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CS4HS at Marquette University. Internet and Impact. Internet. What is the Internet?. The network of hardware and software systems that connects many of the world’s computers Typically, people say the Internet and capitalize the “I” because there is only one Until we meet aliens - PowerPoint PPT Presentation
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Internet and ImpactCS4HS at Marquette University
Internet
What is the Internet? The network of hardware and software systems that
connects many of the world’s computers Typically, people say the Internet and capitalize the “I”
because there is only one Until we meet aliens Or decide to break off from the rest of the world
The World Wide Web is the part of the Internet that is concerned with webpages
The Internet also includes: FTP VOIP Bittorrent Multiplayer video games Much, much more…
Packet switched
The Internet is a packet switched system
Individual pieces of data (called packets) are sent on the network Each packet knows where it is going A collection of packets going from point
A to point B might not all travel the same route
C
BA
D
12
Circuit switched
Traditionally, phone lines have been circuit switched
A specific circuit is set up for a specific communication
Operators used to do this by hand Now it is done automatically Only one path for data
C BA1
Circuit vs. packet switching Which one is faster?
Circuit switching Which one is more
predictable? Circuit switching
So, why is the Internet packet switched? More adaptable
Birth of the Internet The Advanced Research
Projects Agency was created in 1958 to respond to the Russians launching Sputnik
The ARPANET connected its first two major nodes over 10 years later
Packet switching was used so that the network could still communicate after a nuclear strike
What the Internet isn't
A big truck A series of tubes Invented by Al Gore
He never claimed it was But he did create the
High Performance Computing Act of 1991 which funded many efforts that brought the Internet to the masses faster
IP addresses
Computers on the Internet have addresses, not names
Google.com is actually [74.125.67.100]
Google.com is called a domain The Domain Name System or DNS
turns the name into an address
IPv4
Old-style IP addresses are in this form: 74.125.67.100
4 numbers between 0 and 255, separated by dots
That’s a total of 2564 = 4,294,967,296 addresses
But there are 7 billion people on earth…
IPv6 IPv6 are the new IP addresses that are
beginning to be used by modern hardware 8 groups of 4 hexadecimal digits each 2001:0db8:85a3:0000:0000:8a2e:0370:7334 1 hexadecimal digit has 16 possibilities How many different addresses is this? 1632 = 2128 ≈ 3.4×1038 is enough to have 500
trillion addresses for every cell of every person’s body on Earth
Will it be enough?!
Other failures in design
Y2K bug 2 bytes for the date is not enough It’s all just going to get messed up in
Y10K Y2038 bug
Unix and Linux machines often use a signed 32-bit integer to represent seconds since January 1, 1970
Zip codes Vehicle identification numbers
Activity
Write down the most important aspect of your day-to-day life that had not been invented 20 years ago
Be specific! Answers like "the Internet" are too vague
My Trip to NYC
Trip to NYC
It's impossible to make a meaningful list of all the CS innovations that have impact now
Let's go on a journey to New York City that I just took with my parents
On the way, I'll try to note all the CS impacts that we come across
Air travel My parents wanted to come visit me in
Philadelphia for my birthday They live in Indiana They searched on Orbitz.com for the best
flight and then booked it through USAirways.com
How did anyone do this before the Internet? According to a 2011 Forbes article, the travel
agent business has shrunk by 14% (12,500 jobs) in the last 5 years
Bus travel From Philadelphia, we took
Megabus to NYC Booked tickets online Printed them out Waved incomprehensible
printouts at the bus driver $14 round trip per person It is possible to book tickets
on the phone, but almost all their business is online
They don't have offices or even proper bus stops But their buses have free
wireless!
Where did we stay?
We wanted to stay in Brooklyn We used AirBnB.com
People rent out their homes to travelers It's cheaper than a hotel You get full kitchen facilities
We paid $135 a night for three people
It's a level up from CouchSurfing.org
What did we eat? My parents are vegan Finding vegan food is hard
Even in NYC I used Yelp.com to find highly
rated vegan and vegetarian restaurants within walking distance
Sometimes we used AllMenus.com to make sure a non-vegetarian place had options
How did we get around?
We didn't take a single cab We walked everywhere and took the
subway I navigated with the GPS in my
iPhone 3GS We didn't make any wrong turns
Who made this possible?
Web developers at Orbitz.com, USAirways.com, Yelp.com, AirBnB.com, and AllMenus.com
Software developers at Google and Apple
Hardware developers at Apple (and the countless firms they contract with)
Network architects and technicians at AT&T
US government who putting GPS satellites in space
Other Changes
Office productivity software In 1971 a third of all working women in
the US were secretaries Now most people type their own e-mail
and printed correspondence A recent Huffington Post article
suggests that spell checking software is ruining our spelling
Few complain about spreadsheets because it's so hard to do the same work by hand
PowerPoint has made us a nation of boring presenters
Digital divide A recent NY Times article says that
the digital divide has changed Children whose parents do not have
a college degree spend 11.5 hours a day consuming media A 4:40 increase since 1999!
Children with more educated parents spend 10 hours a day consuming media
Although computer use has increased in underprivileged segments of the population, the increase has almost all been entertainment, not education
Wikipedia A 2005 Nature article suggested that Wikipedia
is more accurate than Encyclopedia Britannica But student research suffers as they no longer
learn how to track down obscure references Wikipedia has taken criticism for bias in
coverage and tone Male gender bias US cultural bias Liberal political bias
Its open model allows for anyone to vandalize Staff generally reacts quickly to errors and
defacement
Arab Spring Starting in December 2010, a
movement in the Middle East has ousted rulers of Egypt, Libya, Tunisia, and Yemen
There have been massive protests throughout the region, and tensions are still high in Syria
WikiLeaks exposed corruption and human rights abuses
The Arab Social Media Report by the Dubai School of Government confirms that many activities were organized through Facebook and Twitter
Texting
In 2009, one study showed that 286 million Americans (the vast majority of the population) sent 152.7 billion texts per month, averaging 534 each
In 2007, 700 billion texts were sent in China Half of them were spam The government monitors texts in China
Europe texts heavily as well Most plans have unlimited free texting
Finland is famous for its less-interactive society Finns have a stronger bias to talking on the
phone and texting over real-life interactions Interactive TV shows where you text to play
are popular The Prime Minister of Finland allegedly broke
up with his girlfriend over text in 2006
Impacts of texting Texting allows unprecedented
levels of communication A 2009 study showed that young
adults who used “textisms” (lol, brb) in daily writing were worse formal writers But better informal ones!
Texting reduces focus on life around us A 2008 head on train collision that
killed 25 people was likely due to an engineer texting
A 2009 VA Tech study suggests that texting while driving can increase chances of a crash by a factor of 23
Facebook Facebook is 8 and a half years old 900 million users, almost 13% of the world’s
population 50% of users log on every day The average user has 130 friends
Even with a disappointing IPO, its market capitalization is $61.5 billion
It has become a central part of how many people communicate in the developed world
What are its pros and cons?
Privacy Facebook can drastically reduce privacy
A study from CareerBuilder.com suggests that 37% of hiring managers search social media
Credit card numbers Are stolen over the Internet (though
cryptography has helped a lot) 45.6 million credit card numbers were stolen
from TJ Maxx Can be stolen using RFID readers without any
interaction from you Identity theft is on the rise
At least 641,052 taxpayers were affected by identity theft in 2011, more than twice 2010