Added June 30, 1999; updated June 17, 2000; Updated: September 5, 2006

A few Thinkers concerned with the nature of time have argued that it may be possible to "travel" into the future.  Is time travel really possible?

  Observed phenomena are only basis of science.   

  Ernst Mach

  The only justification for our concepts and systems of concepts is that they serve to represent the complex of our experiences; beyond this they have no legitimacy.

  Albert Einstein

Though I am not qualified to speak to the subject as a scientist or mathematician, I do have some issues to address about the language with which observed phenomena and our perceptions and “concepts and systems of concepts” are explicated.
It seems to me that whether it makes sense to speak of time-travel or space-time travel is a matter of how one chooses to use language -- with this caveat.
If our perceptions and conceptions relate at all to reality, we are, in fact, already “traveling into the future” in multiple ways including the use of various types of “time machines” and have been since our day of birth even before the days of “horseless carriages.”
In fact we cannot avoid doing so.
It took the genius of Albert Einstein to enable us to learn that fact.
Unfortunately, Einstein’s “discovery” is clearly not understood by the masses except in terms of “La La land’s depiction of it.
Moreover, I suspect that most scientists who conceive time-travel as a possibility “in principle” (I’m not sure what that means.), give little thought to how the implications of their and our use and abuse of language affect our understanding of it.
It is important to examine some of the meanings we attribute to such terms as  'time,' ‘motion’ (i.e., travel), ‘space,’ ‘past,’ ‘present,’ and ‘future’ before we consider the concept of "time travel."
In addition, because of the role that quantum mechanics plays in considering time-travel to be possible “in principle,” it will be necessary to examine some of its other terminology as well.
However, before we do that, there are certain philosophical concepts, supportable by evidence that must be understood.
1) Some of our greatest thinkers, particularly Ernst Mach, Albert Einstein, Godfey H. Hardy, and Bertrand Russell have stated unequivocally that the language of mathematics does not describe reality.

Albert Einstein: As far as the laws of mathematics refer to reality, they are not certain, and as far as they are certain, they do not refer to reality.

Bertrand Russell:  Mathematics is the subject in which we don’t know what we are talking about nor whether what we are talking about is true.

Godfrey H. Hardy: A mathematician is someone who not only does not know what he is talking about but, also, does not care.

2) All language, including the language of science, i.e., mathematics, refers to our perceptions and conceptions of an assumed reality.
3) When predictions are publicly “verified” by a continually recurrent repetition of our perceptions, we are justified in accepting recurrence of them as evidence that the language is highly probably “true,” until new evidence proves otherwise.
Numbers and other arithmetical symbols are abstractions from our perceptions of quantity.
Subsequently, as civilization evolved, mathematics replaced numerical symbols, with alphabetical symbols, such as x, y, and z representing variable quantitative values.
Both arithmetic and mathematical symbols have properties of their own, such as being the sum or multiple of other numbers.
Consequently, mathematics reached a point at which it had little if any necessary relevance to a physical reality.
Therein lies a linguistic problem.
Considering that arithmetic and mathematical symbols are shorthand methods of expressing conventional language and avoiding personal and emotional interpretations, it is surprising that much of the language of science, and more so the mathematics of quantum mechanics, leads us to concepts that are far stranger than fiction.
Scientists are not defining their terms conventionally.
It is strange also, that many of the symbols represent concepts that cannot be verified, for example, 1+1=2.
In the assumed real world, where equality does not exist, “ones “ don’t equal each other.
In that sense, even if mathematics is an excellent and useful tool for dealing with our perceptions of “an external world,” it is as much metaphysical language as is theistic language and, at the very least, is as metaphorical as is all language. 
And as the concepts of Relativity and Quantum mechanics increased, the meanings attributed to symbols like “matter, energy, mass,” etc., have been “refined.”
For instance, mathematics informs us that an electron is doing many things and, according to quantum mechanics wave function, is “at” many places, i.e., point instances, at the same time.  It has not always been so defined.
Consider a mathematical “point,” primarily defined to have no dimensions; it is patently clear that it is nothing but a non-physical idea.
All mathematically derived dimensions are, therefore, predicated upon conceptions.
Consequently when it is declared, for instances, that on the hypotenuse of a right triangle there are as many points on each leg as there are on the hypotenuse, when the hypotenuse is infinitely long and a leg is infinitely short, it is not only common sense that arrives at the conclusion that something is amiss but observation and sound logic, as opposed to merely deductive logic, as well.
It is clear that the declaration is giving the impression that a point is something when in fact “nothing,” i.e., “no dimensions,” is the antithesis of “something.”
Hence, it follows that since lines, planes, and solids, fundamentally depend upon a “point,” having no dimensions, yet being “extended” in space, (rather strange use of language) none of them exists ontologically in a physical universe, also, except as ideas.
If this is accepted, and it should be according to available evidence, much of what is said to be knowledge comes into serious question and should be characterized as metaphysical in character.
The above especially relates to all abstract symbols “denoting” an ontological status for terms such as ‘time,’ ‘motion,’ ‘mathematics,’ ‘laws,’ ‘rules,’ ‘principles,’ ‘ideas,’ ‘mind,’ thoughts, ‘constructs that are metaphysical, transcendental, supernatural, or theological,’ and the like.
 Though time is now one of the commonly referred to four dimensions, as with the other three, it too has no length, width, or depth; i.e, time is also not substantive.
The same applies to change, which is a function of physical things.
In other words we are constructing an edifice of ideas and conflating it with “reality” of some kind but definitely not a physical one, unless, of course “physical” (i.e., “matter” and “mass”), is redefined in other than the classical Newtonian sense, as some scientists have suggested it has been in quantum mechanics; but more of this later.
However, there is a very important caveat to consider here also.
On the one hand the “metaphysical,” i.e., abstract, language of arithmetic and mathematics originated as a tool with which to deal with our public perceptions, that are subject to our sense faculties, of an assumed reality.
On the other hand, the metaphysical, i.e., supernatural language of theism is founded, not on perceptions but, rather, on dogma, edicts, decrees, doctrine, fiats, private experiences, and blind faith – language lacking the support of public perception.
As to the term, ‘time,’ we will not dwell on such attributed meanings as “an era,” “a period in history,” “imprisonment,” “a specific moment,” “geologic periods,” “mental time,” and the like.
Lengthy tomes have been written on the nature of “time.”
  For me, one sentence defines it sufficiently:
  “Time is a function of change.”
As Ernst Mach, philosopher and physicist, remarked: “ . . . time is an abstraction at which we arrive by means of the changes of things.
Change is the permeative process that characterizes our universe and different sources of change, i.e., motion, are different kinds of measurement of “time.”
Let’s dispense, also, with concepts of measurements of change, we call “time,” that I suspect you have no interest in: the hour hand of the clock moving from 12 to 1.
            one rotation of Earth: an Earth day as opposed to a Mars day, a Venus day,
             a Lunar day, etc.
            one revolution of the Earth around the sun: an Earth year as opposed to a Jupiter
             year, etc.
            neuronal interactivity: "mental time," which is psychological.
            Then there is also Australian Aboriginal time, which does not seem to "stay put"
             and is called, "Dreamtime."
Let us pretend that we know what we are talking about and assume more than the three dimensions, length, width, and depth with which we define physical things.
That is to say, a thing exists, also, in a fourth dimension, i.e., “time.” [With apologies to Einstein, also in a certain “place” [a fifth dimension: a community, a culture, a nation, etc, and even in space – aspects of reality not deemed worthy of abstraction for theoretical inclusion.]
Otherwise there would be no distinction drawn between a “Miss. Andrea Rene Schievella” at five years of age as opposed to Dr. Andrea Rene Schievella at the age of forty or as a citizen of Italy or the United States, whatever.
For the moment, we shall ignore the "fifth dimension, position in space" as well as the "sixth" dimension, wherein mind is the epistemic measure of all things, and the many more dimensions that a few of today's scientists are conceiving mathematically.
With this bantering around the term, “dimension” it becomes clear that its use and meanings attributed to it are clearly in need of examination.
However, it must be accepted that chronological “time” cannot be conceived in the absence of change.
A universe lacking change would be forever in a state of immeasurable duration.
Where there is process, there is change and consequently the possibility for measurements of change that we call, "time," i.e. “past,” “present,” and “future.”
However, in fact, “past” and “future” are metaphors resulting from an ever-changing “present” universe of matter.
As Einstein intimated, the  “now” of each person, having no ontological status, as well as the  “now” of the present is beyond the purview of science.
The following terms, also, symbolize functions of matter and have no autonomous ontological status: ‘motion,’ ‘change,’ ‘speed,’ ‘action,’ ‘acceleration,’ and the like.
Since “time” has no autonomous ontological status, it is change and interrelations of elements of matter/energy that are the indisputable constants of our universe; and it is the conditions of “force” on the process of change that determines the measurement of “time.
If physical things did not exist and did not move or change, there would be no measurement of change or of a changing present and no speeding up or slowing down in the measurement of change, consequently no measurement of “time”; after all, as a result of Einstein's calculations, not only is motion the "source" of change, it is the displacement of time and space.
We choose to call the changed event, i.e., such measurement of matter in motion and change, “the past,” the process of change, “time,” and the end of the process of change, “the future.”
Matter, moreover, as potential or kinetic energy  (i. e., mass, force, or gravitation, however they may be defined in the future), is the engine of change, as in the physical movement of the hands of a clock.
If the clock, functioning with a spiral spring, were moving at the speed of light in an empty universe would “time” be slowing down?  Would the spiral spring acquire infinite mass and react more slowly with no external forces, other than its encasement, acting upon it?
Surely when a clock malfunctions and does not keep good time, we blame the clock; we don’t say, “Time slowed down” – and refer to this as “time dilation.
Mathematically it is conceptually possible, i.e., linguistically, to “travel” into the “future,” since we can speak of doing it already, second by second, minute by minute, day by day, etc.
As for time traveling machines, all methods of movement and change are “ time travel “devices,” as I will show subsequently.
If, however, as your question suggests, you are thinking of traveling into the past or the distant future, the issue of time dilation, i.e., that time slows down as one’s velocity increases toward the speed of light, must be considered.
”Time dilation,” i.e., the measure of “time,” or the slowing process of change most of which we don’t bother to measure, is rampant all over the earth in our daily “present” lives.
Taking Earth as a point of reference and ignoring the various gravitational forces affecting its movement through the vast emptiness of space beyond its orbit of the sun, consider the following:
Amanda and Andrea are twin sisters.  Amanda lives in England circulating the sun at a speed of 18.5 miles a second.  Andrea, leaving Boston in a time machine, her airplane flying at 500 miles an hour, i.e., almost 7.5 seconds, (or more) is circulating the sun at a speed of 25.5 miles a second as she flies to England to visit Amanda.
We’ll ignore the fact that England is chronologically six hours into Andrea’s future already, according to Greenwich Meridian Time since it can be verified by a phone call that reaches Amanda slightly “in the future,” as is the case in any conversation, that it is “Saturday, in Boston and Sunday” in England “simultaneously.”
Since Earth revolves from West to East and according to Einstein’s time dilation theory, Andrea is traveling faster, aging more slowly and moving into the future faster than is Amanda who is aging much faster, relative to Andrea, while moving more slowly into the future.
Consequently, as time slows down, while Andrea travels to see Amanda, upon seeing her sister, and according to time dilation, Amanda is older than Andrea.
Andrea thinks nothing of it, even though she understands “time dilation” because the aging process is so indiscernible during a mere six hour duration of time.
This time-dilation aging process is occurring all over the world.
Consequently, every moving device, whatever, can be considered to be a time or spacetime-traveling device.
Even a slow walker or runner will age faster (or slower) than a fast one depending on the directions of other imposed motions throughout the universe.
I suspect, however, that none of this concerns you and that what you have in mind is leaping into the past or future.
From my point of view since I believe that “past,” “present,” and “future” are only concepts with no ontological status, traveling into the future or into the past, other than linguistically is utter nonsense.
Common sense, intuition, and even evidence suggest as much.
However, since some scientists postulate “in principle” that it is conceivable despite early fears that they would not be able to explain away possible paradoxes, let us pursue the issue further.
Generally, what is meant by "time travel"?
In the sense with which it is commonly conceived, it is the "transference of a person or thing from one point-instant of time and space to the same point of space at another time."
However, Einstein is reported to have said that traveling into the future is not possible because the “future” has not yet evolved.
If this is the case, then no one in “the past,” believing that the future had not yet evolved, even if it had, would consider trying to travel “into the future.”
And, if the future has evolved, that means that every “moment of the future” is the past of every succeeding future.
Ah, the problems of language usage!
  The entertainment world, however, with its imagined technology and some interpretations of quantum mechanics, have us designating any one of infinite space-time dimensions, and consequently multi-universes, even suggesting temporal inter-visitations with them through “wormholes” that are formed when the two ends of curved space meet – but more of this later.
This seems to involve the issue of how we use, and abuse, language.
There is no such “thing” as a “future” or for that matter a past or present.
Consider the issue of “time dilation” in which twin siblings age at different rates as one is traveling “at” the speed of light into outer space, remaining young upon returning to Earth, and the other becomes exceedingly old having remained on Earth.
I suggest there is only a changing “present.”
In “time dilation,” beyond Earth, as mass increases and the changing (or aging) process slows down with increase in velocity, at the “same time” on earth the aging process remains “normal” leading to the concept that the “normal moving present, on Earth, is moving faster “into the future.”
It is the case, in fact, that on Earth few of us, if any, move “into the future” at the same rate.
As indicated above, each of us has a different “changing present” relative to speed and direction of our daily movements and movements through space.
Hence, “time dilation” should more properly be defined not as the “slowing of time” but, rather, the “slowing of the process of change in the ’present.’”
Most of us are already moving through space at unimaginable speeds as the earth, within the Milky Way moves through space toward the outer boundaries of the universe.
Also, if I happen to walk faster than my wife, “in principle” she is growing older faster than I am but we are in the same “present” (again apologies to Einstein).
It is not ontological time that is slowing.  It is, rather, the changing process of physical substance in the universe that alters the aging process in the changing present that we live in.
As I mentioned above, when the clock experiment was performed, it was not “time” that changed, it was the measuring device that changed its measurement of “time” as a result of gravitational forces being exerted upon its internal mechanism.
The same applies to all things possessing mass in the universe.
For the moment let’s examine the popular concept of time travel.
Consider that I am transferred from this chair, in which I have been sitting since 8:00 o'clock, at 8:15, January 4, 1996 backward in time 10 minutes to, 8:05, to the very same spot on earth where the chair has been since 8:00.
What needs to be understood is that while the transfer was supposed to be taking place, the earth also was traveling through space into the future, nano-second by nano-second, at an indescribable rate of speed, to a different "place" in space.
Consequently, the time travel event transferred me to a point-instant of possibly empty space in the Space-Time-Continuum at which the earth (hence, also the chair) no longer is.
The counter argument, however, is that at that time in the past, the earth is (has remained and always will be there while it is also moving "forward ") at that point-instant in the past., else we would be unable to time travel to it.
If this is the case, we can no longer speak of time travel but must speak of "SPACE-TIME" travel.
Assuming it not to be the case, the "here" (in space) of Jan. 4, 1996 is probably billions of miles distant from the "here" (in space) that I now occupy because aside from the earth's rotating around its axis at a thousand miles an hour, revolving around the sun at 18 miles a second and around the center of our galaxy about 250 miles a second both our sun and our galaxy have been racing toward (or away from) the celestial equator (given Einstein's Balloon Analogy) at speeds at least near half the speed of light, i.e., 93,120 miles a second.
By what stretch of evidence can it be surmised that the ontological status of time, as opposed to time as a function of change, is such that it "moves" through space with the earth?
Consider also that the Pat Schievella sent back in time, if space-time-travel were a reality, would have seen a 10-minutes-younger Pat Schievella sitting in the chair.
This event, Pat seeing Pat, then, also can be revisited after he has returned to his point of departure.
Pat being seen by Pat being seen by Pat ad infinitum because every event in the universe can be revisited.
I leave to you the infinite scenarios that can be imagined.
But this is the least of this nonsense.
For time travel to be possible it would mean the principle that no two objects can occupy the same space at the same time would not hold for the following reasons.
Everything that has happened (past), is happening (present), and is going to happen (future) already exists or it would not be possible to travel forward and backward to them.
In other words "I" am sitting in that chair eternally "at" 8:15, January 4, 1996.
Assuming only TIME travel, as opposed to SPACE-TIME travel, each time I'd sit in that chair or remain sitting there (at the same desk at the same spot on earth), each new or successive time of sitting would exist there, also, eternally or else I (nor anyone else) would be able to travel back or forward to me at those various times.
In other words every event in the history of time that occurred at that point in the space-time continuum would have to exist eternally in order to be able to be "visited" from a different time period.
Moreover, I will continue to be in the process of being born on March 9, 1914 (I don't know the hour, minute of nano-second) throughout eternity.
As well, the moment of my death will exist eternally.
This being the case, such events do not just pop into existence for our time traveling convenience.
Consequently, not only would two objects occupy the same space at the "same time" but, an infinity of objects would, over an infinite amount of time.
Never in the experience of man, according to available evidence, has it been found that such a backward or forward movement in time can occur.
But, it can be said that, "we can SEE the past."
Through human technology, we can "see," in the present, the state of a distant star as it existed billions of years ago.
And, since the star may not even exist any longer, it is not the PHYSICAL star we see.
It is only the light that was emitted from that star trillions of miles away, not only from us but, also, from the point in space from which its light began to move toward us.
If we could travel through time, backward, to the moment that we first observed "a star exploding," and if there were always intelligent beings through-out eternity who could time-travel, that "exploding star" would always be able to be observed at the point-instant at which the explosion began.
That, of course, means that the "star" will eternally “BEGIN” exploding.
Moreover, the star already exists at a different point-instant, and at every point-instant of its path through many trillions of miles away from, "where" it began to explode and certainly even many more trillions of miles away from the point-instant at which it was "BORN."
Some intelligence that existed before the star was born, and went through its process of dying, would be able to time-travel into the future to see it explode and then into the past to see it being formed.
This means, of course, that its non-existence and its existence "existed" at the "same time"--Einstein's non-simultaneity of time to the contrary.
As Hermann Minkowski first noted, there are no such "things" as space and time.  Each is defined in terms of the other.  There is only a “Space-Time Continuum.”
If there is no simultaneity of time, it may not be claimed that, “At the time I sit here at the computer, my wife is asleep on the couch."
Nevertheless "sleeping on the couch" and "sitting at the computer" are events requiring an extended amount of time and even if it may not be said that any two nanoseconds are simultaneous, it may be said that somewhere within the range of the extended period of time both events are occurring "at the same time."
This, of course would require that we define "event" with temporal and spatial properties.
Moreover, nor should the meaning of 'time' be reduced to " nano-seconds because even they would measure different “lengths,” one from another, considering the states of motion, change of spatial locations, and consequently gravitational forces permeating the universe.
If I were to remain seated in my chair from the "date of my birth" to the day of my death or if other objects were to replace my chair in the "same space" and if time-travel were to carry some intelligent being to this room at an infinity of time periods, that being would find, in the same space that my chair initially occupied, me at my various ages and many other objects at their various ages, that may have moved into that space.
In other words, anything that exists never ceases to exist in the space that it occupies or else time-travelers would never find it in the Space-Time "spot" in which it originated.
Moreover, as I’ve indicated above, as experience shows us, if something “moves from” a point-instant in space (but is still there eternally so that it can be “revisited there,”) something else moves into that same point-instant and also remains there eternally (as it also moves through space) so that it can be revisited there.
This allows us to extrapolate the nature of the universe as a solid entity -- a plenum, shades of Parmenides -- in which every point-instant of space is filled with an infinite “number” of events of unchanging matter unless, of course, one wishes to postulate a phenomenological universe or “a” universe of an infinite “number or dimensions stacked one upon the other.
I assume, then that in the course of normal living, our consciousnesses somehow glide through these infinitely permanent point-instants of "events" giving us the illusion of change and passage of time.
In order for future and past events (on Earth, for instance) to be reached in TIME travel, as opposed to SPACE-TIME travel, both must move through space with the earth at the speed at which the earth is moving through space.   In other words the past and the future must never be spatially separated.
The past must not be "left behind" in the Space-Time-Continuum in which it originated.
In other words, an object "here" was, a nano-second later, "there."
Taking heed of Zeno's paradox [I don’t understand why it’s called a paradox, except metaphorically, since it is apparently a fact.], no object is anywhere at some “point-instant” in time, except abstractly.
It is rather, MOVING THROUGH that point-instant.
Since this is the case, it would be impossible to travel backward or forward to that object or event at that point-instant.
The gist of my argument, ‘til now, is predicated primarily on a universe defined in terms of four dimensions.  However, with the advent of Einsteinian relativity, quantum mechanics, string theories (ten, so far, though they’ve been interpreted as one, eleven dimensional, “M” theory), and a conflation of mathematical constructs with reality, a few highly imaginative scientists and mathematicians are seriously speculating about the possible existence of infinitely multiple dimensions in which the universe, as we know it, is similarly but not perfectly duplicated.
Furthermore, they theorize that we may be able to sidetrack having to attain or accede the speed of light for intergalactic travel (and communication?) by bending immaterial space until the two “ends” of the bent spaces touch each other to form a “wormhole” through which, of course, our spaceship (or time machine) will travel.
Before continuing, however, I feel compelled to remind astrophysicist, John Bahall, who remarked, “Philosophy is the kicking up of a lot of dust and then complaining about what you cannot see,” that scientists and mathematicians have long been sounding like, “the pot that called the kettle, ‘black.’”
Speculations derived from quantum mechanics are partly conceived, aside from other theories, on the basis of Schrodinger’s mathematically deduced “wave mechanics” model of the atom in which electrons are not particles but fields of energy.
Since some scientists have deduced, contrary to Schrodinger’s theory, that quanta function as particles as well as waves, electrons can be in multiple (infinity of?) places at the same time.  Hence, they conclude, shades of Leibniz’s Monads, (overly simplistically: plenums, autonomous universes) other dimensions do, in fact, not merely mathematically, exist.
Such speculation apparently ignores, or is unaware of, the admonitions of Einstein, Hardy, and Russell, that mathematics does not describe the universe or anything in it.
According to quantum mechanics, when an electron goes from a to b, being a field of energy and a particle, it is said to be taking many (infinite?) paths at the same time.  Is the “field” solid like a ball or is it like the “surface of a balloon” -- or both?
That an electron may be in “multiple places” simultaneously, firstly, ignores Einstein’s insistence that simultaneity does not exist.  Secondly, it abrogates the law that two physical objects cannot occupy the same space at the same time.
I suppose a counter argument would be that quanta, being energy, have no mass.  If so, how can they be said to behave as a particles?
But, assuming the description of electron behavior how is that evidence that physical multiple objects on the macroscopic level of reality can be in multiple dimensions simultaneously and occupy the same place but in different dimensions -- whatever that can possibly mean?
Moreover, the implication is that objects can move from one dimension to another explaining away any paradox of changing the course of events in the “future” by traveling to the past since “the ‘future’ was going to be different anyway.”
Such perplexing uses of mathematical language, however, make it difficult to talk about "dimensions" that, in reality are not subject to recurring perceptions, i.e., are not accessible to observation, and in the absence of evidence, have no ontological length, width, depth, or time.
Dimensions are mathematical metaphors and as our three authorities, Einstein, Russell, and Hardy, have stated, mathematics does not describe the universe.
How can such language be observationally verified?
Quantum mechanics seems to be even stranger than the language and the concepts of General Relativity.  Even Einstein felt an aversion to those of the latter.
It is a fact that to travel into the past requires that nothing that has come into existence ceases to exist.
Conflating the mathematical construct that quantum particles don’t move merely in one direction but do laterally in infinite directions with the capability of a physical human body doing the same thing on the macroscopic level of existence, and in an infinity of other dimensions, staggers credibility.
Let us suppose that I time-travel to the past into dimension a, and kill my parents preventing my being born.  This creates the paradox that raises the question, “How could I have returned to the past to kill my parents before I was born?”
According to the view of some scientists, if I time-traveled to the past and killed my parents thereby preventing my ever having been born, this would be occurring only in one of the dimensions.  I would still have been born in some other dimension and consequently would reappear in the dimension in which I had not shot my parents, hence no paradox.
That’s a neat trick.  However, it does not eliminate the paradox in the dimension in which I shot my parents even if it explains the eternal existence of every event in the universe making time-travel logically possible -- (but actually?).
After all, anything can be proved logically. But, can it be verified?
Existing in, popping up or transferring to dimension b, or any of the infinity of other dimensions, in which I had not time-traveled to the past not only does not eliminate the paradox, it compounds the existence of paradoxes.
For one thing, it requires an explanation of how it was possible for me to appear in the other dimensions after killing my parents in dimension a.  For another, it does not explain why there are similarities and differences in each of the dimensions.
What if someone witnessed my sudden appearance from the future, killing my parents, seeing me suddenly disappear, then reappearing and seeing my parents still alive?
From the witness’ point of view, unaware of the possibility of the existence of another dimension, what of the paradox observed?
On the one hand, there is no verifiable prediction of concepts interacting with concepts.
On the other, we know and can verifiably predict many ways in which matter interacts with matter.
Surely this is an example that scientists are as guilty of abusing language, as are theists.
Scientists should embark not only on an examination of the material of possible observation but particularly on an examination of how they use language.
The speculations that these scientists should derive from the behavior of electrons is the they still don’t understand all there is to know about an electron and the behavior of its components (quarks and strings) that constitute its field; after all, anything behaving as a wave, is composed of “parts” also – whatever their nature.
The key, here, is the interpretation and conflation of “the many different things, at different places, the electron is doing at the same time,” with the thesis of a reality of many universes, i.e., dimensions, suggesting that what occurs on the quantum mechanical wave function energy level would also apply on the macroscopic, i.e., physical level of reality.
Of course, scientists do not say it will happen.  Rather they pose a probability that it can happen – an extremely remote one, I suggest – as they do, I’m sure.
Let’s be clear, we do not perceive quantum “entities” as we do our assumed physical environment.  And we do not perceive or conceive our physical environment in terms of mathematical concepts.
Obviously the macroscopic level of existence is founded on something.
Unfortunately the metaphysical direction in which science seems to be headed implies that ultimately the world evolved out of nothing, a thesis so long propounded by theists.
Now, we have scientists, discussing the continual expansion of the universe, saying that dark energy is continually being created out of NOTHING, and that Einstein's Universal Constant supports this.
K. C. Cole expressed it in her book: The Hole In The Universe as, “How Scientists Peered Over the Edge of Emptiness and Found Everything.
If ever there were a paradox, consider the above.
If this is a comment on the strange concepts science is pursuing with its dependence on mathematical “evidence,” I suggest that universal scientific acceptance is lacking and that a more moderate, if strange use of, language is in order.
If scientists really believe that something can emerge from nothing, they are as guilty as theologians who build the structure of theistic concepts on language that is neither verifiable nor falsifiable -- as the latter brazenly admit when they say, “One must accept God’s existence on faith.”
The use of the term,  'evidence,' however, calls for caution because we often conflate various "kinds" of evidence: scientific, mathematical, logical, psychological, hypothetical, and so on.
To pursue what is "meant" by evidence is beyond the scope of this discourse. Hopefully my use of the term will be clear enough to support my arguments.
In general, I mean by the term, facts that are accessible to our sense faculties, directly or indirectly.  We shall not inquire into the "meaning" of the term, 'facts.
Consider Einstein's analytic (non-synthetic) equation, e=mc2.  No matter what version one uses, i.e., e=mc2, e/m=c2, e/c2=m, or 1=mc2/e, they are all true by definition; that's the nature of mathematics.
New York City Museum of Natural History's presentation of the life of Einstein gives the impression that he declared that energy has no mass; this despite the apparent evidence that his equation, e=mc2 indicates that it does have mass.  Would Einstein contradict himself?
However, it is argued that the equation does not represent light quanta and physical mass.  It is merely a definition in which "m" and "c" refer respectively to the numerical values, i.e., incorporeal concepts of existing mass and the speed of light in an absolute vacuum.
If this is the case, then Einstein is not addressing physical reality.
But scientist avoid the term, ‘absolute.’  They use such defining language as “vacuum state” referring to a state of space devoid of matter or  (my bold italics) energy.
In other words space is not truly “empty.”
Such a definition allows for a space permeated with universal gravitation  (they may eventually “discover” the “graviton,” defined to have “zero charge and rest mass”), CMB, i.e., cosmic microwave background, and the massless energy of light, unless the latter is impeded by “dark matter.”
The presence of the dark matter, however, would alter the language to “false vacuum."
Moreover, if quanta have no mass, how is it possible for dark matter to impede them and how can the super dense gravity of a dark hole pull them down beyond its event horizon?
Let us reiterate; "m" and "c" in the equation are not referring to mass and light but refer only to numbers, i.e., mathematics.
How is such an equation to be verified?
Isn’t there a difference between a mathematical lack of mass and an actual lack of mass?
Is an explosion of a nuclear bomb sufficient evidence to verify the mathematical language?
Is the equation not, then, an analytic claim, i.e., true by definition as is all mathematics, that cannot be shown to be true or false because no empirical (accessible to the sense faculties) evidence can possibly be discovered to support it?
Since value and speed do not exist physically, they are only mathematical "values" that do not speak to the issue of the behavior of light in different physical media, as for instance, according to one report, as through water or air or as laser beams traveling through caesium atoms at three hundred times the " the speed of light," or the hypothetical tachyons that in order to exist must accede the speed of light.
May we not assume, then, since light is always traveling in some kind of medium, and has an impact effect on its environment suggests that it does have mass?
Otherwise some questions arise: Isn't "something” that has no mass, i.e., is non-dimensional, nothing other than an idea?
If energy, i.e., light has no mass, why is the speed of light altered in different media?
If the energy of m times c squared has no mass, then it is also the case that the energy of photons as PARTICLES has no mass.
Note the dictionary report of the meaning attributed to the term, 'photon': "a quantum of electromagnetic energy having both particle and wave behavior: it has no charge or mass but possesses momentum, i.e., motion [Pure -- when force ceases to be exerted? (Shades of Samuel Alexander’s ultimate substance of the universe)], the energy of light, X rays, gamma, etc. [sic] is carried by photons.” (My brackets.)
If so, how can the motion of light but not the "light" have a causal effect as in causing greater warmth?
Is it possible, or at least conceivable, that pure energy, i.e., light, as opposed to a mathematical symbol, “m,” does in fact have some degree of mass, that registers numerically as zero but requires a different kind of mathematical value assigned to it, and that since matter is convertible to pure energy, the latter is another form of mass-bearing existent as is a gas, air, water, fire, which are different but measurable.
Let us not forget that at one time Neutrinos were considered not to have mass.
After all, aren’t spacecraft engineers conceiving space “ships” propelled by solar winds by the pressure of streams of photons against mile-square-size sails and defense mechanisms that emit sufficient diverting pressure to prevent Yucatan-Peninsula-like meteor impacts that possibly caused the dinosaur extinction?
As the hard cover book, Space 2100: To Mars And Beyond In The Century To Come, describes it, “As sunlight reflects off the surface of a shiny bit of metal, it exchanges the tiniest bit of momentum with the object . . . and the momentum can build up over time to interplanetary speeds."
Exactly what is meant by the term, 'exchange' implying the absence of the impact of mass?
Is momentum, some "existent" also absent mass?
Momentum is, according to the dictionary, "in mechanics a quantity [my emphasis] of motion of a moving object equal to the product of its mass and velocity."
Except as a mental abstraction, it is not possible for motion to exist other than as a continuous change of space-time relocation of matter/energy.
Is not "an exchange of momentum," since it is a "product of mass and velocity," a cause and effect event, and consequently an impact of mass upon mass?
Is Einstein positing a kind of existent different from matter/energy?
Is he perhaps being misinterpreted or is this an issue of the chicken and the egg?
Is it not obvious that there would be no (kinetic) energy in the absence of potential matter/energy?
Which came first a black hole of super-dense matter or the energy of its explosion?
Is it any wonder that theists point to their unverifiable uses of language, as little different from some of the language, now smacking strongly of metaphysics, being used by scientists and mathematicians?
Is it any wonder that positing quantum mechanics and wormholes for the purpose of interstellar and spacetime traveling with no more evidence than the perceptually unsupported language of mathematics has many fellow scientists raising eyebrows?
Even if we could conceive and create the technological means for creating wormholes, how does one bend empty space?
Moreover, how does one locate the desired areas of empty space, in the vastness of the universe, at which to create the wormholes and then bend the empty space at which the wormholes are created trillions of miles apart so that the wormholes will “meet” enabling “traveling through them or to other dimensions?”


Imagine an assumed external reality, i.e., a universe defined by the perceptions, concepts, logic, models, instruments, languages, and mathematical constructs of intelligent creatures such as a chimpanzee, a fly, a bird, a bumblebee, a dolphin, a cat, a dog, a lizard, a snake, whatever; would they define “the universe” as human beings do?  

© 1997 by Pasqual S. Schievella