document_title: Wind wave

question_text: the uninterrupted distance over which the wind blows without change in direction is the

text: Wind wave

text: Wave formation[edit]

text: The great majority of large breakers seen at a beach result from distant winds. Five factors influence the formation of the flow structures in wind waves:[4]

text:
Wind speed or strength relative to wave speed—the wind must be moving faster than the wave crest for energy transfer
The uninterrupted distance of open water over which the wind blows without significant change in direction (called the fetch)
Width of area affected by fetch[clarification needed]
Wind duration — the time for which the wind has blown over the water.
Water depth

tag: ol

text: All of these factors work together to determine the size of wind waves and the structure of the flow within them.

text: The main dimensions associated with waves are:

text:
Wave height (vertical distance from trough to crest)
Wave length (distance from crest to crest in the direction of propagation)
Wave period (time interval between arrival of consecutive crests at a stationary point)
Wave propagation direction

text: A fully developed sea has the maximum wave size theoretically possible for a wind of a specific strength, duration, and fetch. Further exposure to that specific wind could only cause a dissipation of energy due to the breaking of wave tops and formation of "whitecaps". Waves in a given area typically have a range of heights. For weather reporting and for scientific analysis of wind wave statistics, their characteristic height over a period of time is usually expressed as significant wave height. This figure represents an average height of the highest one-third of the waves in a given time period (usually chosen somewhere in the range from 20 minutes to twelve hours), or in a specific wave or storm system. The significant wave height is also the value a "trained observer" (e.g. from a ship's crew) would estimate from visual observation of a sea state. Given the variability of wave height, the largest individual waves are likely to be somewhat less than twice the reported significant wave height for a particular day or storm.[5]

text: Wave formation on an initially flat water surface by wind is started by a random distribution of normal pressure of turbulent wind flow over the water. This pressure fluctuation produces normal and tangential stresses in the surface water, which generates waves. It is assumed that:[6]

text:
The water is originally at rest.
The water is not viscous.
The water is irrotational.
There is a random distribution of normal pressure to the water surface from the turbulent wind.
Correlations between air and water motions are neglected.

text: The second mechanism involves wind shear forces on the water surface. John W. Miles suggested a surface wave generation mechanism which is initiated by turbulent wind shear flows based on the inviscid Orr-Sommerfeld equation in 1957. He found the energy transfer from wind to water surface is proportional to the curvature of the velocity profile of the wind at the point where the mean wind speed is equal to the wave speed. Since the wind speed profile is logarithmic to the water surface, the curvature has a negative sign at this point. This relation shows the wind flow transferring its kinetic energy to the water surface at their interface.

text: Assumptions:

text:
two-dimensional parallel shear flow
incompressible, inviscid water and wind
irrotational water
slope of the displacement of the water surface is small[7]

text: Generally these wave formation mechanisms occur together on the water surface and eventually produce fully developed waves.

text: For example,[8] if we assume a flat sea surface (Beaufort state 0), and a sudden wind flow blows steadily across the sea surface, the physical wave generation process follows the sequence:

text:
Turbulent wind forms random pressure fluctuations at the sea surface. Ripples with wavelengths in the order of a few centimetres are generated by the pressure fluctuations. (The Phillips mechanism[6])
The winds keep acting on the initially rippled sea surface causing the waves to become larger. As the waves grow, the pressure differences get larger causing the growth rate to increase. Finally the shear instability expedites the wave growth exponentially. (The Miles mechanism[6])
The interactions between the waves on the surface generate longer waves[9] and the interaction will transfer wave energy from the shorter waves generated by the Miles mechanism to the waves which have slightly lower frequencies than the frequency at the peak wave magnitudes, then finally the waves will be faster than the cross wind speed (Pierson & Moskowitz[10]).

text:
hideConditions necessary for a fully developed sea at given wind speeds, and the parameters of the resulting waves

Wind conditions

Wave size

Wind speed in one direction
Fetch
Wind duration
Average height
Average wavelength
Average period and speed

19 km/h (12 mph)
19 km (12 mi)
2 hr
0.27 m (0.89 ft)
8.5 m (28 ft)
3.0 sec, 10.2 km/h (9.3 ft/sec)

37 km/h (23 mph)
139 km (86 mi)
10 hr
1.5 m (4.9 ft)
33.8 m (111 ft)
5.7 sec, 21.4 km/h (19.5 ft/sec)

56 km/h (35 mph)
518 km (322 mi)
23 hr
4.1 m (13 ft)
76.5 m (251 ft)
8.6 sec, 32.0 km/h (29.2 ft/sec)

74 km/h (46 mph)
1,313 km (816 mi)
42 hr
8.5 m (28 ft)
136 m (446 ft)
11.4 sec, 42.9 km/h (39.1 ft/sec)

92 km/h (57 mph)
2,627 km (1,632 mi)
69 hr
14.8 m (49 ft)
212.2 m (696 ft)
14.3 sec, 53.4 km/h (48.7 ft/sec)

NOTE: Most of the wave speeds calculated from the wave length divided by the period are proportional to the square root of the wave length. Thus, except for the shortest wave length, the waves follow the deep water theory. The 28 ft long wave must be either in shallow water or intermediate depth.

text: Types of wind waves[edit]

text: Three different types of wind waves develop over time:

text:
Capillary waves, or ripples
Seas
Swells

text: Ripples appear on smooth water when the wind blows, but will die quickly if the wind stops. The restoring force that allows them to propagate is surface tension. Sea waves are larger-scale, often irregular motions that form under sustained winds. These waves tend to last much longer, even after the wind has died, and the restoring force that allows them to propagate is gravity. As waves propagate away from their area of origin, they naturally separate into groups of common direction and wavelength. The sets of waves formed in this manner are known as swells.

text: Individual "rogue waves" (also called "freak waves", "monster waves", "killer waves", and "king waves") much higher than the other waves in the sea state can occur. In the case of the Draupner wave, its 25 m (82 ft) height was 2.2 times the significant wave height. Such waves are distinct from tides, caused by the Moon and Sun's gravitational pull, tsunamis that are caused by underwater earthquakes or landslides, and waves generated by underwater explosions or the fall of meteorites—all having far longer wavelengths than wind waves.

text:
Yet, the largest ever recorded wind waves are common — not rogue — waves in extreme sea states. For example: 29.1 m (95 ft) high waves have been recorded on the RRS Discovery in a sea with 18.5 m (61 ft) significant wave height, so the highest wave is only 1.6 times the significant wave height.[12]
The biggest recorded by a buoy (as of 2011) was 32.3 m (106 ft) high during the 2007 typhoon Krosa near Taiwan.[13]

text: Ocean waves can be classified based on: the disturbing force(s) that create(s) them; the extent to which the disturbing force(s) continue(s) to influence them after formation; the extent to which the restoring force(s) weaken(s) (or flatten) them; and their wavelength or period. Seismic Sea waves have a period of ~20 minutes, and speeds of 760 km/h (470 mph). Wind waves (deep-water waves) have a period of about 20 seconds.

text:
[14]

Wave type
Typical wavelength
Disturbing force
Restoring force

Capillary wave
< 2 cm
Wind
Surface tension

Wind wave
60–150 m (200–490 ft)
Wind over ocean
Gravity

Seiche
Large, variable; a function of basin size
Change in atmospheric pressure, storm surge
Gravity

Seismic sea wave (tsunami)
200 km (120 mi)
Faulting of sea floor, volcanic eruption, landslide
Gravity

Tide
Half the circumference of Earth
Gravitational attraction, rotation of Earth
Gravity

text: The speed of all ocean waves is controlled by gravity, wavelength, and water depth. Most characteristics of ocean waves depend on the relationship between their wavelength and water depth. Wavelength determines the size of the orbits of water molecules within a wave, but water depth determines the shape of the orbits. The paths of water molecules in a wind wave are circular only when the wave is traveling in deep water. A wave cannot "feel" the bottom when it moves through water deeper than half its wavelength because too little wave energy is contained in the small circles below that depth. Waves moving through water deeper than half their wavelength are known as deep-water waves. On the other hand, the orbits of water molecules in waves moving through shallow water are flattened by the proximity of the sea surface bottom. Waves in water shallower than 1/20 their original wavelength are known as shallow-water waves. Transitional waves travel through water deeper than 1/20 their original wavelength but shallower than half their original wavelength.

text: In general, the longer the wavelength, the faster the wave energy will move through the water. For deep-water waves, this relationship is represented with the following formula:

text: where C is speed (celerity), L is wavelength, and T is time, or period (in seconds).

text: The speed of a deep-water wave may also be approximated by:

text: where g is the acceleration due to gravity, 9.8 meters (32 feet) per second squared. Because g and π (3.14) are constants, the equation can be reduced to:

text: when C is measured in meters per second and L in meters. Note that in both formulas the wave speed is proportional to the square root of the wavelength.

text: The speed of shallow-water waves is described by a different equation that may be written as:

text: where C is speed (in meters per second), g is the acceleration due to gravity, and d is the depth of the water (in meters). The period of a wave remains unchanged regardless of the depth of water through which it is moving. As deep-water waves enter the shallows and feel the bottom, however, their speed is reduced and their crests "bunch up," so their wavelength shortens.

text: Wave shoaling and refraction[edit]

text: As waves travel from deep to shallow water, their shape alters (wave height increases, speed decreases, and length decreases as wave orbits become asymmetrical). This process is called shoaling.

text: Wave refraction is the process that occurs when waves interact with the sea bed as the wave crests align themselves as a result of approaching decreasing water depths at an angle to the depth contours. Varying depths along a wave crest cause the crest to travel at different phase speeds, with those parts of the wave in deeper water moving faster than those in shallow water. This process continues until the crests become (nearly) parallel to the depth contours. Rays—lines normal to wave crests between which a fixed amount of energy flux is contained—converge on local shallows and shoals. Therefore, the wave energy between rays is concentrated as they converge, with a resulting increase in wave height.

text: Because these effects are related to a spatial variation in the phase speed, and because the phase speed also changes with the ambient current – due to the Doppler shift – the same effects of refraction and altering wave height also occur due to current variations. In the case of meeting an adverse current the wave steepens, i.e. its wave height increases while the wave length decreases, similar to the shoaling when the water depth decreases.[15]

text: Wave breaking[edit]

text: Some waves undergo a phenomenon called "breaking".[16] A breaking wave is one whose base can no longer support its top, causing it to collapse. A wave breaks when it runs into shallow water, or when two wave systems oppose and combine forces. When the slope, or steepness ratio, of a wave is too great, breaking is inevitable.

text: Individual waves in deep water break when the wave steepness—the ratio of the wave height H to the wavelength λ—exceeds about 0.17, so for H > 0.17 λ. In shallow water, with the water depth small compared to the wavelength, the individual waves break when their wave height H is larger than 0.8 times the water depth h, that is H > 0.8 h.[17] Waves can also break if the wind grows strong enough to blow the crest off the base of the wave.

text: In shallow water the base of the wave is decelerated by drag on the seabed. As a result, the upper parts will propagate at a higher velocity than the base and the leading face of the crest will become steeper and the trailing face flatter. This may be exaggerated to the extent that the leading face forms a barrel profile, with the crest falling forward and down as it extends over the air ahead of the wave.

text: Three main types of breaking waves are identified by surfers or surf lifesavers. Their varying characteristics make them more or less suitable for surfing, and present different dangers.

text:
Spilling, or rolling: these are the safest waves on which to surf. They can be found in most areas with relatively flat shorelines. They are the most common type of shorebreak. The deceleration of the wave base is gradual, and the velocity of the upper parts does not differ much with height. Breaking occurs mainly when the steepness ratio exceeds the stability limit.
Plunging, or dumping: these break suddenly and can "dump" swimmers—pushing them to the bottom with great force. These are the preferred waves for experienced surfers. Strong offshore winds and long wave periods can cause dumpers. They are often found where there is a sudden rise in the sea floor, such as a reef or sandbar. Deceleration of the wave base is sufficient to cause upward acceleration and a significant forward velocity excess of the upper part of the crest. The peak rises and overtakes the forward face, forming a "barrel" or "tube" as it collapses.
Surging: these may never actually break as they approach the water's edge, as the water below them is very deep. They tend to form on steep shorelines. These waves can knock swimmers over and drag them back into deeper water.

text: When the shoreline is near vertical, waves do not break, but are reflected. Most of the energy is retained in the wave as it returns to seaward. Interference patterns are caused by superposition of the incident and reflected waves, and the superposition may cause localised instability when peaks cross, and these peaks may break due to instability. (see also clapotic waves)

text: Physics of waves[edit]

text: Wind waves are mechanical waves that propagate along the interface between water and air; the restoring force is provided by gravity, and so they are often referred to as surface gravity waves. As the wind blows, pressure and friction perturb the equilibrium of the water surface and transfer energy from the air to the water, forming waves. The initial formation of waves by the wind is described in the theory of Phillips from 1957, and the subsequent growth of the small waves has been modeled by Miles, also in 1957.[18][19]

text: In linear plane waves of one wavelength in deep water, parcels near the surface move not plainly up and down but in circular orbits: forward above and backward below (compared the wave propagation direction). As a result, the surface of the water forms not an exact sine wave, but more a trochoid with the sharper curves upwards—as modeled in trochoidal wave theory. Wind waves are thus a combination of transversal and longitudinal waves.

text: When waves propagate in shallow water, (where the depth is less than half the wavelength) the particle trajectories are compressed into ellipses.[21][22]

text: In reality, for finite values of the wave amplitude (height), the particle paths do not form closed orbits; rather, after the passage of each crest, particles are displaced slightly from their previous positions, a phenomenon known as Stokes drift.[23][24]

text: As the depth below the free surface increases, the radius of the circular motion decreases. At a depth equal to half the wavelength λ, the orbital movement has decayed to less than 5% of its value at the surface. The phase speed (also called the celerity) of a surface gravity wave is – for pure periodic wave motion of small-amplitude waves – well approximated by

text: where

text:
In deep water, where

d
≥

1
2

λ

{\displaystyle d\geq {\frac {1}{2}}\lambda }

, so

2
π
d

λ

≥
π

{\displaystyle {\frac {2\pi d}{\lambda }}\geq \pi }

 and the hyperbolic tangent approaches

1

{\displaystyle 1}

, the speed

c

{\displaystyle c}

 approximates

text:
In SI units, with

c

deep

{\displaystyle c_{\text{deep}}}

 in m/s,

c

deep

≈
1.25

λ

{\displaystyle c_{\text{deep}}\approx 1.25{\sqrt {\lambda }}}

, when

λ

{\displaystyle \lambda }

 is measured in metres.
This expression tells us that waves of different wavelengths travel at different speeds. The fastest waves in a storm are the ones with the longest wavelength. As a result, after a storm, the first waves to arrive on the coast are the long-wavelength swells.

text: For intermediate and shallow water, the Boussinesq equations are applicable, combining frequency dispersion and nonlinear effects. And in very shallow water, the shallow water equations can be used.

text: If the wavelength is very long compared to the water depth, the phase speed (by taking the limit of c when the wavelength approaches infinity) can be approximated by

text: On the other hand, for very short wavelengths, surface tension plays an important role and the phase speed of these gravity-capillary waves can (in deep water) be approximated by

text: where

text: When several wave trains are present, as is always the case in nature, the waves form groups. In deep water the groups travel at a group velocity which is half of the phase speed.[26] Following a single wave in a group one can see the wave appearing at the back of the group, growing and finally disappearing at the front of the group.

text:
As the water depth

d

{\displaystyle d}

 decreases towards the coast, this will have an effect: wave height changes due to wave shoaling and refraction. As the wave height increases, the wave may become unstable when the crest of the wave moves faster than the trough. This causes surf, a breaking of the waves.

text:
The movement of wind waves can be captured by wave energy devices. The energy density (per unit area) of regular sinusoidal waves depends on the water density

ρ

{\displaystyle \rho }

, gravity acceleration

g

{\displaystyle g}

 and the wave height

H

{\displaystyle H}

 (which, for regular waves, is equal to twice the amplitude,

a

{\displaystyle a}

):

text: The velocity of propagation of this energy is the group velocity.

text: Wind wave models[edit]

text: Surfers are very interested in the wave forecasts. There are many websites that provide predictions of the surf quality for the upcoming days and weeks. Wind wave models are driven by more general weather models that predict the winds and pressures over the oceans, seas and lakes.

text: Wind wave models are also an important part of examining the impact of shore protection and beach nourishment proposals. For many beach areas there is only patchy information about the wave climate, therefore estimating the effect of wind waves is important for managing littoral environments.

text: Seismic signals[edit]

text: Ocean water waves generate land seismic waves that propagate hundreds of kilometers into the land.[27] These seismic signals usually have the period of 6 ± 2 seconds. Such recordings were first reported and understood in about 1900.

text: There are two types of seismic "ocean waves". The primary waves are generated in shallow waters by direct water wave-land interaction and have the same period as the water waves (10 to 16 seconds). The more powerful secondary waves are generated by the superposition of ocean waves of equal period traveling in opposite directions, thus generating standing gravity waves – with an associated pressure oscillation at half the period, which is not diminishing with depth. The theory for microseism generation by standing waves was provided by Michael Longuet-Higgins in 1950, after in 1941 Pierre Bernard suggested this relation with standing waves on the basis of observations.[28][29]

text: Internal waves[edit]


document_title: List of San Diego Padres seasons

question_text: when was the last time the san diego padres made the playoffs

root

text: List of San Diego Padres seasons

text: The San Diego Padres are a professional baseball franchise based in San Diego, California.

tag: p

text: They began play in 1969, but did not achieve their first winning season until 1978, though they failed to sustain this over the next half-decade. However, in 1984 the Padres surprisingly reached their first-ever postseason appearance and won the National League Championship before losing to a very strong Detroit Tiger outfit in the World Series.

text: This did not usher in a prolonged period of success for the Padres, who failed to achieve a second postseason appearance until 1996, and after a disappointing 1997 they rebounded again with a franchise-best 98 wins and reached the World Series only to face another exceptionally formidable opponent in the late-1990s Yankees dynasty. The Padres yet again faltered, but achieved four consecutive winning seasons for the only time in franchise history between 2004 and 2007 without winning more than one playoff game. The Padres have not played in the postseason since 2006 despite only the fourth 90-win season in franchise history during 2010.

text:
World Series champions †
NL champions *
Division champions ^
Wild card berth (1995–present) ¤

tag: table

text:
Season
Level
League
Division
Finish
Wins
Losses
Win%
GB
Postseason
Awards

1969
MLB
NL
West
6th
52
110
.321
41

1970
MLB
NL
West
6th
63
99
.389
39

1971
MLB
NL
West
6th
61
100
.379
28½

1972
MLB
NL
West
6th
58
95
.379
36½

1973
MLB
NL
West
6th
60
102
.370
39

1974
MLB
NL
West
6th
60
102
.370
42

1975
MLB
NL
West
4th
71
91
.438
37

1976
MLB
NL
West
5th
73
89
.451
29

Randy Jones (CYA)
Butch Metzger (ROY)

1977
MLB
NL
West
5th
69
93
.426
29

1978
MLB
NL
West
4th
84
78
.519
11

Gaylord Perry (CYA)

1979
MLB
NL
West
5th
68
93
.422
22

1980
MLB
NL
West
6th
73
89
.451
19½

1981
MLB
NL
West
6th
23
33
.411
12½

6th
18
36
.333
15½

1982
MLB
NL
West
4th
81
81
.500
8

1983
MLB
NL
West
4th
81
81
.500
10

1984
MLB
NL *
West ^
1st
92
70
.568
—
Won NLCS (Cubs) 3–2
Lost World Series (Tigers) 4–1 *

1985
MLB
NL
West
3rd
83
79
.512
12

1986
MLB
NL
West
4th
74
88
.457
22

1987
MLB
NL
West
6th
65
97
.401
25

Benito Santiago (ROY)

1988
MLB
NL
West
3rd
83
78
.516
11

1989
MLB
NL
West
2nd
89
73
.549
3

Mark Davis (CYA)

1990
MLB
NL
West
4th
75
87
.463
16

1991
MLB
NL
West
3rd
84
78
.519
10

1992
MLB
NL
West
3rd
82
80
.506
16

1993
MLB
NL
West
6th
61
101
.377
43

1994
MLB
NL
West
4th
47
70
.402
12½
Playoffs cancelled

1995
MLB
NL
West
3rd
70
74
.486
8

1996
MLB
NL
West ^
1st
91
71
.562
—
Lost NLDS (Cardinals) 3–0
Ken Caminiti (MVP)
Bruce Bochy (MOY)

1997
MLB
NL
West
4th
76
86
.469
14

1998
MLB
NL *
West ^
1st
98
64
.605
—
Won NLDS (Astros) 3–1
Won NLCS (Braves) 4–2
Lost World Series (Yankees) 4–0 *
Bruce Bochy (MOY)

1999
MLB
NL
West
4th
74
88
.457
26

2000
MLB
NL
West
5th
76
86
.469
21

2001
MLB
NL
West
4th
79
83
.488
13

2002
MLB
NL
West
5th
66
96
.407
32

2003
MLB
NL
West
5th
64
98
.395
36½

2004
MLB
NL
West
3rd
87
75
.537
6

2005
MLB
NL
West ^
1st
82
80
.506
—
Lost NLDS (Cardinals) 3–0

2006
MLB
NL
West ^
1st
88
74
.543
—
Lost NLDS (Cardinals) 3–1

2007
MLB
NL
West
3rd
89
74
.546
1½

Jake Peavy (CYA)

2008
MLB
NL
West
5th
63
99
.389
21

2009
MLB
NL
West
4th
75
87
.463
20

2010
MLB
NL
West
2nd
90
72
.555
2

Heath Bell (ROY)
Bud Black (MOY)

2011
MLB
NL
West
5th
71
91
.435
23

2012
MLB
NL
West
4th
76
86
.469
18

2013
MLB
NL
West
T-3rd
76
86
.469
16

2014
MLB
NL
West
3rd
77
85
.475
17

2015
MLB
NL
West
4th
74
88
.457
18

2016
MLB
NL
West
5th
68
94
.420
23

2017
MLB
NL
West
4th
71
91
.438
33

Regular season
3612
4201
.462
5 Postseason Appearances

Playoff games
12
22
.353
5 Division Titles, 2 League Pennants

Playoff series
3
5
.375
0 World Series Championships

text: Lost 2007 National League Wild Card tie-breaker game to the Colorado Rockies.

tag: ul

text: Record by decade[edit]

text: The following table describes the Padres' MLB win–loss record by decade.

text:
Decade
Wins
Losses
Pct

1960s
52
110
.321

1970s
667
942
.415

1980s
762
805
.486

1990s
758
799
.487

2000s
769
852
.474

2010s
532
602
.469

All-time
3540
4110
.463

text: These statistics are from Baseball-Reference.com's San Diego Padres History & Encyclopedia,[1] and are current as of October 18, 2016.


document_title: Friday the 13th (1980 film)

question_text: who did the killing in the first friday the 13th movie

text: Friday the 13th (1980 film)

text: Plot[edit]

text: In the summer of 1958 at Camp Crystal Lake, two counselors named Barry and Claudette sneak away from a campfire and into a storage barn. They prepare to have sex before an unseen assailant enters and murders them.

text: Twenty-one years later, on June 13, 1979, newly hired camp counselor Annie Phillips asks for directions to the reopened Camp Crystal Lake. An elderly man named Crazy Ralph warns her against going, claiming that the camp has a "death curse." A friendly truck driver named Enos agrees to give Annie a lift halfway to the camp. During the drive, Enos warns Annie about the camp, informing her that a young boy drowned at Crystal Lake in 1957 and about the two murders the following year. After Enos drops her off, Annie hitches another ride from an unseen assailant, who chases her into the woods and slashes her throat.

text: At the camp, counselors Ned, Jack, Bill, Marcie, Brenda, and Alice, along with the owner Steve Christy, refurbish the cabins and facilities. As a thunderstorm approaches, Steve leaves the campground to stock supplies. Meanwhile, the killer arrives at the camp and stalks the counselors. Ned sees someone walk into one of the cabins and follows. As Jack and Marcie have sex in one of the cabin's bunk beds, they are unaware of Ned's body directly above them, with his throat slit. Soon after, Jack is killed when his throat is pierced with an arrow from beneath the bed, and the killer murders Marcie with an axe slammed into her face. Brenda hears a child's voice calling for help and ventures outside her cabin to the archery range, only for the range lights to turn on as she is attacked off-screen. Steve later returns to the camp and is confronted by the unseen killer, who stabs him.

text: Alice and Bill are worried by their friends' disappearances, and they leave the main cabin to investigate. They discover a bloody axe in Brenda's bed, the phones disconnected, and the cars inoperable. When the power goes out, Bill goes to check on the generator and is murdered by the killer. Alice then heads out to look for him. Upon finding Bill's body impaled with arrows to the generator room's door, she flees back to the main cabin to hide only to be traumatized further when Brenda's body is thrown through the window.

text: Alice sees a vehicle pull up and rushes outside, thinking it is Steve. Instead, she is greeted by a middle-aged woman named Mrs. Voorhees, who claims to be an old friend of Steve's. As Alice brings her inside, Mrs. Voorhees begins to reminisce that her son Jason was the young boy who drowned in 1957. She blames his death on the counselors who were supposed to be watching him, but they instead were having sex and not paying attention to Jason's drowning. Revealing herself as the killer, Mrs. Voorhees turns violent and rushes toward Alice with a bowie knife, attempting to kill her. In the ensuing chase, Alice finds Annie's body inside Mrs. Voorhees' car and Steve's body hanging from a tree. Following a confrontation in which Mrs. Voorhees is knocked out, Alice escapes to the shore. Just as she begins to relax, Mrs. Voorhees finds her and attempts to kill her again with a machete. During the final struggle, Alice ultimately decapitates Mrs. Voorhees with her machete. Afterwards, a traumatized Alice boards and falls asleep inside a canoe, which floats out on Crystal Lake.

text: Just as Alice awakens and sees the police arriving, Jason's decomposing body suddenly emerges from the lake and drags her underwater. She then awakens in a hospital, where a police officer and medical staff tend to her. When Alice asks about Jason, the officer says that there was no sign of any boy. Alice says, "Then he's still there," as the lake is shown with a single ripple on the open water.

text: Cast[edit]

text:
Betsy Palmer as Mrs. Voorhees
Adrienne King as Alice Hardy
Harry Crosby III as Bill Brown
Jeannine Taylor as Marcie Cunningham/Stanler
Laurie Bartram as Brenda Jones
Kevin Bacon as Jack Burrell/Marand
Mark Nelson as Ned Rubenstein
Robbi Morgan as Annie Phillips
Peter Brouwer as Steve Christy
Rex Everhart as Enos
Walt Gorney as Crazy Ralph
Willie Adams as Barry Jackson
Debra S. Hayes as Claudette Hayes
Ari Lehman as Jason Voorhees

text: Production[edit]

text: Development[edit]

text: Friday the 13th was produced and directed by Sean S. Cunningham, who had previously worked with filmmaker Wes Craven on the film The Last House on the Left. Cunningham, inspired by John Carpenter's Halloween, wanted Friday the 13th to be shocking, visually stunning and "[make] you jump out of your seat". Wanting to distance himself from The Last House on the Left, Cunningham wanted Friday the 13th to be more of a "roller-coaster ride".[1]

text: Friday the 13th began its life as nothing more than a title. Initially, A Long Night at Camp Blood was the working title during the writing process, but Cunningham believed in his "Friday the 13th" moniker, and quickly rushed out to place an advertisement in Variety. Worried that someone else owned the rights to the title and wanting to avoid potential lawsuits, Cunningham thought it would be best to find out immediately. He commissioned a New York advertising agency to develop his concept of the Friday the 13th logo, which consisted of big block letters bursting through a pane of glass.[5] In the end, Cunningham believed there were "no problems" with the title, but distributor George Mansour stated, "There was a movie before ours called Friday the 13th: The Orphan. It was moderately successful. But someone still threatened to sue. Either Phil Scuderi paid them off, but it was finally resolved."[6]

text: The film was shot in and around the townships of Hardwick, Blairstown and Hope, New Jersey in September 1979. The camp scenes were shot on a working Boy Scout camp, Camp No-Be-Bo-Sco which is located in Hardwick, New Jersey. The camp is still standing and still works as a summer camp.[7][8]

text: Writing[edit]

text: The script was written by Victor Miller, who later went on to write for several television soap operas, including Guiding Light, One Life to Live and All My Children. Miller delighted in inventing a serial killer who turned out to be somebody's mother, a murderer whose only motivation was her love for her child. "I took motherhood and turned it on its head and I think that was great fun. Mrs. Voorhees was the mother I'd always wanted—a mother who would have killed for her kids." Miller was unhappy about the filmmakers' decision to make Jason Voorhees the killer in the sequels. "Jason was dead from the very beginning. He was a victim, not a villain."[9] The idea of Jason appearing at the end of the film was initially not used in the original script, and was actually suggested by makeup designer Tom Savini. Savini stated that "The whole reason for the cliffhanger at the end was I had just seen Carrie, so we thought that we need a 'chair jumper' like that, and I said, 'let's bring in Jason'".[10]

text: Casting[edit]

text: A New York-based firm, headed by Julie Hughes and Barry Moss, was hired to find eight young actors to play the camp's staff members. Cunningham admits that he was not looking for "great actors", but anyone that was likable, and appeared to be a responsible camp counselor. The way Cunningham saw it, the actors would need to look good, read the dialogue somewhat well, and work cheap. Moss and Hughes were happy to find four actors, Kevin Bacon, Laurie Bartram, Peter Brouwer, and Adrienne King, who had previously appeared on soap operas.[11] The role of "Alice" was set up as an open casting call, a publicity stunt used to attract more attention to the film. King earned an audition primarily because she was the friend of someone working in Moss and Hughes’s office. After she auditioned, Moss recalls Cunningham commenting that they saved the best actress for last. As Cunningham explains, he was looking for people that could behave naturally, and King was able to show that to him in the audition.[12]

text:
I didn't even really think of this movie as a horror film. "To me, this was a small independent film about carefree teenagers who are having a rip-roaring time at a summer camp where they happen to be working as counselors. Then they just happen to get killed."
—Jeannine Taylor on how she viewed Friday the 13th.[12]

tag: div

text: With King cast in the role of lead heroine Alice, Laurie Bartram was hired to play Brenda. Kevin Bacon, Mark Nelson and Jeannine Taylor, who had known each other prior to the film, were cast as Jack, Ned, and Marcie respectively. It is Bacon and Nelson's contention that, because the three already knew each other, they already had the specific chemistry the casting director was looking for in the roles of Jack, Ned, and Marcie.[11] Taylor has stated that Hughes and Moss were highly regarded while she was an actress, so when they offered her an audition she felt that, whatever the part, it would "be a good opportunity".[12]

text: Friday the 13th was Nelson's first feature film, and when he went in for his first audition the only thing he was given to read were some comedic scenes. Nelson received a call back for a second audition, which required him to wear a bathing suit, which Nelson acknowledges made him start to wonder if something was off about this film. He did not fully realize what was going on until he got the part and was given the full script to read. Nelson explains, "It certainly was not a straight dramatic role, and it was only after they offered me the part that they gave me the full script to read and I realized how much blood was in it."[12] Nelson believes that Ned used humor to hide his insecurities, especially around Brenda, whom the actor believes Ned was attracted to. Nelson recalls an early draft of the script stating that Ned suffered from polio, and his legs were deformed while his upper body was muscular.[13] Ned is believed to have given birth to the "practical joker victim" of horror films. According to author David Grove, there was no equivalent character in John Carpenter's Halloween, or Bob Clark's Black Christmas before that. He served as a model for the slasher films that would follow Friday the 13th.[14]

text:
I went in to audition for [Moss and Hughes] for something else. They said, "you know, Robbi, you're not really right for this, but there's a movie called Friday the 13th and they need an adorable camp counselor."
—Robbi Morgan on how she landed the role of Annie.[12]

text: The part of Bill was handed over to Harry Crosby, son of Bing Crosby. Robbi Morgan, who plays Annie, was not auditioning for the film when she was offered the role. While in her office, Hughes just looked at Morgan and proclaimed "you're a camp counselor". The next day Morgan was on the set.[11]  Morgan only appeared on-set for a day to shoot all her scenes. Rex Everhart, who portrays Enos, did not film the truck scenes with Morgan, so she had to either act with an imaginary Enos, or exchange dialogue with Taso Stavrakis—Savini's assistant—who would sit in the truck with her.[15] It was Peter Brouwer's girlfriend that helped him land a role on Friday the 13th. After recently being written off the show Love of Life, Brouwer moved back to Connecticut to look for work. Learning that his girlfriend was working as an assistant director for Friday the 13th, Brouwer asked about any openings. Initially told casting was looking for big stars to fill the role of Steve Christy, it was not until Sean Cunningham dropped by to deliver a message to Brouwer's girlfriend, and saw him working in a garden, that Brouwer was hired.[11]

text: Estelle Parsons was initially asked to portray the film's killer, Mrs. Voorhees, but eventually declined. Her agent cited that the film was too violent, and did not know what kind of actress would play such a part. Hughes and Moss sent a copy of the script to Betsy Palmer, in hopes that she would accept the part. Palmer could not understand why someone would want her for a part in a horror film, as she had previously starred in films such as Mister Roberts, The Angry Man, and The Tin Star. Palmer only agreed to play the role because she needed to buy a new car, even when she believed the film to "be a piece of shit."[11] Stavrakis subbed for Betsy Palmer as well, which involved Morgan's character being chased through the woods by Mrs. Voorhees, although the audience only sees a pair of legs running after Morgan. Palmer had just arrived in town when those scenes were about to be filmed, and was not in the physical shape necessary to chase Morgan around the woods. Morgan's training as an acrobat assisted her in these scenes, as her character was required to leap out of a moving jeep when she discovers that Mrs. Voorhees does not intend to take her to the camp.[15] Betsy Palmer explains how she developed the character of Mrs. Voorhees:

text: "Being an actress who uses the Stanislavsky method, I always try to find details about my character. With Pamela... I began with a class ring that I remember reading in the script that she'd worn. Starting with that, I traced Pamela back to my own high school days in the early 1940s. So it's 1944, a very conservative time, and Pamela has a steady boyfriend. They have sex—which is very bad of course—and Pamela soon gets pregnant with Jason. The father takes off and when Pamela tells her parents, they disown her because having... babies out of wedlock isn't something that good girls do. I think she took Jason and raised him the best she could, but he turned out to be a very strange boy. [She took] lots of odd jobs and one of those jobs was as a cook at a summer camp. Then Jason drowns and her whole world collapses. What were the counselors doing instead of watching Jason? They were having sex, which is the way that she got into trouble. From that point on, Pamela became very psychotic and puritanical in her attitudes as she was determined to kill all of the immoral camp counselors."[16]

text: Cunningham wanted to make the Mrs. Voorhees character "terrifying", and to that end he believed it was important that Palmer not act "over the top". There was also the fear that Palmer's past credits, as more of a wholesome character, would make it difficult to believe she could be scary.[17] Ari Lehman, who had previously auditioned for Cunningham's Manny's Orphans, failing to get the part, was determined to land the role of Jason Voorhees. According to Lehman, he went in very intense and afterward Cunningham told him he was perfect for the part.[11] In addition to the main cast, Walt Gorney came on as "Crazy Ralph", the town's soothsayer. The character of Crazy Ralph was meant to establish two functions: foreshadow the events to come, and insinuate that he could actually be the murderer. Cunningham has stated that he was apprehensive about including the character, and is not sure if he accomplished his goal of creating a new suspect.[12]

text: Music[edit]

text:
Friday the 13thSoundtrack album by Harry ManfrediniReleased
January 13, 2012Genre
Film scoreLength
43:54Label
Gramavision RecordsLa-La Land Records

text: When Harry Manfredini began working on the musical score, the decision was made to only play music when the killer was actually present so as to not "manipulate the audience".[18] Manfredini pointed out the lack of music for certain scenes: "There's a scene where one of the girls... is setting up the archery area... One of the guys shoots an arrow into the target and just misses her. It's a huge scare, but if you notice, there's no music. That was a choice."[18] Manfredini also noted that when something was going to happen, the music would cut off so that the audience would relax a bit, and the scare would be that much more effective.[citation needed]

text: Because the killer, Mrs. Voorhees, appears onscreen only during the final scenes of the film, Manfredini had the job of creating a score that would represent the killer in her absence.[18] Manfredini borrows from the 1975 film Jaws, where the shark is likewise not seen for the majority of the film but the motif created by John Williams cued the audience to the shark's invisible menace.[19] Sean S. Cunningham sought a chorus, but the budget would not allow it. While listening to a Krzysztof Penderecki piece of music, which contained a chorus with "striking pronunciations", Manfredini was inspired to recreate a similar sound. He came up with the sound "ki ki ki, ma ma ma" from the final reel when Mrs. Voorhees arrives and is reciting "Kill her, mommy!" The "ki" comes from "kill", and the "ma" from "mommy". To achieve the unique sound he wanted for the film, Manfredini spoke the two words "harshly, distinctly and rhythmically into a microphone" and ran them into an echo reverberation machine.[18] Manfredini finished the original score after a couple of weeks, and then recorded the score in a friend's basement.[19] Victor Miller and assistant editor Jay Keuper have commented on how memorable the music is, with Keuper describing it as "iconographic". Manfredini says, "Everybody thinks it's cha, cha, cha. I'm like, 'Cha, cha, cha? What are you talking about?'"[20]

text: In 1982, Gramavision Records released a LP record of selected pieces of Harry Manfredini's scores from the first three Friday the 13th films.[21] On 13 January 2012, La-La Land Records released a limited edition 6-CD boxset containing Manfredini's scores from the first six films. It sold out in less than 24 hours.[22]

text: Box office[edit]

text: Paramount bought Friday the 13th's distribution rights for $1.5 million, after seeing a screening of the film. They spent approximately $500,000 in advertisements for the film, and then an additional $500,000 when the film began performing well at the box office.[23] Friday the 13th opened theatrically on 9 May 1980 across the United States, ultimately expanding its release to 1,100 theaters. It took in $5,816,321 in its opening weekend, before finishing domestically with $39,754,601.  It was the 18th highest-grossing film that year, facing stiff horror film competition from such high-profile releases as The Shining, Dressed To Kill, The Fog and Prom Night.  The worldwide gross was $59,754,601.[24][25] Friday the 13th was released internationally, which was unusual for an independent film with, at the time, no well-recognized or bankable actors; aside from well-known television and movie actress Betsy Palmer.[26] The film would take in approximately $20 million in international box office receipts.[27] Not factoring in international sales, or the cross-over film with A Nightmare on Elm Street 's Freddy Krueger, the original Friday the 13th is the highest-grossing film of the film series.[28]

text: To provide context with the box office gross of films in 2014, the cost of making and promoting Friday the 13th—which includes the $550,000 budget and the $1 million in advertisement—is approximately $4.5 million. With regard to the US box office gross, the film would have made $177.72 million in adjusted 2017 dollars.[29] On 13 July 2007, Friday the 13th was screened for the first time on Blairstown's Main Street in the very theater which appears shortly after the opening credits.[8] Overflowing crowds forced the Blairstown Theater Festival, the sponsoring organization, to add an extra screening. The event was covered by local media and New York City's Channel 11, WPIX.[30] A 30th Anniversary Edition was released on March 10, 2010.[31] A 35th-anniversary screening was held in the Griffith Park Zoo as part of the Great Horror Campout on March 13, 2015.[32]

text: Reception[edit]

text: The film's most vocal detractor was Gene Siskel, who in his review called Cunningham "one of the most despicable creatures ever to infest the movie business".[33] He also published the address for Charles Bluhdorn, the chairman of the board of Gulf+Western, which owned Paramount, as well as Betsy Palmer's home city and encouraged fellow detractors to write to them and express their contempt for the film. To convince people not to see it, he even gave away the ending.[34] Siskel and Roger Ebert spent an entire episode of their TV show berating the film (and other slasher films of the time) because they felt it would make audiences root for the killer.[35] Leonard Maltin initially awarded the film one star, or 'BOMB', but later changed his mind and awarded the film a star and-a-half "simply because it's slightly better than Part 2" and called it a "gory, cardboard thriller".[36] Variety claimed the film was "low budget in the worst sense—with no apparent talent or intelligence to offset its technical inadequacies—Friday the 13th has nothing to exploit but its title."[37] On Metacritic, which assigns a normalized rating to reviews, the film has a weighted average score of 19 out of 100, based on 5 critics, indicating "Overwhelming dislike".[38]

text: Later on, retrospective reviews were much more positive regarding the film, with praise mainly towards its score, make-up effects, cinematography, charming cast, and Betsy Palmer's role, while it drew criticism for its script and lack of character development.[citation needed] Dave Kehr said that "For all its shoddiness, the film manages, just barely, to achieve its ignoble goals — it delivers what it promises".[citation needed] James Kendrick gave the film a 3 out of 4, calling it "a campfire boogeyman story designed to do little more than build tension and deliver a few well-timed shocks, which it does with precision and even a bit of artistry".[citation needed] Kevin Carr said that "what makes the movie work is that the slasher genre hadn't been set in stone yet, and some choices that director Sean S. Cunningham makes in the film that work against type".[citation needed]

text:
Rotten Tomatoes gave the film 61% on 51 critic reviews, the consensus reading: “Rather quaint by today’s standards, Friday the 13th still has it’s share of bloody surprises and a ‘70s-holdover aesthetic to slightly compel.”[39]
The film was nominated for AFI's 100 Years...100 Thrills.[40] The film was nominated twice at the 1st Golden Raspberry Awards for Worst Picture and Worst Supporting Actress for Betsy Palmer, winning neither.[41]

text: Home media[edit]

text: On 3 February 2009, Paramount Home Entertainment released Friday the 13th on an unrated uncut home video version for the first time in the United States (all previous VHS, LaserDisc and DVD releases were the rated theatrical version). It is available on both DVD and Blu-ray Disc. The uncut version of the film contains approximately 10 seconds of previously unreleased footage. In 2011, the uncut version of Friday the 13th was released in a 4-disc DVD collection with the first three sequels.[42]  The Australia DVD/Blu-ray release was July 1, 2009, and features commentary by Sean S. Cunningham, among several other bonuses.

text: Cultural significance[edit]

text: Contemporary scholars in film criticism, such as Tony Williams, have credited Friday the 13th for initiating the subgenre of the "stalker" or slasher film.[43] Williams views Friday the 13th as "symptomatic of its era," particularly Reagan-era America, and part of a trajectory of films such as The Texas Chain Saw Massacre (1974) and Race with the Devil (1975), which "exemplify a particular apocalyptic vision moving from disclosing family contradictions to self-indulgent nihilism."[43]

text: Cultural critic Graham Thompson also considers the film as a template, along with John Carpenter's Halloween (1978), that "instigated a rush" of films of its type, in which young people away from supervision are systematically stalked and murdered by a masked villain.[44] Film critic Timothy Shary notes in his book Teen Movies: American Youth on Screen (2012) that where Halloween introduced a "more subtle sexual curiosity within its morbid moral lesson," films such as Friday the 13th "capitali[zed] on the reactionary aspect of teen sexuality, slaughtering wholesale those youth who deigned to cross the threshold of sexual awareness."[45]

text: Related works[edit]

text: Sequels[edit]

text: As of 2018, Friday the 13th has spawned ten sequels, including a crossover film with A Nightmare on Elm Street villain Freddy Krueger. Friday the 13th Part 2 (1981) introduced Jason Voorhees, the son of Mrs. Voorhees, as the primary antagonist, which would continue for the remaining sequels (with exception of the fifth movie) and related works. Most of the sequels were filmed on larger budgets than the original. For comparison, Friday the 13th had a budget of $550,000, while the first sequel was given a budget of $1.25 million.[46] At the time of its release, Freddy vs. Jason had the largest budget, at $25 million.[47] All of the sequels repeated the premise of the original, so the filmmakers made tweaks to provide freshness. Changes involved an addition to the title—as opposed to a number attached to the end—like "The Final Chapter" and "Jason Takes Manhattan", or filming the movie in 3-D, as Miner did for Friday the 13th Part III (1982).[48] One major addition that would affect the entire film series was the addition of Jason's hockey mask in the third film; this mask would become one of the most recognizable images in popular culture.[49]

text: A reboot to Friday the 13th came to theaters in February 2009, with Freddy vs. Jason writers Damian Shannon and Mark Swift hired to script the new film.[50] The film focused on Jason Voorhees, along with his trademark hockey mask.[51] The film was produced by Michael Bay, Andrew Form and Brad Fuller through Bay's production company Platinum Dunes, for New Line Cinema.[50] In November 2007, Marcus Nispel, director of the 2003 remake of The Texas Chainsaw Massacre, was hired to direct.[52] The film had its United States release on 13 February 2009.[53]

text: Adaptions and literature[edit]

text: In 1987, seven years after the release of the motion picture, Simon Hawke produced a novelization of Friday the 13th. One of the few additions to the book was Mrs. Voorhees begging the Christy family to take her back after the loss of her son; they agreed.[54] Another addition in the novel is more understanding in Mrs. Voorhees' actions. Hawke felt the character had attempted to move on when Jason died, but her psychosis got the best of her. When Steve Christy reopened the camp, Mrs. Voorhees saw it as a chance that what happened to her son could happen again. Her murders were against the counselors, because she saw them all as responsible for Jason's death.[55]

text: A number of scenes from the film were recreated in Friday the 13th: Pamela's Tale, a two-issue comic book prequel released by WildStorm in 2007. In 2016, the book On Location in Blairstown: The Making of Friday the 13th was released detailing the planning and filming of the movie.[56]