Transcript 155

Physics 155
Physics Behind the Internet
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
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?
Device Physics
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How does electricity work?
How do you make a circuit?
What’s a transistor?
What’s a semi-conductor?
How does a computer work?
How does my digital camera work?
How does my cell phone work?
Photons versus Electrons
Why are lasers an essential part of
communications networks
 Why does my DVD player have a laser?
 Why is photon encoded information so
much better than electron encoded
information?
 Why should I invest money in Photonic
Devices?
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Internet Routing and Chaos
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How do networks work?
How does routing work?
What’s a packet?
What’s packet loss, latency, collision?
How can the internet even function as it grows
exponentially – won’t we run out of addresses?
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?
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.