explain xkcd - User contributions [en]

2486: Board Game Party Schedule

2021-07-08T03:22:20Z

162.158.88.110: /* Explanation */

{{comic
| number = 2486
| date = July 7, 2021
| title = Board Game Party Schedule
| image = board_game_party_schedule.png
| titletext = Several of the guests are secretly playing Meta Board Game Party. Every minute of parallel debate in the breakaway faction earns double victory points!
}}

==Explanation==
{{incomplete|Created by a RESTLESS FACTION. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}

This comic shows a timeline of a gathering to play some sort of fairly complex tabletop game, such as {{w|Warhammer (game)|Warhammer}}, {{w|Star Fleet Battles|Star Fleet Battles}}, or {{w|Squad Leader|Squad Leader}}. These games often have many pages of rules, forms to fill out, and in the case of many battle simulation games can have dozens or even hundreds of counters to position. Often the very complex rules must be explained in detail, which can be extremely dull in a group environment.

Conversely, just beginning like at the time entry point "it will make sense once you play" without explanation often leads to new player frustration that, had they had a complete understanding, they would have made different choices and had a more reasonable chance at victory, or even worse, avoided constantly being informed of "illegal moves".

In addition, since it's a {{w|party|party}}, there are other activities that take place in addition to playing the game, notably ordering and eating food.

By the time you eat, prepare the game, and teach the new players, little time is left to actually play the game.

Often during these gatherings the frustration with the factors above cause people to suggest settling on a simpler or more well known game such as {{w|Catan|Catan}} or card games like {{w|Dominion (card game)|Dominion}}.

The title text observes some of the guests supposedly playing a fictional{{Citation needed}} board game, Meta Board Game Party – a board game about board game parties. Because the quoted rule states that arguing in the “breakaway faction” is worth more victory points, it would be optimal strategy for them to do just that, for as long as possible. This seems to be a sarcastic explanation as to why they tried to get the whole group to play some other game and turned the ensuing debate into 45 minutes of bickering.

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}

:[Caption above:]
:Board Game Party Schedule

:[A timeline is shown, from about 6PM at the top to about 11PM at the bottom. Events are displayed as white rectangles, labeled as follows:]

:before 6PM: people filter in
:6:00–6:25: small talk
:6:25–6:55: debate which game to play
:6:55: remember that you need to order food
:6:55–7:15: debate where to order from
:7:15: pick a place, order
:7:15–7:40: pick a game and start setting up
:7:40–8:20: explain rules to new people
:8:20: food arrives
:8:20–9:00: eat food
:9:00–9:27: resume setting up
:9:27–9:52: more explanation
:9:52–10:13: restless faction tries to start simpler game
:10:13–10:38: general debate
:10:38–10:57: “It will make sense once you play”
:10:57–11:10: finish setting up
:after 11:10 PM: people head home

{{comic discussion}}

Talk:2483: Linked List Interview Problem

2021-07-01T09:09:12Z

162.158.88.110:

Assuming not everyone understands O notation: O(1) means that it always takes the same time, no matter how much data is stored. O(n) means the time is proportional to the amount of data stored - if you have 10 times the data, it takes 10 times as long to find the one you want. {{unsigned ip|108.162.221.84}}

This code won't mail the linked list to a museum - it will mail the memory location of the head of the list to a museum.{{unsigned ip|172.70.130.192}}

just to make sure I get this right.
If I want to save the numbers "1", "2", "3", "4" in an array it could (depending on the programming language) just be "[1,2,3,4]", while a linked list could be "1 (jump to 3rd entry), 4, 2 (jump to 4th entry), 3 (jump to 2nd entry)"?
Then entering 2.5 between 2 and 3 would be complicated in the array as you have to move the 3 and 4 to new places, while in the linked list you just change the direction after to to jump to 5th entry, and add 2.5 and the instruction to jump to 4th entry? While it is of course harder to find a specific entry in the linked list. --[[User:Lupo|Lupo]] ([[User talk:Lupo|talk]]) 06:01, 1 July 2021 (UTC)

Does anyone know when the last comic was that used colors? Is this something worth mentioning? --[[Special:Contributions/162.158.88.42|162.158.88.42]] 06:11, 1 July 2021 (UTC)

: I found the category: [[Category:Comics with color]]. --[[Special:Contributions/162.158.93.153|162.158.93.153]] 06:17, 1 July 2021 (UTC)

I added some words regarding the title text. Feel free to expand/clarify/correct as necessary. [[Special:Contributions/172.69.35.209|172.69.35.209]] 06:57, 1 July 2021 (UTC)

The comic could also be a reference to the [https://en.wikipedia.org/wiki/British_Museum_Algorithm British Museum Algorithm]. --[[Special:Contributions/162.158.88.110|162.158.88.110]] 09:09, 1 July 2021 (UTC)

2034: Equations

2018-09-15T12:18:09Z

162.158.88.110: /* Technical Explanations */ corrected a sign error in Number Theory

{{comic
| number = 2034
| date = August 17, 2018
| title = Equations
| image = equations.png
| titletext = All electromagnetic equations: The same as all fluid dynamics equations, but with the 8 and 23 replaced with the permittivity and permeability of free space, respectively.
}}
==Explanation==
{{incomplete|TODO: some simplified explanations. Do NOT delete this tag too soon.}}

This comic gives a set of equations supposedly from different areas of science in mathematics, physics, and chemistry. To anyone not familiar with the field in question they look pretty similar to what you might find in research papers or on the relevant Wikipedia pages. To someone who knows even a little about the topic, they are clearly very wrong and only seem even worse the more you look at them. In many disciplines, the mathematical description of a large area is summed up in a small number of equations, such as Maxwell's equations for electromagnetism. In similar fashion, the equations here purport to encompass the whole of their given field.

===Simplified Explanations===

;All kinematics equations
Kinematics is the study of the motion of objects. More specifically, it describes how the location, velocity, and acceleration of an object vary over time. The equation shown contains two of these standard kinematic variables, velocity ''v'' and time ''t'', in addition to several quantities (''E'', ''K0'', and ''ρ'') that are completely unrelated to kinematics.

;All number theory equations
Number theory is a branch of mathematics concerned primarily with the study of integers. However, the equation shown contains the non-integer Euler's constant ''e'' (approximately 2.718). It also uses the Greek letter π as an integer-valued variable, even though the symbol π is used in mathematics almost exclusively to denote the well-known ''non''-integer circle constant (approximately 3.14159). Even with π treated as a variable here, one of its uses in the equation is still nonsensical. <math>\pi-\infty</math> uses ∞ as if it were a specific number, which it is not, thus giving an undefined result.

;All chemistry equations
Randall implies that all chemistry is just combustion of chemicals, demonstrated with an incorrect form of a common example chemistry equation of burning Methane and Oxygen (with added heat), to form water and carbon dioxide. However, in this form "HEAT" is an actual molecule, rather than simply indicating the presence of heat to start the reaction. Thus the equation is modified to incorporate the fictional "HEAT" into the reaction. While the H in "HEAT" is the chemical symbol of the element hydrogen, none of the letters E, A, or T are symbols of any actual elements. Also, to account for the second hydrogen in "H(2)EAT" on the products side, the oxygen gas on the reactants side has been altered to be hydroxide, a strong base that would not facilitate traditional combustion.

TODO: other simplified explanations.

===Technical Explanations===
;All kinematics equations
:<math>E = K_0t + \frac{1}{2}\rho vt^2</math>
{{w|Kinematics}} describes the motion of objects without considering mass or forces. The latter is described by {{w|Kinetics (physics)|kinetics}}. The two fields get frequently confused due to the similarity of words.

This equation here literally states: "Energy equals a constant <math>K_0</math> multiplied by time, plus half of density multiplied by speed multiplied by time squared".

The first term here is hard to interpret: it could be correct if <math>K_0</math> is a constant power applied to the system, but this symbol would more normally be used to denote an initial energy, in which case multiplying by <math>t</math> would be wrong. Alternatively, the term is similar to <math>k_B T</math> (sometimes written as ''kT''), a term that often appears in {{w|Statistical_mechanics|statistical mechanics}} equations, where ''kB'' (or ''k'') is {{w|Boltzmann_constant|the Boltzmann constant}}, and ''T'' is the {{w|Thermodynamic_temperature|absolute temperature}}. In this latter case, the term would have units of energy, consistent with the left side of the equation.

The second term looks similar to the kinetic energy term <math> \frac{1}{2}\rho v^2 </math> in [http://hyperphysics.phy-astr.gsu.edu/hbase/pber.html the Bernoulli equation] for fluids. (More properly, this is the kinetic energy ''density'' in the fluid).

The whole equation appears to be a play on the kinematics formula: <math>s = v_0t + \frac{1}{2}\ at^2</math>, where distance travelled (''s'') by a constantly accelerating object is determined by initial velocity (''v0''), time (''t''), and acceleration (''a'')

Kinematics is often one of the first topics covered in an introductory physics course, both at the high school and freshman college levels. As such, mixing in material from more advanced topics like statistical mechanics and the Bernoulli equation, even if done correctly, would be very confusing for a typical student learning kinematics.

;All number theory equations
:<math>K_n = \sum_{i=0}^{\infty}\sum_{\pi=0}^{\infty}(n-\pi)(i+e^{\pi-\infty})</math>
{{w|Number theory}} is a branch of mathematics primarily studying the properties of integers.

Said in English, the equation can be read: "The ''n''th K-number is equal to the sum for all ''i'' from 0 to infinity of the sum for all π from 0 to infinity of ''n'' minus π, multiplied by ''i'' plus ''e'' raised to the power of π minus infinity." (''i'' here is an iteration variable, not the imaginary number constant; ''e'' is Euler's number, approximately 2.718). A twofold misconception can be seen here. The first is the use of π as a variable instead of the circle constant (3.14...). This might be a jab at how in number theory letters and numbers are used interchangeably, but where some letters are suddenly fixed constants.

Further confusion comes from the use of unusual mathematical models. While the term <math>e^{\pi-\infty}</math> is meaningless when considered in standard ("high school") mathematics, it is valid when considered on the {{w|extended real number line}}, a concept unfamiliar to most non-mathematicians and uncommon in number theory. Naively, this would signify that (with the use of π as a variable) the exponent would range from negative infinity to zero. In fact, assuming ''e'' really does mean Euler's constant (or at least a real number strictly greater than 1) the term would be zero for every π < ∞. Ultimately, the sum diverges for every ''n''.

The close proximity of the letters i, e and π also evokes {{w|Euler's identity}} <math>e^{i\pi}+1=0</math> (also written <math>e^{i\pi}=-1</math>), without actually using it, especially since both π and i are used as variables here.

;All fluid dynamics equations
:<math>\frac{\partial}{\partial t}\nabla\cdot \rho = \frac{8}{23}
\int\!\!\!\!\!\!\!\!\!\;\;\bigcirc\!\!\!\!\!\!\!\!\!\;\;\int
\rho\,ds\,dt\cdot \rho\frac{\partial}{\partial\nabla}
</math>
{{w|Fluid dynamics}} describes the movement of non-solid material. In particular for gases, the density <math>\rho</math> is often the most interesting quantity (for liquids, this is often just constant). A unique feature of fluid-dynamic equations is the presence of {{w|Advection|advection terms}}, which take the form of often strange-looking spatial derivatives. This equation turns this up to a new level by differentiating with respect to a differential operator <math>\nabla</math>, which does not make any sense at all. Also it has a contour integral which seems reminiscent to a closed-circle process like in a piston engine, but this does not really fit in the context (differential description of a gas), and it has a pair of {{w|Magic number (programming)|unexplained numbers}} <math>8</math> and <math>23</math>, probably alluding to the {{w|Heat capacity ratio|specific heat ratio}} which is often written out as the fraction <math>\tfrac{7}{5}</math>, whereas most other physics equations [[899: Number Line|avoid including any plain numbers higher than 4]].

The title text stating that the electromagnetism equation is the same as the fluid dynamics equation, but with the arbitrary 8 and 23 replaced with the permittivity and permeability of free space is likely because electromagnetism equations often have relations to fluid dynamics, and because those two constants appear in the vast majority of electromagnetism equations.

;All quantum mechanics equations
:<math>|\psi_{x,y}\rangle = A(\psi) A(|x\rangle \otimes |y\rangle)</math>
{{w|Quantum mechanics}} is a fundamental theory in physics which describes nature at scales of atoms and below. It typically uses the {{w|Bra–ket notation|bra–ket notation}} in its formulae.

This equation takes a state psi in the dimensions of x and y and equates it to an operator A performed on psi multiplied by the same operator performed on the tensor product of x and y. Since the state psi is already the tensor product of the states x and y, this is equivalent to performing the same unknown operator twice on psi, and unless this operator is the identity or is its own inverse such as a bit-flip or Hermitian operator, this equation is therefore incorrect.

;All chemistry equations
:<math>\mathrm{CH}_4 + \mathrm{OH} + \mathrm{HEAT} \rightarrow \mathrm{H}_2\mathrm{O} + \mathrm{CH}_2 + \mathrm{H}_2 \mathrm{EAT}</math>
A {{w|Chemical equation|chemical equation}} represents a chemical reaction as a formula, with the reactant entities on the left-hand side, and the product entities on the right-hand side. The number of each element on the left side must match those on the right side. The energy produced or absorbed in this process is not included in that formula.

This is a modification of the combustion of methane. The correct form is often taught and a good example problem but obviously there are more chemistry problems.<math>\mathrm{HEAT}</math> is normally shorthand for {{w|activation energy}}, but in Randall's version it's jokingly used as a chemical ingredient and becomes <math>\mathrm{H}_2\mathrm{EAT}</math>, taking the hydrogen atom freed by the combustion equation shown. The proper methane combustion equation would be: <math>\mathrm{CH}_4 + 2 \mathrm{O}_2 \rightarrow 2 \mathrm{H}_2\mathrm{O} + \mathrm{CO}_2</math>

While <math>\mathrm{OH}</math> often appears in chemical equations in the form of a negatively charged hydroxide group (<math>\mathrm{OH}^-</math>), the left side of the equation involves a bare <math>\mathrm{OH}</math>, possibly the highly unstable hydroxyl radical (although this would typically be written with a leading dot, e.g. <math>\bullet\mathrm{OH}</math>). Similarly, the right side contains an unstable methylene radical which would generally only appear as an intermediate rather than a product.

;All quantum gravity equations
:<math>\mathrm{SU}(2)\mathrm{U}(1) \times \mathrm{SU}(\mathrm{U}(2))</math>
This is more similar to expressions which appear in {{w|Grand_Unified_Theory|Grand Unified Theory}} (GUT) than general quantum gravity. Unlike some of the other equations, this one has no interpretation which could make it mathematically correct. This is similar to the notations used to describe the symmetry group of a particular phenomena in terms of mathematical {{w|Lie_Group|Lie Groups}}. A real example would be the Standard Model of particle physics which has symmetry according to <math>\rm{SU(3)\times SU(2) \times U(1)}</math>. Here, <math>\rm{SU}</math> and <math>\rm{U}</math> denote the special unitary and unitary groups respectively with the numbers indicating the dimension of the group. Loosely, the three terms correspond to the symmetries of the strong force, weak force and electromagnetism although the exact correspondence is muddied by symmetry breaking and the Higgs mechanism.

Of course, an expression missing an "=" sign, is difficult to interpret as an "equation", because equations normally express an "equality" of some kind. Nobody knows whether Randal refers to a horse, zebra, donkey or other equine here.

Randall's version clearly involves some similar groups although without the <math>\times</math> symbol it is hard to work out what might be happening. A term like <math>\rm{SU(U(2))}</math> has no current interpretation in mathematics, if anyone thinks otherwise and possibly has a solution to the quantum gravity problem they should probably get in touch with someone about that.

;All gauge theory equations
:[[File:All gauge theory equations.png]]
In physics, a {{w|Gauge theory|gauge theory}} is a type of field theory which is invariant to local transformations. The term gauge refers to any specific mathematical formalism to regulate redundant degrees of freedom.

This equation looks broadly similar to the sorts of things which appear in gauge theory such as the equations which define {{w|Yang–Mills_theory#Quantization|Yang-Mills Theory}}. By the time physics has got this far in, people have normally run out of regular symbols making a lot of the equations look very daunting. The actual equations in this field rarely go far beyond the Greek alphabet though and no-one has yet to try putting hats on brackets. The appearance of many sub- and superscripts is normal (this links to the group theory origins of these equations) and for the layperson it can be impossible to determine which additions are labels on the symbols and which are indices for an {{w|Einstein_notation|Einstein Sum}}.

The left-hand side <math>S_g</math> is the symbol for some {{w|Action_(physics)|action}}, in Yang-Mills theory this is actually used for a so-called "ghost action". On the right-hand side we have a large number of terms, most of which are hard to interpret without knowing Randall's thought processes (this is why real research papers should all label their equations thoroughly). The <math>\frac{1}{2\bar{\varepsilon}}</math> looks like a constant of proportionality which often appears in gauge theories. The factor of <math>i = \sqrt{-1}</math> is not unusual as many of these equations use complex numbers. The <math>\eth</math> symbol looks similar to a <math>\partial</math> partial derivative symbol especially as the {{w|Dirac_equation#Covariant_form_and_relativistic_invariance|Dirac Equation}} uses a slashed version as a convenient shorthand.

The rest of the equation cannot be mathematically correct as the choice of indices used does not match that on the left-hand side (which has none). In particle physics subscripts (or superscripts) of greek letters (usually <math>\mu</math> or <math>\nu</math>) indicate terms which transform nicely under Lorentz transformations (special relativity). Roman indices from the beginning of the alphabet relate to various gauge transformation propetries, the triple index seen on <math>p^{abc}_v</math> would likely come from some <math>\rm{SU(3)}</math> transformation (related to the strong nuclear force). Since <math>S_g</math> has none of these (and is thus a scalar which remains constant under these operations), we would need the right-hand side to behave in the same way. Most of the indices which appear are unpaired and so will not result in a scalar making the equation very wrong. For those not familiar with this type of equation, this is similar to the mistake of messing up units, for instance setting a distance equal to a mass.

;All cosmology equations
:<math>H(t) + \Omega + G \cdot \Lambda \, \dots \begin{cases} \dots > 0 & \text{(Hubble model)} \\ \dots = 0 & \text{(Flat sphere model)} \\ \dots < 0 & \text{(Bright dark matter model)} \end{cases}
</math>
This is a parody of equations defining the {{w|Hubble's_law#Derivation_of_the_Hubble_parameter|Hubble Parameter}} <math>H(t)</math> although it looks like Randall has become bored and not bothered to finish his equation. Such equations usually have several <math>\Omega</math> terms representing the contributions of different substances to the energy-density of the Universe (matter, radiation, dark energy etc.). In this context <math>G</math> could be Newton's constant and <math>\Lambda</math> is the cosmological constant (energy density of empty space) although seeing them appear multiplied and on the same footing as <math>H</math> is unusual (the dot is entirely unnecessary). Choosing to make <math>H</math> a function of time <math>t</math> and not of redshift <math>z</math> is also unusual.

The second section looks like the inequalities used to show how the equation varies with the shape of the Universe, based on the value of the curvature parameter <math>\Omega_k</math>. A value of 0 indicates a flat Universe (this is more or less what we observe) while a positive /negative value indicates an open /closed curved Universe. Randall's choice of labels further makes fun of the field as both a flat sphere and bright dark matter are oxymoronic terms which would involve some rather strange model universes.

;All truly deep physics equations
:[[File:All truly deep physics equations.png]]
<math>\hat H</math> is the Hamiltonian operator, which when applied to a system returns the total energy. In this context, U would usually be the potential energy. However, there is also a subscript 0 and a diacritic marking indicating some other variable. Much of physics is based on Lagrangian and Hamiltonian mechanics. The Lagrangian is defined as <math>\hat L = \hat K - \hat U </math> with K being the kinetic energy and U the potential. Hamiltonian mechanics uses the equation <math>\hat H = \hat K + \hat U </math>. The Hamiltonian must be conserved so taking the time derivative and setting it equal to zero is a powerful tool. The "principle of least action" allows most modern physics to be derived by setting the time derivative of the Lagrangian to zero.

==Transcript==
:[Nine equations are listed, three in the top row and two in each of the next three rows. Below each equation there are labels:]

:E = K0t + 1/2 ρvt2
:All kinematics equations

:Kn = ∑i=0∞∑π=0∞(n-π)(i-eπ-∞)
:All number theory equations

:∂/∂t ∇ ⋅ ρ = 8/23 (∯ ρ ds dt ⋅ ρ ∂/∂∇)
:All fluid dynamics equations

:|ψx,y〉 = A(ψ) A(|x〉⊗ |y〉)
:All quantum mechanics equations

:CH4 + OH + HEAT → H2O + CH2 + H2EAT
:All chemistry equations

:SU(2)U(1) × SU(U(2))
:All quantum gravity equations

:Sg = (-1)/(2ε̄) i ð (̂ ξ0 +̊ pε ρvabc η0 )̂ f̵a0 λ(ʒ̆) ψ(0a)
:All gauge theory equations

:[There is a brace linking the three cases together.]
:H(t) + Ω + G⋅Λ ...
:... > 0 (Hubble model)
:... = 0 (Flat sphere model)
:... < 0 (Bright dark matter model)
:All cosmology equations

:Ĥ - u̧0 = 0
:All truly deep physics equations

{{comic discussion}}

[[Category:Science]]
[[Category:Physics]]
[[Category:Math]]
[[Category:Chemistry]]
[[Category:Astronomy]]

1889: xkcd Phone 6

2017-09-13T19:30:03Z

162.158.88.110: /* List of features (clockwise from center/top) */

{{comic
| number = 1889
| date = September 13, 2017
| title = xkcd Phone 6
| image = xkcd_phone_6.png
| titletext = We understand your privacy concerns; be assured that our phones will never store or transmit images of your face.
}}

==Explanation==
{{incomplete|All features need an explanation, the version number war and title text as well. Do NOT delete this tag too soon.}}

This is the sixth entry in the ongoing [[:Category:xkcd Phones|xkcd Phone series]], released the day after Apple announced their new iPhone X with facial recognition features.

===List of features (clockwise from center/top)===

; Front camera (centered for eye contact during video chat)

: Front camera is a common feature of smartphones. The camera lens is located on the same side of the phone's case as the main screen and therefore it is possible to capture the image of the user's face looking at the screen and display the interlocutor's face on the screen simultaneously, enabling video chat. However, as the camera is usually located above the screen, a user looking at the displayed image of the other person directs his or her eyes at the center of the screen and not at the camera's lens. This is very visible on the other end of the chat as if the person talking was looking down and not in the interlocutor's face which is an uncomfortable situation for most people. For this reason, professionals involved in movie or TV-making, like actors or reporters, are trained to look straight into the camera's lens while talking, which creates impression of looking straight at the viewer's face. During a video chat, however, looking into the lens of an above-screen camera does not allow one to see the interlocutor's face clearly because it is then in the peripheral field of vision.

: To solve this conundrum, Randall proposes locating the camera lens right in the middle of the screen. Therefore the user looking at the screen to see the other person's face would be also looking at the lens, creating an impression of a straight look on the other end of the chat. This is absurd since the lens would then take place of some of the center pixels of the screen, not allowing the display the center part of the captured image of the other person's face (like eyes and/or lips) which is most important for nonverbal communication. Such location of the camera lens would also likely interfere with touch-screen function. It will make other applications on the phone difficult to use, since virtually no user interface is designed to accommodate for a blind spot in the center{{Citation needed}}.

; Full-width rear camera

: Phone cameras tend to have lenses which are quite small and round or square -- same width as height. Full-width makes it sound like the camera lens is really wide, as in a long oval or rectangle shape. This generally would not accomplish anything worthwhile, unless it allowed you to take one-shot panorama photos.

; CDC partnership - phone automatically administers seasonal flu vaccine to cheek every year

: U.S. {{w|Centers for Disease Control and Prevention}} is a government agency tasked with addressing public health concerns such as infectious diseases, including seasonal flu. A common way of limiting spread of an infectious disease is {{w|Vaccine|vaccination}}, which most often involves administering a specially prepared medicine via an {{w|intramuscular injection}}. This features implies that the phone would automatically perform such an injection once a year, by shooting a needle out of a small aperture while the user is holding the phone to his or her cheek during a call.

; 12-function

: Most smartphones can be used for more than 12 different things{{Citation needed}}.

; Dishwasher safe

: Usually a feature of plastic containers or fancy dishes. Unlikely to appear on a smartphone, though potentially useful if you need to clean your screen.

; GPS transmitter

: Many smartphones have a receiver for the Global Positioning System, which allows a phone to compute its position based on signals from the constellation of GPS satellites. However, a device with a "GPS transmitter" would broadcast signals that would interfere with the GPS receivers of all devices nearby.

; 3-G acceleration

: Usually, a phone is 3g compatible if it uses a certain standard ("third generation") for data transmission. However, 3-G acceleration implies the phone can accelerate at a rate or 3 times the acceleration of gravity, or approximately 30 m/s².

; Portable, solar-heated
: Portability is pretty much the entire point of using a ''mobile'' phone, so advertising portability is rather pointless. Solar ''power'' charging could be a very useful feature on a phone, but solar ''heating'' usually applies to plumbing, where a water tank is heated by the sun and used to supply hot water to taps. Technically, as the sun heats up everything on Earth, the phone is in fact solar heated.

;Pore-cleaning strip

: Something sticky on that location would be very annoying for people trying to make a call with beards. See also [[777: Pore Strips]]

; Maximum strength

:Medicines are often sold a "Maximum strength", as in the highest dose allowed by law or allowed without a prescription. For phones, there are sometimes "hardened" or "ruggedized" versions which are designed to survive harsher environmental conditions such as surviving drops and collisions, excessive water and dust, etc. So Maximum strength could indicate a "ruggedized" phone, though a screen that extended past the edges would likely have the opposite effect.

; Never needs sharpening

: Phones do not need to be sharpened in the first place{{Citation needed}}. This is a feature more likely to be used in a knife advertisement or apply to a mechanical pencil, which does have the advantage of never needing to be sharpened as opposed to a normal pencil.

; Can survive up to 30 minutes out of water

: This is a play on the common IP-rating of water resistance, which is typically rated for submersion to a rated depth for 30 minutes. A phone which could only be used or carried for 30 minutes and then needed to be immersed in water would be rather inconvenient.

; Exclusive Audubon Society app identifies birds and lets you control their flight

: {{w|National Audubon Society}} is a non-profit organization dedicated to conservation of nature, mainly of birds, also organizing open {{w|birdwatching}} events. An app that identifies bird species, as for example from a photo of a bird made by the smartphone itself, would be cool. An app allowing you to control the bird's flight would be way cooler, but it is not possible at the current state of technology{{Citation needed}} - and it would fly in the face of the Audubon Society core activity. This is a reference to {{w|Unmanned_aerial_vehicle|drones}} (artificial "birds") which are often controlled by a smartphone app. This may also be a reference to [[1425: Tasks]], in which an app that can recognize if a bird is on camera is proposed.

; Extra screen

:Because of the center camera, an additional section of screen was added. This is similar to the new iPhone, which also has a few extra pixels up there.

; Wireless charging port

:Wireless charging has no wires, and needs no port.

; Safe for ages 6-8 months, 10 months, 18 months-3 years, and 12 years and older

:Usually an item is deemed safe for a particular age or older, or (in the case of toys) is recommended for a particular age range. This is unusual in that it's a hodge-podge of age ranges with no apparent reason why some ages are safe and others are not.

; Screen goes past the edge

:A parody of the trend of "edge to edge" displays in recent generations of smartphones

; High thread count CPU

:A CPU thread is a task the CPU performs. Several threads may share memory making them a process. A operating system distributes the CPU's time over all active threads. CPU's don't generally have a limit on the number of threads (some operating systems do), however with a certain number the amount of cycles per thread becomes too low to be of much practical use. This seems to be a joke about bedding, where high thread count is actually a reasonably advertizable statistic.

; Shroud of Turin-style facial transfer unlock

:The {{w|Shroud of Turin}} is claimed to display an image of the face of {{w|Jesus Christ}}, appearing as if it was transferred to the cloth. Presumably, to unlock this phone, the user must press their face against it.

; Fonts developed by NASA

: NASA's expertise is not in fonts{{Citation needed}}, and the fonts on almost all modern phones are the same.

; Includes applicator

: What sanitary towel packages often say.

; Burns clean coal

: There is a push for clean energy production as a result of increased awareness of global warming. While it may be useful for a phone to be able to produce its own energy, coal is by definition not a clean energy source because it produces carbon dioxide. The phone is not stated to have a vent for the CO2 to escape, which would technically make the coal "clean" as it is not entering the atmosphere. However, the gas is instead trapped inside the phone, which will quickly ruin it through a combination of heat and pressure.

; Pre-seasoned

:Pre-seasoned typically refers to cast iron cookware which is ready to use out of the box, as opposed to needing to season it with oil and heat. It can also refer to packaged meats which are ready to cook without needing to be seasoned with herbs and spices.

; Broad-spectrum SPF 30

:The xkcd phone somehow gives an SPF 30 level of skin protection from the sun.

; College-ruled

:College-ruled is a style of notebook paper having narrower lines in order to fit more text per page.

; Sterile packaging

:Useful for medical supplies, less so in a phone.

; Radium backlight

:The discovery of the phosphorescent element radium sparked a brief fad in which some watch makers painted watch faces or hands with the substance so the time could be read at night. However, it was eventually realized that regular exposure to radium could result in radiation poisoning, particularly for the workers assembling and painting the watches. A radium-based backlight would therefore be both potentially dangerous (especially for an object carried on one's person much of the time) but also largely useless, as the phosphorescence of radium is rather dim compared to conventional phone back lights.

; 4K pixels (50×80)

:This refers to having 4,000 pixels in the screen in total, rather than a screen width of ~4000 pixels. TV's advertised as "4K" are typically up to 4096 × 2160 pixels, or 8.8 million pixels. That would be outstanding for a cell phone whereas 4,000 pixels total would be horrendous. As a comparison, the old Commodore VIC-20 with a resolution of 176 × 184 would have over 8 times the pixels of this phone. It is however quite close to the screen resolution of the sturdy Nokia 3310, boasting a total of 4032 pixels positioned 84 × 48.

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}
:[A smartphone is shown, the screen is slightly wider than the case, in the middle is a photo lens, and at the right bottom a small extra part is added to the screen.]
:[On top a bracket ranges nearly over the entire width of the case. The text reads:]
:Full-width rear camera
:[The label at the photo lens is:]
:Front camera (centered for eye contact during video chat)
:[The label on the extra part says:]
:Extra screen
:[At the bottom below the case a label reads:]
:Wireless charging port

:[The labels left to the phone are:]
:4k pixels (50x80)
:Radium backlight
:Sterile packaging
:College-ruled
:Broad spectrum SPF 30
:Pre-seasoned
:Burns clean coal
:Includes applicator
:Fonts developed by NASA
:Shroud of turn-style facial transfer unlock
:High thread count CPU
:Screen goes past the edge
:Safe for ages 6-8 months, 10 months, 18 months-3 years, and 12 years and older

:[The labels right to the phone are:]
:CDC partnership: Phone automatically administers seasonal flu vaccine to check every year
:12-function
:Dishwasher safe
:GPS transmitter
:3-G acceleration
:Portable, solar-heated
:Pore-cleaning strip
:Maximum strength
:Never needs sharpening
:Can survive up to 30 minutes out of water
:Exclusive Audubon Society app identifies birds and lets you control their flight

:[Text below the phone:]
:Introducing
:'''The XKCD PHONE 6, VIII, 10, X, 26, and 1876'''
:We didn't start this nonconsecutive version number war, but we will not lose it.™®©º
{{comic discussion}}

[[Category:xkcd Phones]]

Talk:452: Mission

2017-06-09T16:20:30Z

162.158.88.110:

maybe it got something to do with the saying, "oh this (heist/mission) will be a piece of cake. one could easily misunderstand that

so "highly likely" means "1 time out of 6" for some people :D [[Special:Contributions/141.101.97.215|141.101.97.215]] 12:27, 13 May 2014 (UTC)

Nope, highly likely means (about) two out of three for these people. [[Special:Contributions/141.101.92.221|141.101.92.221]] 11:10, 8 July 2014 (UTC)

The title text could also potentially count as a sort of NetHack reference. [[Special:Contributions/173.245.52.138|173.245.52.138]] 00:11, 12 May 2015 (UTC)

Reminds me of the "Whose Line Is It Anyway?" improv game "Improbable Mission".
[[Special:Contributions/141.101.75.149|141.101.75.149]] 01:38, 8 February 2016 (UTC)

"a hypothesis easily disprovable by looking around any room which isn't a bakery", actually it's not that easy to disprove. Maybe the earth is just in
a local irregularity inside a universe full of scones. Except the bakeries of course, centers of universal equilibrium. [[Special:Contributions/162.158.88.110|162.158.88.110]] 16:20, 9 June 2017 (UTC)

1820: Security Advice

2017-04-05T15:01:03Z

162.158.88.110: /* Security Tip Explanations */

{{comic
| number = 1820
| date = April 5, 2017
| title = Security Advice
| image = security_advice.png
| titletext = Never give your password or bank account number to anyone who doesn't have a blue check mark next to their name.
}}

==Explanation==
{{incomplete|Incomplete. TBD:Complete tip explanations Do NOT delete this tag too soon.}}

The comic depicts a conversation between [[Cueball]] and [[Ponytail]], discussing the fact that giving people security advice has failed to improve their internet security, and in some cases even made things worse (such as requiring complicated passwords leading to people leaving post-it notes with their passwords on their screen, leading to huge security risks). As a result Cueball suggests {{w|reverse psychology|giving bad advice instead}}, in hopes of a positive effect. The last panel contains a list these security tips, which are parodies of actual security tips.

The last tip on the image is most likely a reference to Ingmar Bergman's film [https://en.wikipedia.org/wiki/The_Seventh_Seal#Synopsis The Seventh Seal].

===Security Tip Explanations===
{| class="wikitable"
!Security Tip
!Explanation
|-
|Don't click links to websites
|The usual tip is "Don't click on ''suspicious'' website links." The comic's variation instead implies don't click on any links to any websites, or don't use the internet.
|-
|Use prime numbers in your password
|Long prime numbers are an essential part of modern cryptography and security systems, but don't have any effect when being used in passwords, except for maybe being harder to remember.
|-
|Change your password manager monthly
|It is often recommended to change passwords on a regular basis. However, changing password managers monthly would be quite impractical.
|-
|Hold your breath while crossing the border
|This in its self, wouldn't do anything, but if you hold your breath for too long you could pass out when crossing, or look stressed/suspicious. Overall, this would not help you.
|-
|Install a secure font
|
|-
|Use a 2-factor smoke detector
|A new way to keep accounts secure is 2-factor authentication, which usually means you enter your password, and then look for an email (or go into a mobile app) with a code which you then enter into the website. A 2-factor smoke detector would be useless, because it would require you to verify that there is actually a fire with a code, when the purpose of smoke detectors are to warn you about fires you ''don't'' know about.
|-
|Change your maiden name regularly
|A common security question (a type of 2-factor authentication from the previous tip) asks you for your maiden name.
|-
|Put strange USB drives in a bag of rice overnight
|The usual security tip is "Don't plug strange USB drives into your computer," because sometimes attackers put viruses that infect your system when plugged in. This tip implies that you should "put USB drives in a bag of rice overnight" which is a common technique for drying out water damaged devices, due to rice's absorbent qualities. This would not clean the drive of viruses, and unless the drive was wet (perhaps because you found it outside due to it being called "strange") it would not do anything.
|-
|Use special characters like & and %
|
|-
|Only read content published through Tor.com
|[https://en.wikipedia.org/wiki/Tor_(anonymity_network) Tor] is a software solution to provide anonymity on the web for its users. The website [https://tor.com Tor.com] is the website of fantasy and sci-fi book publisher Tor, which has no relation to the Tor-network.
|-
|Use a burner's phone
|
|-
|Get an SSL certificate and store it in a safe place
|
|-
|If a border guard asks to examine your laptop, you have a legal right to challenge them to a chess game for your soul.
|This tip is likely a reference to Ingmar Bergman's film [https://en.wikipedia.org/wiki/The_Seventh_Seal#Synopsis The Seventh Seal]
|-
|Never give your password or bank account number to anyone who doesn't have a blue check mark next to their name. (Title Text)
|The usual security tip here is ''"only trust accounts claiming to be legitimate if they have a blue check mark next to their name"'', which means that the account is verified as legitimate. This tip suggests only giving your ''password'' to verified accounts, although you shouldn't give your password to ''any'' account.
|}

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}

:Ponytail: We've been trying for decades to give people good security advice.
:Ponytail: But in retrospect, lots of the tips actually made things worse.

:Cueball: Maybe we should try to give ''bad'' advice?
:Ponytail: I guess it's worth a shot.

:Security tips
:(Print out this list and keep it in your bank safe deposit box.)
* Don't click links to websites
* Use prime numbers in your password
* Change your password manager monthly
* Hold your breath while crossing the border
* Install a secure font
* User a 2-factor smoke detector
* Change your maiden name regularly
* Put strange USB drives in a bag of rice overnight
* Use special characters like & and %
* Only read content published through Tor.com
* Use a burner's phone
* Get an SSL certificate and store it in a safe place
* If a border guard asks to examine your laptop, you have a legal right to challenge them to a chess game for your soul.

{{comic discussion}}