurate. Second, Portuguese and Spanish expeditions to the Far East and America sailed out of sight of land for weeks on end, and only astronomical methods could help them in finding their locations on the high seas. Third, the calendar, instituted by Julius Caesar in 44 BCE was no longer accurate. The equinox, which at the time of the Council of Nicea (325 CE) had fallen on the 21st, had now slipped to the 11th. Since the date of Easter (the celebration of the defining event in Christianity) was determined with reference to the equinox, and since most of the other religious holidays through the year were counted forward or backward from Easter, the slippage of the calendar with regard to celestial events was a very serious problem. For the solution to all three problems, Europeans looked to the astronomers.
Nicholas Copernicus (1473-1543) learned the works of Peurbach and Regiomontanus in the undergraduate curriculum at the university of Cracow and then spent a decade studying in Italy. Upon his return to Poland, he spent the rest of his life as a physician, lawyer, and church administrator. During his spare time he continued his research in astronomy. The result was De Revolutionibus Orbium Coelestium ("On the Revolutions of the Celestial Orbs"), which was published in Nuremberg in 1543, the year of his death. The book was dedicated to Pope Paul III and initially caused litle controversy. An anonymous preface (added by Andreas Osiander, the Protestant reformer of Nuremberg) stated that the theory put forward in this book was only a mathematical hypothesis: the geometrical constructions used by astronomers had traditionally had only hypothetical status cosmological interpretations were reserved for the philosophers. Indeed, except for the first eleven chapters of Book I, De Revolutionibus was a technical mathematical work in the tradition of the Almagest .
|Diagram of the Copernican system, from De Revolutions |
[click for larger image]
But in the first book, Copernicus stated that the Sun was the center of the universe and that the Earth had a triple motion around this center. His theory gave a simple and elegant explanation of the retrograde motions of the planets (the annual motion of the Earth necessarily projected onto the motions of the planets in geocentric astronomy) and settled the order of the planets (which had been a convention in Ptolemy's work) definitively. He argued that his system was more elegant than the traditional geocentric system. Copernicus still retained the priviledged status of circular motion and therefore had to construct his planetary orbits from circles upon and within circles, just as his predecessors had done. His tables were perhaps only marginally better than existing ones.
The reception of De Revolutionibus was mixed. The heliocentric hypothesis was rejected out of hand by virtually all, but the book was the most sophisticated astronomical treatise since the Almagest , and for this it was widely admired. Its mathematical constructions were easily transferred into geocentric ones, and many astronomers used them. In 1551 Erasmus Reinhold, no believer in the mobility of the Earth, published a new set of tables, the Prutenic Tables , based on Copernicus's parameters. These tables came to be preferred for their accuracy. Further, De revolutionibus became the central work in a network of astronomers, who dissected it in great detail. Not until a generation after its appearance, however, can we begin point to a community of practicing astronomers who accepted heliocentric cosmology. Perhaps the most remarkable early follower of Copernicus was Thomas Digges (c. 1545-c.1595), who in A Perfit Description of the Coelestiall Orbes (1576) translated a large part of Book I of De Revolutionibus into English and illustrated it with a diagram in which the Copernican arrangement of the planets is imbedded in an infinite universe of stars
|Diagram of the universe by Thomas Digges |
[click for larger image]
The reason for this delay was that, on the face of it, the heliocentric cosmology was absurd from a common-sensical and a physical point of view. Thinkers had grown up on the Aristotelian division between the heavens and the earthly region, between perfection and corruption. In Aristotle's physics, bodies moved to their natural places. Stones fell because the natural place of heavy bodies was the center of the universe, and that was why the Earth was there. Accepting Copernicus's system meant abandoning Aristotelian physics. How would birds find their nest again after they had flown from them? Why does a stone thrown up come straight down if the Earth underneath it is rotating rapidly to the east? Since bodies can only have one sort of motion at a time, how can the Earth have several? And if the Earth is a planet, why should it be the only planet with a moon?
For astronomical purposes, astronomers always assumed that the Earth is as a point with respect to the heavens. Only in the case of the Moon could one notice a parallactic displacement (about 1°) with respect to the fixed stars during its (i.e., the Earth's) diurnal motion. In Copernican astronomy one now had to assume that the orbit of the Earth was as a point with respect to the fixed stars, and because the fixed stars did not reflect the Earth's annual motion by showing an annual parallax, the sphere of the fixed stars had to be immense. What was the purpose of such a large space between the region of Saturn and that of the fixed stars?
|Parallax [click for larger image]|
These and others were objections that needed answers. The Copernican system simply did not fit into the Aristotelian way of thinking. It took a century and a half for a new physics to be devised to undegird heliocentric astronomy. The works in physics and astronomy of Galileo and Johannes Kepler were crucial steps on this road.
There was another problem. A stationary Sun and moving Earth also clashed with many biblical passages. Protestants and Catholics alike often dismissed heliocentrism on these grounds. Martin Luther did so in one of his "table talks" in 1539, before De Revolutionibus had appeared. (Preliminary sketches had circulated in manuscript form.) In the long run, Protestants, who had some freedom to interpret the bible personally, accepted heliocentrism somewhat more quickly. Catholics, especially in Spain and Italy, had to be more cautious in the religious climate of the Counter Reformation, as the case of Galileo clearly demonstrates. Christoph Clavius, the leading Jesuit mathematician from about 1570 to his death in 1612, used biblical arguments against heliocentrism in his astronomical textbook.
The situation was never simple, however. For one thing, late in the sixteenth century Tycho Brahe devised a hybrid geostatic heliocentric system in which the Moon and Sun went around the Earth but the planets went around the Sun. In this system the elegance and harmony of the Copernican system were married to the solidity of a central and stable Earth so that Aristotelian physics could be maintained. Especially after Galileo's telescopic discoveries, many astronomers switched from the traditional to the Tychonic cosmology. For another thing, by 1600 there were still very few astronomers who accepted Copernicus's cosmology. It is not clear whether the execution of Giordano Bruno, a Neoplatonist mystic who knew little about astronomy, had anything to do with his Copernican beliefs. Finally, we must not forget that Copernicus had dedicated De Revolutionibus to the Pope. During the sixteenth century the Copernican issue was not considered important by the Church and no official pronouncements were made.
Galileo's discoveries changed all that. Beginning with Sidereus Nuncius in 1610, Galileo brought the issue before a wide audience. He continued his efforts, ever more boldly, in his letters on sunspots, and in his letter to the Grand Duchess Christina (circulated in manuscript only) he actually interpreted the problematical biblical passage in the book of Joshua to conform to a heliocentric cosmology. More importantly, he argued that the Bible is written in the language of the common person who is not an expert in astronomy. Scripture, he argued, teaches us how to go to heaven, not how the heavens go. At about the same time, Paolo Antonio Foscarini, a Carmelite theologian in Naples, published a book in which he argued that the Copernican theory did not conflict with Scripture. It was at this point that Church officials took notice of the Copernican theory and placed De Revolutionibus on the Index of Forbidden Books until corrected.
Galileo's Dialogue Concerning the Two Chief World Systems of 1632 was a watershed in what had shaped up to be the "Great Debate." Galileo's arguments undermined the physics and cosmology of Aristotle for an increasingly receptive audience. His telescopic discoveries, although they did not prove that the Earth moved around the Sun, added greatly to his argument. In the meantime, Johannes Kepler (who had died in 1630) had introduced physical considerations into the heavens and had published his Rudolphine Tables , based on his own elliptical theory and Tycho Brahe's accurate observations, and these tables were more accurate by far than any previous ones. The tide now ran in favor of the heliocentric theory, and from the middle of the seventeenth century there were few important astronomers who were not Copernicans.
A daily rotation about its center, an annual motion around the Sun, and a conical motion of its axis of rotation. This last motion was made necessary because Copernicus conceptualized the Earth's annual motion as the result of the Earth being embedded in a spherical shell centered on the Sun. Its axis of rotation therefore did not remain parallel to itself with respect to the fixed stars. To keep the axis parallel to itself, Copernicus gave the axis a conical motion with a period just about equal to the year. The very small difference from the annual period accounted for the precesion of the equinoxes, an effect caused by the fact that the Earth's axis (in Newtonian terms) precesses like a top, with a period of about 26,000 years. (Copernicus's ideas about this precession were more cumbersome and based on faulty data.)
Sources: Edward Rosen, Copernicus and the Scientific Revolution (Malabar, FL: Krieger, 1984) is a useful, if eccentric biography of Copernicus with a collection of documents concerning his life. There are two modern, reliable translations of De Revolutionibus : Edward Rosen, tr. On the Revolutions , vol. 2 of Complete works (London: Macmillan, 1972- issued separately, Baltimore: Johns Hopkins Press, 1978) A. M. Duncan, tr., On the Revolutions of the Heavenly Spheres (London: David & Charles New York:Barnes & Noble, 1976). The best account of the Copernican revolution is Thomas S. Kuhn, The Copernican Revolution (Cambridge: Harvard University Press, 1957). For the different receptions of De Revolutionibus , see Robert S. Westman, "Three Responses to the Copernican Theory: Johannes Praetorius, Tycho Brahe, and Michael Maestlin," in The Copernican Achievement , ed. Robert S. Westman (Berkeley and Los Angeles: University of California Press, 1975), pp. 285-345. On Galileo's Copernicanism, see Stillman Drake, "Galileo's Steps to Full Copernicanism and Back, Studies in History and Philosophy of Science , 18 (1987): 93-105 and Maurice A. Finocchiaro, "Galileo's Copernicanism and the Acceptability of Guiding Assumptions," in Scrutinizing Science: Empirical Studies of Scientific Change, ed. Arthur Donovan, Larry Laudan, and Rachel Laudan (Dordrecht Kluwer, 1988), pp. 49-67.
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