Unless they’re assuming a certain resolution of measurement.
i hate the coastline ‘paradox’ and every other ‘paradox’ that’s just a missing variable. “if we measure with a big resolution it’s a smaller number of units and a small resolution is a bigger number!?” that’s not a paradox. that’s just how that variable works always. it’s not confusing or interesting at all.
But if you shrink the “yardstick” down to an infinitesimally small size, the length, effectively, becomes infinite… and it’s the same for all coastlines. They’re all infinitely long.
… but some are longer than others. ;)
You can’t shrink the yardstick down to an infinitesimal size.
Coastlines are not well defined. They change in time with tides and waves. And even if you take a picture and try to measure that, you still have to decide at what point exactly the sea ends and the land starts.
If the criteria for that is “the line is where it would make a fractal” then sure, by that arbitrary decision, it is infinite. However, a way better way to answer the question “where is the line” is to just decide on a fixed resolution (or variable if you want to get fancy), which makes the distinction between sea and land clearer.
It is like saying that an electron is everywhere in the universe, because of Heisenberg’s uncertainty principle. While it is very technically true, just pick a resolution of 1mm^3 and you know exactly where the electron is.
Literally no. Very hard to measure, but strictly still a finite length. Limits and all that jazz.
Limits can resolve to infinity. The coastline paradox is just the observation that the (semi-reasonable) assumption that landmasses are fractal shaped implies the coastline tends towards infinity with smaller yardsticks.
They can… I wasn’t saying they couldn’t… I meant that as to point to the logic you’d use to prove it finite
Max Planck says no…
Didn’t calculus solve this stuff?
Nah, that’s silly. Asia obviously has the longest coastline.
Sure, based on that paradox, the specific measurement of a given coastline will differ. But if you pick a standard (i.e., 1km straight lines), Asia is easily the longest. Doesn’t matter what standard you pick.
The only way the paradox matter here is of you pick different standards for different coastlines. Which, os obviously wrong.
Isn’t it a bit like saying “there’s obviously more real numbers between 0 and 2 than between 0 and 1”? Which, to my knowledge, is a false statement.
The cardinality of the two intervals [0,1] and [0,2] are equivalent. E.g. for every number in the former you could map it to a unique number in the latter and vice versa. (Multiply or divide by two)
However in statistics, if you have a continuous variable with a uniform distribution on the interval [0, 2] and you want to know what the chances are of that value being between [0,1] then you do what you normally would for a discrete set and divide 1 by 2 because there are twice as many elements in the total than there are in half the range.
In other words, for weird theoretical math the amount of numbers in the reals is equivalent to the amount of any elements in a subset of the reals, but other than those weird cases, you should treat it as though they are different sizes.
If between 0 and 1 are an infinite number of real numbers, then between 0 and 2 are twice infinite real numbers, IIRC my college math. I probably don’t.
In math they’d both be equal
Funny that so many uses of maths depends on measurement, and yet so many pure mathematicians seem to be clueless about how we actually measure things and why its useful. It doesn’t even matters about all this bullshit about infinities , were talking about the real world. It’s all about the precision of the tape measure. Here’s a true story from back in the day:
English Mathematician: You’ll need an infinite number of bricks to build a wall around any island’s coastline. French guy: come on over and see Mont Saint Michel it’s vraiment genial!
English Mathematician: Oh that wall is infinitely far away from the true coastline, those bricks are not regulation infinitesimal length. If they’d started from the other corner they’d have got a different shape, and for sure needed infinite number of infinitesimal bricks to actually build that wall. Sloppy french masons. I can prove it I’ll blast them all away with cannon fire until the glorious mathematical truth is revealed underneath.
One year later French inhabitants: fuck off english maths whore!
Ten years more laterer Hi french dudes! I’m back with a greater number of even bigger state of the art truth seeking cannon. I will prove this if its the last thing i do.
One year later . . .
Some infinites are larger than other infinites.
It’s not a true fractal, so the length has some finite bounding. It’s just stupidly large, since you are tracing the atomic structure.
Let F be a geometric object and let C be the set of counterexamples.
F is a True Fractal ⟺ F satisfies all properties P₁, P₂, …, Pₙ
Where for each counterexample c ∈ C that satisfies P₁…Pₙ: Define Pₙ₊₁ := “is not like c”
The definition recurses infinitely as new counterexamples emerge.
Corollary: Coastlines exhibit fractal properties at every scale… except they don’t, because [insert new property], except that’s also not quite right because [insert newer property], except actually [insert even newer property]…
□ (no true scotsman continues fractally)
This motherfucker coming correct with subscripts.
That’s a fair point. I forgot that some infinites are larger than other infinites.
Did you also forget about Dre?
Did you forget about the game?
My new years resolution will be to solve this paradox.
Not all infinities are equal, friend. Asia does have more infinite coastline than other continents.
Its true that not all infinities are equal, but the way we determine which infinities are larger is as follows
Say you have two infinite sets: A and B A is the set of integers B is the set of positive integers
Now, based on your argument, Asia has the largest infinite coastline in the same way A contains more numbers than B, right?
Well that’s not how infinity works. |B| = |A| surprisingly.
The test you can use to see if one infinity is bigger than another is thus:
Can you take each element of A, and assign a unique member of B to it? If so, they’re the same order of infinity.
As an example where you can’t do this, and therefore the infinite sets are truely of different sizes, is the real numbers vs the integers. Go ahead, try to label every real number with an integer, I’ll wait.
I’ll label every real number with the integer 1.
Go ahead, try to label every real number with an integer, I’ll wait.
Why would I be trying to do this though? You’ve got the argument backwards.
Is the set of all real numbers between 0 and 100 bigger or equal to the set of all real numbers between 0 and 1?
It seems like I’m wrong though and these sets are the same “size” lol
Exactly! It is unintuitive, but there are as many infinite elements of the set of all real numbers between 0 and 1, as there are in the set between 0 and 100.
I hope this demonstrates what the people here arguing for the paradox are saying, to the people who are arguing that one is obviously longer.
Just because something is obvious, doesn’t make it true :)
Alright, I concede. I did it wrong but still ended up with the right answer. There are other responses in this thread with correct explanation for why Asia has more coastline
Yeah, if you use an arbitrary standardized measuring stick, the problem goes away, as it is no longer infinite.
Still a fun thought experiment to demonstrate how unintuitive infinities are!
Anyway, major kudos to you for engaging with this thread in good faith! That is so rare these days, I barely venture to comment anymore. Respect.
… and thank you for the opportunity to share a weird math fact!
And it may very well be true, but we can’t prove it mathematically.
It’s correct, though. You’d apply the same scale of measurements to all coastlines, and using a standard of 1km or 0.5km plot points, Asia wins.
