I think this is the wrong question to ask. We know what we want (a consistent foundation for calculus) and we think we know how to get it (with real numbers and infinite sets). But real number might not be the answer.
I think a much better question to ask is 'can we build a consistent foundation for calculus without real numbers and infinite sets?' I believe the answer is yes. Now, this doesn't imply that the alternative requires scrapping everything about real numbers. For example, I believe the alternative would have still have the area of a unit circle being pi, it would just mean something different. — Ryan O'Connor
Like the real numbers, the fundamental objects of the hyperreals are points/numbers. A continuum is constructed by assembling infinite points, each with a corresponding number. And so the hyperreals gets no closer to answering the question 'how can a collection of points be assembled to form a line?' I haven't investigated the constructivists' methods to produce an informed comment but from what I've seen it looks like more of the same. Points/numbers are treated as fundamental.
I don't have a formal theory but I do have an intuition on how the alternative would look. In line with Aristotle's solution to Zeno's Paradox, my view has continua (not points) being fundamental. — Ryan O'Connor
I think the mathematics of calculus would be almost entirely unaffected in moving to a continuum-based view, but before we could even talk about it, you'd have to first be open to (at least temporarily) shedding your point-based biases and look at graphs in a new light. — Ryan O'Connor
I would love to hear your criticisms on my earlier post to you where I drew the polynomial in an unorthodox way. — Ryan O'Connor
I am not well versed beyond such basics as that, so for more on the subject I recommend the Stanford article and the passages in the Church book. — GrandMinnow
'2+1' and '6-3' are different terms, so, even though extensionally they name the same number, — GrandMinnow
the terms themselves have different intensional meanings. — GrandMinnow
You and Bartricks claim that either you-all, or other people, are locked down. Maybe in China. But I am specifically unaware of anyone anywhere being locked down, I submit to you your florid language has contaminated your thinking, making of it a foul thing on a philosophy site. Or maybe you just plain do not know what "lock-down" means. So what is it? Ignorance? Or something worse? — tim wood
My view is that actual infinity should not be permitted in math any more so that than it is permitted in physics, but that's just my view and it's contrary to contemporary math so I'm willing to leave it at that. — Ryan O'Connor
[/quote]switched to a quantum sensor. With an SLR camera I agree that every photo has some degree of blurriness, but with quantum sensors that's not necessarily the case. There is no law which states that we can't know the position of a particle with perfect precision.
Also, I don't think particles are points, but instead excited states of quantum fields. — Ryan O'Connor
Forget about cameras, sensors, and speedometers - it all boils down to the question of whether a line can be constructed by assembling points. — Ryan O'Connor
Your earlier post indicated that you agree that this is a mystery (given the orthodox views)? Why not consider alternate views? — Ryan O'Connor
Are tangent and instantaneous rate of change not the same thing? — Ryan O'Connor
If you reject the notion of instantaneous rate of change, how can you not reject the notion of tangents? — Ryan O'Connor
I'm talking about mathematics. I understand that 0.333... converges to 1/3, but it is only (a useful) convention which states that convergence and equality are the same. If you're saying that it's proved somewhere that the two terms are equivalent then let's leave it at that. — Ryan O'Connor
The Stern-Brocot string for any rational number has finite characters. I don't accept the claim that that LL = LLLRrepeated since LL corresponds to a position in the tree and LLLRrepeated corresponds to a path along the tree. However, let's not waste any more time on 1/3. — Ryan O'Connor
As with your speedometer argument, your addition of a shutter only complicates the issue without providing any further explanatory power. We add a shutter to cameras only to limit the amount of light that the film is exposed to. Without a shutter we can (at least in principle) still take photographs. Remove the shutter and the instant the first photon hits the film we have a photograph. — Ryan O'Connor
And if no further photons hit the film we have an image with absolutely no blurriness. — Ryan O'Connor
This image captures no motion. It is not a video by any definition. I was anticipating you challenging the practicality of such a photograph, which is why I went quantum, but perhaps that's not necessary. — Ryan O'Connor
I understand how videos and flipbooks work, and yes we use stills to create them, but the magic ingredient which you are ignoring is time (specifically non-zero intervals of time). We hold each frame for 1/24 seconds before advancing to the next frame. — Ryan O'Connor
(I believe) Zeno's paradox was already informally solved by Aristotle. I'm just defending his view. And loosely speaking the view is simply that we start with videos, not stills. With videos we not only can capture motion but we can also pause the video to extract a still. With only stills, motion is not possible, as per Zeno. Zeno's paradox is important and seen as unresolved because the notion of stills being fundamental is deeply rooted in our beliefs. — Ryan O'Connor
The lockdowns, OTOH, are the greatest power-grab and policy flaw in the West maybe ever. The fallout from these lockdowns will be felt for decades hence. — synthesis
And who exactly is locked down and where? — tim wood
This is the point. When we use math to figure out things like instantaneous velocity, the volume of a supposed infinitely small tube, etc., — Metaphysician Undercover
it is implied that we know things about reality which we do not. This is a falsely supported certitude. — Metaphysician Undercover
Or have I just created a false dilemma, a non-problem? — I don't get it
I think applying numbers to geometry is how we apply Godel's numbering to physics — Gregory
Yes, because that is the convention, use some math, and figure out the "instantaneous velocity", just like the convention is to place a zero limit on the example of the op. But what these conventions really represent may not be what one would expect from the terms of usage. — Metaphysician Undercover
That's why velocity is always an average, requiring at least two temporal points. Duration is derived, just like distance is. To infer an instantaneous velocity requires a second derivation. — Metaphysician Undercover
Why does a segment with a length of finite digits change into a length multiplied by pi (pi×2×r) when the segment is made into a circle? The circumference will have digits going to infinity while as a segment it did not? This must be readily explained in mathematics but I don't remember ever seeing an explanation on it — Gregory
Nope. They can't see past the headlines. Not ever. — Book273
Most deaths are perfectly normal and not tragic in the least. — synthesis
Please explain how every death is a tragedy. Then explain how deaths are bad. I don't follow either of these assumptions. It's like rain is bad and when rivers flow into the ocean it is a tragedy. Natural, normal and predictable linear systems, somehow bad and tragic? — Book273
Imagine a dark room and a quantum sensor — Ryan O'Connor
I believe that's a false equality. — Ryan O'Connor
The correct statement is "the potentially infinite process defined by 0.333... converges to the number 1/3" not "the number 0.333... equals the number 1/3". — Ryan O'Connor
Decimal notation is flawed in that it cannot be used to precisely represent some rational numbers, like 1/3. If we want a number system which can give a precise notation for any rational number, we should use Stern-Brocot strings, where 1/3 = LL. — Ryan O'Connor
If photographs can't capture motion but videos can, why not conclude that motion happens in the videos? The reason why we are reluctant to come to this conclusion is because we reject the notion of videos being fundamental. — Ryan O'Connor
We want points (photographs) — Ryan O'Connor
to be fundamental and continua (videos) to be composite and as long as we hold this view we will not find a satisfactory resolution to Zeno's paradoxes. — Ryan O'Connor
If you flip things upside down and see continua as fundamental and points as emergent, then everything makes perfect sense. There's no problem with pausing a video to produce a static image. — Ryan O'Connor
It is clear that you appreciate the profoundness of Zeno's Paradox. Zeno presented these paradoxes in response to the criticisms from the 'one from many' camp calling his views ridiculous. Why not consider the 'many from one' view that he supported? He was wayyy ahead of his time so his view did seem to have problems of their own...but in light of modern advancements in physics his view no longer seems crazy. — Ryan O'Connor
Don't stop here, you may just be on your way to becoming a crank! With this admission you have placed yourself on a slippery slope. Instantaneous velocity is no different from the tangent of a function at a point. Do you accept that the derivative corresponds to a limiting process of secants rather than the output of a completed infinite process (i.e. tangent at a point)? — Ryan O'Connor
Only if you consider 0/0 a valid velocity. — Ryan O'Connor
You take a snapshot of a moving car. You look at the photo and ask, "How fast was it going?" — jgill
But fentanyl, oxycodone, heroine, meth, other drugs, and alcohol have been a leading cause of death in the affected demographic for 2 or 3 years, at least -- haven't they? — Bitter Crank
I would not want to minimize the consequences of the lockdown. — Bitter Crank
While I am an old guy and don't get around much any more (every day is a sort of lockdown), — Bitter Crank
that's not true of younger people. Some people think the shutdown in Minnesota contributed to the ferocity of the riots last may that did so much damage, and the crime wave that has followed. I'm not sure about that, but it seems plausible. I'm sure the lockdown has been quite emotionally distressing to children and youth. — Bitter Crank
The lockdown was an economic disaster for service workers in closed businesses -- absolutely no doubt about that. Use of food shelves has been very high. Homelessness has increased too. — Bitter Crank
Still, 530,000 dead from Covid-19 in the US is unlikely to be matched by deaths from domestic turmoil caused by the lockdown. 2.6 million Covid deaths world-wide is more than a blip on the radar, but it's a fraction of world deaths from all causes. — Bitter Crank
By contrast, in the 1918 Influenza Epidemic, about 1/3 of the world's population became infected with influenza and around 50 million died -- that at a time when world population was significantly smaller than now -- below 2B. 50 million dead from influenza was close to a doubling of total deaths world wide. — Bitter Crank
I didn't look at your list of links -- too late just now to do that, bed time coming up. But I still think the strategic business closures, social distancing, mask wearing, and avoidance of group gatherings helped — Bitter Crank
My rough impression is that professionals in the field of philosophy of mathematics usually do know about mathematics. Which philosophers in, say, the last 85 years do you have in mind? — GrandMinnow
They are selfish dicks. — Banno
Bullshit. They are selfish dicks. — Banno
Ethics involves care for others; that seems to be beyond their comprehension. — Banno
The problem with this perspective is that "mathematical existence" means something completely different than "existence" in the philosophical sense. — Metaphysician Undercover
The op does not ask about "mathematical existence", it asks about "existence". — Metaphysician Undercover
If it asked about the mathematical existence of irrational numbers there would be nothing to discuss. Clearly irrational numbers are used by mathematicians therefore they have mathematical existence. — Metaphysician Undercover
The op is asking a philosophical question about the existence of certain mathematical objects, not whether those mathematical objects have mathematical existence. — Metaphysician Undercover
That would be self-evident. So mathematicians who hardly know anything about existence, yet think they do because they know something about mathematical existence really seem to have very little to say about the philosophical question of whether certain mathematical objects which obviously have mathematical existence, have existence. — Metaphysician Undercover
There are many non-fatal consequences of these mental health issues, such as increased self-harm by children. — tim wood
So far you've got nothing, and it's more than a little disturbing that you think you do. — tim wood
stick to math — tim wood
Fishfry is a nice guy, but the quoted statement is BS. — Bitter Crank
Fishfry is a nice guy — Bitter Crank
Can you elaborate on this? Interested on how lockdowns, in themselves, will kill more people. — Trips
But hey, that Covid is nothing, barely even real. So what if in one year it has killed a lot more Americans than were American soldiers killed in all of WWII - but that's probably fake news, right, — tim wood
It is far from clear to me that lockdowns to prevent a virus from spreading are ethically justified. — Bartricks
I am not the one using those terms, but rather my university professor. — Amalac
But you are right in that it probably doesn't make sense when taken literally. — Amalac
Perhaps he was trying to say: It was far more likely for the universe not to have existed, since such a scenario is far simpler than the scenario in which the actual world exists, for the reasons given before.
What would be your response to that then? — Amalac
Why do you think its incoherent and meaningless? — Amalac
They would not argue that a universe without a rock or without the sun or the milky way is infinitely simpler, they would argue: the less things there are in it, the simpler the scenario is. And it reaches its simplest state when there is absolutely nothing in it, where infinitely many things don't exist (or at least where a huge amount of things don't exist). — Amalac
I agree. By treating rationals and irrationals both as the same type of object (i.e. numbers) we blur the line between the output of a finite algorithm and the output of a potentially infinite algorithm. — Ryan O'Connor
Why would you think that someone who has not studied existence would know as much about existence as someone who has studied existence? — Metaphysician Undercover
Like I said in my OP, I think the reason he, like Martin Gardner, says that is beacuse of an argument like this: — Amalac
The point being, that you cannot take the arrow at a particular moment in time. — Metaphysician Undercover
However, just because we apply delineation through our act of retrograde analysis, and create a mathematical notion of temporality, that doesn't mean that the thing did not have a momentum at a particular instant. It's only a question of accuracy. — emancipate
