1. Physics 155 Physics Behind the Internet

2. Why Study This? Teach Physics in a Context Its important for citizens to know how stuff works A technological society can not afford to be ignorant and believe in magic Communications/information has large scale societal consequences

3. Themes of This Course  Communication, Information, Communication Networks and Bandwidth  What are the rules of information?  How does information propagate?  How do you ensure the integrity of information?  How is information encoded?

4. Device Physics How does electricity work? How does electricity work? How do you make a circuit? How do you make a circuit? What’s a transistor? What’s a transistor? What’s a semi-conductor? What’s a semi-conductor? How does a computer work? How does a computer work? How does my digital camera work? How does my digital camera work? How does my cell phone work? How does my cell phone work?

5. Photons versus Electrons Why are lasers an essential part of communications networks Why are lasers an essential part of communications networks Why does my DVD player have a laser? Why does my DVD player have a laser? Why is photon encoded information so much better than electron encoded information? Why is photon encoded information so much better than electron encoded information? Why should I invest money in Photonic Devices? Why should I invest money in Photonic Devices?

6. Internet Routing and Chaos How do networks work?How do networks work? How does routing work?How does routing work? What’s a packet?What’s a packet? What’s packet loss, latency, collision?What’s packet loss, latency, collision? How can the internet even function as it grows exponentially – won’t we run out of addresses?How can the internet even function as it grows exponentially – won’t we run out of addresses?

7. Social Issues Is the Internet a net good to society or a net evil? Does it encourage social isolation? Does it improve or degrade personal communication skills? Who should control the Net? What’s the end game evolution of the Net? Do we want that?

8. Overall This course is not so much a physics course (although you will be exposed to more physics than you realize) – rather it’s a course about science, technology and society. Assignments will be done as mini-research projects by teams of students. Learning how to collaborate is essential.