Wortfish wrote:Newmark wrote:In the
post that I quoted, you gave an example of an irrational number that lies between 0 and 1, that is sqrt(2) -1. What is 1/(sqrt(2) -1)? What is -(sqrt(2) -1)? Just own up to that
"the inverse of all irrational numbers [...] lie within 0 and 1" was wrong, and I'll quit bugging you about it. But if you want to keep painting yourself into a corner, go right ahead.
I don't even understand what your objection amouts to. The sqrt(2) -1 already lies between 0 and 1 and so there is no need to take its inverse. However, the sqrt(2) does not lie within that range, but its inverse does. So, either all positive irrational numbers exist between 0 and 1 or their inverses do. That was always my argument.
Those were not the qualifications you specified in the statement from you I quoted above, which says something else entirely. You should really use more precise language to avoid this sort of confusion. This leaves only the question as to why you think the wholly uncontroversial statement "either all positive irrational numbers exist between 0 and 1 or their inverses do" provides any form of interesting argument for or against anything...
What I don't fail to realize is that what you describe only describes rational numbers. Not any irrational numbers, neither algebraic nor transcendental. Mathematically speaking, the rationals are not an continuum. The rationals are countably infinite (just as the integers), a continuum (such as the reals) is uncountably infinite. Mathematical proofs of these fact do exist. I gave you a constructive proof below about how you can construct reals that can't be rationals below. As I've said, you are not contributing anything new that mathematicians haven't already thought of. Read up on the field, or embarrass yourself further; your choice.
Who cares? A rational approximation to an irrational number is virtually identical so long as you use big enough integers. Do you not think that an infinitely-sided polygon is, for all intents and purposes, a perfect circle?
Mathematicians care. Virtually identical =/= identical. Mathematically speaking, there is a world of difference between the set of rationals and the set of reals. Approximations do have real world applications (in fact, fields such as numerical analysis are wholly devoted to approximations), but that does not in any way invalidate any other field of mathematics. You may not care, but if you really intend to discuss what is and is not logically possibly, your position is rubbish if you cannot justify it with regard to relevant fields.
...and you think this addresses what, exactly? Cantor certainly didn't claim that; if I've mistakenly made that claim anywhere, I immediately concede that I was wrong. But please do continue: how do you think that this fact invalidates Cantor's proof?
And I have proven that all real numbers, including irrational ones, are just scaled inverses of integers approaching infinity.
No, you have not proven that all. That you
think that you have done that is an indication that you quite frankly lack to competence to see why you are wrong. I can do no further for you until you drop your hubristic notions about disproving well-established mathematical fields which you know little to nothing about, and pick up a text book on basic set theory and actually learn something.
I can easily estimate PI to 1000 places precisely by using the division of two big enough integers. It may not be accurate to the 1001st place, so I would then need to use even bigger numbers.
You can also approximate PI to 4, just as your favorite "mathematician" does. But an approximation
is not the same as the real value. That π cannot be accurately written as a fraction has been
proved multiple times.
Which makes make curious about what branch of mathematics you think can model time in any meaningful way. Care to elaborate? And that still leaves open the question as to what you want to replace set theory and calculus with, since you've dismissed central parts of both as "illusion"...
The illusion is in supposing that potential infinities are actual infinities.
Then give me proper definitions of those two terms. In particular, how they relate to various mathematical concepts, such as Dedekind-infinite sets and their cardinalities, and limits. Otherwise, the supposed "illusions" is nothing else than your failure to grasp the relevant definitions.
And you have still not provided us with a coherent model of time that does not rely on set theory.
Sure. Just copy/paste or link your favorite version of that argument (you've posted several), and I'll answer it. Greyman and Thomas has already pointed out most of your fallacies though, but I might be able to squeeze a few moer inconsistencies out of it.
You were the one who brought up the object that has always been moving. I responded in detail but your never replied. My objection was basically that something that has been moving forever has already traversed all possible points and so, as paradoxical and counter-intuitive as it may appear, cannot proceed any further.
Well, since you won't give me a reference to what specific iteration of your argument you want me to address, I'll just pick one that seems to fit best (even if it was an answer to Thomas, not me). If you think I'm addressing the wrong one, it is up to you to supply a correct version. Anyway, let's get started:
Wortfish wrote:1. You suggest that if something has
always been moving , it doesn't follow that it hasn't reached every point.
That is indeed correct. Infinite sets doesn't need to include
every possible element. The negative integers don't include all the integers, the integers don't include all the reals, the reals don't include all the complex numbers, etc. It is also quite possible to have an set that excludes specific elements, e.g. ℤ \ {0} (all the integers except 0), which is still a set of (countably) infinite size. More importantly, it is entirely mathematically possible for an infinite set to have an upper and/or lower bound, e.g. the negative numbers.
I do, quite frankly, have no idea about what your favorite "mathematician"
wibbles on about here, because by any reasonable definition of "complete", his assertions are either trivially wrong or utterly misleading.
2. So, you think it can be true that it has reached point A, but not point B further along the line.
Indeed. If we have reached a specific point, we have an infinity with an upper bound. If you happen to have a "definition" (i use the term very loosely in this case) of infinity that does not allow for upper bounds, e.g. Wortfish-kind infinities, then that definition is simply not applicable to the past. You can't argue against something that doesn't apply to the situation (that would be a strawman), so you need to either based your objections on the model proposed or supply an adequate reason as to why that particular model doesn't apply, of which you have done none.
If I have been counting negative integers up until this point, I have not yet reached zero.
3. This would mean that not enough time has elapsed for it to move to point B.
Since when? Every point in the past (if we model it as the negative integers) is a finite distance in the past. That means that from
any point X in the past, a finite amount of time has elapsed when we reach point A, which is indeed not enough time to reach point B.
The only relevant point to measure from that you can mean would be a "beginning" (in this case, a lower bound). To measure from an undefined point that is not part of the model can tell you absolutely nothing about the distance between any elements in that model. That you insist on doing this (even though I've pointed it out multiple times) is rather dishonest at this point.
Alternatively, you are conflating set size with the relations between the elements in it again, which is simply trivially wrong.
4. But that is ridiculous given that it has had forever to get not just to A but also to B.
Define "forever" as you would use it in the context of a past. If this definition includes "endless", it does not apply to the past, and you should use a term that actually applies to the model being discussed instead (e.g. "beginningless").
In the given model, that is (as I have shown) certainly not "ridiculous".
5. As such, we must conclude that something always moving cannot be at a point for which there are subsequent points.
6. Therefore, if something is at point A, but is yet to reach point B, it must have not always been moving.
7. So, anything currently moving in a straight trajectory must have begun to move at some point.
If we were talking about Wortfish-infinities, you might have had a point. We are not, so all these conclusion doesn't follow from the premises. You are wrong.
In short, for your argument to work, you either need shoehorn in a model that doesn't apply (e.g. Wortfish-kind infinities), or you need to introduce a "beginning" in a model that doesn't need one. Mind you, I am only talking about models based on integers in this post; divisibility would be one about limits.
And while we're talking baout beginnings, let's have a side-order of that too:
Wortfish wrote:Newmark wrote:And around in circles we go. You still haven't explained
why it can't just have been going forever, thus not having the need of "get going". Hint: Craig "supports" his claim that everything must have a beginning by asserting that infinities are impossible...
If I never began my journey to Shangri-la, then I will never reach Shangri-la, or indeed any place. So it is with time. If time has no beginning, there is no journey or flow of time as we ourselves experience.
Insofar that this is an "explanation" for why everything must have a beginning, it relies on your argument above that constant velocity is impossible, which in turn relies on the need to have a beginning. A circular argument is circular.
But this analogy also has quite a problem when you try apply it to time. You see, all that is observed to be required for a moment to flow to the next is the existence of those particular moments. This is literally what we observe
all the time: one moment flowing into the next. What we
don't observe is moments popping into existence out of nowhere all over the place*, which is very much unlike journeys WITHIN time, which we do indeed observe starting quite frequently. If you want this analogy to hold, show me a finite interval of moments that has a beginning (as in, the first movement has no moment preceding it) and an end (no moment follows the last one)...
* By this, I don't mean to discount any cosmologies that proposes that time "began" (for some relevant definition of the word) at some point, e.g. the big bang. But, as far as I know, they deduce this from whatever model they're working from in conjunction with what the available evidence tells us, not from some esoteric notions on the nature of time based on incoherent definitions of "infinity". As I've said, you are perfectly free to (try to) base your argument on cosmology instead, but those who know something about cosmology around here may have a thing or two to say about it.