ah, this finally gets really interesting
I have to admit that I'm relieved that I'm not the only one bothered with a real lack of definition and you guys seem to be struggling with it as well..
welcome billtavis - very nice discussion indeed!
phew, there is so much to reply to, I need to check the forum more frequently.
first: I like the idea of boundaries as a "main-feature" of fractals.
it might not be the one feature, but you can't have a fractal without a boundary - right?
-then again, if you had no boundary, you'd have just 'one thing' and if there is no other thing that one thing might as well be no-thing
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is there any non-theoretical thing that has no boundary?
I can't think of one. (this would fit well with the "everything is fractal" thought.)
Trying to separate the interaction from the container is missing the point, because everything in nature is a fractal pushing up against another fractal!
Second, I think that fractals are present even in this particular situation, they are just hard to see.
Ah, I love it to meet likeminded people! I keep wondering where they all are, as this topic seems so incredibly important, yet no one in my real life surrounding cares a bit.. cheers bill!
I actually think that fractals don't just appear in nature but also in man-made objects. if you e.g. see the tree of evolution as a fractal, you can also see the evolution of man-made design as a fractal.
you probably enjoy this 'little collection' I'm working on:
http://www.pinterest.com/chillheimer/life-is-fractal/I tend to think, though, that perfectly flat planes are not fractal. Let's say you can see the whole plane on a certain scale.
But a perfectly flat plane probably doesn't exist in the universe. If you zoom deep enough, the single atoms will 'bump out of the plane. So I think this only is a theoretical thought and thus not so relevant.
Liquids can stay atop each other in a very clearly separated manner and the boundary can be incredibly smooth.
and yet, if you zoom in close enough the boundary probably becomes fractal, even if it's the 'boundary of the forces active between the atoms' (sorry for repeating myself, this post hat become too long...)
Though (quasi-)self-similarity and scalefreeness are basically the same concept. The difference is just that one is discrete while the other is continuous. So both are important and both describe fractals.
thank you kram for pointing out the difference between self similarity and scalefree-ness. I hadn't really considered this.
I'd argue that a tree isn't a boundary fractal.
I suppose the boundary can be fractal too - bark typically has rather self-similar or scale-free patterns and textures in it - but that's not related to the fractalness you typically consider when talking about a plant: The branching pattern. That pattern can be described as a Lindenmayer-System and it's not a 2D situation but rather a 1D one.
I'd counter that a tree is a boundary fractal, as it extends the boundary of a solid (earth) into a gas(sky) through self similar branching (as a nice addon)..
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And the only reason we don't see any higher-dimensional fractals, in the literal sense of "see", is because we are limited to 3 dimensions in space.....
..The 4D ones would have to incorporate time, so you'd have to watch time in timelapse while being able to slice through the 3D structure to potentially be able to actually "see" the fractalness inherent in this.´
I personally believe that time is fractal. It's only a matter of perspective. There are so many time scales and different speeds happening, comparing femto-seconds to the age of the universe, in a tiny moment countless things can happen, like reactions single atoms. compared to thousands of years, were countless reactions between humans happen. or billions of years where countless interactions between stars happen..
--edt: of course it is, and it's been proven. I keep forgetting important stuff, this topic is so huge..
the heartbeat rate is proven to follow fractal variations in time, as well as the stock market, the frequency and strenght of earthquakes.......
a quote from this interesting article:
http://www.psychologytoday.com/blog/the-chaotic-life/200909/fractal-brains-fractal-thoughtsOther examples include the size of extinction events in animal species, numbers of academic publications (a few researchers do huge amounts of work and the rest of us do just a little), numbers of hits to web-sites, wait times in stop-and-go traffic, and word usage in literature (i.e., zipf's law).As for how exact a match you need: Usually, if it visually seems like a fractal, which a stone surface does, it'll be close enough.
the amount of roughness can be extremely high, try fiddling around in mandelbulb3d with extreme values. you'll see just noise or stuff that doesn't look like fractals at all. and yet it comes from a fractal formula.
I believe that this happens in nature a lot, which is why we don't see directly that absolutely everything is fractal (yes, there I go again
)
Reality is further complicated by the existence of Multifractals which describe most natural, typically considered fractal phenomena better than single-dimension-fractals.
exactly. as reality is a multifractal system of multifractals
there's no way we can easily see the overall connection. that everything is connected. scientifically speaking, like in the m-set.. and as a nice side-effect this fits to what most religions and esoterics say.
for me this 'scientific base' has huge implications. absolutely ground shaking, a different paradigm..
that deserves huge attention!
Is that truly so? Would be nice, but what about the quantum world?
Furthermore, once you get down to the molecular level, speaking of boundaries starts become a little fishy. At that scale, everything would just look like fuzzy balls with vacuous gaps in between. You wouldn't actually see a boundary. Instead of seeing a wall you bounce off of, you see similar-sized individuals you bounce off of.
And even a single free particle in vacuum, where you most definitely do not have a boundary: A quantum physical trajectory effectively acts like brownian motion due to the uncertainty in both velocity and position. That very natural phenomenon most certainly does not stem from some boundary.
If I understand the brownian motion correctly it doesn't happen for one particle in the vacuum and there is no uncertainity, as the one particle will keep flying in the same direction with a constant speed.
Ah, now I get what you mean - heisenbergs uncertainity principle and us not being able to measure where in time and place a particle is. I'm not sure if you can say with certainty
that this is the same thing as brownian motion.
maybe we are just not yet able to measure position/time as we're technologically not advanced enough at this point in time.
It's just roughness (with self-similarity on a multitude of scales).
- Roughness excludes all things smooth (flat plates, circles, spheres, emptyness, lines, points, solids, etc)
which all seem to be theoretical things that only exist in the mathematic realm.
and maybe even these smooth things like lines, spheres, planes are just very special cases of fractals with very special properties.
just like a perfect square always is a square, but not the other way round.
Afterall, I think we've seen 'perfect spheres' in mandelbulb3d.. but maybe we haven't zoomed close enough
- Self-similarity includes the iterative/recursive property of fractals
I tend to think that the iterative-part could be the one main feature. self-similarity comes naturally with it - not so vice-versa..
- A multitude of scale, to wider the definition to include natural things like trees, lungs, (natural) surface roughness, clouds, rivers, etc.
hm.. should it be 'so easy' ?
- recursion
- multitude of scale
and the only necessary 'adjustment screw' is the variable of roughness
seems plausible. and as I think of it, it's exactly what mandelbrot says.
probably my brain needed 9 months to really understand what he meant.
thanks for naming this here youhn!
hm. maybe the only absolutely basic thing needed for fractals is recursion and everything else results from it automatically (if the conditions are right)I need to think more about this..
phew.. 1 hour later... why do discussions about fractals tend to branch out into so many sub-branches that it gets complex close to chaos?!
pun intended?