Editing 135: Substitute

{{comic
| number    = 135
| date      = July 31, 2006
| title     = Substitute
| image     = substitute.png
| titletext = YOU THINK THIS IS FUNNY?
}}

==Explanation==
This comic refers to the film ''{{w|Jurassic Park (film)|Jurassic Park}}'', a 1993 movie based on the 1990 novel by {{w|Michael Crichton}}. The film centers around a billionaire who bought an island and opened a zoo or theme park for dinosaurs that he has cloned from DNA recovered from blood found in fossilized mosquitoes. After a computer programmer shuts down the security systems to steal embryos for a rival company, several of the creatures, among which are the {{w|Velociraptor}}s subject of this comic, run loose and try to devour every human in the theme park.

Velociraptors (often shortened to "raptors") are a species of relatively small, carnivorous {{w|dinosaur}} that play a central role in the original film, as well as its sequels. In the film, packs of Velociraptors antagonize the main characters at various points, even entering buildings. According to newer researches, the Velociraptors in the film were erroneously based on the {{w|Utahraptor}} species of dinosaur. Unlike the movie, in which they are depicted as having a reptilian skin, both species of dinosaur in reality are theorized to have been feathered. The word "raptor" also refers to modern {{w|Bird of prey|birds of prey}}.

[[Randall Munroe|Randall]] is asked to substitute for [[Miss Lenhart]] in math class. The first page of the test he devises contains three questions, which have the recurring theme of humans running from said velociraptors. For the answers, see below. As Randall says in the comic: "This material is more vital than anything you've ever learned," the joke being that Randall is somehow fearful that such a thing could happen. Velociraptors, and in particular, the irrational fear of being attacked by them in the modern world, [[:Category:Velociraptors|appear several times]] in [[xkcd]]. This is the second such instance; the first is [[87: Velociraptors]].

Answers to the first two questions [http://fora.xkcd.com/viewtopic.php?f=7&t=120&start=40 used be found] on the forum board, until it was shut down. The link is now defunct, but there's an [https://web.archive.org/web/20150326152959/http://fora.xkcd.com/viewtopic.php?f=7&t=120&start=40 archived version]:
*The first is 37.30194339616981 meters.
*The second is 57.19 degrees to either side of the wounded raptor, if the raptors at each instant move towards the current position of the person.
*The second is 59.83 degrees to either side of the wounded raptor, if the raptors' trajectories are optimal for catching the person as quickly as possible.

In the title text, Randall asks the kids whether they find this possibility humorous (and they rightfully should, considering that the chances of such a thing occurring are astronomically low{{Citation needed}}).

==Transcript==
:[In a classroom, the board says "Math" on the top-left corner, and "Mr. Munroe" in the middle. A Cueball portrays Randall, standing in front of it, speaking to the class.]
:Randall: Miss Lenhart couldn't be here today, so she asked me to substitute.
:Randall: I've put out your tests. Please get started.

:[A student in the first row raises the exam paper and says:]
:Student: Mr. Munroe, Miss Lenhart never taught us this.

:Randall: That's because Miss Lenhart doesn't understand how important certain kinds of math are.
:Student: But this just looks--
:Randall: This material is more vital than anything you've ever learned
:Student: But--
:Randall: No buts.

:Randall: This is a matter of life and death.

:[Excerpt from the exam paper.]
:<tt>Name: _________</tt>

:[A stick figure is standing, hands over head. A velociraptor is running towards it.]

:<tt>1. The velociraptor spots you 40 meters away and attacks, accelerating at 4 m/s^2 to its top speed of 25 m/s. When it spots you, you begin to flee, quickly reaching your top speed of 6 m/s. How far can you get before you're caught and devoured?</tt>

:<tt>2. You're at the center of a 20m equilateral triangle with a raptor at each corner. The top raptor has a wounded leg and is limited to a top speed of 10 m/s.</tt>

:[A stick figure is shown in the above situation. The picture has a legend "<tt>(Not to scale).</tt>"]

:<tt>The raptors will run toward you. At what angle should you run to maximize the time you stay alive?</tt>

:<tt>3. Raptors can open doors, but they are slowed by them. Using the floor plan on the next page, plot a route through the building, assuming raptors take 5 minutes to open the first door and halve the time for each subsequent door. Remember, raptors run at 10 m/s and they do not know fear.</tt>

==Trivia==
This is the first xkcd comic featuring [[Miss Lenhart]].

{{comic discussion}}

[[Category:Comics featuring Miss Lenhart]]
[[Category:Comics featuring Randall Munroe]]
[[Category:Comics with color]]
[[Category:Velociraptors]]
[[Category:Jurassic Park]]
[[Category:Math]]
[[Category:Physics]]
[[Category:Comics featuring Cueball]]
[[Category:Kids]]