explain xkcd - User contributions [en]

1602: Linguistics Club

2015-11-12T08:58:28Z

141.101.104.10: cleanup

{{comic
| number = 1602
| date = November 11, 2015
| title = Linguistics Club
| image = linguistics_club.png
| titletext = If that's too easy, you could try joining Tautology Club, which meets on the date of the Tautology Club meeting.
}}

==Explanation==
A "[[wiktionary:sesquiannual|sesquiannual]]" meeting is one that occurs one and a half times every year, or once every 8 months. It comes from the Latin prefix "[[wiktionary:sesqui|sesqui-]]", which means "one and a half times", and "[[wiktionary:annual|annual]]", which means "happening once every year". This is not to be confused with [[wiktionary:sesquiennial|sesquiennial]], which means every one and a half years, or 18 months. A linguist or Latin scholar, the joke suggests, should be able to figure sesquiannual out as "half-and-one every year". This is an extension of the common confusion between "biannual," meaning "twice a year", and "biennial", meaning "once every two years". Compare with the {{w|Sesquicentennial Exposition}} celebrating the first 1½ centuries of the United States.

This confusion is related to the distinction between 'biweekly' (which paradoxically means either twice per week or once every two weeks) and 'semiweekly' (once every half-week, i.e., twice a week), and bimonthly (twice a month or every two months). 'Biannual' and 'biennial' only furthers this confusion (as in this case, 'biannual' and 'semiannual' are synonymous when the prefixes usually are not). Outside of the US, the term fortnightly [once every two weeks] is used, clearing up any confusion over the term biweekly.

Regarding the title text, a {{w|tautology (rhetoric)|tautology}} is a statement that is true (or self-evident) because of its logical form, such as "all birds are birds" or "A = A." As such, the statement "the Tautology Club meets on the date of the Tautology Club's meeting" is itself tautological.

While the membership requirement for the original club is merely to know the intended frequency, with the applicant presumably being told at least one meeting date in the cycle so that an attendance can be made, Tautology Club's stipulation appears to require an eligible member to derive a valid meeting date from thin air without any clue at all (and no indication that there is even a regular cycle of any kind). This would definitely be more of a challenge.

The title text has a connection to [[703: Honor Societies]] in which Cueball announces that "the first rule of Tautology Club is the first rule of Tautology Club."

==Transcript==
Megan: You should come to our Linguistic Club's sesquiannual meeting. Membership is open to anyone who can figure out how often we meet.

{{comic discussion}}

[[Category:Comics featuring Megan]]
[[Category:Comics featuring Ponytail]]
[[Category:Language]]

1504: Opportunity

2015-03-27T09:00:11Z

141.101.104.10:

{{comic
| number = 1504
| date = March 27, 2015
| title = Opportunity
| image = opportunity.png
| titletext = We all remember those famous first words spoken by an astronaut on the surface of Mars: "That's one small step fo- HOLY SHIT LOOK OUT IT'S GOT SOME KIND OF DRILL! Get back to the ... [unintelligible] ... [signal lost]"
}}

==Explanation==
{{incomplete/Comic lacks explanation entirely.}}

The last panel is a reference to the Lion King, and it implies that Opportunity has gained sentience. Randall has anthropomorphized space probes in many comics before.

==Transcript==
{{incomplete transcript}}
2010:
Ponytail (at a computer): After six years, Spirit is down, but Opportunity is still going strong.

Hair Bun: Tough little rover!

2015:
Opportunity:
Eleven years, wow!
Wasn't the original mission 90 days?
This is starting to get weird.

2023:
Cueball: The battery is totally disconnected! How can it still be moving?
Megan: Given what it did to the Mars 2020 rover, we may never know.

2450, Tereaformed Mars, Mars Imperial Capital:
Cueball and Megan are standing on a Martian cliff near a sci-fi city.

Cueball: Everything the light touches is our kingdom.
Megan (pointing to some distant mountains): What's over there?
Cueball: That is Opportunity's half of the planet. We must never go there.

:2010:
:[Ponytail and Hair Bun sitting at a Computer.]
:Ponytail: After six years, Spirit is down, but ''Opportunity'' is still going strong.
:Hair Bun: Tough little rover!

:2015:
:[Opportunity driving on the Mars.]
:Offscrean: Eleven years, wow.
:Offscrean 2: Wasn't the original mission 90 days?
:Offscrean: This is starting to get weird.

:2023:
:[Cueball and Megan sitting at a computer.]
:Cueball: The battery is totally disconnected. How can it still be moving?
:Megan: Given what it did to the Mars 2020 rover, we may never know.

:2450, terraformed Mars, martian imperial capital:
:[Some martian inhabits looking like Cueball and Megan pointing in the dark.]
:Cueball-Martian: Everything the light touches is our kingdom.
:Megan-MartianWhat's that dark area?
:Cueball-Martian: This is ''Opportunity's'' half of the planet. We must never go there

{{comic discussion}}

Talk:1504: Opportunity

2015-03-27T08:58:07Z

141.101.104.10:

"Everything the light touches is our kingdom" are Mufasa words from 'The Lion King' (1994) --[[User:JakubNarebski|JakubNarebski]] ([[User talk:JakubNarebski|talk]]) 08:39, 27 March 2015 (UTC)
May someone make this Transcritpt better? [[Special:Contributions/141.101.104.10|141.101.104.10]] 08:58, 27 March 2015 (UTC)

1504: Opportunity

2015-03-27T08:55:29Z

141.101.104.10:

{{comic
| number = 1504
| date = March 27, 2015
| title = Opportunity
| image = opportunity.png
| titletext = We all remember those famous first words spoken by an astronaut on the surface of Mars: "That's one small step fo- HOLY SHIT LOOK OUT IT'S GOT SOME KIND OF DRILL! Get back to the ... [unintelligible] ... [signal lost]"
}}

==Explanation==
{{incomplete/Comic lacks explanation entirely.}}

The last panel is a reference to the Lion King, and it implies that Opportunity has gained sentience. Randall has anthropomorphized space probes in many comics before.

==Transcript==
{{incomplete transcript}}
2010:
Ponytail (at a computer): After six years, Spirit is down, but Opportunity is still going strong.

Hair Bun: Tough little rover!

2015:
Opportunity:
Eleven years, wow!
Wasn't the original mission 90 days?
This is starting to get weird.

2023:
Cueball: The battery is totally disconnected! How can it still be moving?
Megan: Given what it did to the Mars 2020 rover, we may never know.

2450, Tereaformed Mars, Mars Imperial Capital:
Cueball and Megan are standing on a Martian cliff near a sci-fi city.

Cueball: Everything the light touches is our kingdom.
Megan (pointing to some distant mountains): What's over there?
Cueball: That is Opportunity's half of the planet. We must never go there.

:2010:
:[Ponytail and ?Megan? sitting at a Computer.]
:Ponytail: After six years, Spirit is down, but ''Opportunity'' is still going strong.
:Megan: Tough little rover!

:2015:
:[Opportunity driving on the Mars.]
:Offscrean: Eleven years, wow.
:Offscrean 2: Wasn't the original mission 90 days?
:Offscrean: This is starting to get weird.

:2023:
:[Cueball and Megan sitting at a computer.]
:Cueball: The battery is totally disconnected. How can it still be moving?
:Megan: Given what it did to the Mars 2020 rover, we may never know.

:2450, terraformed Mars, martian imperial capital:
:[Some martian inhabits looking like Cueball and Megan pointing in the dark.]
:Cueball-Martian: Everything the light touches is our kingdom.
:Megan-MartianWhat's that dark area?
:Cueball-Martian: This is ''Opportunity's'' half of the planet. We must never go there

{{comic discussion}}

1425: Tasks

2014-09-24T12:26:12Z

141.101.104.10: /* Explanation */

{{comic
| number = 1425
| date = September 24, 2014
| title = Tasks
| image = tasks.png
| titletext = In the 60s, Marvin Minsky assigned a couple of undergrads to spend the summer programming a computer to use a camera to identify objects in a scene. He figured they'd have the problem solved by the end of the summer. Half a century later, we're still working on it.
}}

==Explanation==
{{incomplete|Explain why it is so difficult to identify a particular object in an image. Better background needed on title text.}}
[[Cueball]] appears to be asking [[Ponytail]] to write an app that determines if a given picture is of a bird in a national park. These two requirements, while seemingly about equally hard to a human, vary greatly in difficulty in computer science (CS).

In order to determine whether the user is in a national park, Ponytail plans to determine the the users location, presumably using a GPS or some method of {{w|Mobile phone tracking|mobile phone tracking}}. This location will then be cross checked with a {{w|geographic information system}} (GIS) which will be able to determine whether the co-ordinates lie within a national park boundary.

Determining whether an image is of a particular object is far more difficult. This task falls into the area of {{w|Computer vision|computer vision}}. One of the goals in computer vision is to detect and classify objects within an image. This is a very challenging task since there is a large variability in the object's appearance and background composition. Furthermore, the object might only be partially visible or occluded. In the case of a living bird additional complication arises from the bird's pose (flying, perching in a tree, etc.) since it is not a static object (e.g. street sign). Differentiating between visually similar objects can result in false positives, for example is a photo of a bird in flight or a plane (or superman!). The task is especially difficult when the photo quality may be low.

Today's state-of-the-art algorithms for solving this kind of task mostly use local features (e.g. {{w|Scale-invariant feature transform|SIFT}} or {{w|SURF}} in combination with a {{w|support vector machine}} or {{w|convolutional neural network}}).

The title text mentiones [http://dspace.mit.edu/bitstream/handle/1721.1/6125/AIM-100.pdf The Summer Vision Project] from {{w|Marvin Minsky}} from MIT. In summer 1966 he asked his undergraduate student {{w|Gerald Jay Sussman}} to "spend the summer linking a camera to a computer and getting the computer to describe what it saw" ([http://szeliski.org/Book/]). The project schedule allocated one summer for the completion of this task. This estimation was obviously far underestimated since today dozens of research groups around the world are still working on this topic.

==Transcript==
:[Ponytail sitting at a computer with Cueball standing behind her]
:Cueball: When a user takes a photo, the app should check whether they're in a national park...
:Ponytail: Sure, easy GIS lookup. Gimme a few hours.
:Cueball: ...and check whether the photo is of a bird.
:Ponytail: I'll need a research team and five years.
:In CS, it can be hard to explain the difference between the easy and the virtually impossible

{{comic discussion}}