Network Science

Early in this decade, a group of researchers and educators at NYSCI began looking at what we could communicate to the public about the kinds of networks we encounter in our lives. At the time the logical place to start seemed like computer networks. But the idea of networks is much bigger than just the networks that connect our computers and cell phones, it is even much bigger than the Internet. Networks was quickly becoming a new science, and was revealing things about nature and ourselves that we had been missing during much of the twentieth century because of assumptions we made about how complexity worked. We all thought interconnections in complex systems were random.

But research in the late 1990s revealed patterns that helped us understand how these networks function and evolve. Most surprising, these patterns were found in many different kinds of networks in nature, human culture, and technology. Scientists studying these patterns conclude that nature evolved ways of structuring networks that help make them work. This is what the exhibition “Connections: The Nature of Networks” is about. As part of the development of Connections and the promotion of the learning and communications of network science, NYSCI has supported and participated in a variety of conferences and projects related to network science. On this page find more information and links about the exhibits in Connections as well as other ways NYSCI helps advance and support network science.

Conferences and Workshops

In 2007 we hosted the International Conference and Workshop on Network Science (NetSci07) in collaboration with the University of Notre Dame and Harvard Medical School. This included a Visualizing Network Dynamics Competition, funded by the National Science Foundation and co-sponsored by Indiana University. We have also done presentations for NetSci06 at Indiana University, convened sessions for NetSci08 at Norwich Research Park (University of East Anglia), and we provided remote assistance to some of the organizers for NetSci09, at the Istituto Veneto di Scienze Lettere ed Arti. At NetSci10, we proposed an initiative to bring network science to high school students and teachers and in collaboration with SUNY Binghamton and NSF are sending student researchers and their teachers to do poster presentations and attend NetSci11 at the Central European University in Budapest. Papers, presentations and audio and video recordings for many of the talks for these events are available at the websites linked above.

We have also been active participants and co-organizers of workshops for Indiana University’s Cyberinfrastructure for Network Science. One of the important uses of this cyberinfrastructure is called “scientometrics” (the science of science) in which we can map all of science research and study its structure and evolution. For more information on the most recent workshops see our R&D Page or the workshop page.

The outreach component of the Cyberinfrastructure is the Places and Spaces exhibition. NYSCI hosted the exhibition in 2006/2007, and worked with scientists at Indiana University to create a children’s map of science. A paper on this work was presented at the International Society for Optical Engineering (SPIE) Conference on Visualization and Data Analysis, San Jose in 2009.

Media

We also provided production assistance to Annamaria Talas in creating a documentary on network science: “Connected: the Power of the Six Degrees” and hosted a well-attended U.S. launch event for the film in collaboration with Discovery Science Channel in 2009.

More Information Behind the Exhibits In Connections: The Nature of Networks.

Concepts Important to Connections

It is about networks: the way things are connected.
It is about networks that are built and that occur in culture and nature.

Definition of a Network:

A network is an interconnected system of things. The “things” can also be called nodes and the interconnections can also be called links. Nodes can be people, chemicals, diseases, ants, computers, train stations, telephones, money, televisions, houses/businesses. Links can be information (digital data, language, commerce, synapses), energy (light, electricity, water, food), travel routes (roads, airways, train tracks), or chemical reactions.

What is a Hub?

One characteristic of complex networks that is of particular interest is a special kind of node called a hub. Hubs are nodes that have many more links than most other nodes in a network. In any given network there are usually only a few nodes that are hubs. Since many other nodes are connected to the hubs, they allow information, power, chemical reactions, etc. to move quickly from one part of the network to another. Thus, hubs are very important parts of many kinds of networks.

Examples of Networks:

The brain (any brain, including that of a nematode)
The World Wide Web
Telephone system
Rail transportation system
Interstate highway system
Electrical grid
The Internet
Epidemics
Gossip
Food webs
The economy
Ant and bee nests
Television
Radio
The living cell (metabolic network, such as that of baker’s yeast)

What we hope to communicate to visitors:

Living things are connected things.
If we look at the world around us in terms of networks, we see things in a different way. Instead of pieces, we see them as systems: interconnected wholes in which everything affects everything else.
Topology is the shape of networks, how they look. The shape of networks both determines how they work and is determined by what they do.
Some networks are simple and controllable and others are self-creating and complex. An example of a simple network could be two people talking. An example of a complex network is the Internet or a living cell. Human-made networks (such as roads, computer networks, air travel routes, power grids) are typically predictable and planned. The Internet is an exception to this. It has reached a level of complexity that causes it to evolve on its own. It behaves like a living network because of its complexity.
Emergence is simple rules acting on many simple entities resulting in complex and unpredictable changes. The growth of the World Wide Web, the behavior of ant colonies and flocks and herds of animals are emergent. A complex network has too many connections to be able to predict or control its evolution (changes over time). Both its evolution and topology are said to be emergent. These are also sometimes referred to as self-organizing systems: systems that change their basic structure as a function of their experience and environment, not under the direction of a leader or outside director.

Some interesting links about emergence and network science:
Albert-László Barabási is one of the important researchers in network science.

Here is a Science Now Nova Web Page on Emergence

We are all familiar with the broadcast media. Newspapers, television and radio are considered one-way networks. Today’s Front Pages: By the Newseum, Washington D.C.

Human migration is also a one-way network. The genome changes through time, mutations, and interbreeding. Follow the network of human migration over time in National Geographic’s Atlas of the Human Journey

More information on Exhibit Experiences

Global Observer

Satellite imaging helps us to understand how Earth systems connect. Patterns of change do not happen in just one place. Changes in one system (such as the atmosphere) are accompanied by changes in other systems (such as the ocean). They are all connected. Global Observer allows you to see how some of Earth’s systems interact and how living things in turn affect the earth processes in a form of feedback. The air and climate for Earth are kept steady and hospitable by the interaction of the air, water, and soil with the living things that inhabit them. This interaction between earth processes and living things works like a super-organism: a complex, living network.

What to see and do: Turn the silver spinner to look at changes occurring through time, use the ball to rotate the globe to see different kinds of changes taking place in different climate zones. How does the biological productivity change with seasons?, rainfall?, temperature? Push the button and a short movie explains how the images are gathered and brought together to show interacting atmosphere and ocean systems through the movement of a hurricane across the Atlantic.
For an interactive map of the earth showing some of the various earth processes go to the Jules Verne Voyager: Interactive Map of Earth Processes

Float

Using the Powers of Two (2, 4, 8, 16, 32, , ,), kinetic sculptor and architect, Tim Prentice created this large mobile-like structure overhanging the exhibition. The movement of its nine hundred translucent panels from air circulating in the exhibition is meant in evoke the rippling patterns we might see in such phenomena as a flock of birds moving through the air. The interactions between the air and the panels are ever changing and too complex to predict. The wire structure that holds the whole thing together acts like the simple rules in an emergent system and links all the panels together.
What to see and do: Observe the effects the oscillating fan has on the squares. Then follow the effect outward to the edges. Even beyond the immediate effects of the fan blowing, the movement of the squares continues outward affected by the motion of each previous square due to the structure that links them all together. See and hear Tim at work in his studio here.

Music Composition Table

Music played by a group of people is a good example of a social network. The different parts played by different people (drums, bass, guitar, keyboard, vocals, and other instruments are the nodes and the music they play together are the links.
What to see and do: Using the cables, connect different musical parts together to see how a music network connects. As you change the connections, the music changes, but you can tell the parts are “hearing” each other because they are all synchronized in tempo. What would happen to a real music performance if the musicians were not connected through listening to each other? Would it still be music?

Spider Web

A web is a special network structure (topology) that creates a complex set of interactions and helps make the web useful. The Internet uses a web structure to make sure that information can get from one part of the network to any other, even if part of the network fails.
A spider web is a visible example of how a web structure works. It helps the spider survive. Similar to the World- Wide Web (WWW), the spider web has the following attributes:

The web extends the reach of the spiders by increasing their ability to sense and capture prey. The WWW extends the reach of people to receive information and communicate with others through Hypertext.
The spider uses its location on the web to receive information about what is going on in other parts of the web. The spokes of the web tell the spider where on the web the creature landed, what kind of creature landed in it, how big it is, even whether it is food or a mate. Spiders have very sensitive hairs on their bodies to sense vibrations that occur when a prey animal lands on the web. Male spiders, on the other hand, will pluck or bounce the web rhythmically to tell the female in the middle that it is a friend, not a meal! The World-Wide Web is structured so the browser (such as Firefox or Explorer) can easily find out what is going on in other parts of the WWW through web-like links among all the different Websites.
A spider web is structured so it is durable and can still catch bugs if part of the web is destroyed. The Internet (which hosts the WWW) is designed so that it can still pass information if parts of it are broken. The information goes around the broken part because it has other links it can use.
The spider web has a hub in the middle with the most connections, and where the most information about what is happening in the rest of the web flows. That is, consequently where the spider sits. The WWW has hubs, such as Google with many connections. It is where a significant amount of the Web traffic flows and where people go to get the most information about what is going on around them on the rest of the WWW.
Finally, there are “spiders” on the WWW. A spider (also called a “robot”) on the WWW is a program that goes out to look for certain kinds of information and collects it for indexing, which is how search engines like Google find information.
For a detailed description of how spider webs are made, please go to Dr. Samuel Zschokke’s Page on spiderwebs.
Here is Ben Fry’s Anemone-based interactive showing how website use grows over time.

Ropes and Pulleys

Topology in a network is determined by what the network does, what kinds of patterns of communications are created, and how they change over time (evolve). Ropes and Pulleys demonstrates network evolution through the movement of nodes and links. The pulleys represent nodes in the network and the rope length between them represents the links.
What to see and do: Turn the wheels and observe how the shape of the network evolves. Sometimes the pulleys will cluster, other times they will spread apart. What do you think clustering and spreading apart does to the nodes trying to communicate with each other on the network? Where else in “Connections” do you see clustering?
The artist Kyle Dries explains Ropes and Pulleys in a short movie.

Another way in which social interactions can be observed is by recording where people go. “You are Here” is a series of cameras that watch the exhibit floor and keep track of your movement (you can see them on the long black catenary cable that supports the building). This gives us a big picture of the shape of the paths of visitors interacting with different exhibits and each other on this floor of the museum. This kind of monitoring is being used to research how people might transmit diseases like influenza in public spaces. One project called SocioPatterns was displayed at the Infectious Exhibition at the Science Gallery in Dublin. Watch the video clip here.
What to see and do: Hold the button down to see what the overhead picture is of the exhibit floor. Spin the ball to see how you and other visitors move through time.
Artist Scott Snibbe recorded a brief movie of the exhibit in action on this Webpage.

Electrical grid

Power is distributed to homes and businesses through a network. This makes it possible to reroute power quickly if a failure occurs. But, it also makes it vulnerable to overloading if there are too many failures at once, or they are in a part of the network that is already overloaded. This results in a cascading failure, in which the overload ripples through the network causing a large part of the system to shut down.
What to see and do: press one of the buttons to simulate a failure in the system. Notice how the power continues to flow through remaining paths. Press both buttons and one overload quickly leads to another turning the lights out all over the system.
Here is a brief article describing how power grids are complex networks and why unexpected things can happen.

Telehaptic Arm Wrestling

We use the Internet for finding information, downloading music, and communicating with friends and family. This has made our community more global. But that is just the beginning. Did you know that you can also send and receive touch. This is called telehaptics. Using telehaptics, you can actually feel what is happening at a distance. Telehaptic surgery has been tested by NASA in its NEEMO7 Project to see how well patients can be treated in extreme environments like during space travel.
What to see and do: Arm wrestle with visitors at NYSCI or other museums through the Internet to get an idea of how telehaptics works.

Also note the colorful image overhead of the Internet shown as a network diagram. These complex network diagrams are sometimes affectionately referred to as “hairballs” by scientists because of their complexity. This one is of the Internet. It was created by Bill Cheswick as part of the Internet Mapping Project.

Near

Near demonstrates the way people interact in a social network. It uses an algorithm (a math calculation) called “nearest neighbor” to calculate the shortest path between two people on the white floor. This sounds like it should be easy to do, but when as the number of nodes (in this case people) grows, and are all moving around on the floor, it becomes very complex very quickly. This method is used to understand and identify clusters in networks and also look for a shortest path through many nodes, such as determining the quickest path to a disaster for an emergency vehicle or figuring out the most efficient route for a sales person to take amongst a group of cities.
The person you interact with the most in a social network could be considered your “nearest neighbor”. In complex social networks, this can change as people move, change jobs, or age. A cluster of people with close ties in a social network is called a clique and typically all have similar knowledge (culture). Artist Scott Snibbe has provided more information at his website.
What to see and do: with a group of other people on the floor, move around toward and away from others and watch for the looping arrows to form and jump amongst the other visitors. What kinds of other patterns of links can you see? What are their shapes (diamonds, loops, boxes, etc.) These shapes form the topology of the network.

Multilayer Maps

How are we all connected in Queens? The multilayer map shows some of the networks to which we are connected, including roads, Telephone, cable, and trains. The shape of each network is its topology. Water is a network too. On EPA’s water distribution modeling research page, see how water moves through network from its source. Also, here’s an interesting map that is an interactive picture mosaic of the world.
What to see and do: press the buttons to turn the different network paths on and off. By brushing your hands over the surface of the map, you can move it to familiar landmarks or neighborhoods. How do the topologies compare for the different networks? How are they different? What other kinds of networks do you think exist in Queens?

Live Ant Colony

Ant colonies are complex networks. Ants are very simple organisms that follow simple rules like following the trail with the strongest odor. They must have the colony to survive, they do not live on their own. Ants accomplish very complex tasks without any direction or guidance, like finding the spot farthest away from the nest to pile garbage, or create a single funeral pile from many smaller ones. Ant Colonies are similar to such complex networks as the Internet because it creates itself (self-organizing) without a master plan, but just every “user” following a simple set of rules. Their behavior also creates the structure of the nest. There is no master plan, yet they allocate special chambers for storing food, for keeping eggs, nursing, and caring for young, and disposing of dead. Notice the ant nest cast in the case to the left. The structure of aluminum cast is an indication of the structure of the interactions of the ants within the nest: its topology. This cast was created for us by Dr. Walter Tschinkel, a myrmecologist (ant scientist) at Florida State University. See other casts he has created at this web site.
What to see and do: watch the ants as they perform the various tasks to maintain the colony (disposal of waste, dead ants, obtaining plant material for building their farm and growing the mold they use for food. Notice that some ants are large and some are small. Do they do different kinds of things? You can use the robotic camera to get a closer look.

Video Spin Browser

Flocks or herds of animals are also networks in which simple individual behaviors lead to large-scale synchronization of action and complex patterns (self-organizing).
What to see and do: use the spin browsers to compare and contrast the way different kinds of animals behave in groups. How are they similar? How are they different? Can you see any behavior that might indicate the simple rule they are all following (such as: they all seem to be following the animal in front of them, or they all seem to be following the behavior of the animal to their right)? This phenomenon was used by Operation Migration to assist in reestablishing whooping crane populations in areas where they were going extinct. Computer models of flocking behavior such as Craig Reynolds’ BOIDS have been used to better understand it, as well as make more realistic animation.

Shell Table
In the development of patterns in natural growth, slight changes in rules can result in dramatic differences in the shape of the organism. The pattern of growth in a seashell is a good example. Another example more “close to home” is the genome for a chimpanzee, which is almost the same as that of a human, yet results in a very different organism as it develops.
What to see and do: look at, and feel the seashells to see how dramatic a difference in the resulting shape is created by a simple change in the way the shell grows. Although snails and clams look and function very differently, it only takes a small change in the way the shell is made to end up with one or the other. You can do a computer model of the shell growth from a computer program developed by Stephen Wolfram.

Game of Life

Cellular automata (SEL-yew-ler aw-TOM-uh-tuh) models complex emergent behavior in a computer. All of the “cells” (yellow dots), interact (are connected) through simple rules. The result is complex patterns and behaviors that can change dramatically as the system evolves. A simple change can cause the whole system to die out, stagnate, or bloom in complex patterns, all from small changes in initial conditions. For more information and an online version of the interactive, go to the John Conway Game of Life Web page.
What to see and do: change the starting pattern on the screen and see what happens when you run the program. How do the patterns change in the traffic sign dots? Can you follow the evolution of a “population” of “cells” as they follow their simple rules?

Braided Streams

Rivers are one-way networks. Like branching trees or blood vessels in animals and plants, they flow in only one direction at a time. Their topology is distinctive: smaller rivulets lead to bigger branches which lead to even bigger main watercourses. The shapes of such networks all look very similar, but are constantly changing. Even though a river might be considered a geologic phenomenon, living things must follow the same kinds of patterns in order to get nutrients to all cells and carry away wastes. Watch a video clip of Braided Streams (this one an earlier version in the Exploratorium) in action.
What to see and do: look at the patterns this simulation of a riverbed creates. Then turn the knob to change the speed and direction of the air flowing through the system. Do you see the network branches collapse and reform?