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2

Definition: 2

2

Adjective

1. Being one more than one; "he received two messages".

Noun

1. The cardinal number that is the sum of one and one or a numeral representing this number.

Source: WordNet 1.7.1 Copyright © 2001 by Princeton University. All rights reserved.
 

 

Specialty Definition: 2

DomainDefinition

Computing

2 infix. In translation software written by hackers, infix 2 often represents the syllable _to_ with the connotation `translate to': as in dvi2ps (DVI to PostScript), int2string (integer to string), and texi2roff (Texinfo to [nt]roff). Several versions of a joke have floated around the internet in which some idiot programmer fixes the Y2K bug by changing all the Y's in something to K's, as in Januark, Februark, etc. Source: Jargon File.

Chemistry

Yellow crystals, melting at l42oC: used as a pesticide and herbicide. Source: European Union. (references)

Source: compiled by the editor from various references; see credits.

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Specialty Definition: 1 E6 m²

(From Wikipedia, the free Encyclopedia)

To help compare sizes of different geographic regions, we list here areas between 1 km² (100 hectares) and 10 km² (1000 hectares). See also areas of other orders of magnitude.

See also: Orders of magnitude

External link

Source: adapted by the editor from Wikipedia, the free encyclopedia under a copyleft GNU Free Documentation License (GFDL) from the article "1 E6 m²."

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1882

(From Wikipedia, the free Encyclopedia)

Centuries: 18th century - 19th century - 20th century

Decades: 1830s 1840s 1850s 1860s 1870s - 1880s - 1890s 1900s 1910s 1920s 1930s

Years: 1877 1878 1879 1880 1881 - 1882 - 1883 1884 1885 1886 1887

Events

Arts, Sciences, Literature and Philosophy

Births

Deaths

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1962

(From Wikipedia, the free Encyclopedia)

Centuries: 19th century - 20th century - 21st century

Decades: 1900s 1910s 1920s 1930s 1940s 1950s - 1960s - 1970s 1980s 1990s 2000s

Years: 1957 1958 1959 1960 1961 - 1962 - 1963 1964 1965 1966 1967

See also:

Events

Year in topic

Births

Deaths

Nobel Prizes

Heads of state in 1962

Source: adapted by the editor from Wikipedia, the free encyclopedia under a copyleft GNU Free Documentation License (GFDL) from the article "1962."

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2

(From Wikipedia, the free Encyclopedia)

Centuries: 1st century BC - 1st century - 2nd century

Decades: 40s BC 30s BC 20s BC 10s BC 0s BC - 0s - 10s 20s 30s 40s 50s

4 BC 3 BC 2 BC 1 BC 1 - 2 - 3 4 5 6 7 Events

Births Deaths For the number 2, see two.

Source: adapted by the editor from Wikipedia, the free encyclopedia under a copyleft GNU Free Documentation License (GFDL) from the article "2."

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2 BC

(From Wikipedia, the free Encyclopedia)

Centuries: 2nd century BC - 1st century BC - 1st century

Decades: 50s BC 40s BC 30s BC 20s BC 10s BC - 0s BC - 0s 10s 20s 30s 40s

7 BC 6 BC 5 BC 4 BC 3 BC 2 BC 1 BC 1 2 3 4 Events

Births Deaths

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2002

(From Wikipedia, the free Encyclopedia)

Centuries: 19th century - 20th century - 21st century - 22nd century

Decades: 1950s 1960s 1970s 1980s 1990s - 2000s - 2010s 2020s 2030s 2040s 2050s

Years: 1997 1998 1999 2000 2001 - 2002 - 2003 2004 2005 2006 2007

Months: January - February - March - April - May - June - July - August - September - October - November - December

This is a common year starting on Tuesday (see link for calendar). 2002 was the first palindromic year since 1991 and the last until 2112.

See also:

Events

Years in topic

Births

Deaths

Nobel Prizes

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2ème arrondissement, Paris

(From Wikipedia, the free Encyclopedia)

The 2ème arrondissement is one of the 20 arrondissements of Paris, France. It is located on the Right Bank.

Source: adapted by the editor from Wikipedia, the free encyclopedia under a copyleft GNU Free Documentation License (GFDL) from the article "2ème arrondissement, Paris."

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Alkaline earth metal

(From Wikipedia, the free Encyclopedia)

The alkaline earth metals (earth metal comes from alchemy, which was used to describe metals that resisted fire -- the oxides of the alkaline earth metals are not affected by fire) are a chemical series.

They are the elements in Group 2 of the Periodic Table: Beryllium, Magnesium, Calcium, Strontium, Barium and Radium (not always considered due to its very short half-life).

The alkaline earth metals are silvery colored, soft, low density metals, which react readily with halogens to form ionic salts, and with water, though not as rapidly as the alkali metals, to form strongly alkaline (basic) hydroxides. For example, where sodium and potassium react with water at room temperature, magnesium reacts only with steam and calcium with hot water. These elements all have two electrons in their outermost shell, so the energetically preferred state of achieving a filled electron shell is to lose two electrons to form a doubly charged positive ion.

Source: adapted by the editor from Wikipedia, the free encyclopedia under a copyleft GNU Free Documentation License (GFDL) from the article "Alkaline earth metal."

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April 2

(From Wikipedia, the free Encyclopedia)

April 2 is the 92th day of the year (93th in leap years) in the Gregorian calendar, with 273 days remaining.

Events

Births

Deaths

Holidays and observances

See Also:

April 1 - April 3 - March 2 - May 2 -- listing of all days

January, February, March, April, May, June, July, August, September, October, November, December

Source: adapted by the editor from Wikipedia, the free encyclopedia under a copyleft GNU Free Documentation License (GFDL) from the article "April 2."

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August 2

(From Wikipedia, the free Encyclopedia)

August 2 is the 214th day of the year in the Gregorian Calendar (215th in leap years), with 151 days remaining.

Events

Births

Deaths

Holidays and observances

See Also:

August 1 - August 3 - July 2 - September 2 -- listing of all days

January, February, March, April, May, June, July, August, September, October, November, December

Source: adapted by the editor from Wikipedia, the free encyclopedia under a copyleft GNU Free Documentation License (GFDL) from the article "August 2."

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Binary numeral system

(From Wikipedia, the free Encyclopedia)

The binary or base-two numeral system is a system for representing numbers in which a radix of two is used; that is, each digit in a binary numeral may have either of two different values. Typically, the symbols 0 and 1 are used to represent binary numbers. In contrast, the commonly-used decimal numeral system has a radix of ten, and uses the symbols 0 through 9.

In the binary system, all numbers larger than one require more digits to write than they would in the decimal system. The number two is written "10" in binary; the number six requires three digits in binary, "110", and the number 999 (nine-hundred ninety-nine) requires ten digits in binary, "1111100111". This extra length makes binary somewhat cumbersome for humans, but the binary system is used internally by virtually all modern computers, owing to its relatively straightforward implementation in electronic circuitry.

History

The first known description of a binary numeral system was made by Pingala in his Chhandah-shastra, placed variously in the 5th century BC or the 2nd century BC. Pingala described the binary numeral system in connection with the listing of Vedic meters with short or long syllables. According to one Indian tradition, Pingala was the younger brother of the great grammarian Panini. The modern binary number system was first documented by Gottfried Leibniz. Pingala's system begins with the value one, while Leibniz' begins with zero; the modern binary numeral system begins with zero.

Representation

A binary number can be represented by any sequence of bits (binary digits), which in turn may be represented by any mechanism capable of being in two mutually exclusive states. The following sequences of symbols could all be interpreted as binary numbers representing different values:

11010011
on off off on off on
- | - | | - | - - | - |
o x o o x o o x
N Y N N Y N Y Y Y
The numeric value represented in each case is dependent upon the value assigned to each symbol. In a computer, the numeric values may be represented by two different voltages; on a magnetic disk, magnetic polarities may be used. A "positive", "yes", or "on" state is not necessarily equivalent to the numerical value of one; it depends on the architecture in use.

In keeping with customary representation of numerals using arabic numerals, binary numbers are commonly written using the symbols 0 and 1. When written, binary numerals are often subscripted or suffixed in order to indicate their base, or radix. The following notations are equivalent:

100101 binary (explicit statement of format)
100101b (a suffix indicating binary format)
1001012 (a subscript indicating base-2 notation)

When spoken, binary numerals are usually pronounced by pronouncing each individual digit, in order to distinguish them from decimal numbers. For example, the binary numeral "100" is pronounced "one zero zero", rather than "one hundred", in order to make explicit the fact that a binary numeral is being discussed, as well as for purposes of correctness. Since the binary numeral "100" is equal to the decimal value four, it would be confusing, and numerically incorrect, to refer to the numeral as "one hundred."

Counting in Binary

Counting in binary is similar to counting in any other number system. Beginning with a single digit, counting proceeds through each symbol, in increasing order. Decimal counting uses the symbols 0 through 9, while binary only uses the symbols 0 and 1.

When the symbols for the first digit are exhausted, the next-higher digit (to the left) is incremented, and counting starts over at 0. In decimal, counting proceeds like so:

00, 01, 02, ... 07, 08, 09 (rightmost digit starts over, and the 0 is incremented)
10, 11, 12, ... 17, 18, 19 (rightmost digit starts over, and the 1 is incremented)
20, 21, 22, ...

When the rightmost digit reaches 9, counting returns to 0, and the second digit is incremented. In binary, counting is similar, with the exception that only the two symbols 0 and 1 are used. When 1 is reached, counting begins at 0 again, with the digit to the left being incremented:

000, 001 (rightmost digit starts over, and the second 0 is incremented)
010, 011 (middle and rightmost digits start over, and the first 0 is incremented)
100, 101 (rightmost digit starts over again, middle 0 is incremented)
110, 111...

Binary Arithmetic

Arithmetic in binary is much like arithmetic in other numeral systems. Addition, subtraction, multiplication, and division can be performed on binary numerals. The simplest arithmetic operation in binary is addition. Adding two single-digit binary numbers is relatively simple:

0 + 0 = 0
0 + 1 = 1
1 + 0 = 1
1 + 1 = 10 (the 1 is carried)

Adding two "1" values produces the value "10", equivalent to the decimal value 2. This is similar to what happens in decimal when certain single-digit numbers are added together; if the result exceeds the value of the radix (10), the digit to the left is incremented:

5 + 5 = 10
7 + 9 = 16

This is known as carrying in most numeral systems. When the result of an addition exceeds the value of the radix, we "carry the one" to the left and add the next place value. Carrying works the same way in binary:

    1 1 1 1     (carry)
    0 1 1 0 1
+   1 0 1 1 1
-------------
= 1 0 0 1 0 0
Starting in the rightmost column, 1 + 1 = 10. The 1 is carried to the left, and the 0 is written at the bottom of the rightmost column. The second column from the right is added: 1 + 0 + 1 = 10 again; the 1 is carried, and 0 is written at the bottom. The third column: 1 + 1 + 1 = 11. This time, a 1 is carried, and a 1 is written in the bottom row. Proceeding like this gives the final answer 100100.

Subtraction works in much the same way:

0 - 0 = 0
0 - 1 = 1 (with borrow)
1 - 0 = 1
1 - 1 = 0

In the binary system, however, it is customary to use the two's complement notation for performing subtraction. Briefly stated, this notation represents a negative number, which can then be added to the first number to achieve the operation of subtraction.

Binary multiplication and division are also similar to their decimal counterparts, and in some respects are considerably simpler to perform by hand. For additional information, see Binary arithmetic.

Bitwise Logical Operations

Though not directly related to the numerical interpretation of binary symbols, sequences of bits may be manipulated using Boolean logical operators. When a string of binary symbols are manipulated in this way, it is called a bitwise operation; the logical operators AND, OR, and XOR may be performed on corresponding bits in two binary numerals provided as input. The logical NOT operation may be performed on individual bits in a single binary numeral provided as input. Sometimes, such operations may be used as arithmetic short-cuts, and may have other computational benefits as well. See Bitwise operation.

Binary Compared to Decimal

Written binary numbers often use the symbols 0 and 1. By way of comparison, the decimal numeral system uses the symbols 0 through 9. In either numeral system, digits in successively lower, or less significant, positions represent successively smaller powers of the radix. The starting exponent is one less than the number of digits in the number. For a three-digit number, we would start with an exponent of two. In the decimal system, the radix is 10, so the left-most digit of a three-digit number represents the 102 (hundreds) position. Consider:

352 decimal is equal to:
3 times 102 (3 × 100 = 300) plus
5 times 101 (5 × 10 = 50) plus
2 times 100 (2 × 1 = 2)

In binary, the same relationship exists. Successively lower digits represent successively lower powers of the radix 2, beginning with an exponent of n - 1, where n is the number of digits in the number. Consider a 5-digit binary number:

10110 binary is equal to
1 times 24 (1 × 16 = 16) plus
0 times 23 (0 × 8 = 0) plus
1 times 22 (1 × 4 = 4) plus
1 times 21 (1 × 2 = 2) plus
0 times 20 (0 × 1 = 0)

For a total of 2 + 4 + 16 = 22 in decimal. The left-most digit of this five-digit binary number represents the 24 position, or sixteens. The above procedure is one way to convert from binary into decimal.

The procedure for converting from decimal into binary is somewhat different. To convert from an integer decimal numeral to its binary equivalent, divide the number by two and place the remainder in the ones-place. Divide the result by two and place the remainder in the next place to the left. Continue until the result is zero.

An example:

OperationRemainder
118/2 = 590
59/2 = 291
29/2 = 141
14/2 = 70
7/2 = 31
3/2 = 11
1/2 = 01

Reading the sequence of remainders from the bottom up gives the binary numeral 1110110.

Binary Compared to Hexadecimal

Binary may be converted to and from hexadecimal somewhat more easily. This is due to the fact that the radix of the hexadecimal system (16) is a power of the radix of the binary system (2). More specifically, 16 = 24, so it takes exactly 4 digits of binary to represent one digit of hexadecimal.

The following table shows each 4-digit binary sequence along with the equivalent hexadecimal digit:

BinaryHexadecimal
00000
00011
00102
00113
01004
01015
01106
01117
10008
10019
1010A
1011B
1100C
1101D
1110E
1111F

To convert a hexadecimal number into its binary equivalent, simply substitute the corresponding binary digits:

3A hexadecimal = 0011 1010 binary
E7 hexadecimal = 1110 0111 binary

To convert a binary number into its hexadecimal equivalent, divide it into groups of four bits. If the number of bits isn't a multiple of four, simply insert extra 0 bits at the left (called padding). For example:

1010010 binary = 0101 0010 grouped with padding = 52 hexadecimal
11011101 binary = 1101 1101 grouped = DD hexadecimal

Binary Compared to Octal

Binary is also easily converted to the octal numeral system, since octal uses a radix of 8, which is a power of two (namely, 23, so it takes exactly three binary digits to represent an octal digit). The correspondence between octal and binary numerals is the same as for the first eight digits of hexadecimal in the table above. Binary 000 is equivalent to the octal digit 0, binary 111 is equivalent to octal 7, and so on. Converting from octal to decimal proceeds in the same fashion as it does for hexadecimal:

65 octal = 110 101 binary
17 octal = 001 111 binary

And from binary to octal:

110100 binary = 101 100 grouped = 54 octal
10011 binary = 010 011 grouped with padding = 23 octal

Representing Real Numbers

Non-integers can be represented by using negative powers, which are set off from the other digits by means of a radix point (called a decimal point in the decimal system). For example, the binary number 11.012 thus means:

1 times 21 (1 × 2 = 2) plus
1 times 20 (1 × 1 = 1) plus
0 times 2-1 (0 × (1/2) = 0) plus
1 times 2-2 (1 × (1/4) = 0.25)

For a total of 3.25 decimal.

All Dyadic rational numberss p/2a have a terminating binary numeral -- the binary representation has only finitely many terms after the radix point. Other rational numbers have binary representation, but instead of terminating, they recur, with a finite sequence of digits repeating indefinitely. For instance

1/310 = 1/112 = 0.0101010101...2
1210/1710 = 11002 / 100012 = 0.10110100 10110100 10110100...2
The phenomenon that the binary representation of any rational is either terminating or recurring also occurs in other radix-based numeral systems. See, for instance, the explanation in Decimal. Another similarity is the existence of alternative representations for any terminating representation, relying on the fact that 0.111111... is the sum of the geometric series 2-1 + 2-2 + 2-3 + ... which is 1.

Binary numerals which neither terminate nor recur represent Irrational numbers. For instance,

See also

Register, Unary numeral system, Ternary, Octal, Decimal, Hexadecimal, Floating point, p-adic numbers, truncated binary encoding.

External links

Source: adapted by the editor from Wikipedia, the free encyclopedia under a copyleft GNU Free Documentation License (GFDL) from the article "Binary numeral system."

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December 2

(From Wikipedia, the free Encyclopedia)

December 2 is the 336th day (337th on leap years) of the year in the Gregorian calendar. There are 29 days remaining.

Events

Births

Deaths

Holidays and observances

See also

December 1 - December 3 - November 2 - January 2 -- listing of all days

January, February, March, April, May, June, July, August, September, October, November, December

Source: adapted by the editor from Wikipedia, the free encyclopedia under a copyleft GNU Free Documentation License (GFDL) from the article "December 2."

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February 2

(From Wikipedia, the free Encyclopedia)

February 2 is the 33rd day of the year in the Gregorian Calendar. There are 332 days remaining, (333 in leap years).

Events

Births

Deaths

Holidays and observances

See Also:

February 1 - February 3 - January 2 - March 2 -- listing of all days

January, February, March, April, May, June, July, August, September, October, November, December

Source: adapted by the editor from Wikipedia, the free encyclopedia under a copyleft GNU Free Documentation License (GFDL) from the article "February 2."

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Inch

(From Wikipedia, the free Encyclopedia)

An inch is an Imperial unit of length. Sweden also briefly had a "decimal inch" based on the metric system: see below for more.

According to some sources, the inch was originally defined informally as the distance between the tip of the thumb and the first joint of the thumb. Another source says that the inch was at one time defined in terms of the yard, supposedly defined as the distance between Henry I of England's nose and his thumb. There are twelve inches in a foot, and three feet in a yard.

Historically, the inch has referred to several slightly different units of length, used in different parts of the world. Today there are two units called the "inch" still in use, both being largely confined to the United States. Other countries, which previously had their own separate definitions of the inch, have converted to using the metric system instead. When the inch being referred to is not specified, it almost always means the international inch.

The international inch is defined in terms of the metric system of units to be exactly 25.4 mm. This definition was agreed upon by the U.S. and the British Commonwealth in 1958. Prior to that, the U.S. and Canada each had their own, slightly different definition of the inch in terms of metric units, while the U.K. and other Commonwealth countries defined the inch in terms of the Imperial Standard Yard. The definition adopted was the Canadian definition.

However, the U.S. continued to use its previous national definition of the inch for surveying purposes. This inch, known as the U.S. survey inch, is defined so that 1 metre is exactly 39.37 survey inches. 1 survey inch equals approximately 25.40000508 mm, or 1.000002 international inches. Whilst the difference between the two units is only approximately two parts per million, the difference between the two units makes a significant difference of many meters when the unit is used to define measurements made on the scale of distances of thousands of kilometers.

The thou (pronounced "thow" as in thousandth, not "thou" as in the pronoun) is a unit sometimes used in engineering equivalent to one-thousandth of an international inch, and thus defined to be 25.4 μm. Use of the thou is now generally deprecated in favour of the use of SI units.

The unit is sometimes denoted by a quotation mark (ex. 30" = 30 inches).

See also: imperial unit, Gry.

Sweden

In the 19th century, Sweden devised a way into the metric world. First, in 1855-1863 the existing "working inch" was changed into a "decimal inch" which was 1/10 foot or approximately 0.03 meters. Proponents argued that a decimal system simplifies calculations, but having two different inch measures turned out to be so complicated that in 1878-1889 it was agreed to introduce the metric units.

External link

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January 2

(From Wikipedia, the free Encyclopedia)

January 2 is the 2nd day of the year in the Gregorian Calendar. There are 363 days remaining (364 in leap years).

Events

Births

Deaths

Holidays and observances

See Also:

January 1 - January 3 - December 2 - February 2 -- listing of all days

January, February, March, April, May, June, July, August, September, October, November, December

Source: adapted by the editor from Wikipedia, the free encyclopedia under a copyleft GNU Free Documentation License (GFDL) from the article "January 2."

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July 2

(From Wikipedia, the free Encyclopedia)

July 2 is the 183rd day of the year (184th in leap years) in the Gregorian Calendar, with 182 days remaining.

It is the middle day of a non-leap year, because there are 182 days before and 182 days after. It has the same day of week as new year's day (of non-leap year) and new year's eve.

Events

Births

Deaths

Holidays and observances

See Also:

July 1 - July 3 - June 2 - August 2 -- listing of all days

January, February, March, April, May, June, July, August, September, October, November, December

Source: adapted by the editor from Wikipedia, the free encyclopedia under a copyleft GNU Free Documentation License (GFDL) from the article "July 2."

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June 2

(From Wikipedia, the free Encyclopedia)

June 2 is the 153rd day of the year in the Gregorian calendar (154th in leap years), with 212 days remaining.

Events

Births

Deaths

Holidays and observances

See Also:

June 1 - June 3 - May 2 - July 2 -- listing of all days

January, February, March, April, May, June, July, August, September, October, November, December

Source: adapted by the editor from Wikipedia, the free encyclopedia under a copyleft GNU Free Documentation License (GFDL) from the article "June 2."

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List of The Twilight Zone episodes

(From Wikipedia, the free Encyclopedia)

This is a list of Twilight Zone episodes. Warning: Episode summaries may contain spoilers.

Season 1 (Fall 1959 — Summer 1960)

Season 2 (Fall 1960 — Summer 1961)