document_title: Great Red Spot

question_text: how big is the giant red spot on jupiter

text: Great Red Spot

text: Observation history[edit]

text: The Great Red Spot may have existed since before 1665, but the present spot was first seen only after 1830 and well-studied only after a prominent apparition in 1879.  The storm people had seen in the 1600s may have been a different storm than the one we see today.[4] A long gap separates its period of current study after 1830 from its seventeenth-century discovery; whether the original spot dissipated and reformed, whether it faded, or even if the observational record was simply poor, are all unknown.[5]

text: For example, its first sighting is often credited to Robert Hooke, who described a spot on the planet in May 1664; however, it is likely that Hooke's spot was in the wrong belt altogether (the North Equatorial Belt, versus the current Great Red Spot's location in the South Equatorial Belt). Much more convincing is Giovanni Cassini's description of a "permanent spot" the following year.[6] With fluctuations in visibility, Cassini's spot was observed from 1665 to 1713; however, the 118-year observational gap makes the identity of the two spots inconclusive, and the older spot's shorter observational history and slower motion than the modern spot make their identity unlikely.[7]

text: A minor mystery concerns a Jovian spot depicted in a 1711 canvas by Donato Creti, which is exhibited in the Vatican.[8][9] Part of a series of panels in which different (magnified) heavenly bodies serve as backdrops for various Italian scenes, and all overseen by the astronomer Eustachio Manfredi for accuracy, Creti's painting is the first known to depict the Great Red Spot as red. No Jovian feature was explicitly described as red before the late 1800s.[9]

text: On February 25, 1979,[10] when the Voyager 1 spacecraft was 9.2 million kilometres (5.7 million miles) from Jupiter it transmitted the first detailed image of the Great Red Spot back to Earth. Cloud details as small as 160 kilometres (100 miles) across were visible. The colorful, wavy cloud pattern seen to the left (west) of the Red Spot is a region of extraordinarily complex and variable wave motion.

text: At the start of 2004, the Great Red Spot had approximately half the longitudinal extent it had a century ago, when it reached a size of 40,000 kilometres. At the present rate of reduction it would become circular by 2040. It is not known how long the spot will last, or whether the change is a result of normal fluctuations.[11]

text: A smaller spot, designated Oval BA, formed recently (March 2000) from the merger of three white ovals,[12][13] has turned reddish in color. Astronomers have named it the Little Red Spot or Red, Jr. As of June 5, 2006, the Great Red Spot and Oval BA appeared to be approaching convergence.[14] The storms pass each other about every two years but the passings of 2002 and 2004 were of little significance. Amy Simon-Miller, of the Goddard Space Flight Center, predicted the storms would have their closest passing on July 4, 2006. She worked with Imke de Pater and Phil Marcus of UC Berkeley, and a team of professional astronomers since April 2006 to study the storms using the Hubble Space Telescope; on July 20, the two storms were photographed passing each other by the Gemini Observatory without converging.[15] In May 2008 a third storm turned red.[16]

text: The Great Red Spot should not be confused with the Great Dark Spot, a feature observed near the northern pole of Jupiter in 2000 with the Cassini–Huygens spacecraft.[17] Note that a feature in the atmosphere of Neptune was also called the Great Dark Spot. The latter feature was imaged by Voyager 2 in 1989, and may have been an atmospheric hole rather than a storm and it was no longer present as of 1994 (although a similar spot had appeared farther to the north).

text: NASA's Juno Spacecraft flew over the Great Red Spot on July 11, 2017, taking several images of the Spot from about 5,000 miles (8,000 km) above the surface.[18]

text: Structure[edit]

text: The oval object rotates counter-clockwise, with a period of about six Earth days[19] or fourteen Jovian days. Measuring in at 10,159 miles (16,350 kilometers) in width (as of April 3, 2017) Jupiter's Great Red Spot is 1.3 times as wide as Earth.[20] The cloud-tops of this storm are about eight kilometres above the surrounding cloud-tops.

text: Infrared data have long indicated that the Great Red Spot is colder (and thus, higher in altitude) than most of the other clouds on the planet.[21] However, recent infrared measurements of the upper atmosphere show far more heat above the Great Red Spot than the rest of the planet; "acoustic waves" rising from the storm have been proposed as an explanation for Jupiter's temperature.[22]

text: Careful tracking of atmospheric features revealed the spot's counter-clockwise circulation as far back as 1966, observations dramatically confirmed by the first time-lapse movies from the Voyager fly-bys.[23] The spot is confined by a modest eastward jet stream to its south and a very strong westward one to its north.[24] Though winds around the edge of the spot peak at ~120 metres per second (432 kilometres per hour), currents inside it seem stagnant, with little inflow or outflow.[25] The rotation period of the spot has decreased with time, perhaps as a direct result of its steady reduction in size.[26]

text:
The Great Red Spot's latitude has been stable for the duration of good observational records, typically varying by about a degree. Its longitude, however, is subject to constant variation.[27][28]
Because Jupiter does not rotate uniformly at all latitudes, astronomers have defined
three different systems for defining the longitude. System II is used for latitudes of more than 10°, and was originally based on the average rotational period of the Great Red Spot of 9h 55m 42s.[29][30] Despite this, however, the spot has "lapped" the planet in System II at least 10 times since the early nineteenth century. Its drift rate has changed dramatically over the years and has been linked to the brightness of the South Equatorial Belt, and the presence or absence of a South Tropical Disturbance.[31]

text: It is not known exactly what causes the Great Red Spot's reddish color. Theories supported by laboratory experiments suppose that the color may be caused by complex organic molecules, red phosphorus, or a compound containing sulphur, but a consensus has yet to be reached.[citation needed]

text: The Great Red Spot varies greatly in hue, from almost brick-red to pale salmon, or even white. In fact, the spot occasionally "disappears", becoming evident only through the Red Spot Hollow, which is its niche[clarify] in the South Equatorial Belt (SEB). Its visibility is apparently coupled to the SEB; when the belt is bright white, the spot tends to be dark, and when it is dark, the spot is usually light. These periods when the spot is dark or light occur at irregular intervals; as of 1997, during the preceding 50 years, the spot was darkest in the periods 1961–1966, 1968–1975, 1989–1990, and 1992–1993.[5]

text: Mechanical dynamics[edit]

text: There is no definitive theory as to what is causing the formation or color of the storm that is known as the Great Red Spot. Laboratory studies are examining the effects that cosmic rays or UV Light from the Sun are having on the chemical composition of the clouds of Jupiter. In particular whether the Sun's radiation is reacting with ammonium hydrosulfide in the planet's outer atmosphere to create the deep red color.[32] Research has shown that the storm produces extreme amounts of heat because it is simultaneously generating gravity waves and acoustic waves. When these turbulent energy waves collide 500 mi (800 km) above the red spot, they are creating extremely high temperatures in the planet's upper atmosphere. The effect is described as being like "crashing [..] ocean waves on a beach".[33] The reason the storm has continued to exist for centuries is because of the physical nature of Jupiter. As there is no planetary surface to provide friction (only a liquid core of hydrogen), circulating gas eddies persist for a very long time in the atmosphere because there is nothing to oppose their angular momentum.[34]

text: Culture and Films[edit]

text: In Ice Age: Collision Course, the Spot is created when Mars hit Jupiter and bounced off.


document_title: List of U.S. cities with large African-American populations

question_text: what city in the us has the largest african american population

root

text: Cities with the highest percentage of Blacks or African-Americans[edit]

text:
Top Ten cities with 100,000 or more total population and the highest percentages of Blacks or African-Americans, alone or with other races[1]

City
Total Population
Black or African American, alone or with other races
Black or African American, alone
Mixed-race Black/African-American

Rank
Percentage of total population
Rank
Percentage of
total population
Rank
Percentage of
total population

Detroit, MI
713,777
1
84.3
1
82.7
83
1.6

Jackson, MS
173,514
2
80.1
2
79.4
242
0.7

Miami Gardens, FL
107,167
3
77.9
3
76.3
91
1.6

Birmingham, AL
212,237
4
74.0
4
73.4
257
0.6

Baltimore, MD
620,961
5
65.1
5
63.7
134
1.3

Memphis, TN
646,889
6
64.1
6
63.3
225
0.8

New Orleans, LA
343,831
7
61.2
7
60.2
184
1.0

Flint, MI
102,434
8
59.5
9
56.6
9
2.9

Montgomery, AL
205,764
9
57.4
8
56.6
231
0.8

Savannah, GA
136,286
10
56.7
10
55.4
139
1.3

tag: table

text:
Ten cities with 100,000 or more total population and the highest percentage "Black in combination" (mixed with other races)[1]

City
Total
population
Black or African American, alone or mixed with other races
Black or African American, alone
Mixed-race Black/African-American

Rank
Percent of
total population
Rank
Percent of
total population
Rank
Percent of
total population

Lansing, MI
114,297
69
27.8
78
23.7
1
4.1

Tacoma, WA
198,397
132
15.0
145
11.2
2
3.8

Killeen, TX
127,921
40
37.9
46
34.1
3
3.8

Syracuse, NY
145,170
51
33.1
57
29.5
4
3.6

Providence, RI
178,042
109
19.4
114
16.0
5
3.3

Fairfield, CA
105,321
111
19.0
118
15.7
6
3.3

Rochester, NY
210,565
29
44.9
33
41.7
7
3.2

Fayetteville, NC
200,564
31
44.8
32
41.9
8
2.9

Vallejo, CA
115,942
81
24.9
83
22.1
10
2.9

text: Cities with the highest number of Black or African American people[edit]

text:
Ten cities with 100,000 or more total population
and the highest number of Blacks or African Americans[2]

City
Total
population
Black or African American,
alone or mixed with other races
Black or African American,
alone
Mixed-race Black/African-American

Rank
Number
Rank
Number
Rank
Number

New York, NY
8,175,133
1
2,228,145
1
2,088,510
1
139,635

Chicago, IL
2,695,598
2
913,009
2
887,608
3
25,401

Philadelphia, PA
1,526,006
3
686,870
3
661,839
4
25,031

Detroit, MI
713,777
4
601,988
4
590,226
13
11,762

Houston, TX
2,099,451
5
514,217
5
498,466
8
15,751

Memphis, TN
646,889
6
414,928
6
409,687
58
5,241

Baltimore, MD
620,961
7
403,998
7
395,781
29
8,217

Los Angeles, CA
3,792,621
8
402,448
8
365,118
2
37,330

Washington, DC
601,723
9
314,352
9
305,125
22
9,227

Dallas, TX
1,197,816
10
308,087
10
298,993
23
9,094

text: Select cities with a large percentage of Black or African American people[edit]

text: [dubious – discuss]

tag: p

text: The following data was sourced from the 2010 U.S. Census.[citation needed]

text:
Rank
City
Percentage Black or African American
Total Black or African American

1
Detroit, MI
82.7
590,226

2
Jackson, MS
79.4
137,716

3
Chester, PA
77.8
26,429

4
Miami Gardens, FL
76.3
81,776

5
Orangeburg, SC
75.04
13,964

6
Birmingham, AL
73.4
155,791

7
Albany, GA
71.6
55,442

8
Baltimore, MD
63.7
395,781

9
Memphis, TN
63.3
409,687

10
New Orleans, LA
60.2
206,871

11
Baton Rouge, LA
58.5
126,250

12
Wilmington, DE
58
41,326

13
Flint, MI
56.6
57,939

14
Savannah, GA
55.4
75,507

15
Augusta, GA
54.7
107,182

16
Shreveport, LA
54.7
109,022

17
Montgomery, AL
54.5
116,524

18
Atlanta, GA
54.0
226,894

19
Cleveland, OH
53.3
211,672

20
Portsmouth, VA
53.3
50,878

21
Harrisburg, PA
52.4
25,957

22
Newark, NJ
52.4
145,085

23
Valdosta, GA
51.1
27,860

24
Washington, D.C.
50.7
305,125

25
Richmond, VA
50.6
103,342

26
Mobile, AL
50.6
98,691

27
St. Louis, MO
49.2
157,160

28
Danville, VA
48.3
43,055

29
Beaumont, TX
47.3
55,931

30
North Charleston, SC
47.2
45,964

31
Jackson, TN
45.7
29,802

32
Columbus, GA
45.5
86,398

33
Cincinnati, OH[3]
45.0
123,157

34
Saginaw, MI
44.9
23,127

35
Inglewood, California
43.9
48,164

36
Philadelphia, PA
43.4
661,839

37
Norfolk, VA
43.1
104,672

38
Dayton, OH
42.9
60,705

39
Suffolk, VA
42.7
36,120

40
Little Rock, AR
42.3
81,889

41
Columbia, SC
42.2
54,537

42
Fayetteville, NC
41.9
82,235

43
Rochester, NY
41.7
87,897

44
Durham, NC
41.0
93,517

45
Fort Pierce, FL
40.9
17,617

46
Newport News, VA
40.7
73,514

47
Greensboro, NC
40.6
109,586

48
Milwaukee, WI
40.0
237,769

49
Hartford, CT
38.7
48,331

50
Buffalo, NY
38.6
100,774

51
Penn Hills, PA
37.1
15,688

52
McKeesport, PA
36.5
7,201

53
Bronx, NY[4]
36.5
505,200

54
New Haven, CT
35.4
45,938

55
Tallahassee, FL
35.0
63,475

56
Charlotte, NC
35.0
240,482

57
Chattanooga, TN
34.9
58,507

58
Winston-Salem, NC
34.7
79,598

59
Brooklyn, NY[4]
34.3
860,083

60
High Point, NC
33.0
34,532

61
Chicago, IL
32.9
887,608

62
Compton, CA
32.9
31,688

63
Cheltenham, PA
32.8
12,097

64
Hopkinsville, KY
31.9
10,273

65
Paterson, NJ
31.7
46,314

66
Greenville, SC
31.5
18,422

67
Huntsville, AL
31.2
56,229

68
Brockton, MA
31.2
30,147

69
Jacksonville, FL
30.7
252,421

70
Kansas City, MO
29.9
137,540

71
Raleigh, NC
29.3
117,160

72
Orlando, FL
28.1
66,876

73
Columbus, OH
28.0
220,241

74
Oakland, CA
28.0
109,471

75
Nashville, TN
27.7
181,387

76
Hawthorne, CA
27.7
23,385

77
Upper Darby, PA
27.5
22,769

78
Indianapolis, IN
27.2
226,671

79
Toledo, OH
27.2
69,243

80
Kansas City, KS
26.8
39,080

81
Richmond, CA
26.6
27,542

82
South Bend, IN
26.6
26,906

83
Tampa, FL
26.2
87,872

84
Pittsburgh, PA
26.1
79,710

85
Charleston, SC
25.4
30,496

86
Dallas, TX
25.0
298,993

87
Boston, MA
24.4
150,437

88
Houston, TX
23.6
498,466

89
Springfield, MA
22.3
34,073

90
Louisville, KY
22.2
136,611

91
Queens, NY[4]
20.1
446,098

92
North Las Vegas, NV
19.9
47,502

93
Virginia Beach, VA
19.6
85,935

94
Minneapolis, MN
18.6
71,160

95
Erie, PA
16.8
17,141

96
Victorville, CA
16.8
19,483

97
Port St. Lucie, FL
16.3
27,876

98
Aurora, CO
15.7
51,196

99
Manhattan, NY[4]
15.6
246,687

100
Oklahoma City, OK
15.1
87,354

101
San Bernardino, CA
15.0
31,582

102
Sacramento, CA
14.6
68,335

103
Lexington, KY
14.5
46,110

104
Bowling Green, KY
13.9
9,067


document_title: Automatic rifle

question_text: when did the first automatic gun come out

text: Automatic rifle

text: History[edit]

text: Cei-Rigotti[edit]

text: The world's first automatic rifle was the Italian Cei-Rigotti. Introduced in 1900, these 6.5mm Carcano or 7.65×53mm gas-operated, selective-fire, carbines attracted considerable attention at the time.[1][2] They used 10-, 20- and 50-round box magazines.[2] The Cei-Rigotti had several failings, including frequent jams and erratic shooting.[2] In the end, no Army took an interest in the design and the rifle was abandoned before it could be further developed.[2]

text: Browning Automatic Rifle[edit]

text: The Browning Automatic Rifle (BAR) was one of the first practical automatic rifles. The BAR made its successful combat debut in World War I, and approximately 50,000 were made before the war came to an end.[3][4] The BAR arose from the concept of "Walking Fire", an idea urged upon the Americans by the French who used the Chauchat light machine gun to fulfill that role.[5] The BAR never entirely lived up to the designer's hopes; being neither a rifle nor a machinegun.[6] "For its day, though, it was a brilliant design produced in record time by John Browning, and it was bought and used by many countries around the world. It was the standard squad light automatic of the U.S. infantry during World War II and saw use in every theater of war."[7] The BAR was praised for its reliability and stopping power. "The US forces abandoned the BAR in the middle 1950s, though it was retained in reserve stocks for several years; it survived in smaller countries until the late 1970s."[8]

text: FG 42[edit]

text: The FG 42 is a selective fire automatic rifle[9][10] or battle rifle[11][12][13] produced in Germany during World War II. The weapon was developed specifically for the use of the Fallschirmjäger airborne infantry in 1942 and was used in limited numbers until the end of the war. It served as a squad automatic rifle in much the same role as the Browning BAR. It combined the firepower of a light machine gun in a lightweight package no larger than the standard-issue Kar 98k bolt-action rifle. It was considered one of the most advanced weapon designs of World War II.[14][15] The FG 42 influenced post-war small arms development and most of its design was copied by the US Army when they developed the M60 machine gun.[16]

text: Sturmgewehr 44 (Assault rifle)[edit]

text: The Germans were the first to pioneer the assault rifle concept, during World War II, based upon research that showed that most firefights happen within 400 meters and that contemporary rifles were over-powered for most small arms combat. The Germans sought to develop a select-fire intermediate powered rifle combining the firepower of a submachine gun with the accuracy and range of a rifle. This was done by shortening the standard 7.92×57mm cartridge to 7.92×33mm and giving it a lighter 125-grain bullet, that limited range but allowed for more controllable automatic fire. The result was the Sturmgewehr 44.[17][18][19][20]

text: Like the Germans, the Soviets were influenced by experience showing most combat happens within 400 meters and that their soldiers were consistently outgunned by heavily armed German troops, especially those armed with the Sturmgewehr 44 assault rifles.[21][22] The Soviets were so impressed with the Sturmgewehr 44, that after World War II, they held a design competition to develop an assault rifle of their own.[23][24] The winner was the AK-47.[20] It was finalized, adopted and entered widespread service in the Soviet army in the early 1950s.[22] Its firepower, ease of use, low production costs, and reliability was perfectly suited for the Red Army's new mobile warfare doctrines.[22] The AK-47 was widely supplied or sold to nations allied with the USSR and the blueprints were shared with several friendly nations (the People's Republic of China standing out among these with the Type 56).[22] The AK-47 and AKM type rifles are the most produced firearms in history.

text: M14 rifle (Battle rifle)[edit]

text: The U.S. Army was influenced by combat experience with semi-automatic weapons such as the M1 Garand and M1 carbine, which enjoyed a significant advantage over enemies armed primarily with bolt-action rifles.[25] Although U.S. Army studies of World War II combat accounts had very similar results to that of the Germans and Soviets, the U.S. Army maintained its traditional views and preference for high-powered semi-automatic rifles.[20]

text: After World War II, the United States military started looking for a single automatic rifle to replace the M1 Garand, M1/M2 Carbines, M1918 Browning Automatic Rifle, M3 "Grease Gun" and Thompson submachine gun.[20] However, early experiments with select-fire versions of the M1 Garand proved disappointing.[26] During the Korean War, the select-fire M2 Carbine largely replaced submachine guns in US service.[27] Although, combat experience suggested that the .30 Carbine round was underpowered.[28] American weapons designers reached the same conclusion as the Germans and Soviets: an intermediate round was necessary, and recommended a small caliber, high velocity-cartridge.[29]

text: However, senior American commanders having faced fanatical enemies and experienced major logistical problems during World War II and the Korean War,[30][31][32][33][34] insisted that a single powerful .30 caliber cartridge be developed, that could not only be used by the new automatic rifle, but by the new general purpose machine gun (GPMG) in concurrent development.[35][36] This culminated in the development of the 7.62×51mm NATO cartridge and the M14 rifle[35] which was basically an improved select-fire M1 Garand with a 20-round magazine.[37] The U.S. also adopted the M60 GPMG.[35] Its NATO partners adopted the FN FAL and HK G3 rifles, as well as the FN MAG and Rheinmetall MG3 GPMGs.

text: FN FAL[edit]

text: The FN FAL is a 7.62×51mm NATO, selective fire, automatic rifle produced by the Belgian armaments manufacturer Fabrique Nationale de Herstal (FN). During the Cold War, it was adopted by many North Atlantic Treaty Organization (NATO) countries, most notably with the British Commonwealth as the L1A1. It is one of the most widely used rifles in history, having been used by more than 90 countries.[38] The FAL was predominantly chambered for the 7.62mm NATO round, and because of its prevalence and widespread use among the armed forces of many western nations during the Cold War it was nicknamed "The right arm of the Free World".[39]

text: H&K G3[edit]

text: The H&K G3 is a 7.62×51mm NATO, selective fire, automatic rifle produced by the German armament manufacturer Heckler & Koch GmbH (H&K) in collaboration with the Spanish state-owned design and development agency CETME (Centro de Estudios Técnicos de Materiales Especiales).[40] The rifle proved successful in the export market, being adopted by the armed forces of over 60 countries.[41] After World War II, German technicians involved in developing the Sturmgewehr 45, continued their research in France at CEAM. The StG45 mechanism was modified by Ludwig Vorgrimler and Theodor Löffler at the Mulhouse facility between 1946 and 1949. Vorgrimler later went to work at CETME in Spain and developed the line of CETME automatic rifles based on his improved Stg45 design. Germany eventually purchased the license for the CETME design and manufactured the Heckler & Koch G3 as well as an entire line of weapons built on the same system, one of the most famous being the MP5 SMG.

text: M16 rifle[edit]

text: The first confrontations between the AK-47 and the M14 (assault rifle vs battle rifle) came in the early part of the Vietnam War. Battlefield reports indicated that the M14 was uncontrollable in automatic mode and that soldiers could not carry enough ammo to maintain fire superiority over the AK-47.[42] A replacement was needed: A medium between the traditional preference for high-powered rifles such as the M14, and the lightweight firepower of the M2 Carbine.

text: As a result, the Army was forced to reconsider a 1957 request by General Willard G. Wyman, commander of the U.S. Continental Army Command (CONARC) to develop a .223 caliber (5.56 mm) select-fire rifle weighing 6 lbs (2.7 kg) when loaded with a 20-round magazine.[20] The 5.56mm round had to penetrate a standard U.S. helmet at 500 yards (460 meters) and retain a velocity in excess of the speed of sound while matching or exceeding the wounding ability of the .30 Carbine cartridge.[43]

text: This request ultimately resulted in the development of a scaled-down version of the ArmaLite AR-10, called ArmaLite AR-15 rifle.[44][45][46] However, despite overwhelming evidence that the AR-15 could bring more firepower to bear than the M14, the Army opposed the adoption of the new rifle.[46] In January 1963, Secretary of Defense Robert McNamara concluded that the AR-15 was the superior weapon system and ordered a halt to M14 production.[46] At the time, the AR-15 was the only rifle available that could fulfill the requirement of a universal infantry weapon for issue to all services. After modifications (Most notably: the charging handle was re-located from under the carrying handle like AR-10 to the rear of the receiver),[45] the new redesigned rifle was subsequently adopted as the M16.[46][47]

text: The M16 entered U.S. service in the mid-1960s and was much lighter than the M14 it replaced, allowing soldiers to carry more ammunition.[47] Despite its early failures, the M16 proved to be a revolutionary design and stands as the longest continuously serving rifle in American military history.[48][49] It is a benchmark against which other assault rifles are judged,[46]and used by 15 NATO countries, and more than 80 countries worldwide[50]

text: During the 1960s, other countries would follow the Americans lead and begin to develop 5.56×45mm assault rifles, most notably Germany with the Heckler & Koch HK33. The HK33 was essentially a smaller 5.56mm version of the 7.62×51mm Heckler & Koch G3 rifle. As one of the first 5.56mm assault rifles on the market, it would go on to become one of the most widely distributed assault rifles. The HK33 featured a modular design with a wide range of accessories (telescoping butt-stocks, optics, bipods, etc.) that could be easily removed and arranged in a various configurations.

text: 5.56mm NATO[edit]

text: The adoption of the M16, the H&K33, and the 5.56×45mm cartridge inspired an international trend towards relatively small-sized, lightweight, high-velocity military service cartridges that allow a soldier to carry more ammunition for the same weight compared to the larger and heavier 7.62×51mm NATO cartridge. The 5.56mm cartridge is also much easier to shoot.[51][52][53] In 1961 marksmanship testing, the U.S. Army found that 43% of ArmaLite AR-15 shooters achieved Expert, while only 22% of M-14 rifle shooters did so. Also, a lower recoil impulse allows for more controllable automatic weapons fire.[51][54][55]

text: Therefore, in March 1970, the U.S. recommended that all NATO forces adopt the 5.56×45mm cartridge.[56] This shift represented a change in the philosophy of the military's long-held position about caliber size. By the middle of the 1970s, other armies were looking at assault rifle type weapons. A NATO standardization effort soon started and tests of various rounds were carried out starting in 1977.[56] The U.S. offered the 5.56×45mm M193 round, but there were concerns about its penetration in the face of the wider introduction of body armor.[20] In the end, the Belgian 5.56×45mm SS109 round was chosen (STANAG 4172) in October 1980.[56] The SS109 round was based on the U.S. cartridge but included a new stronger, heavier, 62 grain bullet design, with better long range performance and improved penetration (specifically, to consistently penetrate the side of a steel helmet at 600 meters).[20]

text: During the 1970s, the USSR developed the AK-74 and the 5.45×39mm cartridge, which has similar physical characteristics to the U.S. 5.56×45mm cartridge.[57] Also during the 1970s, Finland, Israel, South Africa and Sweden introduced AK type rifles in 5.56×45mm.[58] During the 1990s, the Russians developed the AK-101 in 5.56×45mm NATO for the world export market.[59][60] In addition, Bulgaria, Czechoslovakia, Hungary, Poland and former countries of Yugoslavia have also rechambered their locally produced assault rifle variants to 5.56mm NATO.[61][62] The adoption the 5.56mm NATO and 5.45×39mm cemented the worldwide trend toward small caliber, high-velocity cartridges.

text: Steyr AUG (Bullpup rifle)[edit]

text: In 1977, Austria introduced the 5.56×45mm Steyr AUG bullpup rifle, often cited as the first successful bullpup rifle,[63][64][65] finding service with the armed forces of over twenty countries. It was highly advanced for the 1970s, combining in the same weapon the bullpup configuration, a polymer housing, dual vertical grips, an optical sight as standard, and a modular design. Highly reliable, light, and accurate, the Steyr AUG showed clearly the potential of the bullpup layout. In 1978, France introduced the 5.56×45mm FAMAS bullpup rifle. In 1985, the British introduced the 5.56×45mm L85 bullpup rifle. In the late 1990s, Israel introduced the Tavor TAR-21 and China's People's Liberation Army's adopted QBZ-95. By the turn of the century, the bullpup design had achieved world-wide acceptance.


document_title: Horses in the United States

question_text: when were horses introduced to the united states

text: Horses in the United States

text: Evolution[edit]

text: Fossils of the earliest direct ancestor to the modern horse, Eohippus have been found in the Eocene layers of North American strata, mainly in the Wind River basin in Wyoming.[4] Fossils found at the Hagerman Fossil Beds in Idaho, called the Hagerman horse or Equus simplicidens are from the Pliocene, dating to about 3.5 million years ago (mya). Paleontologists determined the fossils represented the oldest remains of the genus Equus.[5] The genus Equus, which includes all extant equines, was plentiful in North America and spread into the Old World by about 2.5 mya.[6]

text: A 2005 genetic study of fossils found evidence for three genetically divergent equid lineages in Pleistocene North and South America.[7][8] Recent studies suggest all North American fossils of caballine-type horses, including both the domesticated horse and Przewalski's horse,[8] belong to the same species: E. ferus. Remains attributed to a variety of species and lumped as New World stilt-legged horses probably all belong to a second closely related species that was endemic to North America.[7] Digs in western Canada have unearthed clear evidence horses existed in North America as recently as 12,000 years ago.[9] Other studies produced evidence that horses in the Americas existed until 8,000–10,000 years ago.[6]

text: Extinction and return[edit]

text: All Equidae in North America ultimately became extinct, along with several other megafauna. The causes of this extinction have been debated. Given the suddenness of the event and because these mammals had been flourishing for millions of years previously, something quite unusual must have happened. The first main hypothesis attributes extinction to climate change. For example, in Alaska, beginning approximately 12,500 years ago, the grasses characteristic of a steppe ecosystem gave way to shrub tundra, which was covered with unpalatable plants.[10][11] However, it has been proposed that the steppe-tundra vegetation transition in Beringia may have been a consequence, rather than a cause, of the extinction of megafaunal grazers.[12]

text: The other hypothesis suggests extinction was linked to overexploitation of native prey by newly arrived humans. The extinctions were roughly simultaneous with the end of the most recent glacial advance and the appearance of the big game-hunting Clovis culture.[13][14] Several studies have indicated humans probably arrived in Alaska at the same time or shortly before the local extinction of horses.[14][15][16]

text: Horses returned to the Americas thousands of years later, well after domestication of the horse, beginning with Christopher Columbus in 1493. These were Iberian horses first brought to Hispaniola and later to Panama, Mexico, Brazil, Peru, Argentina, and, in 1538, Florida.[17] The first horses to return to the main continent were 16 specifically identified horses brought by Hernán Cortés in 1519. Subsequent explorers, such as Coronado and De Soto brought ever-larger numbers, some from Spain and others from breeding establishments set up by the Spanish in the Caribbean.[18]

text: These domesticated horses were the ancestral stock of the group of breeds or strains known today as the Colonial Spanish Horse. They predominated through the southeast and western United States from 16th century until about 1850, when crossbreeding with larger horse breeds changed the phenotype and diluted the Spanish bloodlines.[19] Later, some horses became strayed, lost or stolen, and proliferated into large herds of feral horses that became known as mustangs.[18] Modern domesticated horses that retain Colonial Spanish type include the Spanish Mustang, Choctaw horse, Florida Cracker horse, and the Marsh Tacky.[20] One somewhat obscure and largely debunked hypothesis posits that horses survived the ice age in North America. This idea mostly comes from Dakota/Lakota oral histories, which refer to straight-backed ponies, around 13 hands tall, with very powerful lungs. [21]

text: Historic period[edit]

text: European settlers brought a variety of horses to the Americas. The first imports were smaller animals suited to the size restrictions imposed by ships. Starting in the mid-19th century, larger draft horses began to be imported, and by the 1880s, thousands had arrived.[22] Formal horse racing in the United States dates back to 1665, when a racecourse was opened on the Hempstead Plains near Salisbury in what is now Nassau County, New York[23]

text: There are multiple theories for how Native American people obtained horses from the Spanish, but early capture of stray horses during the 16th century was unlikely due to the need to simultaneously acquire the skills to ride and manage them. It is unlikely that Native people obtained horses in significant numbers to become a horse culture any earlier than 1630–1650. From a trade center in the Santa Fe, New Mexico area, the horse spread slowly north.[24] The Comanche people were thought to be among the first tribes to obtain horses and use them successfully.[25] By 1742, there were reports that the Crow and Blackfoot people had horses.[24] The horse became an integral part of the lives and culture of Native Americans, especially the Plains Indians, who viewed them as a source of wealth and used them for hunting, travel, and warfare.[26]

text: In the 19th century, horses were used for many jobs. In the west, they were ridden by cowboys for handling cattle on the large ranches of the region and on cattle drives.[27] In cities, including transporting people via carriage and horse-drawn public transport. They were used for hauling freight and for farming. In some cases, their labor was deemed more efficient than using steam-powered equipment to power certain types of mechanized equipment. At the same time, the maltreatment of horses in cities such as New York, where over 130,000 horses were used, led to the creation of the first ASPCA in 1866.[28] In the 19th century, the Standardbred breed of harness racing horse developed in the United States,[29] and many Thoroughbred horse races were established.

text: At the start of the 20th century, the United States Department of Agriculture began to establish breeding farms for research, to preserve American horse breeds, and to develop horses for military and agricultural purposes.[22] However, after the end of World War I, the increased use of mechanized transportation resulted in a decline in the horse populations, with a 1926 report noting horse prices were the lowest they had been in 60 years.[30] Horse numbers rebounded in the 1960s, as horses came to be used for recreational purposes.[31]

text: Statistics[edit]

text: In 1912, the United States and Russia held the most horses in the world, with the U.S. having the second-highest number.[32] There were an estimated of 20 million horses in March 1915 in the United States.[33] A USDA census in 1959 showed the horse population had dropped to 4.5 million. Numbers began to rebound somewhat, and by 1968 there were about 7 million horses, mostly used for riding.[31] In 2005, there were about 9 million horses.[34]

text: There are about 33,000 free-roaming horses in the western United States under the supervision of the Bureau of Land Management.[35] Additional feral horse populations exist elsewhere in the United States, especially on several islands off the Atlantic coast, where the National Park Service oversees populations of the Banker horse in North Carolina,[36] the Cumberland Island horse in Georgia,[37] and the horses on the Maryland side of Assateague Island, home to the Chincoteague pony.[38] In Canada, a similar Atlantic population is the Sable Island horse of Nova Scotia.[39]