document_title: Guardians of the Galaxy Vol. 2

question_text: when does gotg 2 come out in canada

question_tokens: when does gotg 2 come out in canada

text: Guardians of the Galaxy Vol. 2

text: Plot[edit]

text: In 2014, Peter Quill, Gamora, Drax, Rocket, and Baby Groot are renowned as the Guardians of the Galaxy. Ayesha, leader of the Sovereign race, has the Guardians protect valuable batteries from an inter-dimensional monster in exchange for Gamora's estranged sister Nebula, who was caught attempting to steal the batteries. After Rocket steals some for himself, the Sovereign attacks the Guardians' ship with a fleet of drones. These are destroyed by a mysterious figure, and the Guardians crash-land on a nearby planet. There this figure reveals himself as Quill's father, Ego, and invites Quill, Gamora, and Drax to his home planet. Rocket and Groot remain behind to repair the ship and guard Nebula.

text: Ayesha hires Yondu Udonta and his crew, who have been exiled from the greater Ravager community for child trafficking, to recapture the Guardians. They capture Rocket, but when Yondu hesitates to turn over Quill, whom he raised, his lieutenant Taserface leads a mutiny with help from Nebula. Taserface imprisons Rocket and Yondu aboard Yondu's ship and executes Yondu's loyalists. Nebula leaves to find and kill Gamora, whom she blames for the torture inflicted on her by their father, Thanos. While imprisoned, Rocket and Yondu bond. Groot and Kraglin, a remaining Yondu loyalist, free Rocket and Yondu, and they destroy the ship and its crew as they escape, though not before Taserface warns the Sovereign.

text: Ego, a god-like Celestial that manipulated the matter around its consciousness to form this "home" planet, explains that it projected a humanoid guise to travel the universe and discover a purpose, eventually falling in love with Quill's mother Meredith. Ego hired Yondu to collect the young Quill after Meredith's death, but the boy was never delivered and Ego has been searching for him ever since. He teaches Quill to manipulate Celestial power. Nebula arrives at Ego's planet and tries to kill Gamora, but the pair reach an uneasy alliance when they discover caverns filled with skeletal remains. Ego reveals to Quill that in his travels he planted seedlings on thousands of worlds which can terraform them into new extensions of himself, but they can only be activated by the power of two Celestials. To that end, he impregnated countless women and hired Yondu to collect the children, but killed them all when they failed to access the Celestial power. Under Ego's influence, Quill helps him activate the seedlings, which begin to consume every world, but Quill fights back when Ego reveals that he killed Meredith due to the distraction she posed.

text: Mantis, Ego's naive empath servant, grows close to Drax and warns him of Ego's plan. Gamora and Nebula also learn of the plan as Rocket, Yondu, Groot and Kraglin arrive. As they come under attack from the Sovereign's dromes, the reunited Guardians find Ego's brain at the planet's core. Rocket makes a bomb using the stolen batteries, which Groot plants on the brain. Quill fights Ego with his newfound Celestial powers to distract him long enough for the other Guardians and Mantis to escape. The bomb then explodes, killing Ego and disintegrating the planet. Yondu sacrifices himself to save Quill, who realizes that the reason Yondu kept him was to spare him from the fate of Ego's other progeny, and that Yondu was Quill's true "daddy". Having reconciled with Gamora, Nebula still chooses to leave and attempt to kill Thanos by herself. The Guardians hold a funeral for Yondu, which is attended by dozens of Ravager ships, acknowledging Yondu's sacrifice and accepting him as a Ravager again.

text: In a series of mid- and post-credit scenes, Kraglin takes up Yondu's telekinetic arrow and control-fin; Ravager leader Stakar Ogord reunites with his ex-teammates; Groot starts growing back to normal size, exhibiting typical teenage behavior in the process;[N 1] Ayesha creates a new artificial being with whom she plans to destroy the Guardians, naming him Adam;[N 2] and a group of uninterested Watchers abandon their informant, who is discussing several experiences on Earth.

text: Cast[edit]

text:
Chris Pratt as Peter Quill / Star-Lord:
The half-human, half-Celestial leader of the Guardians of the Galaxy who was abducted from Earth as a child and raised by a group of alien thieves and smugglers called the Ravagers.[6][7] Pratt said Quill is now famous throughout "the galaxy for having saved so many people... He feels like he's part of this group, a leader of this group. He's a little more responsible and trying to stay out of trouble, but not necessarily doing the best job."[8] Pratt stated that working on the film forced him to come to terms with the death of his own father.[9] Pratt returns as part of a multi-film contract with Marvel.[10] Wyatt Oleff once again portrays a young Quill.[11]

Zoe Saldana as Gamora:
A member of the Guardians and an orphan from an alien world who seeks redemption for her past crimes. She was trained by Thanos to be his personal assassin.[7] Saldana described Gamora's role in the team as "the voice of reason", saying, "She's surrounded by all these dudes who are so stupid half the time,"[12] and added that she is the "Mom" of the team, saying that she is "just a meticulous, detailed, professional individual."[13] Regarding Gamora's relationship with Nebula, Saldana described it as "volatile" and added, "we're starting somewhere very crazy but appropriate given where we had ended things off in the first" film.[14]

Dave Bautista as Drax the Destroyer:
A member of the Guardians and highly skilled warrior in search for vengeance against Thanos for his family's slaughter.[7] Bautista waited for the final version of the script to not take "away from the magic", which he felt happened when he read early drafts of for the first film.[15] He added that "wasn't crazy about my part [in Vol. 2, initially]. It went a different direction than what I thought they were going to go with Drax," noting he did not "think Drax was that significant in the film". The part "clicked" for Bautista after the table read with the other cast.[16] Bautista called Drax "more funny, driven" than in the first film, and having "a sense of innocence and heartbreak about him",[12] despite "most people's first perception of Drax [that] he's just a big, muscly brute".[17] Bautista's makeup took only 90 minutes to apply, down from four hours for the first film. He would have to sit in a sauna at the end of the day to get the makeup off, after his makeup test found it too "abrasive".[13]

Vin Diesel as Baby Groot:
A member of the Guardians who is a tree-like humanoid and the accomplice of Rocket.[18] The character began growing from a sapling at the end of the first film with the intention of being fully grown by the sequel, but writer/director James Gunn eventually decided to keep him as "Baby Groot"; this contributed to Gunn's setting of the film only a few months after the first.[19] Baby Groot does not have any of his previous memories,[20] having to "start all over, so to speak. So we're going to see this goofy, adorable, baby Groot [just] kinda learning as he goes."[21] Prop master Russell Bobbitt created a 1:1 scale model of the 10-inch (25 cm) Baby Groot for filming, to use as a lighting reference and sometimes as a puppet for the actors to interact with.[22] As Groot only communicates with the phrase "I am Groot" in different inflections, Gunn created a "Groot Version" of the script for himself and Diesel, which contains each of Groot's lines in English.[23] Diesel used a higher register of his voice for Baby Groot, which was pitched up by seven to nine semitones depending on the take. He also delivered lines slowly to avoid any time stretching issues.[24] Diesel recorded Groot's voice for sixteen foreign-language releases of the film (up from six in the first film).[25] Sean Gunn provided on-set reference for adolescent Groot in the post-credit sequence.[26]

Bradley Cooper as Rocket:
A member of the Guardians who is a genetically modified raccoon bounty hunter and mercenary, who is also a master of weapons and military tactics.[7] Sean Gunn once again served as the stand-in for the character during filming,[27] with Cooper's performance also referenced.[26] Sean Gunn said that "Rocket has the same sort of crisis of faith [that he had in the first film] about whether or not he belongs in this family",[28] with James Gunn adding, "this is really about Rocket ... accepting his place within a group of people, which probably seemed like a good idea for two seconds when they were kind of getting along and saving the planet, and now's it's like, he's just not very comfortable with the idea". Feige stated that the relationship between Rocket and Groot has changed, saying, "Groot was Rocket's protector in the first movie, [and now] Rocket is Groot's protector."[13]

Michael Rooker as Yondu Udonta:
A blue-skinned buccaneer who is the leader of the Ravagers, a fatherly figure to Quill,[29] and member of the Guardians.[30] Yondu has a larger head fin in the film, to look closer to his comic counterpart,[31] and Rooker worked with the prosthetic department to add gaps to his prosthetic teeth, "just like real teeth", to aid him in whistling as the character.[32] Rooker explained that, for the sequel, Gunn "wanted people to experience more in-depth what Yondu was thinking and how he's feeling—a more serious Yondu." Rooker noted the complex relationship between Yondu and Quill where "we don't agree on things...they are constantly at each other's throats [but] Yondu truly cares about this kid."[33] Gunn refused to [end the film with Yondu's death] for a long time...But, at the end of the day, I knew that's where it needed to go ... This is a story about a father's love for his son, his ultimate love, so much love that he sacrifices himself for that, and that's what Yondu is. He is 100 percent Peter Quill's father" despite Ego being Quill's biological father.[34] Before the release of Vol. 2, Rooker spent time on the set of Avengers: Infinity War to counteract rumors that he was not in that film because of his death in this one.[35]

Karen Gillan as Nebula:
An adopted daughter of Thanos who was raised with Gamora as siblings,[36] and a reluctant member of the Guardians.[14] Gillan stated the film would further explore the sisterly relationship between Nebula and Gamora,[37] including their backstory "and what happened to these two girls growing up and actually how awful it was for them and how it's ruined their relationship",[13] adding "we're [also] going to start to see how much pain [Thanos] actually caused [Nebula]... we really start to see the emotional crack in her character".[38] While Gillan had to shave her head for the first film, she only had to shave half of her head for the sequel, taking away the underneath part and leaving the top.[38] Gillan's makeup took two and a half hours to apply, down from five hours for the first film.[22]

Pom Klementieff as Mantis:
A member of the Guardians with empathic powers who lives with Ego.[39][40] Executive producer Jonathan Schwartz said the character "has never really experienced social interaction", and learns about "social intricacies" from the other Guardians.[41] Klementieff added, "She was really lonely and by herself, so it's a completely new thing to meet these people and to discover new things", comparing this to a child making awkward mistakes in social situations. Mantis and Drax have an "interesting" relationship in the film due to both being "complete odd balls".[13] Steve Englehart, Mantis's co-creator, was disappointed with the character's portrayal, saying, "That character has nothing to do with Mantis ... I really don't know why you would take a character who is as distinctive as Mantis is and do a completely different character and still call her Mantis."[42]

Elizabeth Debicki as Ayesha:
The golden High Priestess and the leader of the Sovereign people,[43][44][45] a genetically engineered race who are "gold and perfect and wanting to be physically and mentally impeccable." Gunn was "very specific" when writing the character, and after casting director Sarah Finn suggested Debicki, Gunn "knew right away that she was the one". Gunn highlighted the actress's beauty and 6 ft 3 in (1.91 m) height. Debicki wore platform shoes to increase her height to 6 ft 7 in (2.01 m).[33]

Chris Sullivan as Taserface:
The leader of a mutinous group of the Ravagers.[43][45] Gunn originally posted a photo of the comic book character on his social media after landing Guardians of the Galaxy, calling him "the dumbest character of all time" and saying he would never feature the character in a film. After eventually deciding to use the character in the sequel, Gunn felt the character had given himself the name Taserface and is "a real dumbass".[46] Sullivan's makeup took two-and-a-half to three-and-a-half hours to apply each day.[47]

Sean Gunn as Kraglin:
Yondu's second-in-command in the Ravagers.[36] Kraglin has an expanded role compared to the previous film—Sean Gunn explained, "In the first film he did a lot of just saying yes and being at Yondu's side, but in this movie things take a little bit of a different turn as Kraglin has a little bit of a crisis of conscience and has to decide whether he's going to stick with Yondu or join forces with the growing faction of mutineers."[33][48]

Sylvester Stallone as Stakar Ogord:
A high-ranking Ravager who has a history with Yondu.[31][49] Stallone called his character's relationship with Yondu "pretty intense and it's kind of a father/son type of thing".[33] For Stakar's acceptance of Yondu as a Ravager at the end of the film, Gunn asked Stallone to channel the "That'll do pig" line from the film Babe.[50] Gunn described Stakar as "very important to the Marvel Universe",[51] and said that "it's our plan to see more of Stallone" in future MCU films, though he was not sure then if that would include Vol. 3.[52]

Kurt Russell as Ego:
An ancient Celestial who is Quill's father.[31][43] Pratt was the first to suggest to Gunn that he consider Russell for the role; he portrays an avatar of Ego who is more traditionally seen in the comics in his "Living Planet" form.[53] Russell appreciated why he was wanted for the role after seeing Pratt's performance in the first film, feeling "That's my kinda guy. I know where that kind of goof comes from." He added, "I bring the right things [from previous roles]...I connected the dots from some of the things I've done in the past."[54] Ego replaces Quill's original comic father of J'son,[55] and was allowed to be used in the film after 20th Century Fox reached a deal with Marvel Studios to return the film rights of Ego for changing the power set of Negasonic Teenage Warhead, whom Fox wanted to use in Deadpool (2016).[56] Gunn originally thought Marvel held the rights to the character, and stated that, had the deal with Fox not been made, there was "no back up plan, and it would [have been] nearly impossible to just drop another character in," given the extensive work done surrounding the character.[57] For the film's opening sequence, set in 1980 Missouri, Aaron Schwartz served as facial reference for the young Ego.[58][59]

text: Additionally, reprising their roles from the first film are Laura Haddock as Meredith Quill, Gregg Henry as her father, Seth Green as the voice of Howard the Duck, and canine actor Fred as Cosmo.[60][59][61] Members of Yondu's Ravager crew appearing in the film include Evan Jones as Retch, Jimmy Urine as Half-Nut, Stephen Blackehart as Brahl,[45] Steve Agee as Gef,[45][62] Mike Escamilla as Scrote,[63] Joe Fria as Oblo, Terence Rosemore as Narblik,[45] and Tommy Flanagan as Tullk,[64][45][65] as well as Charred Walls of the Damned drummer and Howard Stern Show personality Richard Christy in a cameo appearance.[66] Many of these actors are close friends with Gunn.[33] The other members of Stakar and Yondu's old team, based on the comic's original incarnation of the Guardians of the Galaxy, include Michael Rosenbaum as Martinex, Ving Rhames as Charlie-27, and Michelle Yeoh as Stakar's female counterpart Aleta Ogord.[52][61] Also included in the team are the CG characters Krugarr and Mainframe, with the latter voiced, in an uncredited cameo, by Miley Cyrus.[52][67] Rosenbaum had previously auditioned to play Peter Quill in Vol. 1.[68] Gunn cast Yeoh because of his love of 1990s Hong Kong films,[69] and Cyrus after admiring "the tone of her voice" while watching her as a judge on The Voice.[67] He added that the team would return in future MCU films alongside Stallone's Stakar.[52]

text: Stan Lee appears as an informant to the Watchers, discussing previous adventures that include his cameos in other MCU films; he specifically mentions his time as a FedEx delivery man, referring to Lee's cameo in Captain America: Civil War.[70] This acknowledged the fan theory that Lee may be portraying the same character in all his cameos,[71] with Gunn noting that "people thought Stan Lee is [Uatu the Watcher] and that all of these cameos are part of him being a Watcher. So, Stan Lee as a guy who is working for the Watchers was something that I thought was fun for the MCU."[70][71] Feige added that Lee "clearly exists, you know, above and apart from the reality of all the films. So the notion that he could be sitting there on a cosmic pit stop during the jump gate sequence in Guardians…really says, so wait a minute, he's this same character who's popped up in all these films?"[72] Lee filmed several different versions of the scene, including an alternative where he references his role in Deadpool, which would have been the first acknowledgment of the X-Men film series by an MCU film.[71] Gunn later admitted that the Civil War reference is a continuity error, given Vol. 2 is set before the events of Civil War, saying, "I screwed up; I wasn't thinking. But I'm going to say that probably Stan Lee used the guise of a Fed Ex guy more than one time."[70]

text: David Hasselhoff makes a cameo appearance as himself, when Ego shape-shifts to his likeness,[11] while Rob Zombie once again has a Ravager voice cameo.[73][59] Footage of Jeff Goldblum dancing as the Grandmaster from the set of Thor: Ragnarok is used briefly during the end credits, with Feige explaining that Marvel "thought it would be fun to put it in there" and hint at the connection between that character and the Collector, who appeared in the first Guardians film.[74] Ben Browder, the star of the series Farscape which Gunn is a big fan of, cameos as a Sovereign Admiral.[75] Jim Gunn Sr. and Leota Gunn, parents of James and Sean Gunn, also make cameo appearances in the film.[76]

text: Production[edit]

text: Development[edit]

text:
"There are general ideas for what the sequel is and where it goes and who's involved and what happens and what we find out about our characters. So it's very general and that could change ... but I know a lot about who these characters are and where they came from and where they're going. I'm excited by the possibility of creating a sequel because we had to do a lot of setup in [the first] movie and with a sequel we don't have to do that setup which will make it so much easier for me."

—James Gunn, writer and director of Guardians of the Galaxy Vol. 2, on the state of the sequel in August 2014[77]

tag: div

text: In May 2014, Disney CEO Bob Iger talked about the future of Guardians of the Galaxy, saying, "We believe it has strong franchise potential."[78] He added that their goal was to create "another Avengers".[79] Director and co-screenwriter James Gunn said he would like to return for a sequel, and was contractually obligated to if asked.[80] The next month, producer Kevin Feige said there are "places we can take [the franchise] and we have ideas of where we'd like to go" based on the wide array of characters, worlds and storylines from the comics.[81] In July 2014, Guardians of the Galaxy co-screenwriter Nicole Perlman confirmed a sequel, saying it was "going to happen" due to the positive internal response to the first film at Disney, and that Gunn would write and direct.[82][83] At San Diego Comic-Con International soon after, the sequel was given a release date of July 28, 2017.[84]

text: Gunn had begun work on the film within a month, and said there would be at least one more Guardian from the comics appearing in the film.[85][86] In October, Gunn confirmed that all five original Guardians and other characters from the original film would return,[87] and the release date was moved up to May 5, 2017.[88] In the following months, Michael Rooker said he would return for the sequel as Yondu, and was looking forward to exploring new areas of the character;[29][89] Chris Pratt, who played Peter Quill / Star-Lord in the first film, confirmed the sequel would be one of his next projects;[6] and Bradley Cooper expressed interest and excitement when asked if he would return as Rocket for the sequel.[90] Vin Diesel also confirmed he would return as Groot.[18] In March 2015, Gunn revealed that filming would take place in Atlanta, Georgia with "major crew changes" from the first film, and that his brother, Sean Gunn, would return as Kraglin alongside Karen Gillan as Nebula.[36][91] He also discussed his relationship with Marvel, explained that the company "let me go and do my thing, and I truly listen to their notes and ideas. I've never been told to put in any character or plot element at all… When they trust you they give you a wide berth… we just fit."[91]

text: In May, Gunn said the sequel would feature fewer characters than the first film, and that he had planned to introduce two major new characters in the script—Mantis and Adam Warlock.[7][5] Talks had begun with an actor Gunn had in mind to portray Mantis,[92] while he had decided to remove Warlock due to the film "getting too busy", explaining, "one of the main things with Guardians of the Galaxy is not to add a bunch of characters, not to make it bigger in that way but to go deeper with the characters… and getting to know them more emotionally… everything is just getting too sprawling and too crazy for me in these superhero comic book movies."[7] Gunn added, "I adored what we had done with him. I think we did something really creative and unique with Adam Warlock. But it was one character too many and I didn't want to lose Mantis and Mantis was more organically part of the movie anyway."[5] He noted that Warlock could appear in future Guardians films, and is considered "a pretty important part" of the cosmic side of the Marvel Cinematic Universe.[93][5] The character's future introduction is hinted at in one of the film's mid-credits scenes.[4] Gunn noted that Marvel gave him "some blowback" for including the Warlock teaser because they felt fans would believe the character would be appearing in Avengers: Infinity War and its sequel, which was not the case. By including the scene, Gunn promised Marvel he would use his social media presence to clarify for fans that the character would not be seen in either Avengers film.[94]

text: Writing[edit]

text: After the film's announcement, Gunn said he knew "a lot of where I want to go [in the sequel]",[95] having written the backstory of Peter Quill, his father, and his history with Yondu during the making of the first film with the intention of exploring them in a future film.[19] Gunn wanted to give the sequel a different structure from the first film, since "one of the reasons people like Guardians is because it's fresh and different, so the second one will be fresh and different from the first one."[96] Before starting on the script, Gunn hoped to further explore Drax the Destroyer, Nebula, Kraglin, and the Collector, and expand on Xandarian, Kree, Krylorian, and Ravager culture.[95][97] He also hoped to introduce more female characters in the sequel, though wanted to avoid including "earthlings" such as Carol Danvers,[98] as well as Novas Richard Rider or Sam Alexander, saying, "I think Quill being the only earthling is important. That serves the entire movie-going audience and not just the handful of Nova [and Carol Danvers] fans."[99]

text: Feige said exploring Quill's father "would certainly be part of a next Guardians adventure…I think there's a reason we seeded it at the very end of the [first] film like that."[100] Gunn also stated that he wanted to make sure "Yondu's place in everything made sense" in regards to his relationship to Quill and his father, and also revealed Quill's father would not be J'son as in the comics.[55] Gunn "was less confident [Marvel] was going to buy in on Baby Groot than" including Ego the Living Planet, since "adult Groot was the most popular character from the first film and I didn't think they'd want to risk a good thing." However, by changing Groot, Gunn felt it "opened the film up" creatively, allowing Gunn to bring out "new aspects of our other characters."[101] Gunn said Thanos would only appear in the sequel "if he helps our story and he will not show up at all if not. Thanos is not the most important thing in Guardians 2, that's for damn sure. There's the Guardians themselves and other threats the Guardians are going to be facing that are not Thanos."[55] Feige later confirmed that Thanos would not appear in the sequel, as he was being saved for a "grander" return.[102][103] When asked about how the film would connect with the other Phase Three films in the Marvel Cinematic Universe, Gunn said, "I don't feel beholden to that stuff at all. I think it's really about the Guardians and what they are doing."[104]

text: Gunn set the film two-to-three months after the first film,[105][93] "because he felt the group are just such fragile egos and he didn't think this story could start years later."[93] Major planets visited in the film include Sovereign, Berhart and Contraxia. Feige also stated two or three other worlds would be seen, as well as "a little bit of Earth in this film, but it's not these characters going to Earth."[13] In December 2014, Gunn revealed the story for the film was written, saying, "It's [still] constantly shifting, but I feel like it's pretty strong. I'm excited about it."[106] By early February 2015, Gunn was "a few short weeks" away from submitting a full story treatment to Marvel, and said that when he first presented his idea for the sequel to the company they thought it was "risky". He described it as "not really based on anything" from the comics, being mainly an original story.[107][108] Gunn later referred to the full treatment as a "scriptment", "a 70-page combination of a script and a treatment and it goes through every beat of the movie".[7] By April, he was preparing to write the screenplay,[107] and in May he was hoping to complete the script before he began work on The Belko Experiment in June 2015.[92]

text: Pre-production[edit]

text: On June 2, 2015, Gunn announced on social media that he had completed the first draft of the screenplay, and that the film's title would not simply be Guardians of the Galaxy 2.[109] The same week, he confirmed the return of Zoe Saldana, Dave Bautista, and Cooper as Gamora, Drax, and Rocket, respectively.[7] At the end of the month, Gunn announced the film's title as Guardians of the Galaxy Vol. 2,[110] saying he "came up with a LOT of titles for Vol. 2. But because 'Guardians of the Galaxy' is already so wordy, it seemed strange to add another bunch of words after it. I liked Vol. 2 the best, so that's what I stuck on the cover of the screenplay—and, fortunately, [Marvel] liked it."[111]

text: In September 2015, Gunn said in a Facebook post that he wanted to use Sneepers, an alien race that first appeared in Marvel Comics in 1964, as background characters in the film, but was advised against it by Marvel's legal department because the name was too similar to snípur, the Icelandic word for clitoris.[112] The Marvel legal department later cleared the use of Sneepers in the film, in part because of all the media coverage Gunn's initial post received.[113] At the end of the month, Feige stated casting announcements would be made "over the next few months before the end of the year",[114] and by the end of October, Pom Klementieff was cast as Mantis.[39][40] Also, Matthew McConaughey was offered the role of the film's antagonist,[115] but had passed on it in favor of The Dark Tower. McConaughey felt he would have been "an amendment" in Vol. 2 in "a colorful part [made] for another big-name actor."[116] In December, Gunn said that he was corresponding with John C. Reilly about him reprising his role as Nova Corpsman Rhomann Dey,[117] while Kurt Russell entered early talks to play Quill's father.[118] After the death of David Bowie, Gunn said that there were discussions for Bowie to appear in the film as a member of Yondu's original crew.[119][120] Gunn also stated that he had completed the final draft of the script.[121] Benicio del Toro, who portrayed the Collector in the first film, expressed interest in portraying the character again, despite Marvel not contacting him about the sequel;[122] Gunn explained that the Collector "just didn't fit" into Vol. 2.[123] In early February, comedian Steve Agee was revealed to be in the film.[62]

text: Prop master Russell Bobbitt had difficulty finding the cassette decks that had been used in the first film, and all of the Sony Walkman headsets they sourced for the sequel were broken. Sony also did not have any headsets available for filming, while three pairs Bobbitt found on eBay cost around $1,800 and were not the exact model. Bobbitt eventually created six from scratch for Vol. 2. Other props he created for the film included two sets of blasters for Quill, with removable blaster cartridges, and "steampunk-looking weapons and belts" for the Ravagers;[22] Bobbitt explained that four different weapons were designed for the latter group, and then 15–20 versions of those were produced to be used by the various Ravager actors (there could be up to 85–95 Ravagers per scene). For their belts, the props team cut the leather themselves rather than buying existing belts, and then parts from different electronic devices such as radios and cell phones were glued together to make each belt "a unique piece of art". The prop department also made edible props for certain scenes: a prop of a stinkbug-inspired insect was made from chocolate and injected with black honey so it could be eaten on screen and "when he bit down the honey poured out of his mouth"; similarly, a "yarrow root" was designed based on enlarged images of pollen, and then created with non-dairy white chocolate to be eaten onscreen.[33]

text: Filming[edit]

text: Pre-shooting began on February 11, 2016,[124] at Pinewood Atlanta Studios in Fayette County, Georgia,[125] under the working title Level Up,[93] with Henry Braham serving as cinematographer and Scott Chambliss as production designer.[7][126] Gunn noted that many of the crew from the first film, such as cinematographer Ben Davis and production designer Charles Wood, signed on to work on Doctor Strange, and due to a late change in production schedule for that film, were unable to work on Vol. 2.[127][128]

text: Principal photography began on February 17,[43] with Marvel confirming that Russell had joined the cast, and revealing that Elizabeth Debicki and Chris Sullivan had also been cast, all in undisclosed roles.[43] The production used all 18 stages at Pinewood Atlanta, an increase in stage space from what was used for the first film. Gunn said the sequel required more sets than the first and "our sets are very large, even though a lot of the film is CGI. I like to have as many practical sets as we can and make the environments as real as possible so it balances out the CGI elements." Despite this, Gunn noted that there were less locations featured in the sequel, with the focus instead on being more specific and detailed with the fewer places shown. Sets constructed for the film included: several for the Sovereign planet, for which Chambliss used a "1950s pulp fiction variation on 1930s art deco design aesthetic"; the Ravager's main ship in the film, the Eclector, which was constructed in sections to provide a complete 360-degree view of the ship as well as the ability to move sections around and portray different areas of the ship; and the Iron Lotus establishment on the "pleasure planet" of Contraxia, which Chambliss wanted to feel like it had been put together from "a whole yard of repurposed junk where old spaceships are cast away and industrial materials that aren't of use anymore are just left to rot", creating a "kind of neon jungle in its own way and covered in ice and snow." Interiors for other ships were also constructed, to limit the amount of blue screen the actors had to interact with;[33] this includes the cockpit of Quill's ship that had been built for the first film before being stored in London which was transported to Atlanta for the sequel.[129]

text: Vol. 2 was the first film to be shot with an 8K resolution camera, the Red Weapon 8K.[130] Gunn had wanted to use a different camera than the Alexa 65 that had been used for several other Marvel films, because he found it to be a "very big and heavy camera". He wanted a camera that could deliver equivalent image quality to the Alexa 65, and tested multiple options. He eventually met with Red, whom he had a positive experience with working on The Legend of Tarzan, and they introduced him to an early prototype for the Weapon 8K. He, Gunn, and Marvel decided to use the camera in September 2015, when only that single prototype existed, and spent months working with Red to get the camera ready for filming.[129] For the sequence where Rocket and Yondu escape from the Ravagers, a Phantom Camera was used to film scenes up to 2000 frames per second, with the footage able to be moved from slow-motion to high-speed within a single shot. Each shot using the camera had to be carefully set up and choreographed.[131] Additional scenes were also shot in IMAX and its aspect ratio.[93] Braham filmed almost 85 percent of the film using a stabilizing technology he had contributed to called Stabileye, which he called "a handheld dolly" which allowed "a spontaneity to the way the camera moves that is different and that felt appropriate for this movie." For filming the cockpits of spaceships, Braham surrounded the practical sets with video panels and other light sources that he could use to create realistic lighting no matter the environment outside the ship. Exteriors of the ships were filmed with the camera on a technocrane, but any shots inside the cockpits again used the Stabileye which is "so small that you can get it in there next to the actors".[129]

text: In April, Gunn stated that Reilly would not be part of the film, and that Glenn Close would be filming scenes to reprise her role of Nova Prime Irani Rael from the first film, though it was unclear whether they would make it to the final cut of the sequel.[19] He added that there were many other characters he could not include in the film due to rights issues, as 20th Century Fox "owns so many awesome cosmic villains and minor characters that I'd love to play around with" such as Annihilus and Kang the Conqueror.[123] When filming Stan Lee's cameo, Gunn also filmed two other cameos with Lee including one for Doctor Strange, to limit the amount of travel Lee had to do.[76][132] Additional filming for Vol. 2 took place in Cartersville, Georgia,[133] a state park north of Portland, Oregon,[26] and in St. Charles, Missouri.[134] The Georgia International Convention Center served as additional soundstage space after pre-production on Spider-Man: Homecoming began at several Pinewood Atlanta soundstages.[93] Principal photography wrapped on June 16, 2016.[135]

text: Post-production[edit]

text: At San Diego Comic-Con 2016, Russell and Debicki were revealed to be playing Ego, Quill's father, and Ayesha, respectively.[31] Sylvester Stallone was also revealed to be in the film,[31] with his role later revealed as Stakar Ogord.[49] Gunn also introduced multiple actors who were playing Ravager characters, since the Ravagers have a larger presence in the film.[45] On the decision to reveal Russell as Ego and Quill's father when he did, Gunn felt that since "people were going to figure it out eventually… it was better that we took the reins in our own hands" and make the reveal. Gunn also felt that this would move the focus of audiences from wanting to discov er who Quill's father is to "the story and the relationship that these characters have".[136] In August 2016, Gunn confirmed the film would feature a post-credits scene,[105] later stating there would be five in total, with four mid-credits scenes and one post-credits.[137][138] Gunn also planned a sixth scene, where the Ravager Gef is found "mortally wounded" on the ship, but "it ended up being a little confusing."[139]

text: In November, Gillan revealed that the film was undergoing reshoots.[140] That February, it was reported that the film had scored a perfect 100 in test screenings, the highest for any Marvel Studios film. The Hollywood Reporter noted this score could not necessarily be compared to any non-Marvel movies due to Marvel's specific testing process that selects its audience "from a more select pool of recruits, what it terms 'friends and families screenings'".[141] In March 2017, Gunn revealed that Michael Rosenbaum would appear in the film,[51] and that Gunn would provide reference for Baby Groot's dancing "in a much bigger way [than the first film]. I actually had to do like a full day's worth of dancing to get Groot's dance down this time. Last time it was me in front of an iPhone, and this time it's me dancing on a huge soundstage and shooting it from five different angles."[142] Fred Raskin and Craig Wood returned from the first film to serve as editors.[43] On scenes that were cut from the film, Gunn said Nathan Fillion, who had had a voice cameo in the first film, was going to appear as Simon Williams in a sequence that would have shown several movie posters for films starring Williams, including films in which he portrays Arkon and Tony Stark.[143][144] Gunn chose Williams for Fillion's cameo because he wanted Fillion to have a bigger role in the MCU at some point and so didn't want to give him a role that could prevent him from taking a more substantial one later. Gunn still considered Fillion's cameo canon to the MCU, despite it being cut.[145] He also confirmed that Close's scenes had been cut from the film, because it felt like he "was trying to cram Nova Prime into the second movie as opposed to having it happen organically."[76]

text: Visual effects[edit]

text: Visual effects for the film were created by Framestore, Weta Digital, Trixter, Method Studios, Animal Logic, Scanline VFX, Lola VFX, Luma, and Cantina Creative.[146] Previsualization was done by The Third Floor.[147] Framestore created 620 shots for the film, Weta Digital created 530, Method Studios more than 500, and Animal Logic created 147.[26] Framestore once again created Rocket and Groot,[148][26] with Method Studios, Weta Digital and Trixter also working on Rocket. Framestore rebuilt Rocket "from the ground up" for Vol. 2, giving him an updated fur simulation, new facial shapes and phonemes, as well as a new eye rig, which came from a rig used for the character Gnarlack from Fantastic Beasts and Where to Find Them.[26] Trixter's work on Rocket included when he sets off a trap for the Ravagers, additionally working on the sequence when Rocket, Yondu and Kraglin jump across space.[26] Other work from Framestore included creatures, spaceships,[26] Ayesha's lair, the space chase, the Eclector scenes, and the adolescent Groot post-credit scene.[149]

text: Framestore also created the film's opening sequence.[26] Despite appearing as a single shot, it ultimately was composed of 11 different visual effect shots. Gunn provided reference video for Baby Groot's dancing in the sequence.[147] Framestore animation supervisor Arsland Elver noted that the majority of the opening sequence includes CGI and digital doubles, with three moments (Quill falling on the ground near Baby Groot, Gamora talking to Baby Groot, and Drax rolling behind Baby Groot) actually photography.[149] As with the first film, Sarofsky created the typography for the opening, using the same style from Guardians of the Galaxy for consistency, "this time in rusty gold and glowing blue neon". Executive Creative Director Erin Sarofsky noted the challenge of placing the credits while the sequence was being refined by Framestore. Sarofsky proposed several different options for the credits, including having "a little hovering character that projected a hologram up on the screen", but Gunn did not want another character in the sequence to deal with. A simpler 2D option was used instead. Sarofsky also worked on the end credits, the first time for the company, integrating the actual credits from company Exceptional Minds with designs inspired by old music album art, taking albums and scanning them for their old textures and scratches.[149]

text: The destruction of the Ravager ship the Eclector was handled by Weta Digital.[150] Weta Digital also handled Ego during his fight with Quill, utilizing a digital double of Russell for many of their shots. Weta also needed to create a digital double for David Hasselhoff for the moment when Ego shifts into Hasselhoff's guise. Guy Williams, Weta's visual effects supervisor, said, "We tried morphing to a live action Hoff – but it did not hold up as well. The Kurt version looked better than the Hoff version,..and while we had built a very detailed Kurt digi-double,- we didn't want to go to the same level on the Hoff for just two shots. But in the end we did have to do a partial build digi-double of the Hoff. The reason we did the Kurt digi-double in the first place was to make sure all the effects stuck correctly to the body… so we went with the approach of a full digi-double, the hair, the side of the face everything on Kurt. For the Hoff, we got pretty close, but it is not quite as detailed as for Kurt."[151] Additional work by Weta included the inside of Ego's planet, known as the Planet Hollow, which was inspired by the fractal art of Hal Tenny, who Gunn hired to help design Ego's environment.[148][152] Gunn added that there are "over a trillion polygons on Ego's planet," calling it "the biggest visual effect of all time. There's nothing even close to it."[152]

text: Animal Logic and Method Studios also worked on the various parts of Ego's planet, with Animal Logic focusing on Ego's cathedral, and Method on the arrival sequence and Baby Groot's "not that button" sequence in the Planet Hollow. Animal Logic's work for Ego's cathedral was also based on fractal art. The team at Animal Logic were initially brought on to the film to work on the story vignettes that were used to explain the backstory, which started as oil paintings before evolving to falling sand, and eventually the final plastic sculptures that were used. Method also created the film's final sequence for Yondu's funeral. To make Rocket shedding a tear convincing, Method used in-house footage of Animation Supervisor Keith Roberts "performing the scene for reference, studying the macro facial movements like minor eye darts or blinks, in addition to what was filmed on set and in the sound booth by" Cooper. Additional work included the scenes on the planet Berhart.[26] Lola VFX worked on de-aging Russell, having previously done similar work in other MCU films; they also added to various characters, including Nebula. To achieve the younger Ego, Lola referenced Russell's performance in Used Cars, as "he had a lot of the [facial] action" the visual effects artists were looking for. They also used a younger stand in, Aaron Schwartz, since he had "big broad jaw, chin, and most importantly the way the laugh lines move[d] and crease[d] as he talk[ed]", similar to Russell's.[151] Laura Haddock, reprising her role from the first film of Meredith Quill in the sequence, was also slightly de-aged to play the younger version of that character.[134] Luma worked on the Sovereign people and their world, and Adam Warlock's cocoon.[26]

text: Music[edit]

text: By August 2014, Gunn had "some ideas listed, but nothing for sure" in terms of songs to include in Quill's Awesome Mix Vol. 2 mixtape,[96] for which he felt "a little pressure for the soundtrack because so many people loved [the first film's soundtrack] and we went platinum and all that other stuff. But I feel like the soundtrack in the second one is better."[153] By June 2015, Gunn had chosen all of the songs and built them into the script,[7] calling Awesome Mix Vol. 2 "more diverse" than the first one, with "some really incredibly famous songs and then some songs that people have never heard."[154] Tyler Bates had returned to score the film by August 2015.[155] As with Guardians of the Galaxy, Bates wrote some of the score first so Gunn could film to the music, as opposed to Bates scoring to the film.[117] Recording for the score began in January 2017 at Abbey Road Studios.[156] Guardians of the Galaxy Vol. 2: Awesome Mix Volume 2, along with the film score album composed by Bates, were released on April 21, 2017.[157][158] A cassette version of Awesome Mix Volume 2 was released on June 23, 2017, while a deluxe edition vinyl LP featuring both Awesome Mix Volume 2 and Bates' score was released on August 11, 2017.[159]

text: Release[edit]

text: Guardians of the Galaxy Vol. 2 made its world premiere in Tokyo on April 10, 2017,[160] and its Hollywood premiere on April 19 at the Dolby Theatre.[161] The film began its international release on April 25, in Australia, New Zealand, and Italy,[162] alongside a total of 37 markets in its first weekend, with 176 IMAX screens in 35 of those markets.[163] Its North American release on May 5 took place in 4,347 theaters, of which over 3,800 were in 3D,[164] 388 in IMAX and IMAX 3D,[164][165] 588 premium large-format, and 194 D-Box locations.[164] The film's opening in China was in 400 IMAX theaters, the largest ever for the country.[166] On May 4, 2017, 550 theaters in the United States had a special RealD Guardians of the Galaxy double feature event before preview screenings of Vol. 2. Guests who attended received an exclusive mini poster and a set of souvenir collectible buttons.[167] Vol. 2 was originally intended to be released on July 28, 2017.[84]

text: Marketing[edit]

text: In June 2016, Marvel announced plans for an expanded merchandising program for the film from the original, with Groot playing a central role.[168] Gunn ensured the film's female characters received more representation in the merchandise than in the first.[169] Paul Gitter, senior VP of licensing at Disney Consumer Products, said they intended to build Guardians of the Galaxy into a tentpole franchise. Partners in the campaign included Hasbro, Lego, Funko, LB Kids,[170] GEICO, Ford Motor Company, Go-Gurt, Hanes, Synchrony Bank, Dairy Queen, M&M's, Screenvision, Sprint Corporation and Wrigley Company.[168] Additionally, Marvel partnered with Doritos for their Rock Out Loud campaign to create a custom "limited-edition series of Doritos bags featuring a built-in cassette tape deck-inspired player that plays" Awesome Mix Vol. 2 and can be recharged. The custom bags were available to purchase on Amazon.com, with Doritos also hosting Rock Out Loud pop-up recording booths in New York and Los Angeles where fans could sing the songs from Awesome Mix Vol. 2 and have the opportunity to win various prizes, including the custom bags, concert tickets, and free bags of Doritos."[171]

text: In July 2016, Gunn, Pratt and other members of the cast attended San Diego Comic-Con to promote the film,[172] showing footage and revealing additional character information.[31] On October 19, a "sneak peek" teaser was released ahead of the first full teaser trailer. Ethan Anderton of /Film felt the teaser was strong, despite not showing any of the new characters or relying on Baby Groot,[173] while The A.V. Club's Esther Zuckerman called it "an immediate crowd-pleaser".[174] According to media-measurement firm comScore and its PreAct service, the teaser was the top trailer for the week it released, generating 108,000 new social media conversations.[175] In early December, before Gunn revealed the first teaser trailer at Comic Con Experience 2016,[176][177] he said that finding scenes and moments to showcase in the trailer without revealing too much of the film resulted in hard choices, since "people really go through every single little shot and try to figure out what the movie's about. And there's a lot of mysteries in Guardians 2."[178] Describing the teaser trailer, Jacob Hall of /Film felt, "It's telling that this trailer can get away without actually selling the plot of the movie. Audiences didn't fall in love with the first Guardians of the Galaxy because they were entranced by yet another Marvel Studios movie built around a villain who gets his hands on an Infinity Stone…the bulk of this trailer is dedicated to this group bouncing off one another, which is the real star attraction."[179] The teaser trailer had 81 million views in 24 hours, becoming the second-most viewed teaser behind Beauty and the Beast and largest Marvel Studios teaser ever. Additionally, Sweet's "Fox on the Run" reached number one on the iTunes Rock Chart after featuring in the teaser.[180]

text: A second trailer aired during Super Bowl LI. Germain Lussier for io9 called it "hilarious",[181] while Anderton said it was "one hell of a" Super Bowl spot, "one that probably overshadows the game itself for people like me… There's plenty of badass cosmic action, the humor we all love, a stellar soundtrack, and some great new footage from the sequel."[182] The spot generated the most Twitter conversation volume during the game with 47,800 conversations, according to comScore, who measured the volume of trailers that aired during the game from the time it aired through the end of the game. The film also topped a Fandango survey of fans' favorite film trailer during the Super Bowl.[183] An additional trailer debuted on February 28, 2017, on Jimmy Kimmel Live!. Haleigh Foutch at Collider.com felt the trailer added "hype" to the film, and was "just an all-around wonderful trailer, lit up with the wacky humor and irreverent charm that made the first film such a hit, with an extra dose of visual splendor."[184] Pratt and Saldana appeared at the 2017 Kids' Choice Awards, where they debuted an exclusive clip.[185] In mid-July, Marvel created a 1980s-inspired infomercial and an 800 number to promote the film's home media release.[186]

text: Home media[edit]

text: Guardians of the Galaxy Vol. 2 was released on digital download by Walt Disney Studios Home Entertainment on August 8, 2017, and on Blu-ray, Blu-ray 3D, Ultra HD Blu-ray and DVD on August 22.[187][188] The Ultra HD Blu-ray version is the first Disney home media release in 4K resolution.[189] The digital and Blu-ray releases include behind-the-scenes featurettes; audio commentary; deleted scenes; a blooper reel; and a music video for the song "Guardians Inferno". The digital release also exclusively features the breakdown of three scenes, from their initial ideas to their completed versions, and a behind-the-scenes look at the Disney California Adventure ride Guardians of the Galaxy – Mission: Breakout![187] The 1970s-style music video for "Guardians Inferno" was directed by David Yarovesky, and features Hasselhoff alongside James Gunn, Pratt, Saldana, Bautista, Klementieff, Gillan, Rooker, and Sean Gunn. Stan Lee and Guillermo Rodriguez also make cameo appearances in the video.[190][191]

text: The digital release of the film had the most digital downloads and largest opening week of any Marvel Studios film.[192] The physical releases in its first week of sale were the top home media release, selling "nearly three times as many discs as the rest of the top 10 sellers combined", according to NPD VideoScan data. The Blu-ray version accounted for 83% of the sales, with 10% of total sales coming from the Ultra HD Blu-ray version.[193] In its second week, the film was once again the top home media release.[194] As well, in the United Kingdom where it was also the top film, total sales of Vol. 2 were more than the other films in the top 40 combined.[195]

text: Reception[edit]

text: Box office[edit]

text: Guardians of the Galaxy Vol. 2 grossed $389.8 million in the United States and Canada, and $473.7 million in other countries, for a worldwide total of $863.5 million.[2] The film had earlier surpassed the first film's gross ($773 million) by Memorial Day weekend with $783.3 million worldwide,[196] and became the fifth-highest-grossing MCU film a week later.[197]

text: Since tickets went on sale on April 24, 2017, the film was the number one seller on Fandango, and surpassed the advance sales of Avengers: Age of Ultron in the similar time frame.[198] Over 80% of sales on MovieTickets.com were for the film ahead of its release.[164] Vol. 2 earned $146.5 million in its opening weekend,[199] with IMAX contributing $13 million.[166] The $17 million that came from Thursday night previews was the highest preview amount of 2017.[164] The film had previously been projected to earn upwards of $160 million in its opening weekend,[167][200] with Deadline.com predicting that the film could reach the $179 million debut of Captain America: Civil War.[201] It remained at number one in its second weekend,[202] and fell to second in its third, behind Alien: Covenant.[203] Vol. 2 remained at number two in its fourth weekend, this time behind Pirates of the Caribbean: Dead Men Tell No Tales, and crossed $337.6 million, surpassing the domestic gross of the first film.[204] By its fifth weekend, the film fell to fourth,[205] and in its next, fell to fifth.[206] Vol. 2 continued to remain in the top 10 for two more weeks, placing ninth in its seventh weekend,[207] and tenth in its eighth weekend.[208]

text: Outside of the United States and Canada, the film earned $106 million in its first weekend from 37 markets, becoming the top film in all markets except Portugal, Turkey and Vietnam. IMAX contributed $5 million to the opening weekend gross. The film also outperformed the first film's opening weekend in all markets except Belgium.[163] In its second weekend, it opened as the top film in South Korea, China, and Russia.[166] It was the highest opening for an MCU film in Austria,[163] the second-highest MCU opening in Australia ($11.8 million), the Netherlands ($500,000),[162][163] Germany ($9.3 million), and the United Kingdom ($16.9 million),[163] and was the third-highest in New Zealand ($400,000), Italy ($1.4 million),[162] and Russia ($11.6 million).[166] The New Zealand and Netherlands openings were also the highest of 2017 for the countries,[162] while Germany and the United Kingdom's were the second-highest for 2017.[162][163] South Korea had the biggest opening day of 2017 ($3.3 million), the biggest May opening day, the third-highest opening day for an MCU film,[209] and the second-best opening weekend of 2017 ($13.3 million). The opening-weekend gross surpassed the entire earnings from the first film in the country.[166] Ukraine had the second-largest opening ever, while in Puerto Rico, the film was the largest IMAX opening.[166] By its third weekend, multiple markets saw their gross for Vol. 2 surpass the total gross from the first film,[210] followed by China a week later.[211] Its fifth weekend saw Vol. 2's gross in other markets ($451.1 million) surpass the international gross of the first film ($440 million).[196] The film's three biggest markets in total earnings were: China ($99.3 million), the United Kingdom ($51.3 million), and Germany ($28 million).[197]

text: Critical response[edit]

text: On the review aggregator website Rotten Tomatoes, the film has an approval rating of 82%, based on 319 reviews, with an average rating of 7.1/10. The site's critical consensus reads, "Guardians of the Galaxy Vol. 2's action-packed plot, dazzling visuals, and irreverent humor add up to a sequel that's almost as fun—if not quite as thrillingly fresh—as its predecessor."[212] On Metacritic, the film has a score of 67 out of 100, based on 47 critics, indicating "generally favorable reviews".[213] Audiences polled by CinemaScore gave the film an average grade of "A" on an A+ to F scale.[164]

text: Owen Gleiberman of Variety called the film "an extravagant and witty follow-up, made with the same friendly virtuosic dazzle… and just obligatory enough to be too much of a good thing." He cautioned that "this time you can sense just how hard [Gunn] is working to entertain you. Maybe a little too hard."[214] Mike Ryan at Uproxx noted the continued sense of humor and tone from the first film, and appreciated Gunn's difference in overall structure in the sequel (which he compared to The Empire Strikes Back). Ryan was positive of the cast, particularly Rooker in his expanded role as "the heart" of the film.[215] Writing for Rolling Stone, Peter Travers called the film a "blast" and gave it three stars out of four, praising the film for its tone and fun, soundtrack, and characters. He noted that "Vol. 2 can't match the sneak-attack surprise of its predecessor…[but] the followup, while taking on some CGI bloat and sequel slickness, hasn't lost its love for inspired lunacy.[216] Chicago Sun-Times's Richard Roeper also gave the film three stars, writing, "Guardians of the Galaxy Vol. 2 isn't quite as much fun, not quite as clever, not quite as fresh as the original—but it still packs a bright and shiny and sweet punch." Roeper continued that "even with all the silliness and all the snarkiness, the Guardians can put a lump in your throat", and praised the cast, especially Rooker, with "one of the best roles in the movie".[217]

text: At The Hollywood Reporter, Todd McCarthy said "Guardians of the Galaxy Vol. 2 plays like a second ride on a roller-coaster that was a real kick the first time around but feels very been-there/done-that now."[218] Mara Reinstein of Us Weekly gave the film two-and-a-half stars out of four, feeling "excited audiences desperate for escapism [will] lap up the film's inherent joyfulness", but Gunn "has doubled down on all his once-nifty novelties. Strip them away and what remains is a bloated semi-mess."[219] Kenneth Turan of the Los Angeles Times was positive of the film's soundtrack and cast, especially Russell, but felt Gunn was trying too hard to re-capture the magic of the first film, and the increased scope of effects and action becomes weary. Turan concluded, "There are enough reminders of the first Guardians to make the sequel an acceptable experience, [but it's] less like itself and more like a standard Marvel production."[220] Manohla Dargis at The New York Times said the film "certainly has its attractions, but most of them are visual rather than narrative." She also felt Gunn was trying too hard, and found many elements of the sequel to be too serious even with Russell balancing that with a much-needed "unforced looseness".[221]

text: Accolades[edit]

text:
Year
Award
Category
Recipient(s)
Result
Ref(s)

2017
Teen Choice Awards
Choice Sci-Fi Movie
Guardians of the Galaxy Vol. 2
Won
[222]

Choice Sci-Fi-Movie Actor
Chris Pratt
Won

Choice Sci-Fi-Movie Actress
Zoe Saldana
Won

Choice Movie Ship
Chris Pratt and Zoe Saldana
Nominated

Dragon Awards
Best Science Fiction or Fantasy Movie
Guardians of the Galaxy Vol. 2
Nominated
[223]

text: Sequel[edit]

text: In November 2014, when Gunn said he had the "basic story" for Vol. 2 while working on the first film, he also said he had ideas for a potential third film.[224] Despite this, Gunn was unsure in June 2015 if he would be involved with a third Guardians film, saying it would depend on his feelings after making Vol. 2.[7] In April 2016, Feige said the future MCU films are "still a big chess board for 2020 and beyond, but certainly I would say Guardians 3 is [one film that's] up there. I don't know what exactly the order will be."[225] In March 2017, Gunn stated there would be a third film "for sure. We're trying to figure it out,"[226] also adding, "There are no specific plans for Guardians of the Galaxy Vol. 3. But we know unless something goes horribly—which is always possible, you never know—I think that Marvel would want to make another movie."[227] He also reiterated he was still unsure if he would be involved with the film, and that he would figure out his involvement and his next project "over the next couple of weeks."[226] The following month, Gunn announced he would return to write and direct Guardians of the Galaxy Vol. 3.[228] Klementieff is expected to reprise her role as Mantis.[229] Vol. 3 is scheduled to be released in 2020.[230]

text: Notes[edit]

text:
Jump up ^ Gunn said this sequence with an adolescent Groot is set "years after" the ending of the film, with the character appearing in the same state in Avengers: Infinity War.[3]
Jump up ^ Identified offscreen as Adam Warlock, who director James Gunn initially planned to feature prominently in the film. The character is hinted at in this mid-credits scene to set up a future appearance in the MCU.[4][5]

tag: ol


document_title: Lymph duct

question_text: where does the right lymphatic duct receives lymph from

root

text: Lymph duct

text:
Lymph duct

The thoracic and right lymphatic duct

Details

Drains to
Subclavian veins

Latin
Ductus lymphaticus

Anatomical terminology
[edit on Wikidata]

tag: table

text: A lymph duct is a great lymphatic vessel that empties lymph into one of the subclavian veins. There are two lymph ducts in the body—the right lymphatic duct and the thoracic duct. The right lymphatic duct drains lymph from the right upper limb, right side of thorax and right halves of head and neck. The thoracic duct drains lymph into the circulatory system at the left brachiocephalic vein between the left subclavian and left internal jugular veins.

tag: p


document_title: White House Chief of Staff

question_text: who takes care of the president's schedule

question_tokens: who takes care of the president 's schedule

text: White House Chief of Staff

text: History[edit]

text: The duties of the White House chief of staff vary greatly from one administration to another and, in fact, there is no legal requirement that the president even fill the position. However, since at least 1979, all presidents have found the need for a chief of staff, who typically oversees the actions of the White House staff, manages the president's schedule, and decides who is allowed to meet with the president. Because of these duties, the chief of staff has at various times been labeled "The Gatekeeper", or "the power behind the throne".[citation needed]

text: Originally, the duties now performed by the chief of staff belonged to the president's private secretary and were fulfilled by crucial confidants and advisers such as George B. Cortelyou, Joseph Tumulty, and Louis McHenry Howe to Presidents Theodore Roosevelt, Woodrow Wilson, and Franklin Roosevelt, respectively.[2] The private secretary served as the president's de facto chief aide in a role that combined personal and professional assignments of highly delicate and demanding natures, requiring great skill and discretion.[3] The job of gatekeeper and overseeing the president's schedule was separately delegated to the appointments secretary, as with FDR's aide Edwin "Pa" Watson.

text: From 1933 to 1939, as he greatly expanded the scope of the federal government's policies and powers in response to the Great Depression, Roosevelt relied on his "Brain Trust" of top advisers. Although working directly for the president, they were often appointed to vacant positions in agencies and departments, from whence they drew their salaries since the White House lacked statutory or budgetary authority to create new staff positions. It was not until 1939, during Franklin D. Roosevelt's second term in office, that the foundations of the modern White House staff were created using a formal structure. Roosevelt was able to get Congress to approve the creation of the Executive Office of the President, which would report directly to the president. During World War II, Roosevelt created the position of "Chief of Staff to the Commander in Chief" for his principal military adviser,William D. Leahy.

text: In 1946, in response to the rapid growth of the U.S. government's executive branch, the position of "Assistant to the President of the United States" was established. Charged with the affairs of the White House, it was the immediate predecessor to the modern chief of staff. It was in 1953, under Republican President Dwight D. Eisenhower, that the president's preeminent assistant was designated the "White House Chief of Staff".

text: Assistant to the president became a rank generally shared by the chief of staff with such senior aides as deputy chiefs of staff, the White House counsel, the White House press secretary, and others. This new system did not catch on immediately. Democrats Kennedy and Johnson still relied on their appointments secretaries instead, and it was not until the Nixon administration that the chief of staff took over maintenance of the President's schedule. This concentration of power in the Nixon and Ford White House (whose last chief of staff was Dick Cheney) led presidential candidate Jimmy Carter to campaign in 1976 with the promise that he would not appoint a chief of staff. And indeed, for the first two and a half years of his presidency, he appointed no one to the post.[4][5]

text: The average tenure for a White House chief of staff is a little more than 18 months.[6] John R. Steelman, under Harry S. Truman, was the last chief of staff to serve for an entire presidential administration. (Andrew Card and Denis McDonough each served at least one entire presidential term of office under Presidents George W. Bush and Barack Obama, respectively). Steelman also holds the record for longest-serving chief of staff (six years). Most White House chiefs of staff are former politicians, and many continue their political careers in other senior roles. Lyndon Johnson's chief of staff W. Marvin Watson became postmaster general later in LBJ's term. Richard Nixon's Chief of Staff Alexander Haig became secretary of state under Ronald Reagan. Cheney later became a Congressman for Wyoming, secretary of defense under George H. W. Bush and vice president in the George W. Bush administration. Donald Rumsfeld was another chief of staff for Ford and subsequently served as secretary of defense both in the Ford administration and decades later, also in the George W. Bush administration. Rahm Emanuel left the House of Representatives to become Barack Obama's chief of staff and subsequently became mayor of Chicago. Jack Lew, President Obama's fourth chief of staff, was later appointed Secretary of the Treasury.

text: Role[edit]

text: This section needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (September 2013) (Learn how and when to remove this template message)

text: Chris Whipple, author of The Gatekeepers: How the White House Chiefs of Staff Define Every Presidency, loosely describes the role of a White House chief of staff through his interview with former President Barack Obama: "During the last days of his presidency, Barack Obama observed: 'One of the things I've learned is that the big breakthroughs are typically the result of a lot of grunt work—just a whole lot of blocking and tackling.' Grunt work is what chiefs of staff do."[6]

text: The responsibilities of the chief of staff are both managerial and advisory and can include the following:

text:
Select key White House staff and supervise them;
Structure the White House staff system;
Control the flow of people into the Oval Office;
Manage the flow of information;
Protect the interests of the president;
Negotiate with Congress, other members of the executive branch, and extra-governmental political groups to implement the president's agenda; and
Advise the president on various issues, including telling the president what he does not want to hear.[6]

tag: ul

text: Richard Nixon's first chief of staff, H. R. Haldeman, garnered a reputation in Washington for the iron hand he wielded in the position—famously referring to himself as "the president's son-of-a-bitch", he was a rigid gatekeeper who would frequently meet with administration officials in place of the president, then report himself to Nixon on the officials' talking points. Journalist Bob Woodward, in his books All the President's Men and The Secret Man, wrote that many of his sources, including the famous Deep Throat, displayed a genuine fear of Haldeman.[7][8]

text: In popular culture[edit]

text:
In the 1993 film Dave, Frank Langella plays White House Chief of Staff Bob Alexander.
In the NBC television drama The West Wing (1999–2006), the role of White House Chief of Staff was held by Leo McGarry (John Spencer), and later by C. J. Cregg (Allison Janney) in the Bartlet Administration and by Josh Lyman (Bradley Whitford) in the Santos Administration.
In the 1995 movie The American President, White House Chief of Staff A. J. McInerney in the Shepherd Administration was played by Martin Sheen, who later went on to play President Jed Bartlet in The West Wing, created and largely written by The American President screenwriter Aaron Sorkin.
Jeff Perry portrayed White House Chief of Staff Cyrus Beene in the ABC drama Scandal. Portia de Rossi portrayed White House Chief of Staff Elizabeth North in the same series following the firing of Cyrus Beene by President Grant in the Season 4 finale. Darby Stanchfield portrays Abby Whelan, President Fitzgerald Grant's chief of staff until the end of his presidency after being asked to fire Cyrus. Kerry Washington stars in the series as Olivia Pope, and now acts as Mellie Grant's current chief of staff.
In House of Cards, Michael Kelly portrays Underwood's presidential chief of staff, Doug Stamper, who was also his vice presidential chief of staff. Sakina Jaffrey portrayed previous President Garrett Walker's Chief of Staff, Linda Vasquez.
In the HBO television comedy Veep, Kevin Dunn plays the role of the White House Chief of Staff Ben Cafferty. Anna Chlumsky portrayed President Selina Meyer's Chief of Staff.
In the Fox television series 24, several people have played the role of White House Chief of Staff: Jude Ciccolella as Mike Novick, D. B. Woodside as Wayne Palmer, John Allen Nelson as Walt Cummings, Peter MacNicol as Tom Lennox, Bob Gunton as Ethan Kanin, Sprague Grayden as Olivia Taylor, Chris Diamantopoulos as Rob Weiss, and most recently Tate Donovan as Mark Boudreau in 24: Live Another Day.
In the CBS television series Madam Secretary, the White House Chief of Staff, Russell Jackson, is played by Željko Ivanek.
In the ABC television series Designated Survivor, Adan Canto plays White House Chief of Staff Aaron Shore, who assumes the position of chief of staff under newly sworn in President Tom Kirkman,who ascends from his former position of Secretary of Housing and Urban Development, after President Richmond, the vice president and cabinet are killed during a terrorist attack at the State of the Union address. Shore is later replaced by Emily Rhodes (Italia Ricci) as Chief of Staff and subsequently becomes National Security Advisor.
In Tom Clancy's Ryanverse, Arnie Van Damm is White House Chief of Staff to three presidents, Fowler, Durling and Ryan.


document_title: Absolute difference

question_text: the difference of the absolute value of two numbers

text: Absolute difference

text: The absolute difference of two real numbers x, y is given by |x − y|, the absolute value of their difference. It describes the distance on the real line between the points corresponding to x and y. It is a special case of the Lp distance for all 1 ≤ p ≤ ∞ and is the standard metric used for both the set of rational numbers Q and their completion, the set of real numbers R.

text: As with any metric, the metric properties hold:

text:
|x − y| ≥ 0, since absolute value is always non-negative.
|x − y| = 0   if and only if   x = y.
|x − y| = |y − x|     (symmetry or commutativity).
|x − z| ≤ |x − y| + |y − z|     (triangle inequality); in the case of the absolute difference, equality holds if and only if x ≤ y ≤ z.

text: By contrast, simple subtraction is not non-negative or commutative, but it does obey the second and fourth properties above, since x − y = 0 if and only if x = y, and x − z = (x − y) + (y − z).

text: The absolute difference is used to define other quantities including the relative difference, the L1 norm used in taxicab geometry, and graceful labelings in graph theory.

text: When it is desirable to avoid the absolute value function – for example because it is expensive to compute, or because its derivative is not continuous – it can sometimes be eliminated by the identity

text: This follows since |x − y|2 = (x − y)2 and squaring is monotonic on the nonnegative reals.


document_title: Conservation of energy

question_text: who made the law of conservation of energy

text: Conservation of energy

text: History[edit]

text: This section needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (November 2015) (Learn how and when to remove this template message)

text: In physics, the law of conservation of energy states that the total energy of an isolated system in a given frame of reference remains constant — it is said to be conserved over time.[7] In other words, this law means that energy can neither be created nor destroyed; rather, it can only be transformed from one form to another. For instance, chemical energy is converted to kinetic energy when a stick of dynamite explodes. If one adds up all the chemical energy that is expended in the explosion, one will get the exact amount of kinetic energy that is generated. Classically, conservation of energy was distinct from conservation of mass; however, special relativity showed that mass could be converted to energy and vice versa by E = mc2, and science now takes the view that mass–energy is conserved. Ancient philosophers as far back as Thales of Miletus c. 550 BCE had inklings of the conservation of some underlying substance of which everything is made. However, there is no particular reason to identify this with what we know today as "mass-energy" (for example, Thales thought it was water). Empedocles (490–430 BCE) wrote that in his universal system, composed of four roots (earth, air, water, fire), "nothing comes to be or perishes";[8] instead, these elements suffer continual rearrangement.

text: In 1605, Simon Stevinus was able to solve a number of problems in statics based on the principle that perpetual motion was impossible.

text: In 1638, Galileo published his analysis of several situations—including the celebrated "interrupted pendulum"—which can be described (in modern language) as conservatively converting potential energy to kinetic energy and back again. Essentially, he pointed out that the height a moving body rises is equal to the height from which it falls, and used this observation to infer the idea of inertia. The remarkable aspect of this observation is that the height to which a moving body ascends on a frictionless surface does not depend on the shape of the surface.

text: In 1669, Christian Huygens published his laws of collision. Among the quantities he listed as being invariant before and after the collision of bodies were both the sum of their linear momentums as well as the sum of their kinetic energies. However, the difference between elastic and inelastic collision was not understood at the time. This led to the dispute among later researchers as to which of these conserved quantities was the more fundamental. In his Horologium Oscillatorium, he gave a much clearer statement regarding the height of ascent of a moving body, and connected this idea with the impossibility of a perpetual motion. Huygens' study of the dynamics of pendulum motion was based on a single principle: that the center of gravity of a heavy object cannot lift itself.

text: The fact that kinetic energy is scalar, unlike linear momentum which is a vector, and hence easier to work with did not escape the attention of Gottfried Wilhelm Leibniz. It was Leibniz during 1676–1689 who first attempted a mathematical formulation of the kind of energy which is connected with motion (kinetic energy). Using Huygens' work on collision, Leibniz noticed that in many mechanical systems (of several masses, mi each with velocity vi),

text: was conserved so long as the masses did not interact. He called this quantity the vis viva or living force of the system. The principle represents an accurate statement of the approximate conservation of kinetic energy in situations where there is no friction. Many physicists at that time, such as Newton, held that the conservation of momentum, which holds even in systems with friction, as defined by the momentum:

text: was the conserved vis viva. It was later shown that both quantities are conserved simultaneously, given the proper conditions such as an elastic collision.

text: In 1687, Isaac Newton published his Principia, which was organized around the concept of force and momentum. However, the researchers were quick to recognize that the principles set out in the book, while fine for point masses, were not sufficient to tackle the motions of rigid and fluid bodies. Some other principles were also required.

text: The law of conservation of vis viva was championed by the father and son duo, Johann and Daniel Bernoulli. The former enunciated the principle of virtual work as used in statics in its full generality in 1715, while the later based his Hydrodynamica, published in 1738, on this single conservation principle. Daniel's study of loss of vis viva of flowing water led him to formulate the Bernoulli's principle, which relates the loss to be proportional to the change in hydrodynamic pressure. Daniel also formulated the notion of work and efficiency for hydraulic machines; and he gave a kinetic theory of gases, and linked the kinetic energy of gas molecules with the temperature of the gas.

text: This focus on the vis viva by the continental physicists eventually led to the discovery of stationarity principles governing mechanics, such as the D'Alembert's principle and Lagrangian and Hamiltonian formulations of mechanics.

text:
Émilie du Châtelet (1706 – 1749) proposed and tested the hypothesis of the conservation of total energy, as distinct from momentum. Inspired by the theories of Gottfried Leibniz, she repeated and publicized an experiment originally devised by Willem 's Gravesande in 1722 in which balls were dropped from different heights into a sheet of soft clay. Each ball's kinetic energy - as indicated by the quantity of material displaced - was shown to be proportional to the square of the velocity. The deformation of the clay was found to be directly proportional to the height the balls were dropped from, equal to the initial potential energy. Earlier workers, including Newton and Voltaire, had all believed that "energy" (so far as they understood the concept at all) was not distinct from momentum and therefore proportional to velocity. According to this understanding, the deformation of the clay should have been proportional to the square root of the height from which the balls were dropped from. In classical physics the correct formula is

E

k

=

1
2

m

v

2

{\displaystyle E_{k}={\frac {1}{2}}mv^{2}}

, where

E

k

{\displaystyle E_{k}}

 is the kinetic energy of an object,

m

{\displaystyle m}

 its mass and

v

{\displaystyle v}

 its speed. On this basis, Châtelet proposed that energy must always have the same dimensions in any form, which is necessary to be able to relate it in different forms (kinetic, potential, heat…).[9][10]

text: Engineers such as John Smeaton, Peter Ewart, Carl Holtzmann, Gustave-Adolphe Hirn and Marc Seguin recognized that conservation of momentum alone was not adequate for practical calculation and made use of Leibniz's principle. The principle was also championed by some chemists such as William Hyde Wollaston. Academics such as John Playfair were quick to point out that kinetic energy is clearly not conserved. This is obvious to a modern analysis based on the second law of thermodynamics, but in the 18th and 19th centuries the fate of the lost energy was still unknown.

text: Gradually it came to be suspected that the heat inevitably generated by motion under friction was another form of vis viva. In 1783, Antoine Lavoisier and Pierre-Simon Laplace reviewed the two competing theories of vis viva and caloric theory.[11] Count Rumford's 1798 observations of heat generation during the boring of cannons added more weight to the view that mechanical motion could be converted into heat, and (as importantly) that the conversion was quantitative and could be predicted (allowing for a universal conversion constant between kinetic energy and heat). Vis viva then started to be known as energy, after the term was first used in that sense by Thomas Young in 1807.

text: The recalibration of vis viva to

text: which can be understood as converting kinetic energy to work, was largely the result of Gaspard-Gustave Coriolis and Jean-Victor Poncelet over the period 1819–1839. The former called the quantity quantité de travail (quantity of work) and the latter, travail mécanique (mechanical work), and both championed its use in engineering calculation.

text: In a paper Über die Natur der Wärme(German "On the Nature of Heat/Warmth"), published in the Zeitschrift für Physik in 1837, Karl Friedrich Mohr gave one of the earliest general statements of the doctrine of the conservation of energy in the words: "besides the 54 known chemical elements there is in the physical world one agent only, and this is called Kraft [energy or work]. It may appear, according to circumstances, as motion, chemical affinity, cohesion, electricity, light and magnetism; and from any one of these forms it can be transformed into any of the others."

text: Mechanical equivalent of heat[edit]

text: A key stage in the development of the modern conservation principle was the demonstration of the mechanical equivalent of heat. The caloric theory maintained that heat could neither be created nor destroyed, whereas conservation of energy entails the contrary principle that heat and mechanical work are interchangeable.

text: In the middle of the eighteenth century, Mikhail Lomonosov, a Russian scientist, postulated his corpusculo-kinetic theory of heat, which rejected the idea of a caloric. Through the results of empirical studies, Lomonosov came to the conclusion that heat was not transferred through the particles of the caloric fluid.

text: In 1798, Count Rumford (Benjamin Thompson) performed measurements of the frictional heat generated in boring cannons, and developed the idea that heat is a form of kinetic energy; his measurements refuted caloric theory, but were imprecise enough to leave room for doubt.

text: The mechanical equivalence principle was first stated in its modern form by the German surgeon Julius Robert von Mayer in 1842.[12] Mayer reached his conclusion on a voyage to the Dutch East Indies, where he found that his patients' blood was a deeper red because they were consuming less oxygen, and therefore less energy, to maintain their body temperature in the hotter climate. He discovered that heat and mechanical work were both forms of energy and in 1845, after improving his knowledge of physics, he published a monograph that stated a quantitative relationship between them.[13]

text: Meanwhile, in 1843, James Prescott Joule independently discovered the mechanical equivalent in a series of experiments. In the most famous, now called the "Joule apparatus", a descending weight attached to a string caused a paddle immersed in water to rotate. He showed that the gravitational potential energy lost by the weight in descending was equal to the internal energy gained by the water through friction with the paddle.

text: Over the period 1840–1843, similar work was carried out by engineer Ludwig A. Colding, although it was little known outside his native Denmark.

text: Both Joule's and Mayer's work suffered from resistance and neglect but it was Joule's that eventually drew the wider recognition.

text: In 1844, William Robert Grove postulated a relationship between mechanics, heat, light, electricity and magnetism by treating them all as manifestations of a single "force" (energy in modern terms). In 1846, Grove published his theories in his book The Correlation of Physical Forces.[14] In 1847, drawing on the earlier work of Joule, Sadi Carnot and Émile Clapeyron, Hermann von Helmholtz arrived at conclusions similar to Grove's and published his theories in his book Über die Erhaltung der Kraft (On the Conservation of Force, 1847).[15] The general modern acceptance of the principle stems from this publication.

text: In 1850, William Rankine first used the phrase the law of the conservation of energy for the principle.[16]

text: In 1877, Peter Guthrie Tait claimed that the principle originated with Sir Isaac Newton, based on a creative reading of propositions 40 and 41 of the Philosophiae Naturalis Principia Mathematica. This is now regarded as an example of Whig history.[17]

text: Mass–energy equivalence[edit]

text: Matter is composed of such things as atoms, electrons, neutrons, and protons. It has intrinsic or rest mass. In the limited range of recognized experience of the nineteenth century it was found that such rest mass is conserved. Einstein's 1905 theory of special relativity showed that it corresponds to an equivalent amount of rest energy. This means that it can be converted to or from equivalent amounts of other (non-material) forms of energy, for example kinetic energy, potential energy, and electromagnetic radiant energy. When this happens, as recognized in twentieth century experience, rest mass is not conserved, unlike the total mass or total energy. All forms of energy contribute to the total mass and total energy.

text: For example, an electron and a positron each have rest mass. They can perish together, converting their combined rest energy into photons having electromagnetic radiant energy, but no rest mass. If this occurs within an isolated system that does not release the photons or their energy into the external surroundings, then neither the total mass nor the total energy of the system will change. The produced electromagnetic radiant energy contributes just as much to the inertia (and to any weight) of the system as did the rest mass of the electron and positron before their demise. Likewise, non-material forms of energy can perish into matter, which has rest mass.

text: Thus, conservation of energy (total, including material or rest energy), and conservation of mass (total, not just rest), each still holds as an (equivalent) law. In the 18th century these had appeared as two seemingly-distinct laws.

text: Conservation of energy in beta decay[edit]

text: The discovery in 1911 that electrons emitted in beta decay have a continuous rather than a discrete spectrum appeared to contradict conservation of energy, under the then-current assumption that beta decay is the simple emission of an electron from a nucleus.[18][19] This problem was eventually resolved in 1933 by Enrico Fermi who proposed the correct description of beta-decay as the emission of both an electron and an antineutrino, which carries away the apparently missing energy.[20][21]

text: First law of thermodynamics[edit]

text: For a closed thermodynamic system, the first law of thermodynamics may be stated as:

text:
where

δ
Q

{\displaystyle \delta Q}

 is the quantity of energy added to the system by a heating process,

δ
W

{\displaystyle \delta W}

 is the quantity of energy lost by the system due to work done by the system on its surroundings and

d

U

{\displaystyle \mathrm {d} U}

 is the change in the internal energy of the system.

text:
The δ's before the heat and work terms are used to indicate that they describe an increment of energy which is to be interpreted somewhat differently than the

d

U

{\displaystyle \mathrm {d} U}

 increment of internal energy (see Inexact differential). Work and heat refer to kinds of process which add or subtract energy to or from a system, while the internal energy

U

{\displaystyle U}

 is a property of a particular state of the system when it is in unchanging thermodynamic equilibrium. Thus the term "heat energy" for

δ
Q

{\displaystyle \delta Q}

 means "that amount of energy added as the result of heating" rather than referring to a particular form of energy. Likewise, the term "work energy" for

δ
W

{\displaystyle \delta W}

 means "that amount of energy lost as the result of work". Thus one can state the amount of internal energy possessed by a thermodynamic system that one knows is presently in a given state, but one cannot tell, just from knowledge of the given present state, how much energy has in the past flowed into or out of the system as a result of its being heated or cooled, nor as the result of work being performed on or by the system.

text: Entropy is a function of the state of a system which tells of limitations of the possibility of conversion of heat into work.

text: For a simple compressible system, the work performed by the system may be written:

text:
where

P

{\displaystyle P}

 is the pressure and

d
V

{\displaystyle dV}

 is a small change in the volume of the system, each of which are system variables. In the fictive case in which the process is idealized and infinitely slow, so as to be called quasi-static, and regarded as reversible, the heat being transferred from a source with temperature infinitesimally above the system temperature, then the heat energy may be written

text:
where

T

{\displaystyle T}

 is the temperature and

d

S

{\displaystyle \mathrm {d} S}

 is a small change in the entropy of the system. Temperature and entropy are variables of state of a system.

text: If an open system (in which mass may be exchanged with the environment) has several walls such that the mass transfer is through rigid walls separate from the heat and work transfers, then the first law may be written:[22]

text:
where

d
M

{\displaystyle dM}

 is the added mass and

u
′

{\displaystyle u'}

 is the internal energy per unit mass of the added mass, measured in the surroundings before the process.

text: Noether's theorem[edit]

text: The conservation of energy is a common feature in many physical theories. From a mathematical point of view it is understood as a consequence of Noether's theorem, developed by Emmy Noether in 1915 and first published in 1918. The theorem states every continuous symmetry of a physical theory has an associated conserved quantity; if the theory's symmetry is time invariance then the conserved quantity is called "energy". The energy conservation law is a consequence of the shift symmetry of time; energy conservation is implied by the empirical fact that the laws of physics do not change with time itself. Philosophically this can be stated as "nothing depends on time per se". In other words, if the physical system is invariant under the continuous symmetry of time translation then its energy (which is canonical conjugate quantity to time) is conserved. Conversely, systems which are not invariant under shifts in time (an example, systems with time dependent potential energy) do not exhibit conservation of energy – unless we consider them to exchange energy with another, external system so that the theory of the enlarged system becomes time invariant again. Conservation of energy for finite systems is valid in such physical theories as special relativity and quantum theory (including QED) in the flat space-time.

text: Relativity[edit]

text: With the discovery of special relativity by Henri Poincaré and Albert Einstein, energy was proposed to be one component of an energy-momentum 4-vector. Each of the four components (one of energy and three of momentum) of this vector is separately conserved across time, in any closed system, as seen from any given inertial reference frame. Also conserved is the vector length (Minkowski norm), which is the rest mass for single particles, and the invariant mass for systems of particles (where momenta and energy are separately summed before the length is calculated—see the article on invariant mass).

text:
The relativistic energy of a single massive particle contains a term related to its rest mass in addition to its kinetic energy of motion. In the limit of zero kinetic energy (or equivalently in the rest frame) of a massive particle, or else in the center of momentum frame for objects or systems which retain kinetic energy, the total energy of particle or object (including internal kinetic energy in systems) is related to its rest mass or its invariant mass via the famous equation

E
=
m

c

2

{\displaystyle E=mc^{2}}

.

text: Thus, the rule of conservation of energy over time in special relativity continues to hold, so long as the reference frame of the observer is unchanged. This applies to the total energy of systems, although different observers disagree as to the energy value. Also conserved, and invariant to all observers, is the invariant mass, which is the minimal system mass and energy that can be seen by any observer, and which is defined by the energy–momentum relation.

text: In general relativity, energy–momentum conservation is not well-defined except in certain special cases. Energy-momentum is typically expressed with the aid of a stress–energy–momentum pseudotensor. However, since pseudotensors are not tensors, they do not transform cleanly between reference frames. If the metric under consideration is static (that is, does not change with time) or asymptotically flat (that is, at an infinite distance away spacetime looks empty), then energy conservation holds without major pitfalls. In practice, some metrics such as the Friedmann–Lemaître–Robertson–Walker metric do not satisfy these constraints and energy conservation is not well defined.[23] The theory of general relativity leaves open the question of whether there is a conservation of energy for the entire universe.

text: Quantum theory[edit]

text: In quantum mechanics, energy of a quantum system is described by a self-adjoint (or Hermitian) operator called the Hamiltonian, which acts on the Hilbert space (or a space of wave functions) of the system. If the Hamiltonian is a time-independent operator, emergence probability of the measurement result does not change in time over the evolution of the system. Thus the expectation value of energy is also time independent. The local energy conservation in quantum field theory is ensured by the quantum Noether's theorem for energy-momentum tensor operator. Note that due to the lack of the (universal) time operator in quantum theory, the uncertainty relations for time and energy are not fundamental in contrast to the position-momentum uncertainty principle, and merely holds in specific cases (see Uncertainty principle). Energy at each fixed time can in principle be exactly measured without any trade-off in precision forced by the time-energy uncertainty relations. Thus the conservation of energy in time is a well defined concept even in quantum mechanics.