By definition, theoretical MEANS unproven guesses that are and can not be proven true.
Sorry, no. That's the lay definition, which is completely different from the scientific definition, a fact that unfortunately creates confusion among laypeople. In science, a theory is what I said -- a systematic model that posits an explanation for a set of observed data and makes predictions that can be tested to assess the validity of the theory.
https://en.wikipedia.org/wiki/Scientific_theory
That is why they are THEORIES and not FACTS.
A theory is much bigger than a fact. A "fact" (a lay term that has no meaning in science) is merely an observed data point -- e.g. "An apple falls out of a tree" or "A planet moves through the sky on a certain path." A theory, such as Newton's Theory of Universal Gravitation, is the larger model that ties those facts together and explains their common underlying cause -- e.g. "Masses are attracted to other masses by a force described by this set of equations." The advantage of fitting isolated facts into a larger theory is that the theory makes predictions
beyond the existing facts, and that lets us test those predictions and find out if the theory is valid or not. If the predictions are inaccurate, we refine or replace the theory until we have one that explains those new facts (like how Einstein's General Theory of Relativity replaced Newton's gravitational theory, or rather, showed that Newton's theory was merely an approximation of how Einstein's theory applied in a limited range of conditions) -- and that new theory makes new predictions that can in turn be tested to lead to even more new discoveries and insights.
Put another way, "facts" are like points on a graph -- you measure them and note down where they fall. A theory is like the equation describing a curve that passes through all those points. Different equations give different possible curves that those points could be part of -- and by letting you calculate the whole curve, it lets you predict where new points would fall. By measuring those points and seeing which curve they coincide with, you can rule out the curves that don't fit. And if all your measurements fit a particular curve no matter how many you take, then it's reasonable to conclude that that's the right curve and that its equation is probably a correct prediction of the points you haven't measured yet. Sure, there's a finite chance it could be wrong, but there's no reason to assume that until you get data that doesn't fit the theory.
We have been building on guesswork framework for decades. Then we set out to prove what we think we know, even though absolutely none of it can be proven.
There is no "proof" in science, no. Proof is used in mathematics, where things can be unambiguously verified. Science merely reports the results of observations and experiments, and whether a theoretical prediction is confirmed or refuted. In physics, there is always a degree of uncertainty, but that does not mean it's mere guesswork. A guess,
by definition, is made in the absence of evidence. Scientific conclusions and deductions are formed on the basis of evidence, making them the exact opposite of guesswork. Being less than 100% certain is not the same thing as knowing nothing at all.
The work of engineers making things that work with cause and effect in real 3D space has absolutely nothing to do with the underlying theories of unprovable things that we are guessing about in the depths of space, or in the annals of the past.
That's completely untrue. Everything in the universe follows the same laws. That's the power and wonder of science, the reason why it's so amazingly important -- because it enables us to learn about one thing by studying another thing. I recommend James Burke's TV miniseries (and books)
Connections and
The Day the Universe Changed, which were very good at showing how a discovery in one aspect of science connected to many other aspects and how intricately it's all interconnected. Both versions of
Cosmos, the original Carl Sagan version and the recent Neil DeGrasse Tyson version, are also very good at showing this.
Anyway, I don't know why you're even arguing with me about this. We're talking about a work of fiction presenting a fanciful and mostly absurd version of time travel. The idea was put forth that, conjecturally, there ought to be an "original" unaltered timeline that was changed by time travel. I merely pointed out that the idea of a self-consistent time loop makes more sense than one might expect, because it's mathematically consistent even though it doesn't fit our conventional assumptions about causality. Whether it's physically real isn't even the point. If anything, the most likely physical reality is that time travel is completely impossible and it's a moot point anyway. So this is all a discussion of hypothetical matters. It's a discussion of what's
plausible, not what's real. And the fact that there are actual equations demonstrating that a recursive causal time loop, an event causing itself to happen, is mathematically and logically permissible means that such a thing is, in fact, a reasonable conjecture, even if it doesn't seem that way.