I'm dismissive because your level of certainty is overly high for your level (as expressed) of knowledge. You are picking your favorite use of a language term and dictating that others use it, and dismissing other uses as being wrong. You aren't doing this as part of a technical discipline or domain specific sub language as far as I can tell -- you are doing it personally. It is ridiculously arrogant and non constructive. I suspect I'm witnessing the expert paradox -- the more knowledgeable you are about a subject (physics, mathematics) the less certain you are about being right about things. You act extremely certain.
When you go on about "what actually exists is 'change' ... not 'time'", what you have done there is made language less useful. People have a grasp of what they call time, and they have at least a vague grasp of what they would call "time travel". You claim that "what actually exists" as if your claims have merit that is unassailable -- that is patently ridiculous, arrogant, and non constructive. You do not know if time is a "4th dimension", or if the "universe just changes" -- well, you might think you know, but you are wrong about your knowledge. Your certainty is in error.
I'm relatively certain about your error, because I know that I don't know if time exists as a physical dimension or not, and I know why I know I don't know that. And your behavior doesn't seem to indicate any reason to doubt my own doubt.
So, why do I have doubt about if time really exists as a dimension? Well, we can build 2 and 3 dimensional physical models that do not change in time, yet have a time-like direction behavior in one of the spacial dimensions. We can build thought constructs (or computer models) that have 4 spacial dimensions and contain within it, to the interior "perception", a time-like dimension and 3 space-like dimensions. Some current work in physics is building pairs of models in which one acts as a "hologram" of the other -- a different dimensional physics model that captures the evolution of the other. In a sense, both models refer to the same modeled "reality" insofar as the interior perception of what is going on would be, yet are modeled completely different.
These models seem to have an internal complexity that is "reality-like" to some extent. And there doesn't seem to be a magic barrier between them and the models we have of our reality (which, as it happens, is currently best modeled by a physics that includes time as a dimension...)
And in many of these models, yes, one could build "time travel" in that behaves vaguely like various forms of science fiction.
For a toy example, start with a 1 dimensional binary finite automata with a diameter 3 evolution rule. This can easily generate time-like behavior in the y direction (with entropy and such). Such systems are easily made Turing complete, and (presuming something analogous to the Church-Turing thesis holds) we should be able to set up initial conditions for a sufficiently large (ridiculously so) system to contain the computation of intelligent life, whose existence is described completely in a 2 dimensional computation that is (once finished) unchanging.
We then add in a diameter n>3 "time travel" rule, where if a particular pattern occurs, we go "backwards" (or leftwards) and change the state of an "earlier" bit.
Make that n large enough and the pattern obscure enough, and one could arrange it so that it would extremely rarely happen. Alternatively, one could use it as a core part of the computation of the results, where it happens on small scales all of the time, but it takes an extremely contrived pattern for it to back-propogate more than a trivial distance.
I don't know if we could pull this off, but I don't see any reason why we couldn't. And the difference between the experience of "beings" within such a model universe and ours would be one of degree, not kind. Now, Occam's razor says I shouldn't presume such a contrived example: but our best simple physics models keep on permitting time-travel like behavior (if under ridiculous circumstances!)
Now, on top of those reasons to doubt what you hold to be certain, there is your claim about "we must travel at one second per second". We can change the rate at which we travel through time. It is called relativity. We can, in a geometric sense, change our rate of travel through time relative to each other.
We even seem to have particles going backwards through time in our models of certain subatomic events. Maybe there is a simpler way to work out these problems without that -- but I'm not going to take your word for it.
Eddie Editor wrote:Likewise, I was not merely being pedantic when I said that ‘an infinite number’ misleads us. I think it is important to be aware that ‘infinity’ is utterly in a class of one. Beyond our primitive mathematics, it has nothing to do with very big numbers.
I can name multiple different infinite cardinalities. This might not match what your use of the term infinite is, but at this point, why should I care?
Your claims of absolute certainty about things does not generate confidence that you know what you are talking about.
So yes, I still hold, Semantics are uninteresting. Your level of certainty illuminates your lack of knowledge.