create account

Research diaries #4: The beauty of chaos by mathowl

View this thread on: hive.blogpeakd.comecency.com
· @mathowl ·
$55.41
Research diaries #4: The beauty of chaos
*A while back @alexanderalexis wrote [about the beauty of order](/@alexanderalexis/is-beauty-the-flip-side-of-entropy). So that inspired me to write about the beauty of chaos. In this post I will give an introduction to deterministic chaos.*

We will be looking at the [logistic map](https://en.wikipedia.org/wiki/Logistic_map). You can think of this map as describing time evolution of a one dimensional point. Here time moves at discrete steps so time 0, time 1, time 2, time 3 etc. We will be looking at how the position of the point changes of these time steps, this is called its evolution. The logistic has a parameter which we can tweak to generate different evolutions of our point over time. Instead of looking at the whole evolution will be just looking at what the evolution looks like after a long time. We then end up with the image below:

<center>
![logisticmap.jpg](https://files.peakd.com/file/peakd-hive/mathowl/23yJffRLKszSuvPp8o6bjk6UiWkQHykbddzLGHgJ4cgTz8P7WvuKzGS572FR5U1mfzJxH.jpg)
</center>

On the x-axis is the parameter, mu, and on the y-axis the evolution. I starts with a single point then as we increase the parameter it doubles we get 2 points for a single parameter, then it doubles again, we get 4 points, then doubles again, 8, then 16, then 32, etc..but then from the red line the points go crazy! We can zoom in a bit and then see what is going on:

<center>
![logisticmap2.jpg](https://files.peakd.com/file/peakd-hive/mathowl/23tmmXSdNmBCCi2DMRJVcKajFM4bnijUwP8qGijs8vsqAE6K4tKFG9mAkWRmLiF5c6mGg.jpg)
</center>

The parameter corresponding to the red line is called the onset of chaos. Not all states beyond this parameter are chaotic. You can see there are parameters where it seems to be filling a line-segment and then suddenly it reduces to a couple of points. It seems to be fairly unpredictable what state corresponds to which parameter. 

## What is chaos?

So how to identify chaos? Informally, points which start very close exhibit different behaviour as time passes. In the image below we follow the chaotic evolution of two points which start very close to each other. We observe that for about the first 10 time steps they look very similar by then over time evolution 1 and evolution 2 behave completely different.

![evo.jpg](https://files.peakd.com/file/peakd-hive/mathowl/23t8DBmzfHqGYFV9ykqNet99AHihdT7CDnVzh8ndrr2JnHMTnRaeSGwLX6yD68dpWCusf.jpg)

The evolution of a single point is deterministic. Meaning that the past determines all future positions of the point. Chaos here means that an inexactness in determining the starting position will yield a completely different evolution. Quoting Lorenz, the father of deterministic chaos,

>>Chaos: When the present determines the future, but the approximate present does not approximately determine the future. [source](http://mpe.dimacs.rutgers.edu/2013/03/17/chaos-in-an-atmosphere-hanging-on-a-wall/)


## What is the driving mechanics of chaos?

 We look at the mu=1 case. We graph the state at time t against the next state at time t+1. If we study what happens to the curve projected on the x-axis versus the y-axis we see that the curve gets stretched and folded. The stretching makes sure that points which are close to each other will move away from each other and the folding makes sure that the points don't run off to infinity.  

<center>
![chaosspecial.jpg](https://files.peakd.com/file/peakd-hive/mathowl/23tHbKhJnw4U9kdkWeykkZh81m6Eeivtz6sFFsonMCzpkk8YnqksAqbiWXivp8eLbbSGz.jpg)
</center>

## In conclusion

The logistic map is a toy model. There are many more complicated systems that exhibit chaos. A famous example is the butterfly attractor in the [Lorenz system](https://en.wikipedia.org/wiki/Lorenz_system). The Lorenz system is derived from a weather-type model. So probably it comes as no surprise that in weather modelling chaos plays an important role. To me it is remarkable that chaos underlying complicated weather models can be captured by something as simple as the equations for the logistic map. But this is one of the marvels of math: a couple lines of equations can contain a whole theory.


<center>
**Cat tax**
![WeChat Image_20211223050406.jpg](https://files.peakd.com/file/peakd-hive/mathowl/AJpk6nv5vGetjv8wwUF23nunDpkweGnEon7T53BCTu32EaXVm7KmDCigd2crYmN.jpg)
</center>



πŸ‘  , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , and 620 others
properties (23)
authormathowl
permlinkresearch-diaries-4-the-beauty-of-chaos
categoryhive-196387
json_metadata"{"app":"peakd/2021.09.1","format":"markdown","description":"When the present determines the future, but the approximate present does not approximately determine the future. EL","tags":["stemgeeks","stem","mathematics","math","chaos","neoxian","palnet","cat","proofofbrain"],"users":["alexanderalexis"],"image":["https://files.peakd.com/file/peakd-hive/mathowl/23yJffRLKszSuvPp8o6bjk6UiWkQHykbddzLGHgJ4cgTz8P7WvuKzGS572FR5U1mfzJxH.jpg","https://files.peakd.com/file/peakd-hive/mathowl/23tmmXSdNmBCCi2DMRJVcKajFM4bnijUwP8qGijs8vsqAE6K4tKFG9mAkWRmLiF5c6mGg.jpg","https://files.peakd.com/file/peakd-hive/mathowl/23t8DBmzfHqGYFV9ykqNet99AHihdT7CDnVzh8ndrr2JnHMTnRaeSGwLX6yD68dpWCusf.jpg","https://files.peakd.com/file/peakd-hive/mathowl/23tHbKhJnw4U9kdkWeykkZh81m6Eeivtz6sFFsonMCzpkk8YnqksAqbiWXivp8eLbbSGz.jpg","https://files.peakd.com/file/peakd-hive/mathowl/AJpk6nv5vGetjv8wwUF23nunDpkweGnEon7T53BCTu32EaXVm7KmDCigd2crYmN.jpg"]}"
created2021-12-29 20:57:00
last_update2021-12-29 20:57:00
depth0
children16
last_payout2022-01-05 20:57:00
cashout_time1969-12-31 23:59:59
total_payout_value27.990 HBD
curator_payout_value27.423 HBD
pending_payout_value0.000 HBD
promoted0.000 HBD
body_length4,314
author_reputation44,993,635,814,620
root_title"Research diaries #4: The beauty of chaos"
beneficiaries[]
max_accepted_payout1,000,000.000 HBD
percent_hbd10,000
post_id108,971,287
net_rshares25,560,355,865,470
author_curate_reward""
vote details (684)
@alexanderalexis ·
$0.09
Thanks for the mention!

Post a bit math-heavy for me, but I'm slowly working to fix that. A very long-term project!

The butterfly attractor you mention - is that the butterfly effect? It certainly reminds me of it, small initial differences or inexactness leading to large differences in the future.
πŸ‘  , , , ,
properties (23)
authoralexanderalexis
permlinkr4zjdq
categoryhive-196387
json_metadata{"app":"hiveblog/0.1"}
created2021-12-31 15:08:15
last_update2021-12-31 15:08:15
depth1
children2
last_payout2022-01-07 15:08:15
cashout_time1969-12-31 23:59:59
total_payout_value0.044 HBD
curator_payout_value0.042 HBD
pending_payout_value0.000 HBD
promoted0.000 HBD
body_length301
author_reputation1,916,610,782,909
root_title"Research diaries #4: The beauty of chaos"
beneficiaries
0.
accounthiveonboard
weight100
1.
accountroomservice
weight100
max_accepted_payout1,000,000.000 HBD
percent_hbd10,000
post_id109,025,682
net_rshares42,506,498,934
author_curate_reward""
vote details (5)
@cyprianj ·
Loved maths until they hit me with the one called further mathematics....the story changed.
Maths is actually interesting.
πŸ‘  
properties (23)
authorcyprianj
permlinkre-alexanderalexis-r53pal
categoryhive-196387
json_metadata{"tags":["hive-196387"],"app":"peakd/2021.09.1"}
created2022-01-02 21:06:24
last_update2022-01-02 21:06:24
depth2
children0
last_payout2022-01-09 21:06:24
cashout_time1969-12-31 23:59:59
total_payout_value0.000 HBD
curator_payout_value0.000 HBD
pending_payout_value0.000 HBD
promoted0.000 HBD
body_length122
author_reputation75,398,556,172,423
root_title"Research diaries #4: The beauty of chaos"
beneficiaries[]
max_accepted_payout1,000,000.000 HBD
percent_hbd10,000
post_id109,093,311
net_rshares1,329,599,440
author_curate_reward""
vote details (1)
@mathowl ·
$0.02
You are welcome ^^

If you need help with math let me know :D

The butterfly in the Lorenz system refers to the shape of the chaotic attractor which looks like a butterly. The story about the butterfly wings that make a small initial differences or inexactness which then causes hurricane is not why the butterfly attractor is called the butterfly attractor. However the phenomenon driving the butterfly story is what drives the chaos in the butterfly attractor. 

I hope that wasn't too confusing :3
πŸ‘  , , , , ,
properties (23)
authormathowl
permlinkre-alexanderalexis-r5149b
categoryhive-196387
json_metadata{"tags":["hive-196387"],"app":"peakd/2021.09.1"}
created2022-01-01 11:36:51
last_update2022-01-01 11:36:51
depth2
children0
last_payout2022-01-08 11:36:51
cashout_time1969-12-31 23:59:59
total_payout_value0.009 HBD
curator_payout_value0.008 HBD
pending_payout_value0.000 HBD
promoted0.000 HBD
body_length500
author_reputation44,993,635,814,620
root_title"Research diaries #4: The beauty of chaos"
beneficiaries[]
max_accepted_payout1,000,000.000 HBD
percent_hbd10,000
post_id109,047,870
net_rshares10,679,416,781
author_curate_reward""
vote details (6)
@braveboat ·
$0.07
Fascinating!  And I thought chaos was just something that happened in my life!  lol

I am not a math or theoretical thinker, but your narrative was quite illuminating.  I respect the kind of minds that can both understand and relate their knowledge.

Thanks for sharing this expose on chaos...

Wishing you happiness, health, and prosperity in 2022!

Cheers!
πŸ‘  
properties (23)
authorbraveboat
permlinkre-mathowl-r52w4p
categoryhive-196387
json_metadata{"tags":["hive-196387"],"app":"peakd/2021.09.1"}
created2022-01-02 10:36:27
last_update2022-01-02 10:36:27
depth1
children1
last_payout2022-01-09 10:36:27
cashout_time1969-12-31 23:59:59
total_payout_value0.033 HBD
curator_payout_value0.033 HBD
pending_payout_value0.000 HBD
promoted0.000 HBD
body_length358
author_reputation19,599,810,741,901
root_title"Research diaries #4: The beauty of chaos"
beneficiaries[]
max_accepted_payout1,000,000.000 HBD
percent_hbd10,000
post_id109,076,370
net_rshares36,759,858,075
author_curate_reward""
vote details (1)
@mathowl ·
$0.02
Thanks for stopping by :3

The 40k chaos gods approve your illumination 
https://static.wikia.nocookie.net/warhammer40k/images/3/39/ChaosLord6.jpg/revision/latest?cb=20130208223434

Best wishes for the new year ^^
πŸ‘  ,
properties (23)
authormathowl
permlinkr530ck
categoryhive-196387
json_metadata{"image":["https://static.wikia.nocookie.net/warhammer40k/images/3/39/ChaosLord6.jpg/revision/latest?cb=20130208223434"],"app":"hiveblog/0.1"}
created2022-01-02 12:07:33
last_update2022-01-02 12:07:33
depth2
children0
last_payout2022-01-09 12:07:33
cashout_time1969-12-31 23:59:59
total_payout_value0.010 HBD
curator_payout_value0.008 HBD
pending_payout_value0.000 HBD
promoted0.000 HBD
body_length213
author_reputation44,993,635,814,620
root_title"Research diaries #4: The beauty of chaos"
beneficiaries[]
max_accepted_payout1,000,000.000 HBD
percent_hbd10,000
post_id109,078,030
net_rshares11,712,020,828
author_curate_reward""
vote details (2)
@ecency ·
Your content has been **voted** as a part of [Encouragement program](https://ecency.com/ecency/@good-karma/encouragement-program-continues-82eafcd10a299). Keep up the good work! <br><br>Use Ecency daily to boost your growth on platform! <br><br><b>Support Ecency</b><br>[Vote for new Proposal](https://hivesigner.com/sign/update-proposal-votes?proposal_ids=%5B197%5D&approve=true)<br>[Delegate HP and earn more](https://ecency.com/hive-125125/@ecency/daily-100-curation-rewards)
properties (22)
authorecency
permlinkre-202211t135021717z
categoryhive-196387
json_metadata{"tags":["ecency"],"app":"ecency/3.0.16-welcome","format":"markdown+html"}
created2022-01-01 13:50:24
last_update2022-01-01 13:50:24
depth1
children0
last_payout2022-01-08 13:50:24
cashout_time1969-12-31 23:59:59
total_payout_value0.000 HBD
curator_payout_value0.000 HBD
pending_payout_value0.000 HBD
promoted0.000 HBD
body_length478
author_reputation549,971,524,037,747
root_title"Research diaries #4: The beauty of chaos"
beneficiaries[]
max_accepted_payout1,000,000.000 HBD
percent_hbd10,000
post_id109,050,172
net_rshares0
@gentleshaid ·
$0.09
There is this user that use to write about chaos consistently in the past. I can't really recall his username now but certain you will find his post interesting.

The cat looks calm though, a complete antithesis.  
πŸ‘  , , , ,
properties (23)
authorgentleshaid
permlinkre-mathowl-r4z3rs
categoryhive-196387
json_metadata{"tags":["hive-196387"],"app":"peakd/2021.09.1"}
created2021-12-31 09:30:57
last_update2021-12-31 09:30:57
depth1
children2
last_payout2022-01-07 09:30:57
cashout_time1969-12-31 23:59:59
total_payout_value0.044 HBD
curator_payout_value0.041 HBD
pending_payout_value0.000 HBD
promoted0.000 HBD
body_length214
author_reputation336,909,548,459,865
root_title"Research diaries #4: The beauty of chaos"
beneficiaries[]
max_accepted_payout1,000,000.000 HBD
percent_hbd10,000
post_id109,019,461
net_rshares42,176,627,293
author_curate_reward""
vote details (5)
@mathowl ·
$0.02
Ah yes I remember him but also forgot his username. We almost got into a fight :3
πŸ‘  , , , ,
properties (23)
authormathowl
permlinkre-gentleshaid-r5141e
categoryhive-196387
json_metadata{"tags":["hive-196387"],"app":"peakd/2021.09.1"}
created2022-01-01 11:32:06
last_update2022-01-01 11:32:06
depth2
children1
last_payout2022-01-08 11:32:06
cashout_time1969-12-31 23:59:59
total_payout_value0.009 HBD
curator_payout_value0.007 HBD
pending_payout_value0.000 HBD
promoted0.000 HBD
body_length81
author_reputation44,993,635,814,620
root_title"Research diaries #4: The beauty of chaos"
beneficiaries[]
max_accepted_payout1,000,000.000 HBD
percent_hbd10,000
post_id109,047,807
net_rshares10,687,164,965
author_curate_reward""
vote details (5)
@clinton19 ·
🀣
properties (22)
authorclinton19
permlinkre-mathowl-202211t231141289z
categoryhive-196387
json_metadata{"tags":["hive-196387"],"app":"ecency/3.0.23-mobile","format":"markdown+html"}
created2022-01-01 22:11:42
last_update2022-01-01 22:11:42
depth3
children0
last_payout2022-01-08 22:11:42
cashout_time1969-12-31 23:59:59
total_payout_value0.000 HBD
curator_payout_value0.000 HBD
pending_payout_value0.000 HBD
promoted0.000 HBD
body_length1
author_reputation51,144,622,728,573
root_title"Research diaries #4: The beauty of chaos"
beneficiaries[]
max_accepted_payout1,000,000.000 HBD
percent_hbd10,000
post_id109,061,905
net_rshares0
@lemouth ·
$0.10
Do you mind detailing more the mechanism behind the splitting of one points into two? How does that work here?
πŸ‘  , , , , , ,
properties (23)
authorlemouth
permlinkr4xdb2
categoryhive-196387
json_metadata{"app":"hiveblog/0.1"}
created2021-12-30 11:01:54
last_update2021-12-30 11:01:54
depth1
children3
last_payout2022-01-06 11:01:54
cashout_time1969-12-31 23:59:59
total_payout_value0.049 HBD
curator_payout_value0.047 HBD
pending_payout_value0.000 HBD
promoted0.000 HBD
body_length110
author_reputation337,216,208,445,084
root_title"Research diaries #4: The beauty of chaos"
beneficiaries[]
max_accepted_payout1,000,000.000 HBD
percent_hbd10,000
post_id108,985,201
net_rshares47,059,389,930
author_curate_reward""
vote details (7)
@mathowl ·
$0.02
With splitting you mean what happens directly after mu \approx 0.75?

I am plotting the orbit. So denote the logistic map by f_\mu. And what I plot is the set \{ f^n(x_0) : n \in N, n> big number    \} for x_0=1/2.  So after \mu \approx 0.75 the orbit is an attracting period-2 orbit. 

I am not sure if that answers your question :3
πŸ‘  , , ,
properties (23)
authormathowl
permlinkr4xe8x
categoryhive-196387
json_metadata{"app":"hiveblog/0.1"}
created2021-12-30 11:22:09
last_update2021-12-30 11:22:09
depth2
children1
last_payout2022-01-06 11:22:09
cashout_time1969-12-31 23:59:59
total_payout_value0.010 HBD
curator_payout_value0.009 HBD
pending_payout_value0.000 HBD
promoted0.000 HBD
body_length333
author_reputation44,993,635,814,620
root_title"Research diaries #4: The beauty of chaos"
beneficiaries[]
max_accepted_payout1,000,000.000 HBD
percent_hbd10,000
post_id108,985,537
net_rshares10,703,271,441
author_curate_reward""
vote details (4)
@lemouth · (edited)
I am not sure too but I think that I got it (as you insisted on the orbit). Thanks!
properties (22)
authorlemouth
permlinkr4y72x
categoryhive-196387
json_metadata{"app":"hiveblog/0.1"}
created2021-12-30 21:45:00
last_update2021-12-30 21:45:57
depth3
children0
last_payout2022-01-06 21:45:00
cashout_time1969-12-31 23:59:59
total_payout_value0.000 HBD
curator_payout_value0.000 HBD
pending_payout_value0.000 HBD
promoted0.000 HBD
body_length83
author_reputation337,216,208,445,084
root_title"Research diaries #4: The beauty of chaos"
beneficiaries[]
max_accepted_payout1,000,000.000 HBD
percent_hbd10,000
post_id108,999,497
net_rshares0
@mathowl ·
$0.02
I think you want to know how to determine the bifurcation at mu=0.75?

So f_mu has two fixed points. One at 0 and one at (-1+4mu)/(4mu). The single line up to mu=0.75 follows (-1+4mu)/(4mu) because it is a stable fixed point. Then at mu=0.75 we have that f_\mu'(-1+4mu)/(4mu)=-1 and for mu>0.75 we have that |f_\mu'(-1+4mu)/(4mu)|>1 so it becomes unstable.

If you investigate the map f_mu \circ f_mu you see that two fixed points are being "created" as we pass mu=0.75. For the original map f_mu the fixed points of f_mu \circ f_mu correspond to a period 2-orbit. 

This transition is called a transcritical bifurcation because the stability of the fixed point at (-1+4mu)/(4mu) changes.

πŸ‘  , , , , ,
properties (23)
authormathowl
permlinkre-lemouth-r4xmny
categoryhive-196387
json_metadata{"tags":["hive-196387"],"app":"peakd/2021.09.1"}
created2021-12-30 14:23:57
last_update2021-12-30 14:23:57
depth2
children0
last_payout2022-01-06 14:23:57
cashout_time1969-12-31 23:59:59
total_payout_value0.010 HBD
curator_payout_value0.008 HBD
pending_payout_value0.000 HBD
promoted0.000 HBD
body_length690
author_reputation44,993,635,814,620
root_title"Research diaries #4: The beauty of chaos"
beneficiaries[]
max_accepted_payout1,000,000.000 HBD
percent_hbd10,000
post_id108,989,207
net_rshares10,605,334,883
author_curate_reward""
vote details (6)
@steemseph ·
$0.10
At first I noticed one umbrella/beach ball top/broken spiderweb shape, but then I noticed two more. Is it a fractal chaos if time is extended… like x 1000 more time increments?
πŸ‘  , , , , , ,
properties (23)
authorsteemseph
permlinkre-mathowl-r4wxq5
categoryhive-196387
json_metadata{"tags":["hive-196387"],"app":"peakd/2021.09.1"}
created2021-12-30 05:25:18
last_update2021-12-30 05:25:18
depth1
children1
last_payout2022-01-06 05:25:18
cashout_time1969-12-31 23:59:59
total_payout_value0.050 HBD
curator_payout_value0.047 HBD
pending_payout_value0.000 HBD
promoted0.000 HBD
body_length176
author_reputation86,361,213,784,910
root_title"Research diaries #4: The beauty of chaos"
beneficiaries[]
max_accepted_payout1,000,000.000 HBD
percent_hbd10,000
post_id108,979,811
net_rshares46,693,434,069
author_curate_reward""
vote details (7)
@mathowl ·
$0.22
I guess with time increments you mean the parameter mu? Yes if you choose a finer grid the complexity persists. The second picture is a bit similar to the first eventhough we are zooming in. So it has fractal properties. ^^
πŸ‘  , , , ,
properties (23)
authormathowl
permlinkr4zjb3
categoryhive-196387
json_metadata{"app":"hiveblog/0.1"}
created2021-12-31 15:06:42
last_update2021-12-31 15:06:42
depth2
children0
last_payout2022-01-07 15:06:42
cashout_time1969-12-31 23:59:59
total_payout_value0.111 HBD
curator_payout_value0.109 HBD
pending_payout_value0.000 HBD
promoted0.000 HBD
body_length223
author_reputation44,993,635,814,620
root_title"Research diaries #4: The beauty of chaos"
beneficiaries[]
max_accepted_payout1,000,000.000 HBD
percent_hbd10,000
post_id109,025,660
net_rshares107,700,184,435
author_curate_reward""
vote details (5)
@steemstem ·
re-mathowl-research-diaries-4-the-beauty-of-chaos-20220101t133354531z
<div class='text-justify'> <div class='pull-left'>
 <img src='https://stem.openhive.network/images/stemsocialsupport7.png'> </div>

Thanks for your contribution to the <a href='/trending/hive-196387'>STEMsocial community</a>. Feel free to join us on <a href='https://discord.gg/9c7pKVD'>discord</a> to get to know the rest of us!

Please consider delegating to the @stemsocial account (85% of the curation rewards are returned).

You may also include @stemsocial as a beneficiary of the rewards of this post to get a stronger support.&nbsp;<br />&nbsp;<br />
</div>
properties (22)
authorsteemstem
permlinkre-mathowl-research-diaries-4-the-beauty-of-chaos-20220101t133354531z
categoryhive-196387
json_metadata{"app":"stemsocial"}
created2022-01-01 13:33:54
last_update2022-01-01 13:33:54
depth1
children0
last_payout2022-01-08 13:33:54
cashout_time1969-12-31 23:59:59
total_payout_value0.000 HBD
curator_payout_value0.000 HBD
pending_payout_value0.000 HBD
promoted0.000 HBD
body_length565
author_reputation262,017,435,115,313
root_title"Research diaries #4: The beauty of chaos"
beneficiaries[]
max_accepted_payout1,000,000.000 HBD
percent_hbd10,000
post_id109,049,859
net_rshares0