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5 Familiar Numbers and the Logic Behind Them

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Given how digital the world has become, we are hardly bothered by having to deal with one string of numbers after the next: credit card numbers, social security numbers, IP addresses and so on. Do these numbers hold any meaning, or are they just random sequences in a database? Read on to find out.

1. Credit Card Numbers

The string of digits that make up credit card numbers have a distinct, if subtle, structure.  The first digit signifies which system it belongs to: 3 is for travel and entertainment cards like American Express, 4 is Visa, 5 is Mastercard, and 6 is Discover.  The rest of the credit card number is used differently by each company -- for Visa cards, digits 2 through 6 are a bank number, 7-12 or 7-15 are the account number, and either 13 or 16 is a check digit, a number that is the result of a  series of simple but generally secret computations with the other digits that helps verify the full number isn't fake.  In an AmEx card, digits three and four indicate the type of card and currency, 5-11 are the account number, 12-14 are the card number within the account and 15 is a check digit (AmEx card numbers are 15 instead of 16 digits).

2. Zip Codes

zipcode1Zip codes were invented by Robert Aurand Moon and by 1963 were widely used by the United States Postal Service. The five-digit number is a code for an exact location, with each successive digit indicating a more specific place. The first digit indicates a group of states; for example, a 1 directs mail to Delaware, New York, and Pennsylvania. The next two indicate a sectional center facility -- a zip code beginning with 108 directs mail to the facility New Rochelle, NY. The last two digits represent a village or town near the facility or a location within a metropolitan area. Typically in a non-metropolitan area a city gets the first area code, and surrounding villages and towns receive zip codes in alphabetical order (for example, Glenmont, NY has 12077 and Gloversville, NY has 12078). And in case you were wondering, ZIP is an acronym that stands for Zone Improvement Plan. 

3. Telephone Numbers

rotaryEveryone's a little more familiar with telephone numbers -- there's country code, necessary if dialing internationally (1 is the United States), and area codes, which indicate a broad geographic area. The next three digits indicate a smaller area, and the last four are a random permutation.  The area code and first three digits of a phone number are referred to in the telephone business as NPA-NXX.  These numbers convey a unit of purchase for telephone companies, as they will generally buy one NPA-NXX, or one combination. The ownership reveals why cell providers are often so tetchy about carrying a number from one to another, or vice versa: you would be stealing a phone number from one company and giving it to another.

4. IP Addresses

tcpip_ip_addressIP addresses, at their most basic level, identify individual computers to the Internet. They are a series of four numbers punctuated by periods that look something like 255.143.68.1. Each of these numbers (such as 255 in the example) is referred to as an octet. Each octet can have a value between 0 and 255 (so if you see an IP address with any octet higher than 255, it's fake). Together the octets of an IP address contain information about the type of network and, to an extent, the location of a computer. The first octet, called the class, tells you the size of a network a computer is in. A Class A network has a first octet between 0 and 127 and can have over 16 million IP addresses; a Class B network has a first octet between 128 and 191 and have about 65,000 addresses; a Class C network, used for most homes, has a first octet of 192-223 and can have 254 addresses. There are also Class D and E networks with first octets of 224-255 that are used for more specialized purposes. Most IP trackers use a location database to determine where an IP address is coming from, so there is not a direct scheme for the other octets. However, due to the modern use of subnetworks within a network, IP addresses are often masked. Therefore, it is no longer directly possible to tell the type of network a computer hails from.

5. Social Security Numbers

sscardSocial Security numbers are nine-digit strings that most Americans are assigned at birth, and are generally used as an identifier as well as a qualifier for various kinds of insurance and income from the government.  The first three numbers tell where the person first applied for the card; if the card was applied for at birth and the mailing address used was also the residential address, the numbers tell the rough location of birth (doesn't apply to babies born during vacation in Panama, but in general this is true).  The next two digits are called the group number, and allow SSNs of the same area number to be broken into smaller groups.  They are assigned in the following order: odd numbers 01-09, evens 10-98, evens 02-08, odds 11-99.  The last four digits, the serial numbers, are assigned consecutively 0001-9999.

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10 Classic Books That Have Been Banned
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From The Bible to Harry Potter, some of the world's most popular books have been challenged for reasons ranging from violence to occult overtones. In honor of Banned Books Week, which runs from September 24 through September 30, 2017, here's a look at 10 classic book that have stirred up controversy.

1. THE CALL OF THE WILD

Jack London's 1903 Klondike Gold Rush-set adventure was banned in Yugoslavia and Italy for being "too radical" and was burned by the Nazis because of the author's well-known socialist leanings.

2. THE GRAPES OF WRATH

Though John Steinbeck's 1939 novel, about a family of tenant farmers who are forced to leave their Oklahoma for California home because of economic hardships, earned the author both the National Book Award and a Pulitzer Prize, it also drew ire across America become some believed it promoted Communist values. Kern County, California—where much of the book took place—was particular incensed by Steinbeck's portrayal of the area and its working conditions, which they considered slanderous.

3. THE LORAX

The cover of Dr. Seuss' The Lorax
Google Play

Whereas some readers look at Dr. Seuss's Lorax and see a fuzzy little character who "speaks for the trees," others saw the 1971 children's book as a danger piece of political commentary, with even the author reportedly referring to it as "propaganda."

4. ULYSSES

James Joyce's 1922 novel Ulysses may be one of the most important and influential works of the early 20th century, but it was also deemed obscene for both its language and sexual content—and not just in a few provincial places. In 1921, a group known as The New York Society for the Suppression of Vice successfully managed to keep the book out of the United States, and United States Post Office regularly burned copies of it. But in 1933, the book's publisher, Random House, took the case—United States v. One Book Called Ulysses—to court and ended up getting the ban overturned.

5. ALL QUIET ON THE WESTERN FRONT

In 1929, Erich Maria Remarque—a German World War I veteran—wrote the novel All Quiet on the Western Front, which gives an accounting of the extreme mental and physical stress the German soldiers faced during their time in the war. Perhaps unsurprisingly, the book's realism didn't sit well with Nazi leaders, who feared the book would deter their propaganda efforts.

6. ANIMAL FARM

The cover of George Orwell's Animal Farm
Public Domain, Wikimedia Commons

The original publication of George Orwell's 1945 allegorical novella was delayed in the U.K. because of its anti-Stalin themes. It was confiscated in Germany by Allied troops, banned in Yugoslavia in 1946, banned in Kenya in 1991, and banned in the United Arab Emirates in 2002.

7. AS I LAY DYING

Though many people consider William Faulkner's 1930 novel As I Lay Dying a classic piece of American literature, the Graves County School District in Mayfield, Kentucky disagreed. In 1986, the school district banned the book because it questioned the existence of God.

8. LOLITA

Sure, it's well known that Vladimir Nabokov's Lolita is about a middle-aged literature professor who is obsessed with a 12-year-old girl who eventually becomes her stepdaughter. It's the kind of storyline that would raise eyebrows today, so imagine what the response was when the book was released in 1955. A number of countries—including France, England, Argentina, New Zealand, and South Africa—banned the book for being obscene. Canada did the same in 1958, though it later lifted the ban on what is now considered a classic piece of literature—unreliable narrator and all.

9. THE CATCHER IN THE RYE

Cover of The Catcher in the Rye

Reading J.D. Salinger's The Catcher in the Rye is practically a rite of passage for teenagers in recent years, but back when it was published in 1951, it wasn't always easy for a kid to get his or her hands on it. According to TIME, "Within two weeks of its 1951 release, J.D. Salinger’s novel rocketed to No. 1 on the New York Times best-seller list. Ever since, the book—which explores three days in the life of a troubled 16-year-old boy—has been a 'favorite of censors since its publication,' according to the American Library Association."

10. THE GIVER

The newest book on this list, Lois Lowry's 1993 novel The Giverabout a dystopia masquerading as a utopiawas banned in several U.S. states, including California and Kentucky, for addressing issues such as euthanasia.

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Data Viz Project, Ferdio // CC BY-NC-ND 4.0
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Design
From Donut Charts to Bubble Maps, This Site Will Help You Choose the Best Way to Visualize Your Data
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Data Viz Project, Ferdio // CC BY-NC-ND 4.0

For many researchers, gathering data is the fun part of their job. But figuring out how to convey those numbers in a clear and visually appealing way is where they lose confidence. The Data Viz Project streamlines this step: With more than 150 types of data visualizations organized by different categories, finding the perfect format for your information is quick and painless.

According to Co.Design, the compendium comes from the Copenhagen-based infographics agency Ferdio and it took four years to develop. It started as a collection of physical graphs and charts posted on the walls of their office before moving online for all employees to use. Now, they’re making the project accessible to the public.

The website includes all the basic visualizations, like the line graph, the pie chart, and the Venn diagram. But it also makes room for the obscure: The chord diagram, the violin plot, and the convex treemap are a few of the more distinctive entries.

At first, the number of options can seem overwhelming, but narrowing them down is simple. If you’re looking for a specific type of visualization, like a chart, diagram, or table, you can select your category from the list labeled "family." From there you can limit your results even further by selecting the type of data you're inputting, the intended function (geographical data, trend over time), and the way you want it to look (bars, pyramids, pictographs).

Each image comes with its own description and examples of how it can be used in the real world. Check out some examples below to expand your own data visualization knowledge.

Alluvial Diagram
Alluvial Diagram

Arc Diagram
Arc Diagram

Hive Plot
Hive Plot

Hexagonal Binning
Hexagonal Binning

Violin Plot
Violin Plot

Packed Circle Chart
Packed Circle Chart

Kagi Chart
Kagi Chart

Sorted Stream Graph
Sorted Stream Graph

[h/t Co.Design]

All images courtesy of Ferdio // CC BY-NC-ND 4.0

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