# Nonlinear Systems- 5 Feedback loops & Non-Equilibrium

In this video we will discuss the second source of nonlinearity, what are call feedback loops, where the previous output to the system has some effect on its environment and this then in turn feeds back to affect the current or future input to the system making exponential growth and decay possible.

For full courses, transcriptions and downloads please see: http://www.complexityacademy.io

Transcription excerpt:

If we were to draw a model of a linear system it would look something like this, there would be an input to the system, some process and an output, as we can see the input and the output to the system are independent from each other. The value that we input to the system now, is not in any way affected by the previous output. There are of cause phenomena where this holds true, such as the flipping of a coin, the value I will get from flipping a coin now will not be dependent in any way on the value I got the last time I flipped it, in mathematics this is called the Markov property. But the fact is that many things in our world don’t behave like this, meaning that current input variables to the system are dependent on a previous outputs and current outputs will effect future inputs. The state of the weather yesterday will effect the state of the weather today, the amount of money I have in my account today will through interest effect the amount I have tomorrow and so on. This phenomena where the output of a system is "fed back" to become inputs as part of a chain…

- Kind: Short
- Year: 2015
- Runtime: 6 min
- By: Complexity Academy
- Genres: Science
- Archive: [Wikimedia Commons](https://commons.wikimedia.org/wiki/File:Nonlinear_Systems-_5_Feedback_loops_%26_Non-Equilibrium.webm)
- Licence or status: [CC BY 3.0](https://creativecommons.org/licenses/by/3.0) (as the archive states it)
- Credit: Complexity Academy
- Who can watch: Tweens profiles and older (the archive gives no rating; placed by Invisible Network from its collection and subjects)

[Watch now](https://invisiblenetwork.ai/watch/archive/commons/58002325?play=1)