https://www.explainxkcd.com/wiki/api.php?action=feedcontributions&user=162.158.58.93&feedformat=atomexplain xkcd - User contributions [en]2024-03-29T10:23:22ZUser contributionsMediaWiki 1.30.0https://www.explainxkcd.com/wiki/index.php?title=1909:_Digital_Resource_Lifespan&diff=1574441909: Digital Resource Lifespan2018-05-23T01:47:39Z<p>162.158.58.93: /* Table */ note concerns in comic</p>
<hr />
<div>{{comic<br />
| number = 1909<br />
| date = October 30, 2017<br />
| title = Digital Resource Lifespan<br />
| image = digital_resource_lifespan.png<br />
| titletext = I spent a long time thinking about how to design a system for long-term organization and storage of subject-specific informational resources without needing ongoing work from the experts who created them, only to realized I'd just reinvented libraries.<br />
}}<br />
<br />
==Explanation==<br />
<br />
In this chart, [[Randall]] laments the tendency of digital resources to quickly become obsolete or non-functional. By taking a general subject, such as xkcd's core subjects of "romance, sarcasm, math, and language", one can see that a useful tool such as a smartphone or computer app or interactive CD-ROM (essentially, software) does not have the lasting power of printed books (e.g. textbooks, for many general subjects) and microfilm/microfiche. The printed resources, not having to rely on a computerized platform for use, are far more reliable despite being less mobile and taking up physical space. The only digital source which is still working is {{w|Portable Document Format}} (aka PDF) which encapsulates fixed layout flat documents, and is supported for years already by {{w|Adobe Systems}} and is part of {{w|International Organization for Standardization|ISO}} standards, so has a widespread support, and should be still viewable in foreseeable future.<br />
<br />
The title text makes a statement that libraries do not require the support of ''original'' authors/experts to organize and store vast resources for any subject imaginable. This is true, but omits the fact that ongoing efforts are required by experts in information organization and storage -- namely, librarians. Physical books and microfilm/microfiche need controlled storage environments, manual handling for storage, retrieval, distribution (in library terms, "circulation"), and the like. Thus, a library can require significant resources in personnel and facilities, but is usually seen as a "public good" for the benefit of society; thus, many communities and educational institutions invest in creating and maintaining a library despite the costs.<br />
<br />
Archive.org refers to {{w|The Internet Archive}}, a non-profit organization that maintains the {{w|Wayback Machine}}, one of the largest archives of the {{w|World Wide Web}}. When a website is taken offline, copies of its content can often be found backed-up on the Wayback Machine. The Wayback Machine is primarily designed to back up {{w|Website|websites}}, however, and will often not be able to save information stored in a site's {{w|Database|databases}}, as alluded to in the comic. The Internet Archive has a part for non-website archives, but it cannot hold recent databases either due to copyright problems.<br />
<br />
==Table==<br />
<br />
{| class="wikitable"<br />
!style="width:20%"|Caption<br />
!style="width:20%"|Type of Resource<br />
!style="width:60%"|Explanation<br />
|-<br />
|Book on Subject<br />
|{{w|Book|Physical Books}}<br />
|This is the most familiar physical resource and used as the baseline for other (digital) resources.<br />
Under optimal conditions, a book can last indefinitely for future generations. Additionally, there are books from the ancient times that are still readable today.{{Citation needed}}<br />
|-<br />
|<nowiki>[Subject].pdf</nowiki><br />
|{{w|Portable Document Format}}<br />
|This is the most familiar digital resource, with the probable exception of the internet. A format originally developed by Adobe, the majority of the format is now an {{w|Portable_Document_Format#History_and_standardization|ISO standard}} which means a compliant reader and writer can be made independently (which avoids the majority of the pitfalls described on later resources).<br />
A PDF file is designed to be portable (it is even in the acronym), which means unless the creator of the PDF uses a web-only feature (which is non-standard), it can be opened everywhere a PDF reader is found. Authors may also opt for a stricter, "archival" version ({{w|PDF/A}}) which ensures that both required files are placed on the same PDF file and only documented formats are used to prevent the reliance on non-standardized formats.<br />
|-<br />
|<nowiki>[Subject] Web Database</nowiki><br />
|{{w|Database}}<br />
|Another type of a digital resource which is, in itself, is like a digital library. Unlike a physical library however, it is usually only stored in a single file or server (there are instances that the database is distributed, but it is rare), which means that a failure to that server means that the database is wiped out, not to mention the gigantic space it takes (that is why the whole database are not stored in a digital archive, like the Internet Archive). <br />
Additionally, unlike PDFs, there are almost-infinite ways of storing and retrieving data in a database, which means that when the method used becomes unsupported (like the Java scenario, which is of now is completely unusable in web browsers), the data in it is effectively lost (whether or not the data-in-question is still physically on the server).<br />
|-<br />
|<nowiki>[Subject] Mobile App</nowiki><br />
<small>(Local University Project)</small><br />
|{{w|Mobile app|Mobile App}}<br />
|A type of digital resource that expands upon the idea of a web database. It allows easy access on a mobile device, however, as it is stated that it is a local university project, which means that support for it lasts only at most for a few years (which is not enough to maintain an application).<br />
Additionally, {{w|Operating System|Operating Systems}} can get obsolete (like the {{w|Symbian}} platform used on older {{w|Nokia}} phones) or critical changes to it breaks older applications (like on the [http://www.bbc.com/news/technology-41319675 Apple iOS]).<br />
|-<br />
|<nowiki>[Subject] Analysis Software</nowiki><br />
|{{w|Application software|Desktop Application}}<br />
|A type of executable program that is found on desktop systems. It allows reliable access on a desktop system, which means that (assuming the program is offline) it can survive on its own. However, {{w|Operating System|Operating Systems}} can get obsolete (like the {{w|Classic Mac OS}} platform used on older {{w|Macintosh|Mac}} computers) or critical changes to it breaks older applications (like the new security features on {{w|Microsoft Windows|Windows}} which breaks older non-compliant programs).<br />
|-<br />
|<nowiki>Interactive [Subject] CD-ROM</nowiki><br />
|{{w|Application software|Desktop Application}}, {{w|CD-ROM|CD-ROMs}}<br />
|A CD can hold anything from music to videos to applications. It also allows better offline access, and such were used in the 1990s and the early 2000s. It is still a fancy desktop application, which means that the situation on the analysis software applies here, not to mention the fact that a new invention can replace an obsolete one (for example, {{w|Microsoft Encarta}} was discontinued in 2010 due to the ease-of-access of {{w|Main Page|Wikipedia}}).<br />
Additional issues mentioned are that CDs can become "{{w|Disc rot|scratched}}", in which case, the data becomes corrupted or unreadable. Also, many modern laptops do not have CD-ROM drives anymore, making it difficult to use CDs as a storage medium.<br />
Additionally, this also covers the changes in a physical system: in the 1980s, {{w|Floppy disk|floppy diskettes}} were used, which was replaced in the 1990s by the CDs and DVDs, which then was replaced by {{w|Thumb drive|thumb drives}} in the 2000s, which is then supplemented (and in some cases, replaced entirely) by wireless device-to-device transfers (like {{w|Bluetooth}}) and internet file transfers using online storage (like {{w|Dropbox}} and {{w|Google Drive}}).<br />
<br />
|-<br />
|<nowiki>Library Microfilm [Subject] Collection</nowiki><br />
|{{w|Microfilm}}<br />
|This is a physical resource used by libraries to preserve (or to create a copy) of a collection, usually those things that are rare or would cause a social or political issue when damaged. Although great preservation is needed to prevent damage to a film, the system used is standardized and knowledge to build a reader or a printer off a microfilm is widely available, like a PDF file. This comparison might look like a physical version of PDFs: standardized, common (books can be of any size imagined) format.<br />
|-<br />
|}<br />
<br />
==Transcript==<br />
{{incomplete transcript|Needs reorganization?}}<br />
:My access to resources on [SUBJECT] over time:<br />
<br />
:[Below, a timeline and a graph with gray bars is shown:]<br />
<br />
:[1980s-past 2020:] <br />
:Book on subject<br />
<br />
:[Early 2000s-past 2020:] <br />
:[SUBJECT].pdf <br />
<br />
:[2000-2010:] <br />
:[SUBJECT] web database <br />
::Site goes down, backend data not on archive.org<br />
::[Small bar, 2000-2016/17:] <br />
:::Java frontend no longer runs<br />
<br />
:[2010-2015/16:] <br />
:[SUBJECT] mobile app (Local university project) <br />
::Broken on new OS, not updated<br />
<br />
:[2000-2010:] <br />
:[SUBJECT] analysis software<br />
::Broken on new OS, not updated<br />
<br />
:[Late 1990s-late 2000s:] <br />
:Interactive [SUBJECT] CD-ROM <br />
::CD scratched; new computer has no CD drive anyway.<br />
<br />
:[1980s-past 2020:] <br />
:Library microfilm [SUBJECT] collection<br />
<br />
:[Caption below the panel:]<br />
:It's unsettling to realize how quickly digital resources can disappear without ongoing work to maintain them.<br />
<br />
{{comic discussion}}<br />
<br />
[[Category:Timelines]]</div>162.158.58.93https://www.explainxkcd.com/wiki/index.php?title=1909:_Digital_Resource_Lifespan&diff=1574421909: Digital Resource Lifespan2018-05-23T01:43:25Z<p>162.158.58.93: /* Table */ whoops, delete</p>
<hr />
<div>{{comic<br />
| number = 1909<br />
| date = October 30, 2017<br />
| title = Digital Resource Lifespan<br />
| image = digital_resource_lifespan.png<br />
| titletext = I spent a long time thinking about how to design a system for long-term organization and storage of subject-specific informational resources without needing ongoing work from the experts who created them, only to realized I'd just reinvented libraries.<br />
}}<br />
<br />
==Explanation==<br />
<br />
In this chart, [[Randall]] laments the tendency of digital resources to quickly become obsolete or non-functional. By taking a general subject, such as xkcd's core subjects of "romance, sarcasm, math, and language", one can see that a useful tool such as a smartphone or computer app or interactive CD-ROM (essentially, software) does not have the lasting power of printed books (e.g. textbooks, for many general subjects) and microfilm/microfiche. The printed resources, not having to rely on a computerized platform for use, are far more reliable despite being less mobile and taking up physical space. The only digital source which is still working is {{w|Portable Document Format}} (aka PDF) which encapsulates fixed layout flat documents, and is supported for years already by {{w|Adobe Systems}} and is part of {{w|International Organization for Standardization|ISO}} standards, so has a widespread support, and should be still viewable in foreseeable future.<br />
<br />
The title text makes a statement that libraries do not require the support of ''original'' authors/experts to organize and store vast resources for any subject imaginable. This is true, but omits the fact that ongoing efforts are required by experts in information organization and storage -- namely, librarians. Physical books and microfilm/microfiche need controlled storage environments, manual handling for storage, retrieval, distribution (in library terms, "circulation"), and the like. Thus, a library can require significant resources in personnel and facilities, but is usually seen as a "public good" for the benefit of society; thus, many communities and educational institutions invest in creating and maintaining a library despite the costs.<br />
<br />
Archive.org refers to {{w|The Internet Archive}}, a non-profit organization that maintains the {{w|Wayback Machine}}, one of the largest archives of the {{w|World Wide Web}}. When a website is taken offline, copies of its content can often be found backed-up on the Wayback Machine. The Wayback Machine is primarily designed to back up {{w|Website|websites}}, however, and will often not be able to save information stored in a site's {{w|Database|databases}}, as alluded to in the comic. The Internet Archive has a part for non-website archives, but it cannot hold recent databases either due to copyright problems.<br />
<br />
==Table==<br />
<br />
{| class="wikitable"<br />
!style="width:20%"|Caption<br />
!style="width:20%"|Type of Resource<br />
!style="width:60%"|Explanation<br />
|-<br />
|Book on Subject<br />
|{{w|Book|Physical Books}}<br />
|This is the most familiar physical resource and used as the baseline for other (digital) resources.<br />
Under optimal conditions, a book can last indefinitely for future generations. Additionally, there are books from the ancient times that are still readable today.{{Citation needed}}<br />
|-<br />
|<nowiki>[Subject].pdf</nowiki><br />
|{{w|Portable Document Format}}<br />
|This is the most familiar digital resource, with the probable exception of the internet. A format originally developed by Adobe, the majority of the format is now an {{w|Portable_Document_Format#History_and_standardization|ISO standard}} which means a compliant reader and writer can be made independently (which avoids the majority of the pitfalls described on later resources).<br />
A PDF file is designed to be portable (it is even in the acronym), which means unless the creator of the PDF uses a web-only feature (which is non-standard), it can be opened everywhere a PDF reader is found. Authors may also opt for a stricter, "archival" version ({{w|PDF/A}}) which ensures that both required files are placed on the same PDF file and only documented formats are used to prevent the reliance on non-standardized formats.<br />
|-<br />
|<nowiki>[Subject] Web Database</nowiki><br />
|{{w|Database}}<br />
|Another type of a digital resource which is, in itself, is like a digital library. Unlike a physical library however, it is usually only stored in a single file or server (there are instances that the database is distributed, but it is rare), which means that a failure to that server means that the database is wiped out, not to mention the gigantic space it takes (that is why the whole database are not stored in a digital archive, like the Internet Archive). <br />
Additionally, unlike PDFs, there are almost-infinite ways of storing and retrieving data in a database, which means that when the method used becomes unsupported (like the Java scenario, which is of now is completely unusable in web browsers), the data in it is effectively lost (whether or not the data-in-question is still physically on the server).<br />
|-<br />
|<nowiki>[Subject] Mobile App</nowiki><br />
<small>(Local University Project)</small><br />
|{{w|Mobile app|Mobile App}}<br />
|A type of digital resource that expands upon the idea of a web database. It allows easy access on a mobile device, however, as it is stated that it is a local university project, which means that support for it lasts only at most for a few years (which is not enough to maintain an application).<br />
Additionally, {{w|Operating System|Operating Systems}} can get obsolete (like the {{w|Symbian}} platform used on older {{w|Nokia}} phones) or critical changes to it breaks older applications (like on the [http://www.bbc.com/news/technology-41319675 Apple iOS]).<br />
|-<br />
|<nowiki>[Subject] Analysis Software</nowiki><br />
|{{w|Application software|Desktop Application}}<br />
|A type of executable program that is found on desktop systems. It allows reliable access on a desktop system, which means that (assuming the program is offline) it can survive on its own. However, {{w|Operating System|Operating Systems}} can get obsolete (like the {{w|Classic Mac OS}} platform used on older {{w|Macintosh|Mac}} computers) or critical changes to it breaks older applications (like the new security features on {{w|Microsoft Windows|Windows}} which breaks older non-compliant programs).<br />
|-<br />
|<nowiki>Interactive [Subject] CD-ROM</nowiki><br />
|{{w|Application software|Desktop Application}}, {{w|CD-ROM|CD-ROMs}}<br />
|A CD can hold anything from music to videos to applications. It also allows better offline access, and such were used in the 1990s and the early 2000s. It is still a fancy desktop application, which means that the situation on the analysis software applies here, not to mention the fact that a new invention can replace an obsolete one (for example, {{w|Microsoft Encarta}} was discontinued in 2010 due to the ease-of-access of {{w|Main Page|Wikipedia}}).<br />
Additionally, this also covers the changes in a physical system: in the 1980s, {{w|Floppy disk|floppy diskettes}} were used, which was replaced in the 1990s by the CDs and DVDs, which then was replaced by {{w|Thumb drive|thumb drives}} in the 2000s, which is then supplemented (and in some cases, replaced entirely) by wireless device-to-device transfers (like {{w|Bluetooth}}) and internet file transfers using online storage (like {{w|Dropbox}} and {{w|Google Drive}}).<br />
|-<br />
|<nowiki>Library Microfilm [Subject] Collection</nowiki><br />
|{{w|Microfilm}}<br />
|This is a physical resource used by libraries to preserve (or to create a copy) of a collection, usually those things that are rare or would cause a social or political issue when damaged. Although great preservation is needed to prevent damage to a film, the system used is standardized and knowledge to build a reader or a printer off a microfilm is widely available, like a PDF file. This comparison might look like a physical version of PDFs: standardized, common (books can be of any size imagined) format.<br />
|-<br />
|}<br />
<br />
==Transcript==<br />
{{incomplete transcript|Needs reorganization?}}<br />
:My access to resources on [SUBJECT] over time:<br />
<br />
:[Below, a timeline and a graph with gray bars is shown:]<br />
<br />
:[1980s-past 2020:] <br />
:Book on subject<br />
<br />
:[Early 2000s-past 2020:] <br />
:[SUBJECT].pdf <br />
<br />
:[2000-2010:] <br />
:[SUBJECT] web database <br />
::Site goes down, backend data not on archive.org<br />
::[Small bar, 2000-2016/17:] <br />
:::Java frontend no longer runs<br />
<br />
:[2010-2015/16:] <br />
:[SUBJECT] mobile app (Local university project) <br />
::Broken on new OS, not updated<br />
<br />
:[2000-2010:] <br />
:[SUBJECT] analysis software<br />
::Broken on new OS, not updated<br />
<br />
:[Late 1990s-late 2000s:] <br />
:Interactive [SUBJECT] CD-ROM <br />
::CD scratched; new computer has no CD drive anyway.<br />
<br />
:[1980s-past 2020:] <br />
:Library microfilm [SUBJECT] collection<br />
<br />
:[Caption below the panel:]<br />
:It's unsettling to realize how quickly digital resources can disappear without ongoing work to maintain them.<br />
<br />
{{comic discussion}}<br />
<br />
[[Category:Timelines]]</div>162.158.58.93https://www.explainxkcd.com/wiki/index.php?title=1909:_Digital_Resource_Lifespan&diff=1574411909: Digital Resource Lifespan2018-05-23T01:42:51Z<p>162.158.58.93: /* Table */ spelling</p>
<hr />
<div>{{comic<br />
| number = 1909<br />
| date = October 30, 2017<br />
| title = Digital Resource Lifespan<br />
| image = digital_resource_lifespan.png<br />
| titletext = I spent a long time thinking about how to design a system for long-term organization and storage of subject-specific informational resources without needing ongoing work from the experts who created them, only to realized I'd just reinvented libraries.<br />
}}<br />
<br />
==Explanation==<br />
<br />
In this chart, [[Randall]] laments the tendency of digital resources to quickly become obsolete or non-functional. By taking a general subject, such as xkcd's core subjects of "romance, sarcasm, math, and language", one can see that a useful tool such as a smartphone or computer app or interactive CD-ROM (essentially, software) does not have the lasting power of printed books (e.g. textbooks, for many general subjects) and microfilm/microfiche. The printed resources, not having to rely on a computerized platform for use, are far more reliable despite being less mobile and taking up physical space. The only digital source which is still working is {{w|Portable Document Format}} (aka PDF) which encapsulates fixed layout flat documents, and is supported for years already by {{w|Adobe Systems}} and is part of {{w|International Organization for Standardization|ISO}} standards, so has a widespread support, and should be still viewable in foreseeable future.<br />
<br />
The title text makes a statement that libraries do not require the support of ''original'' authors/experts to organize and store vast resources for any subject imaginable. This is true, but omits the fact that ongoing efforts are required by experts in information organization and storage -- namely, librarians. Physical books and microfilm/microfiche need controlled storage environments, manual handling for storage, retrieval, distribution (in library terms, "circulation"), and the like. Thus, a library can require significant resources in personnel and facilities, but is usually seen as a "public good" for the benefit of society; thus, many communities and educational institutions invest in creating and maintaining a library despite the costs.<br />
<br />
Archive.org refers to {{w|The Internet Archive}}, a non-profit organization that maintains the {{w|Wayback Machine}}, one of the largest archives of the {{w|World Wide Web}}. When a website is taken offline, copies of its content can often be found backed-up on the Wayback Machine. The Wayback Machine is primarily designed to back up {{w|Website|websites}}, however, and will often not be able to save information stored in a site's {{w|Database|databases}}, as alluded to in the comic. The Internet Archive has a part for non-website archives, but it cannot hold recent databases either due to copyright problems.<br />
<br />
==Table==<br />
<br />
{| class="wikitable"<br />
!style="width:20%"|Caption<br />
!style="width:20%"|Type of Resource<br />
!style="width:60%"|Explanation<br />
|-<br />
|Book on Subject<br />
|{{w|Book|Physical Books}}<br />
|This is the most familiar physical resource and used as the baseline for other (digital) resources.<br />
Under optimal conditions, a book can last indefinitely for future generations. Additionally, there are books from the ancient times that are still readable today.{{Citation needed}}<br />
|-<br />
|<nowiki>[Subject].pdf</nowiki><br />
|{{w|Portable Document Format}}<br />
|This is the most familiar digital resource, with the probable exception of the internet. A format originally developed by Adobe, the majority of the format is now an {{w|Portable_Document_Format#History_and_standardization|ISO standard}} which means a compliant reader and writer can be made independently (which avoids the majority of the pitfalls described on later resources).<br />
A PDF file is designed to be portable (it is even in the acronym), which means unless the creator of the PDF uses a web-only feature (which is non-standard), it can be opened everywhere a PDF reader is found. Authors may also opt for a stricter, "archival" version ({{w|PDF/A}}) which ensures that both required files are placed on the same PDF file and only documented formats are used to prevent the reliance on non-standardized formats.<br />
|-<br />
|<nowiki>[Subject] Web Database</nowiki><br />
|{{w|Database}}<br />
|Another type of a digital resource which is, in itself, is like a digital library. Unlike a physical library however, it is usually only stored in a single file or server (there are instances that the database is distributed, but it is rare), which means that a failure to that server means that the database is wiped out, not to mention the gigantic space it takes (that is why the whole database are not stored in a digital archive, like the Internet Archive). <br />
Additionally, unlike PDFs, there are almost-infinite ways of storing and retrieving data in a database, which means that when the method used becomes unsupported (like the Java scenario, which is of now is completely unusable in web browsers), the data in it is effectively lost (whether or not the data-in-question is still physically on the server). Also noted is that the <br />
|-<br />
|<nowiki>[Subject] Mobile App</nowiki><br />
<small>(Local University Project)</small><br />
|{{w|Mobile app|Mobile App}}<br />
|A type of digital resource that expands upon the idea of a web database. It allows easy access on a mobile device, however, as it is stated that it is a local university project, which means that support for it lasts only at most for a few years (which is not enough to maintain an application).<br />
Additionally, {{w|Operating System|Operating Systems}} can get obsolete (like the {{w|Symbian}} platform used on older {{w|Nokia}} phones) or critical changes to it breaks older applications (like on the [http://www.bbc.com/news/technology-41319675 Apple iOS]).<br />
|-<br />
|<nowiki>[Subject] Analysis Software</nowiki><br />
|{{w|Application software|Desktop Application}}<br />
|A type of executable program that is found on desktop systems. It allows reliable access on a desktop system, which means that (assuming the program is offline) it can survive on its own. However, {{w|Operating System|Operating Systems}} can get obsolete (like the {{w|Classic Mac OS}} platform used on older {{w|Macintosh|Mac}} computers) or critical changes to it breaks older applications (like the new security features on {{w|Microsoft Windows|Windows}} which breaks older non-compliant programs).<br />
|-<br />
|<nowiki>Interactive [Subject] CD-ROM</nowiki><br />
|{{w|Application software|Desktop Application}}, {{w|CD-ROM|CD-ROMs}}<br />
|A CD can hold anything from music to videos to applications. It also allows better offline access, and such were used in the 1990s and the early 2000s. It is still a fancy desktop application, which means that the situation on the analysis software applies here, not to mention the fact that a new invention can replace an obsolete one (for example, {{w|Microsoft Encarta}} was discontinued in 2010 due to the ease-of-access of {{w|Main Page|Wikipedia}}).<br />
Additionally, this also covers the changes in a physical system: in the 1980s, {{w|Floppy disk|floppy diskettes}} were used, which was replaced in the 1990s by the CDs and DVDs, which then was replaced by {{w|Thumb drive|thumb drives}} in the 2000s, which is then supplemented (and in some cases, replaced entirely) by wireless device-to-device transfers (like {{w|Bluetooth}}) and internet file transfers using online storage (like {{w|Dropbox}} and {{w|Google Drive}}).<br />
|-<br />
|<nowiki>Library Microfilm [Subject] Collection</nowiki><br />
|{{w|Microfilm}}<br />
|This is a physical resource used by libraries to preserve (or to create a copy) of a collection, usually those things that are rare or would cause a social or political issue when damaged. Although great preservation is needed to prevent damage to a film, the system used is standardized and knowledge to build a reader or a printer off a microfilm is widely available, like a PDF file. This comparison might look like a physical version of PDFs: standardized, common (books can be of any size imagined) format.<br />
|-<br />
|}<br />
<br />
==Transcript==<br />
{{incomplete transcript|Needs reorganization?}}<br />
:My access to resources on [SUBJECT] over time:<br />
<br />
:[Below, a timeline and a graph with gray bars is shown:]<br />
<br />
:[1980s-past 2020:] <br />
:Book on subject<br />
<br />
:[Early 2000s-past 2020:] <br />
:[SUBJECT].pdf <br />
<br />
:[2000-2010:] <br />
:[SUBJECT] web database <br />
::Site goes down, backend data not on archive.org<br />
::[Small bar, 2000-2016/17:] <br />
:::Java frontend no longer runs<br />
<br />
:[2010-2015/16:] <br />
:[SUBJECT] mobile app (Local university project) <br />
::Broken on new OS, not updated<br />
<br />
:[2000-2010:] <br />
:[SUBJECT] analysis software<br />
::Broken on new OS, not updated<br />
<br />
:[Late 1990s-late 2000s:] <br />
:Interactive [SUBJECT] CD-ROM <br />
::CD scratched; new computer has no CD drive anyway.<br />
<br />
:[1980s-past 2020:] <br />
:Library microfilm [SUBJECT] collection<br />
<br />
:[Caption below the panel:]<br />
:It's unsettling to realize how quickly digital resources can disappear without ongoing work to maintain them.<br />
<br />
{{comic discussion}}<br />
<br />
[[Category:Timelines]]</div>162.158.58.93https://www.explainxkcd.com/wiki/index.php?title=588:_Pep_Rally&diff=157438588: Pep Rally2018-05-23T01:33:32Z<p>162.158.58.93: /* Explanation */ links to wikipedia</p>
<hr />
<div>{{comic<br />
| number =588<br />
| date =May 25, 2009<br />
| title =Pep Rally<br />
| image =pep_rally.png<br />
| titletext =You know, pep rallies weirded me out in high school, and they've only gotten creepier in retrospect.<br />
}}<br />
<br />
==Explanation==<br />
Any American who went to high school remembers the convocations they had during {{w|High school football|football}} or basketball season, in which class would be interrupted and everyone was crowded into the gymnasium for a {{w|pep rally}}. Cheerleaders would cheer, they'd play the school fight song, the {{w|Cheerleading|cheerleaders}} might do a routine, and the team would be introduced.<br />
<br />
This is used to inspire {{w|school spirit}} and get people excited about attending the games, so that they'd come to the games and spend money on tickets and concessions. A common boast at pep rallies is "Our school is the best!"<br />
<br />
"But wait," says one of the students, quite logically. Why is ''our'' school the best? The student population is simply made up of students living in the general ZIP code of the school's location. There's no intrinsic reason why ''this'' school is any better than the rest of them in any way that really matters in real life. And even having the #1 basketball or football team in the state doesn't mean the students there are any "better" than anyone else.<br />
<br />
This comic subverts the usual expectation of unanimous agreement with the cheerleader's sentiment, and reminds you that people who go to other schools, root for other teams, aren't ''bad people'' — and [[Randall]] would no doubt argue that this is the same of people who follow a different religion than you, are a different ethnicity, or have a different political party affiliation.<br />
<br />
The title text says that Randall was weirded out by pep rallies growing up, and now that he's older, finds them even ''more'' creepy.<br />
<br />
==Transcript==<br />
:[Ponytail stands in front of crowded bleachers (with only Cueballs in it), waving pompoms high in the air.]<br />
:Ponytail: Lakeview High is the best!<br />
:Crowd: Yeah!<br />
:Someone on the bleachers: Wait, why?<br />
<br />
:[Zoom on Ponytail, now with her hands and pompoms down.]<br />
:Ponytail: What?<br />
:Voice #1 (off-screen): A guy on the North High football team helped me rebuild my deck. <br />
:Voice #1 (off-screen): :It seems ungrateful to presume we're better.<br />
<br />
:[Same picture with Ponytail now just listening.]<br />
:Voice #1 (off-screen): I mean, school districts are just based on zip codes.<br />
:Voice #2 (off-screen): Their principal donated a kidney to my dad.<br />
<br />
:[Ponytail looks down.]<br />
:Voice #1 (off-screen): I'm texting with my friend there now. He says it's okay, and we're invited to their events if we want. <br />
:Voice #1 (off-screen): But he sounded kind of hurt.<br />
:Voice #2 (off-screen): Why are we doing this, rally, again?<br />
<br />
{{comic discussion}}<br />
<br />
[[Category:Comics featuring Ponytail]]<br />
[[Category:Comics featuring Cueball]]<br />
[[Category:Multiple Cueballs]]<br />
[[Category:Sport]]</div>162.158.58.93https://www.explainxkcd.com/wiki/index.php?title=123:_Centrifugal_Force&diff=157437123: Centrifugal Force2018-05-23T01:04:30Z<p>162.158.58.93: /* Explanation */ linked in what if 157 also</p>
<hr />
<div>{{comic<br />
| number = 123<br />
| date = July 3, 2006<br />
| title = Centrifugal Force<br />
| image = centrifugal force.png<br />
| titletext = You spin me right round baby, right round, in a manner depriving me of an inertial reference frame. Baby.<br />
}}<br />
<br />
==Explanation==<br />
[[Black Hat]] has strapped {{w|James Bond}} to a centrifuge and claims the {{w|Centrifugal force|centrifugal}} force will be lethal. Bond objects that there is no such thing, but just {{w|Centripetal force|centripetal}} force. The notion of centrifugal force is a common one, as we experience it whenever we turn. Teachers will initially teach Newtonian mechanics in an inertial frame, and in inertial frames, the centrifugal force is zero. Instead, a body that moves in a circle does so because of a centripetal force (acting towards the centre of the rotation). This is a reasonable, and correct view, but is a subtle point that many students find hard to grasp, as it seems to contradict their personal experience of centrifugal forces. For the sake of exposition, teachers may claim that "There is no such thing as centrifugal force." This however is also a misconception, which is addressed in the explanation below:<br />
;Observers' point of view (Black Hat, us, etc.)<br />
:James Bond is moving in a circle, and is therefore accelerating. The force keeping him there is an inward force of contact against the centrifuge, a centripetal force. Via Newton's {{w|Newton's laws of motion#Newton's third law|third law}}, since the centrifuge is pushing Bond inward, Bond is pushing the centrifuge outward. The centrifuge's material is strong enough not to break under this force, however.<br />
;James Bond's point of view<br />
:In James Bond's frame of reference, Bond is at rest. He is kept there by two forces: the above-mentioned inward force of contact against the centrifuge, and an ''outward centrifugal force''. He feels both forces.<br />
<br />
As mentioned in the explanation, as the centrifuge rotates faster, the forces needed to keep him in motion get larger, so the force he feels gets larger. This will eventually kill him. The conclusion will be the same regardless of which frame of reference is chosen.<br />
<br />
Teachers of mechanics are well aware of this; however, in introductory expositions, these ideas are often not taught. In theoretical mechanics, one describes the positions and velocities of the particles in a model relative to a frame of reference. This means that a time is chosen to be time 0, and positions are chosen to be (0,0,0), (1,0,0), (0,1,0) and (0,0,1). With these chosen, the position and time of any particle in the system can be described. It is an axiom of Newtonian Mechanics that there exist "Inertial Frames." In an inertial frame, a particle will remain at rest or at a constant speed unless acted on by an external force, and Newton's second law takes a simple form: F = ma. The surface of the Earth approximates an inertial frame. In a non-inertial frame, such as one rotating with a giant centrifuge, or moving with an accelerating vehicle, a particle will accelerate, relative to the frame. Newton's second law, when formed in such a frame, is much more complicated, as it has terms for the linear acceleration of the frame, the angular acceleration of the frame, the centrifugal force, and the {{w|Coriolis force}}. These extra terms are sometimes called "fictitious forces," as they result from the choice of the frame of reference. The mathematics required to describe problems in a non-inertial frame is more sophisticated, and all problems may be solved using an inertial frame. Thus is reasonable that teachers at school level "{{w|lie to children}}" and teach the mechanics in inertial frames.<br />
<br />
The final statement by Black Hat is that said by {{w|Auric Goldfinger}} in {{w|Goldfinger (film)|Goldfinger}} in response to James Bond's question "Do you expect me to talk?"<br />
<br />
The title text is inspired by {{w|Dead or Alive (band)|Dead or Alive's}} famous song from 1985, "{{w|You Spin Me Round (Like a Record)|You Spin Me Round}}".<br />
<br />
Randall feels very strongly that the centrifugal force is a real thing. He links to this comic in the first footnote of his [[what if?|What if?]] article [https://what-if.xkcd.com/92/ One-Second Day] and the 6th footnote of [https://what-if.xkcd.com/157/ Earth-Moon Fire Pole], stating that it is a real thing. <br />
<br />
As can also be seen in the [https://twitter.com/bohacekp/status/531500491180875776/photo/1 footnote on page 132] in his [[what if?#The book|What if? book]], he will even fight you about it. From the book:<br> <br />
"Furthermore, if you're on the equator, you're being flung outward by a centrifugal force<sup>1</sup>." <br />
<br><sup>"1</sup>Yes, centrifugal. I will fight you."<br />
<br>(The article itself is about what happens if you lose all your DNA, so it has not much to do with this "real" force... The sentence is just stating that the actual weight loss from losing all your DNA is similar to the weight loss you would experience by moving from the poles to the equator due to this force.)<br />
<br />
==Transcript==<br />
:[James Bond is strapped to a giant wheel suspended from the ceiling. Black Hat is standing next to two levers.]<br />
:Black hat: How do you like my centrifuge, mister Bond? When I throw this lever, you will feel centrifugal force crush every bone in your body.<br />
:[Same scene, but a closer shot.]<br />
:Bond: You mean centripetal force. There's no such thing as centrifugal force.<br />
:Black hat: A laughable claim, mister Bond, perpetuated by overzealous teachers of science. Simply construct Newton's laws in a rotating system and you will see a centrifugal force term appear as plain as day.<br />
:[Closer shot, only Bond's head is visible.]<br />
:Bond: Come now, do you really expect me to do coordinate substitution in my head while strapped to a centrifuge?<br />
:Black hat: No, Mister Bond. I expect you to die.<br />
{{comic discussion}} <br />
<br />
[[Category:Comics featuring Black Hat]]<br />
[[Category:Physics]]<br />
[[Category:Comics featuring Cueball]]<br />
[[Category:Footer comics]] <!-- in footer staring around Oct 13, 2006 --></div>162.158.58.93https://www.explainxkcd.com/wiki/index.php?title=199:_Right-Hand_Rule&diff=136272199: Right-Hand Rule2017-03-02T06:20:43Z<p>162.158.58.93: /* Explanation */ some problems with these rules...</p>
<hr />
<div>{{comic<br />
| number = 199<br />
| date = December 20, 2006<br />
| title = Right-Hand Rule<br />
| image = right_hand_rule.png<br />
| titletext = To really expand your mind try some noncartesian porn. Edwin Abbot Abbott has nothing on "Girls on Girls in Tightly Closed Nonorientable Spaces"<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|This needs explanations for the individual methods. A more in-depth explanation of the title text would also be great.}}<br />
The {{w|right-hand rule}} is a mathematics and physics trick to learning how to find the {{w|cross product}} of two Cartesian vectors in three dimensions. First, position your right arm in the direction of the first vector (in the example diagram in the comic, this is to the left). Then, curl your fingers in the direction of the second vector (out of the page/screen, in the example). Now point your thumb perpendicular to the other fingers, and it will point in the direction of the cross product of those two vectors (upwards, in the example). Note that reversing the order of the two vectors also reverses the direction of the cross product.<br />
<br />
The book rule is an actual alternative to the right hand rule that might be useful to some physics students doing exercises out of their textbooks. However, it would give incorrect results with books in languages that are read from right to left, as well as most Jewish prayer books.<br />
<br />
The gun rule also technically works, but it would be extremely impractical, expensive, and dangerous to use and fire a loaded gun every time you want to find the result vector. It would also be very awkward to hold the gun in line with the vectors. It also assumes the safety latch is consistently on the same side of all guns; if a gun was made with the safety latch on the other side, then it would give incorrect results.<br />
<br />
The body rule is for males only, which is very limiting for a rule that is meant to make math and physics problems easier. With the right arm oriented along one vector and the legs along the second, the result vector is found along the penis of the person, which is conveniently erected by watching porn.<br />
<br />
The title text refers to {{w|Edwin Abbott Abbott}}, author of the book Flatland, a story about a two dimensional world.<br />
<br />
{{w|Orientability}} is a property that refers to a space with continuously varying {{w|surface normal}}s, which are essentially just vectors that are perpendicular to the surface of the space. Nearly every space commonly encountered is orientable; this is likely why the porn is referred to as mind expanding and superior to Edwin Abbot Abbott's work.<br />
<br />
==Transcript==<br />
:[Picture of a right hand with fingers curved, thumb pointed away, with axes drawn to demonstrate the right-hand rule of physics.]<br />
:Alternatives to the Right-Hand Rule in vector multiplication:<br />
:[A slightly-open book with labeled axes drawn on.]<br />
:Book Rule: Open the front cover along the first vector and the back cover along the second. The result vector is along the spine, out the top.<br />
:[A handgun with axes.]<br />
:Handgun Rule: Point the grip along the first vector and rotate it so that the second vector is on the safety latch side. Fire. The result vector is toward the bullet holes.<br />
:[A person with right arm extended.]<br />
:Body Rule (males only): Point your right arm along the first vector and your legs along the second, then watch some porn.<br />
<br />
{{comic discussion}}<br />
[[Category:Math]]<br />
[[Category:Physics]]</div>162.158.58.93