zguodong2006的个人博客分享 http://blog.sciencenet.cn/u/zguodong2006


[转载]Networks at the Heart of Complex Systems

已有 400 次阅读 2019-4-19 10:42 |个人分类:complexity science|系统分类:人文社科|文章来源:转载

Section 1.2
Networks at the Heart of Complex Systems

“I think the next century will be the century of complexity.”

Stephen Hawking

We are surrounded by systems that are hopelessly complicated. Consider for example the society that requires cooperation between billions of individuals, or communications infrastructures that integrate billions of cell phones with computers and satellites. Our ability to reason and comprehend our world requires the coherent activity of billions of neurons in our brain. Our biological existence is rooted in seamless interactions between thousands of genes and metabolites within our cells.

These systems are collectively called complex systems, capturing the fact that it is difficult to derive their collective behavior from a knowledge of the system’s components. Given the important role complex systems play in our daily life, in science and in economy, their understanding, mathematical description, prediction, and eventually control is one of the major intellectual and scientific challenges of the 21st century.

The emergence of network science at the dawn of the 21st century is a vivid demonstration that science can live up to this challenge. Indeed, behind each complex system there is an intricate network that encodes the interactions between the system’s components:

  1. The network encoding the interactions between genes, proteins, and metabolites integrates these components into live cells. The very existence of this cellular network is a prerequisite of life.

  2. The wiring diagram capturing the connections between neurons, called the neural network, holds the key to our understanding of how the brain functions and to our consciousness.

  3. The sum of all professional, friendship, and family ties, often called the social network, is the fabric of the society and determines the spread of knowledge, behavior and resources.

  4. Communication networks, describing which communication devices interact with each other, through wired internet connections or wireless links, are at the heart of the modern communication system.

  5. The power grid, a network of generators and transmission lines, supplies with energy virtually all modern technology.

  6. Trade networks maintain our ability to exchange goods and services, being responsible for the material prosperity that the world has enjoyed since WWII (Image 1.2).

Networks are also at the heart of some of the most revolutionary technologies of the 21st century, empowering everything from Google to Facebook, CISCO, and Twitter. At the end, networks permeate science, technology, business and nature to a much higher degree than it may be evident upon a casual inspection. Consequently, we will never understand complex systems unless we develop a deep understanding of the networks behind them.

The exploding interest in network science during the first decade of the 21st century is rooted in the discovery that despite the obvious diversity of complex systems, the structure and the evolution of the networks behind each system is driven by a common set of fundamental laws and principles. Therefore, notwithstanding the amazing differences in form, size, nature, age, and scope of real networks, most networks are driven by common organizing principles. Once we disregard the nature of the components and the precise nature of the interactions between them, the obtained networks are more similar than different from each other. In the following sections we discuss the forces that have led to the emergence of this new research field and its impact on science, technology, and society.




该博文允许注册用户评论 请点击登录 评论 (0 个评论)


Archiver|手机版|科学网 ( 京ICP备14006957 )

GMT+8, 2019-5-22 01:06

Powered by ScienceNet.cn

Copyright © 2007- 中国科学报社