question: Does space time exist within the empty parts of the universe?
comment: The fabric of spacetime is never truly "empty." According to quantum mechanics, "empty" space has a zero point energy that is non-zero, which is to say empty space actually has energy. Also, the absence of matter does not mean spacetime doesn't exist. Spacetime is a term that generally refers to the universe as a whole, and the "fabric" of spacetime is an abstraction of the idea of space warping due to relativity. Even without the presence of matter, the "fabric" is still there, and it's not really "empty" because virtual particles constantly pop in and out of existence.
passages: Various superstring theories have effective low-energy limits that correspond to classical spacetimes with alternate dimensionalities than the apparent dimensionality of the observed universe. It has been argued that all but the (3+1) dimensional world represent "dead worlds" with no observers. Therefore, on the basis of anthropic arguments, it would be "predicted" that the observed universe should be one of (3+1) spacetime.
  
  Space and time may not be fundamental properties, but rather may represent emergent phenomena whose origins lie in quantum entanglement.
   In general, God's time would not be related to our time. God might be able to operate within our time without being constrained to do so. However, God could then step outside this game for any purpose. Thus God's time must be aligned with our time if human activities are relevant to God's purpose. (In a relativistic universe, presumably this means—at any point in spacetime—time measured from t=0 at the Big Bang or end of inflation.)
   This is due to the "weak anthropic principle", according to which intelligent beings like humans cannot exist in any other way. String theories appear to allow this situation for certain regions of the Universe, but there may be other regions of the Universe where more than four dimensions are prominent. Furthermore, supergravity, p-brane and string theories all describe different situations with similar results, as if using different approximations of the same theory.
   Albert Einstein in 1920: "We may say that according to the general theory of relativity space is endowed with physical qualities; in this sense, therefore, there exists an Aether. According to the general theory of relativity space without Aether is unthinkable; for in such space there not only would be no propagation of light, but also no possibility of existence for standards of space and time (measuring-rods and clocks), nor therefore any space-time intervals in the physical sense. But this Aether may not be thought of as endowed with the quality characteristic of ponderable media, as consisting of parts which may be tracked through time. The idea of motion may not be applied to it."
   Even though this paper gives the impression that the mystery of where our universe originated is solved, it is not. In his paper Tryon mentions how there is this "larger space in which our Universe is embedded," but this place is given only a very vague and short description. Additionally, while Tryon says our universe came into being from an accident of the laws of physics, he does not say what created the laws of physics, leaving the mystery incompletely solved.
  
  Section::::Works.
  
  BULLET::::- Tryon, Edward P. "Is the Universe a Vacuum Fluctuation?", in "Nature", 246(1973), pp. 396–397.
  
  Section::::See also.
   In 1984, another set of theories called the "string theories", where basic objects are not particles but two-dimensional strings, became popular among physicists. They were claimed to explain the existence of certain particles better than supergravity and other theories. However, according to string theories, instead of the usual four spacetime dimensions, the Universe could have dozens of them. It is imagined that humans do not experience the other dimensions because these are too tightly curled up. 
   In terms of the metric expansion of space, it is in the dark-energy-dominated era, after the universe's matter content has become diluted enough for metric expansion to be dominated by vacuum energy (dark energy). It is also in the universe's Stelliferous Era, after enough time for superclusters to have formed (at about 5 billion years), but before the accelerating expansion of the universe has removed the local supercluster beyond the cosmological horizon (at about 150 billion years).
  
  Section::::Grammar.
   Static interpretation of time
  
  The static interpretation of time is a view of time which arose in the early years of the 20th century from Einstein's special relativity and Hermann Minkowski's extension of special relativity in which time and space were famously united in physicists' thinking as spacetime.
   Because of the minus sign, the spacetime interval between two distinct events can be zero. If formula_17 is positive, the spacetime interval is "timelike", meaning that two events are separated by more time than space. If formula_17 is negative, the spacetime interval is "spacelike", meaning that two events are separated by more space than time. Spacetime intervals are zero when formula_22. In other words, the spacetime interval between two events on the world line of something moving at the speed of light is zero. Such an interval is termed "lightlike" or "null". A photon arriving in our eye from a distant star will not have aged, despite having (from our perspective) spent years in its passage.
   Perhaps the simplest version is that "any" set can be a universe, so long as the object of study is confined to that particular set. If the object of study is formed by the real numbers, then the real line R, which is the real number set, could be the universe under consideration. Implicitly, this is the universe that Georg Cantor was using when he first developed modern naive set theory and cardinality in the 1870s and 1880s in applications to real analysis. The only sets that Cantor was originally interested in were subsets of R.
   Aristotle argued that a "vacuum" (that is, a place where there is no matter) is impossible. Material objects can come into existence only in place, that is, occupy space. Were something to come from nothing, "the place to be occupied by what comes into existence would previously have been occupied by a vacuum, inasmuch as no body existed." But a vacuum is impossible, and matter must be eternal.
   More generally, a spacetime is considered singular if it is geodesically incomplete, meaning that there are freely-falling particles whose motion cannot be determined beyond a finite time, being after the point of reaching the singularity. For example, any observer inside the event horizon of a non-rotating black hole would fall into its center within a finite period of time. The classical version of the Big Bang cosmological model of the universe contains a causal singularity at the start of time ("t"=0), where all time-like geodesics have no extensions into the past. Extrapolating backward to this hypothetical time 0 results in a universe with all spatial dimensions of size zero, infinite density, infinite temperature, and infinite spacetime curvature.
   This dramatic result has raised issues: what happened between the singularity of the Big Bang and the Planck time, which, after all, is the smallest observable time. When might have time separated out from the spacetime foam; there are only hints based on broken symmetries (see Spontaneous symmetry breaking, Timeline of the Big Bang, and the articles in ).
   Our modern conception of time is based on Einstein's theory of relativity and Minkowski's spacetime, in which rates of time run differently in different inertial frames of reference, and space and time are merged into spacetime. Time may be quantized, with the theoretical smallest time being on the order of the Planck time. Einstein's general relativity as well as the redshift of the light from receding distant galaxies indicate that the entire Universe and possibly space-time itself began about 13.8 billion years ago in the Big Bang. Einstein's theory of special relativity mostly (though not universally) made theories of time where there is something metaphysically special about the present seem much less plausible, as the reference-frame-dependence of time seems to not allow the idea of a privileged present moment.
   Historically, there have been differing views on the concept of absolute space and time. Gottfried Leibniz was of the opinion that space made no sense except as the relative location of bodies, and time made no sense except as the relative movement of bodies. George Berkeley suggested that, lacking any point of reference, a sphere in an otherwise empty universe could not be conceived to rotate, and a pair of spheres could be conceived to rotate relative to one another, but not to rotate about their center of gravity, an example later raised by Albert Einstein in his development of general relativity.
   Augustine of Hippo wrote that God is outside of time—that time exists only within the created universe. Thomas Aquinas took the same view, and many theologians agree. On this view, God would perceive something like a block universe, while time might appear differently to the finite beings contained within it.
  
  Section::::The flow of time.:Modern period.
   Some philosophers appeal to a specific theory that 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.
  
  Recently Hrvoje Nikolić has argued that a block time model solves the black hole information paradox.
  
  Section::::Objections.
   For example, Aristotelian space and time has both absolute position and special places, such as the center of the cosmos, and the circumference. Newtonian space and time has absolute position and is Galilean invariant, but does not have special positions.
  
  Section::::Structure of space-time.:Holes.
  
  With the general theory of relativity, the traditional debate between absolutism and relationalism has been shifted to whether spacetime is a substance, since the general theory of relativity largely rules out the existence of, e.g., absolute positions. One powerful argument against spacetime substantivalism, offered by John Earman is known as the "hole argument".
   All canonical theories of general relativity have to deal with the problem of time. In quantum gravity, the problem of time is a conceptual conflict between general relativity and quantum mechanics. In canonical general relativity, time is just another coordinate as a result of general covariance. In quantum field theories, especially in the Hamiltonian formulation, the formulation is split between three dimensions of space, and one dimension of time. Roughly speaking, the problem of time is that there is none in general relativity. This is because in general relativity the Hamiltonian is a constraint that must vanish. However, in any canonical theory, the Hamiltonian generates time translations. Therefore, we arrive at the conclusion that "nothing moves" ("there is no time") in general relativity. Since "there is no time", the usual interpretation of quantum mechanics measurements at given moments of time breaks down. This problem of time is the broad banner for all interpretational problems of the formalism.
   These arguments often center on what it means for something to be "unreal". Modern physicists generally believe that time is as "real" as space – though others, such as Julian Barbour in his book "The End of Time", argue that quantum equations of the universe take their true form when expressed in the timeless realm containing every possible "now" or momentary configuration of the universe, called 'platonia' by Barbour.
   Special relativity eliminates absolute time (although Gödel and others suspect absolute time may be valid for some forms of general relativity) and general relativity further reduces the physical scope of absolute space and time through the concept of geodesics. There appears to be absolute space in relation to the distant stars because the local geodesics eventually channel information from these stars, but it is not necessary to invoke absolute space with respect to any system's physics, as its local geodesics are sufficient to describe its spacetime.
  
  Section::::See also.
  
  BULLET::::- Absolute rotation
  
  BULLET::::- Absolute theory
  
  BULLET::::- "Apeiron"
  
  BULLET::::- Bucket argument
   Space is one of the few fundamental quantities in physics, meaning that it cannot be defined via other quantities because nothing more fundamental is known at the present. On the other hand, it can be related to other fundamental quantities. Thus, similar to other fundamental quantities (like time and mass), space can be explored via measurement and experiment.
  
  Today, our three-dimensional space is viewed as embedded in a four-dimensional spacetime, called Minkowski space (see special relativity). The idea behind space-time is that time is hyperbolic-orthogonal to each of the three spatial dimensions.
  
  Section::::Physics.:Relativity.
   But Taylor told an interviewer "the 'way down' that that refers to is actually entropy in the universe." This reference goes along with the other mention of physics in the song, quoting Einstein and referring obliquely to his Theory of Relativity as it pertains to time: "It's all in your point of view" -- because measurements of time differ depending on the observer.
  
  Section::::Reception.
   Explanatory gap
  
  In philosophy of mind and consciousness, the explanatory gap is the difficulty that physicalist theories have in explaining how physical properties give rise to the way things feel when they are experienced. It is a term introduced by philosopher Joseph Levine. In the 1983 paper in which he first used the term, he used as an example the sentence, "Pain is the firing of C fibers", pointing out that while it might be valid in a physiological sense, it does not help us to understand how pain feels.
   Avshalom Elitzur vehemently rejects the block universe interpretation of time. At the Time in Cosmology conference, held at the Perimeter Institute for Theoretical Physics in 2016, Elitzur said: "I’m sick and tired of this block universe, ... I don’t think that next Thursday has the same footing as this Thursday. The future does not exist. It does not! Ontologically, it’s not there." Elitzur and Shahar Dolev argue that quantum mechanical experiments such as the Quantum Liar and the evaporation of black holes challenge the mainstream block universe model, and support the existence of an objective passage of time. Elitzur and Dolev believe that an objective passage of time and relativity can be reconciled, and that it would resolve many of the issues with the block universe and the conflict between relativity and quantum mechanics. Additionally, Elitzur and Dolev believe that certain quantum mechanical experiments provide evidence of apparently inconsistent histories, and that spacetime itself may therefore be subject to change affecting entire histories.
  
presuppositions: There are empty parts of the universe. Parts of the universe are emtpy.
corrections: The fabric of spacetime is never truly empty. No part of the universe is truly empty.
raw_presuppositions: There are empty parts of the universe. Parts of the universe are emtpy.
raw_corrections: The fabric of spacetime is never truly empty. No part of the universe is truly empty.