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| '''Eternalism''' is a ] approach to the ] nature of ], which takes the view that all points in time are equally "real" (they all have the same ontological status), as opposed to the ] idea that only the present is real.<ref>{{Cite book|title=General Philosophy of Science: Focal Issues |first=Theo A.F.|last=Kuipers|publisher=North Holland|year=2007|isbn=978-0-444-51548-3|page=326|url=http://books.google.com/books?id=qUMuFaXjNjEC&lpg=PP1&pg=PA326#v=onepage&q&f=false}}</ref> |
'''Eternalism''' is a ] approach to the ] nature of ], which takes the view that all points in time are equally "real" (they all have the same ontological status), as opposed to the ] idea that only the present is real.<ref>{{Cite book|title=General Philosophy of Science: Focal Issues |first=Theo A.F.|last=Kuipers|publisher=North Holland|year=2007|isbn=978-0-444-51548-3|page=326|url=http://books.google.com/books?id=qUMuFaXjNjEC&lpg=PP1&pg=PA326#v=onepage&q&f=false}}</ref> This would mean that ] events are "already there", and that there is no ] flow of time. Modern advocates often take inspiration from the ], with some such as ] invoking ], which says that the question of whether two events occur at the same time is not absolute, but depends on the observer's reference frame. Some also take inspiration from the way that the mathematical formulation of relativity treats time as a single dimension in a four-dimensional ].<ref>{{Citation | last1 = Peterson | first1 = Daniel | last2 = Silberstein | first2 = Michael | editor-last = Petkov | editor-first = Vesselin | contribution = Relativity of Simultaneity and Eternalism: In Defense of the Block Universe | year = 2009 | url = http://books.google.com/books?id=t35AR6-F5QQC&lpg=PP1&pg=PA208#v=onepage&q&f=false | title = Space, Time, and Spacetime: Physical and Philosophical Implications of Minkowski's Unification of Space and Time | page = 208}}</ref> However, the philosophical proposal dates back at least to ] ], first published in '']'' in 1908, only three years after the first paper on relativity. Eternalism, defined as the view that there are no ontological differences between past, present and future, is also known as the "'''block universe'''" theory<ref name="Dowden2001">{{cite web |first=Bradley |last=Dowden |year=2001 |title=Time |url=http://www.iep.utm.edu/time/ |accessdate=25 July 2012|quote=The third and more popular theory is that there are no significant ontological differences among present, past, and future because the differences are merely subjective. This view is called “the block universe theory” or “eternalism.”}}</ref><ref name="Dowden2009">{{cite book |first=Bradley |last=Dowden |year=2009 |title=The Metaphysics of Time: A Dialogue |series=New Dialogues in Philosophy |publisher=Rowman & Littlefield |isbn=9780742560314 |lccn=2009021319 |url=http://books.google.com/books?id=PPkwb6XsvOwC&pg=PA149 |page=149 |quote=Block universe theory: Metaphysical theory that implies all of the past, present, and future is real. The name derives from the fact that a Minkowski diagram would represent events as points in a block if space and time were to be finite in all directions. Also called "eternalism."}}</ref><ref>{{cite book|first=Dennis |last=Dieks |year=2008 |title=The Ontology of Spacetime II |url=http://books.google.com/books?id=Ov6zaiANlgsC&lpg=PP1&pg=PA229#v=onepage&q&f=false |page=229 |quote=It is commonly held that relativity favors the "block universe" view (known also as "eternalism"), according to which all events enjoy the same ontological status regardless of their location}}</ref><ref>{{cite book|first=Michael |last=Rea|year=2009 |title=Arguing About Metaphysics |url=http://books.google.com/books?id=yzZRAAAAYAAJ&q=eternalism+same+%22block+universe%22#search_anchor |page=223 |quote=It does not help, either, that there is a tendency to conflate eternalism — the four-dimensional "block universe" view — with causal determinism.}}</ref> (the term '''"block time"''' is also used, with some authors treating it as interchangeable with "block universe"<ref name="Carroll2010">{{cite book |first=S.M. |last=Carroll |year=2010 |title=From Eternity to Here: The Quest for the Ultimate Theory of Time |publisher=Dutton |isbn=9780525951339 |lccn=2009023828 |url=http://books.google.com/books?id=Uak1wtcXrjwC&pg=PT39 |page=39 |quote=In the philosophic literature, this is sometimes called the "block time" or "block universe" perspective, thinking of all space and time as a single existing block of spacetime. For our present purposes, the important point is that we ''can'' think about time in this way. Rather than carrying a picture in the back of our minds in which times is a substance that flows around us or through which we move, we can think of an ordered sequence of correlated events, together constituting the entire universe. Time is then something we reconstruct from the correlations in these events.}}</ref>, and some<ref>{{cite book |first=J.J.A. |last=Mooij |year=2005 |title=Time and Mind: The History of a Philosophical Problem |publisher=Brill Academic Pub |isbn=9789004141520 |url=http://books.google.com/books?id=cTEKAQAAMAAJ&q=%22block+universe%22+%22block+time%22#search_anchor |page=224 |quote=This four-dimensional manifold was assigned the name 'block universe'. Its temporal dimension, block time, was the objective counterpart of the ongoing and passing time that people experience internally.}}</ref> defining it specifically as the temporal dimension of the block universe) due to its description of ] as an unchanging four-dimensional "block"<ref>"Block" here refers to the idea of spacetime as something fixed and unchanging, like a solid block, and not to the actual geometric shape of space or spacetime.</ref> (the name is inspired by the depiction of spacetime in the ]s used in ])<ref name="Dowden2009" />,<ref> as opposed to the view of the world as a three-dimensional space modulated by the passage of time. | ||
| ==Problems with the flow of time== | ==Problems with the flow of time== | ||
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| ===Determinism and indeterminism=== | ===Determinism and indeterminism=== | ||
| Previously, it was noted that people tend to have very different attitudes towards the past and the future. This might be explained by an underlying attitude that the future is not fixed, but can be changed, and is therefore worth worrying about. If that is correct, the flow of time is perhaps less important to our intuitions than an open, undetermined, future. In other words, a flow-of-time theory with a strictly ] future (which nonetheless does not exist at the present) would not satisfy common-sense intuitions about time. If indeterminism can be removed from flow-of-time theories, can it be added to Eternalist theories? Surprisingly, the answer is a qualified "yes" in the form of ] theories, where multiple alternate futures exist in a fixed framework, but individual observers have no way of knowing which alternative, or "branch" they will end up in. | Previously, it was noted that people tend to have very different attitudes towards the past and the future. This might be explained by an underlying attitude that the future is not fixed, but can be changed, and is therefore worth worrying about.* If that is correct, the flow of time is perhaps less important to our intuitions than an open, undetermined, future. In other words, a flow-of-time theory with a strictly ] future (which nonetheless does not exist at the present) would not satisfy common-sense intuitions about time. If indeterminism can be removed from flow-of-time theories, can it be added to Eternalist theories? Surprisingly, the answer is a qualified "yes" in the form of ] theories, where multiple alternate futures exist in a fixed framework, but individual observers have no way of knowing which alternative, or "branch" they will end up in. | ||
| {{Or|date=April 2012}} | |||
| In his discussion with ], ] argued against determinism: | |||
| {{quote|The main topic of our conversation was indeterminism. I tried to persuade him to give up his determinism, which amounted to the view that the world was a four-dimensional Parmenidean block universe in which change was a human illusion, or very nearly so. (He agreed that his had been his view, and while discussing it I called him "Parmenides".) I argued that if men, or other organisms, could experience change and genuine succession in time, then this was real. It could not be explained away by a theory of the successive rising into our consciousness of time slices which in some sense coexist; for this kind of "rising into consciousness" would have precisely the same character as that succession of changes which the theory tries to explain away. I also brought in the somewhat obvious bilogical arguments: that the evolution of life, and the way organisms behave, especially higher animals, cannot really be understood on the basis of any theory which interprets time as if it were something like another (anisotropic) space coordinate. After all, we do ''not'' experience space coordinates. And this is because they are simply nonexistent: we must beware of hypostatizing them; they are constructions which are almost wholly arbitrary. Why should we then experience the time coordinate—to be sure, the one appropriate to our inertial system—not only as real but also as absolute, that is, as unalterable and independent of anything we can do (except changing our state of motion)? | |||
| The ''reality of time and change'' seemed to me the crux of realism. (I still so regard it, and it has been so regarded by some idealistic opponents of realism, such as Schrödinger and Gödel.) | |||
| When I visited Einstein, Schilpp's ''Einstein'' volume in ''The Library of Living Philosophers'' had just been published; this volume contained a now famous contribution of Gödel's which employed, against the reality of time and change, arguments from Einstein's two relativity theories. Einstein had come out in that volume strongly in favour of realism. And he clearly disagreed with Gödel's idealism: he suggested in his reply that Gödel's solutions of the cosmological equations might have "to be excluded on physical grounds". | |||
| Now I tried to present to Einstein-Parmenides as strongly as I could my conviction that a clear stand must be made against any idealistic view of time. And I also tried to show that, though the idealistic view was compatible with both determinism and indeterminism, a clear stand should be made in favour of an "open" universe—one in which the future was in no sense contained in the past or the present, even though they do impose severe restrictions on it. I argued that we should not be swayed by our theories to give up realism (for which the strongest arguments were based on common sense), though I think that he was ready to admit, as I was, that we might be forced one day to give it up if very powerful arguments (of Gödel's type, say) were to be brought against it. I therefore argued that with regard to time, and also to indeterminism (that is, the incompleteness of physics), the situation was precisely similar to the situation with regard to realism. Appealing to his own way of expressing things in theological terms, I said: if God had wanted to put everything into the world from the beginning, He would have created a universe without change, without organisms and evolution, and without man and man's experience of change. But He seems to have thought that a live universe with events unexpected even by Himself would be more interesting than a dead one.<ref name="Popper2002">{{cite book |first=K.R. |last=Popper |year=2002 |title=Unended Quest: An Intellectual Autobiography |series=Routledge Classics |publisher=Routledge |isbn=9780415285896 |lccn=2002067996 |url=http://books.google.com/books?id=CxND59gFftMC&pg=PA148 |pages=148–150}}</ref>|Karl Popper|''Unended Quest: An Intellectual Autobiography''}} | |||
| == Relation to physics == | == Relation to physics == | ||
Revision as of 13:39, 27 July 2012
Eternalism is a philosophical approach to the ontological nature of time, which takes the view that all points in time are equally "real" (they all have the same ontological status), as opposed to the presentist idea that only the present is real. This would mean that future events are "already there", and that there is no objective flow of time. Modern advocates often take inspiration from the theory of relativity, with some such as Rietdijk and Putnam invoking relativity of simultaneity, which says that the question of whether two events occur at the same time is not absolute, but depends on the observer's reference frame. Some also take inspiration from the way that the mathematical formulation of relativity treats time as a single dimension in a four-dimensional spacetime. However, the philosophical proposal dates back at least to McTaggart's B-Theory of time, first published in The Unreality of Time in 1908, only three years after the first paper on relativity. Eternalism, defined as the view that there are no ontological differences between past, present and future, is also known as the "block universe" theory (the term "block time" is also used, with some authors treating it as interchangeable with "block universe", and some defining it specifically as the temporal dimension of the block universe) due to its description of space-time as an unchanging four-dimensional "block" (the name is inspired by the depiction of spacetime in the Minkowski diagrams used in special relativity),Cite error: A <ref> tag is missing the closing </ref> (see the help page).
The comment summarizes the main objections. In more detail, they are:
Subjective sense of flow
Whilst the idea that there is some objective sense in which time is flowing can be denied, the fact that conscious beings feel as though it is in some sense flowing cannot. However, if the flow of time didn't have an objective existence, then it is argued conscious beings would simultaneously experience all moments in their lives. A response is that since the brain presumably perceives time through information processing of external stimuli, not by extrasensory perception, and obeys the laws of causality, it is hard to see how the flow of time, whether it exists or not, could make any subjective difference: all conscious beings are built to perceive time as a chain of events, whether or not it occurs as such.
Apparent differences between past, present and future
Many of our common-sense attitudes treat the past, present and future differently.
- We apparently fear death because we believe that we will no longer exist after we die. But if Eternalism is correct, death is just one of our temporal borders, and should be no more worrisome than birth.
- You are about to go to the dentist, or you have already been. Commonsense says you should prefer to have been. But if Eternalism is correct, it shouldn't matter which situation you're in.
- When some unpleasant experience is behind us, we feel glad that it is over. But if the Eternalism is correct, there is no such property as being over or no longer happening now—it continues to exist timelessly.
Status of conscious observers
Eternalists often appeal to the idea that the flow of time is a subjective illusion. However, Eternalism takes its inspiration from physics and needs to give a physical account of observers. One could, for instance, portray conscious observers as moving through the block universe, in some physically inexplicable way, in order to account for the subjective sense of a flow of time. But there is no need to do so to explain the subjective flow of time. Their opponents claim that the time-flow itself, as an objective phenomenon, is physically inexplicable, and that physics is simply misrepresenting time in treating it as a dimension.
Determinism and indeterminism
Previously, it was noted that people tend to have very different attitudes towards the past and the future. This might be explained by an underlying attitude that the future is not fixed, but can be changed, and is therefore worth worrying about.* If that is correct, the flow of time is perhaps less important to our intuitions than an open, undetermined, future. In other words, a flow-of-time theory with a strictly determined future (which nonetheless does not exist at the present) would not satisfy common-sense intuitions about time. If indeterminism can be removed from flow-of-time theories, can it be added to Eternalist theories? Surprisingly, the answer is a qualified "yes" in the form of multiverse theories, where multiple alternate futures exist in a fixed framework, but individual observers have no way of knowing which alternative, or "branch" they will end up in.
Relation to physics
Eternalism takes its inspiration from physics, especially the Rietdijk-Putnam argument, in which the relativity of simultaneity is used to show that each point in the universe can have a different set of events that are in its present moment. According to Presentism this is impossible because there is only one present moment that is instantaneous and encompasses the entire universe.
Some philosophers also appeal to a specific theory which is "timeless" in a more radical sense than the rest of physics, the theory of quantum gravity. This theory is used, for instance, in Julian Barbour's theory of timelessness. On the other hand, George Ellis argues that time is absent in cosmological theories because of the details they leave out.
Relation to Eastern body of thought
In Buddhism, a special term Dharmadhatu is translated as 'total field of events and meanings' or 'field of all events and meanings.' Here the 'Block Universe' seems to be encompassing not only every possible event in the physical universe but also having a psychological component. See: Śūnyatā, section "Eternalism"
In fiction
Eternalism is a major theme in Kurt Vonnegut’s novel, Slaughterhouse-Five. The Tralfamadorians, an alien species in the novel, have a four-dimensional sight and can therefore see all points in time simultaneously. They explain that since all moments exist simultaneously, everyone is always alive. The hero, Billy Pilgrim, lives his life out of sequence, which, among other things, means that his point of death occurs at a random point in his life rather than at the end of it.
Eternalism also appears in the comic book series Watchmen by Alan Moore. In one chapter, Dr. Manhattan explains how he perceives time. Since past, present, and future events all occur at the "same time" for him, he speaks about them all in the present tense. For example, he says "Forty years ago, cogs rain on Brooklyn" referring to an event in his youth when his father throws old watch parts out a window. His last line of the series is "Nothing ends, Adrian. Nothing ever ends."
See also
Footnotes and references
- Kuipers, Theo A.F. (2007). General Philosophy of Science: Focal Issues. North Holland. p. 326. ISBN 978-0-444-51548-3.
- Peterson, Daniel; Silberstein, Michael (2009), "Relativity of Simultaneity and Eternalism: In Defense of the Block Universe", in Petkov, Vesselin (ed.), Space, Time, and Spacetime: Physical and Philosophical Implications of Minkowski's Unification of Space and Time, p. 208
- Dowden, Bradley (2001). "Time [Internet Encyclopedia of Philosophy]". Retrieved 25 July 2012.
The third and more popular theory is that there are no significant ontological differences among present, past, and future because the differences are merely subjective. This view is called "the block universe theory" or "eternalism."
- ^ Dowden, Bradley (2009). The Metaphysics of Time: A Dialogue. New Dialogues in Philosophy. Rowman & Littlefield. p. 149. ISBN 9780742560314. LCCN 2009021319.
Block universe theory: Metaphysical theory that implies all of the past, present, and future is real. The name derives from the fact that a Minkowski diagram would represent events as points in a block if space and time were to be finite in all directions. Also called "eternalism."
- Dieks, Dennis (2008). The Ontology of Spacetime II. p. 229.
It is commonly held that relativity favors the "block universe" view (known also as "eternalism"), according to which all events enjoy the same ontological status regardless of their location
- Rea, Michael (2009). Arguing About Metaphysics. p. 223.
It does not help, either, that there is a tendency to conflate eternalism — the four-dimensional "block universe" view — with causal determinism.
- Carroll, S.M. (2010). From Eternity to Here: The Quest for the Ultimate Theory of Time. Dutton. p. 39. ISBN 9780525951339. LCCN 2009023828.
In the philosophic literature, this is sometimes called the "block time" or "block universe" perspective, thinking of all space and time as a single existing block of spacetime. For our present purposes, the important point is that we can think about time in this way. Rather than carrying a picture in the back of our minds in which times is a substance that flows around us or through which we move, we can think of an ordered sequence of correlated events, together constituting the entire universe. Time is then something we reconstruct from the correlations in these events.
- Mooij, J.J.A. (2005). Time and Mind: The History of a Philosophical Problem. Brill Academic Pub. p. 224. ISBN 9789004141520.
This four-dimensional manifold was assigned the name 'block universe'. Its temporal dimension, block time, was the objective counterpart of the ongoing and passing time that people experience internally.
- "Block" here refers to the idea of spacetime as something fixed and unchanging, like a solid block, and not to the actual geometric shape of space or spacetime.
- "Platonia", Julian Barbour's time-skeptical website
- Ellis (2006). "Physics in the Real Universe: Time and Spacetime". Gen.Rel.Grav. 38 (12): 1797–1824. arXiv:gr-qc/0605049. doi:10.1007/s10714-006-0332-z.
External links
- Biswas; Shaw; Modak (1999). "Time in Quantum Gravity". Int.J.Mod.Phys. D. 10 (4): 595. arXiv:gr-qc/9906010. doi:10.1142/S0218271801001384.
- Davies, Paul (2002). "That Mysterious Flow". Scientific American. 287 (3): 40–45. doi:10.1038/scientificamerican0902-40.
{{cite journal}}: Unknown parameter|month=ignored (help) - Dorato,Mauro - Kant, Godel and Relativity
- Markosian, Ned (2002). "Time: 8. The 3D/4D Controversy". Stanford Encyclopedia of Philosophy. Retrieved 2006-12-20.
- Nikolic, Hrvoje. "Block time: Why many physicists still don't accept it?" (PDF).
- Petkov, Vesselin (2005). "Is There an Alternative to the Block Universe View?" (PDF). PhilSci Archive. Retrieved 2006-12-20.
- Duda, J (2009). "Four-dimensional understanding of quantum mechanics". arXiv:0910.2724/.
{{cite arXiv}}: Check|arxiv=value (help)
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