question: how the perception of time and distance is relative based on varying properties of gravity and speed?
comment: Because space and time are the same thing. They are just different dimensions of spacetime. So if I dump it down to make it easy to understand the relation. If you increase your speed in the dimensions of space, you decrease your speed in the dimension of time.
passages: While this seems self-contradictory, a similar oddity occurs in everyday life. If two persons A and B observe each other from a distance, B will appear small to A, but at the same time A will appear small to B. Being familiar with the effects of perspective, there is no contradiction or paradox in this situation.
   In special relativity, however, the distance between two points is no longer the same if measured by two different observers when one of the observers is moving, because of Lorentz contraction. The situation is even more complicated if the two points are separated in time as well as in space. For example, if one observer sees two events occur at the same place, but at different times, a person moving with respect to the first observer will see the two events occurring at different places, because (from their point of view) they are stationary, and the position of the event is receding or approaching. Thus, a different measure must be used to measure the effective "distance" between two events.
   Einstein taught us that neither time, nor distance are well-defined physical concepts. Instead, their measurement is relative to our frame of reference – how fast we were traveling in the universe and in what direction. Our physical frame of reference can be viewed as our language or labeling convention. Einstein showed that neither time nor distance were well-defined concepts, but could be measured in an infinite number of ways. The same is true of the deficit. Just like absolute time and distance are not well defined, the deficit and related conventional fiscal measures has no economic meaning.
   In 1905, Albert Einstein published his special theory of relativity, which led to the concept that space and time can be viewed as a single construct known as "spacetime". In this theory, the speed of light in a vacuum is the same for all observers—which has the result that two events that appear simultaneous to one particular observer will not be simultaneous to another observer if the observers are moving with respect to one another. Moreover, an observer will measure a moving clock to tick more slowly than one that is stationary with respect to them; and objects are measured to be shortened in the direction that they are moving with respect to the observer.
   Fig. 2-8 illustrates the invariant hyperbola for all events that can be reached from the origin in a proper time of 5 meters (approximately ). Different world lines represent clocks moving at different speeds. A clock that is stationary with respect to the observer has a world line that is vertical, and the elapsed time measured by the observer is the same as the proper time. For a clock traveling at 0.3"c", the elapsed time measured by the observer is 5.24 meters (), while for a clock traveling at 0.7"c", the elapsed time measured by the observer is 7.00 meters (). This illustrates the phenomenon known as "time dilation". Clocks that travel faster take longer (in the observer frame) to tick out the same amount of proper time, and they travel further along the x–axis than they would have without time dilation. The measurement of time dilation by two observers in different inertial reference frames is mutual. If observer O measures the clocks of observer O′ as running slower in his frame, observer O′ in turn will measure the clocks of observer O as running slower.
   Time dilation is a difference in the elapsed time measured by two clocks, either due to them having a velocity difference relative to each other, or by their being differently situated in a gravitational field. After compensating for varying signal delays due to the changing distance between an observer and a moving clock (i.e. Doppler effect), the observer will measure the moving clock as ticking slower than a clock that is at rest in the observer's own reference frame. A clock that is close to a massive body (and which therefore is at lower gravitational potential) will record less elapsed time than a clock situated further from the said massive body (and which is at a higher gravitational potential). 
   Common sense would dictate that, if the passage of time has slowed for a moving object, said object would observe the external world's time to be correspondingly sped up. Counterintuitively, special relativity predicts the opposite. When two observers are in motion relative to each other, each will measure the other's clock slowing down, in concordance with them being moving relative to the observer's frame of reference.
   where r and "t" represent shifts in the origin of space and time, and v is the relative velocity of the two inertial reference frames. Under Galilean transformations, the time "t" − "t" between two events is the same for all reference frames and the distance between two simultaneous events (or, equivalently, the length of any object, |r − r|) is also the same.
  
  Section::::Special relativity.
   It may be helpful to visualize this situation using spacetime diagrams. For a given observer, the "t"-axis is defined to be a point traced out in time by the origin of the spatial coordinate "x", and is drawn vertically. The "x"-axis is defined as the set of all points in space at the time "t" = 0, and is drawn horizontally. The statement that the speed of light is the same for all observers is represented by drawing a light ray as a 45° line, regardless of the speed of the source relative to the speed of the observer.
   The equation "t' "= constant defines a "line of simultaneity" in the ("x', t' ") coordinate system for the second (moving) observer, just as the equation "t" = constant defines the "line of simultaneity" for the first (stationary) observer in the ("x, t") coordinate system. From the above equations for the Lorentz transform it can be seen that "t"' is constant if and only if "t – v x/c" = constant. Thus the set of points that make "t" constant are different from the set of points that makes "t' "constant. That is, the set of events which are regarded as simultaneous depends on the frame of reference used to make the comparison.
   When a signal is produced in the horizontal plane, its angle in relation to the head is referred to as its azimuth, with 0 degrees (0°) azimuth being directly in front of the listener, 90° to the right, and 180° being directly behind.
  
  Section::::Different methods for measuring ITDs.
  
  BULLET::::- For an abrupt stimulus such as a click, onset ITDs are measured. An onset ITD is the time difference between the onset of the signal reaching two ears.
   According to Einstein's special theory of relativity, it is impossible to say in an "absolute" sense that two distinct events occur at the same time if those events are separated in space. If one reference frame assigns precisely the same time to two events that are at different points in space, a reference frame that is moving relative to the first will generally assign different times to the two events (the only exception being when motion is exactly perpendicular to the line connecting the locations of both events).
   Clocks that are far from massive bodies (or at higher gravitational potentials) run more quickly, and clocks close to massive bodies (or at lower gravitational potentials) run more slowly. For example, considered over the total time-span of Earth (4.6 billion years), a clock set at the peak of Mount Everest would be about 39 hours ahead of a clock set at sea level. This is because gravitational time dilation is manifested in accelerated frames of reference or, by virtue of the equivalence principle, in the gravitational field of massive objects.
   Each line drawn parallel to a spatial axis ("x", "x′") represents a line of simultaneity. All events on such a line have the same time value ("ct", "ct′"). Likewise, each line drawn parallel to a temporal axis ("ct", "ct′") represents a line of equal spatial coordinate values ("x", "x′").
   Time dilation and length contraction are not optical illusions, but genuine effects. Measurements of these effects are not an artifact of Doppler shift, nor are they the result of neglecting to take into account the time it takes light to travel from an event to an observer. For example, considering time, the elapsed time between two events, measured by identical clocks held by different observers which are moving relative to one another (measured perhaps in seconds), is different.
   In four-dimensional spacetime, the analog to distance is the "interval". Although time comes in as a fourth dimension, it is treated differently than the spatial dimensions. Minkowski space hence differs in important respects from four-dimensional Euclidean space. The fundamental reason for merging space and time into spacetime is that space and time are separately not invariant, which is to say that, under the proper conditions, different observers will disagree on the length of time between two "events" (because of time dilation) or the distance between the two events (because of length contraction). But special relativity provides a new invariant, called the "spacetime interval", which combines distances in space and in time. All observers who measure time and distance carefully will find the same spacetime interval between any two events. Suppose an observer measures two events as being separated in time by formula_4 and a spatial distance formula_5. Then the spacetime interval formula_6 between the two events that are separated by a distance formula_7 in space and by formula_8 in the formula_9-coordinate is:
   Relativity of simultaneity
  
  In physics, the relativity of simultaneity is the concept that "distant simultaneity" – whether two spatially separated events occur at the same time – is not absolute, but depends on the observer's reference frame. 
  
  Section::::Description.
   Section::::Common sense and human scale.
  
  "Common sense" ideas tend to relate to events within human experience, and thus commensurate with these scales. There is thus no commonsense intuition of, for example, interstellar distances or speeds approaching the speed of light.
   A spacelike spacetime interval gives the same distance that an observer would measure if the events being measured were simultaneous to the observer. A spacelike spacetime interval hence provides a measure of "proper distance", i.e. the true distance = formula_27 Likewise, a timelike spacetime interval gives the same measure of time as would be presented by the cumulative ticking of a clock that moves along a given world line. A timelike spacetime interval hence provides a measure of the "proper time" = formula_28.
  
  Section::::Spacetime in special relativity.:Invariant hyperbola.
   Section::::Gravitational time dilation.
  
  Gravitational time dilation is experienced by an observer that, at a certain altitude within a gravitational potential well, finds that his local clocks measure less elapsed time than identical clocks situated at higher altitude (and which are therefore at higher gravitational potential).
   Time dilation and length contraction are not merely appearances. Time dilation is explicitly related to our way of measuring "time intervals" between events which occur at the same place in a given coordinate system (called "co-local" events). These time intervals (which can be, and are, actually measured experimentally by relevant observers) are "different" in another coordinate system moving with respect to the first, unless the events, in addition to being co-local, are also simultaneous. Similarly, length contraction relates to our measured distances between separated but simultaneous events in a given coordinate system of choice. If these events are not co-local, but are separated by distance (space), they will "not" occur at the same "spatial distance" from each other when seen from another moving coordinate system.
   The Kappa effect or perceptual time dilation is a form of temporal illusion verifiable by experiment, wherein the temporal duration between a sequence of consecutive stimuli is thought to be relatively longer or shorter than its actual elapsed time, due to the spatial/auditory/tactile separation between each consecutive stimuli. The kappa effect can be displayed when considering a journey made in two parts that take an equal amount of time. Between these two parts, the journey that covers more distance may appear to take longer than the journey covering less distance, even though they take an equal amount of time.
   (not illustrated) Drawing a vertical line through A so that it intersects the "x"' axis demonstrates that, even as OB is foreshortened from the point of view of observer O, OA is likewise foreshortened from the point of view of observer O′. In the same way that each observer measures the other's clocks as running slow, each observer measures the other's rulers as being contracted.
   A second, similar type of time travel is permitted by general relativity. In this type a distant observer sees time passing more slowly for a clock at the bottom of a deep gravity well, and a clock lowered into a deep gravity well and pulled back up will indicate that less time has passed compared to a stationary clock that stayed with the distant observer.
   Time has historically been closely related with space, the two together merging into spacetime in Einstein's special relativity and general relativity. According to these theories, the concept of time depends on the spatial reference frame of the observer, and the human perception as well as the measurement by instruments such as clocks are different for observers in relative motion. For example, if a spaceship carrying a clock flies through space at (very nearly) the speed of light, its crew does not notice a change in the speed of time on board their vessel because everything traveling at the same speed slows down at the same rate (including the clock, the crew's thought processes, and the functions of their bodies). However, to a stationary observer watching the spaceship fly by, the spaceship appears flattened in the direction it is traveling and the clock on board the spaceship appears to move very slowly.
  