explain xkcd - User contributions [en]

2317: Pinouts

2020-06-09T01:01:31Z

162.158.78.50: /* HDMI */ Added real pin descriptions to the bottom.

{{comic
| number = 2317
| date = June 8, 2020
| title = Pinouts
| image = pinouts.png
| titletext = The other side of USB-C is rotationally symmetric except that the 3rd pin from the top is designated FIREWIRE TRIBUTE PIN.
}}

==Explanation==
{{incomplete|Created by a FIREWIRE TRIBUTE PIN. Should include a column for the actual purpose of the pin. Do NOT delete this tag too soon.}}
Electronics connecters are designed to transport both information and power. A {{w|pinout}} diagram describes the function of each pin such as to communicate data, transport power, physical function (keying), etc. In this comic there is an absurd alternative to the actual pins used in connectors.

The real life diagrams are as follows: [http://unitedtechnologies.com.pk/Nti/image/10ci.png HDMI], [https://www.arrow.com/en/research-and-events/articles/micro-connector-usb-pinout Micro USB], [https://www.allaboutcircuits.com/technical-articles/introduction-to-usb-type-c-which-pins-power-delivery-data-transfer/ USB-C].

=== HDMI ===

{| class="wikitable" style="text-align: center;"
! Label !! Explanation !! Pin No. !! Actual purpose
|-
| +3.3V DC
| 3.3V is a typical voltage in digital electronics. The "+" Indicates a
| 1
| TMDS Data2+
|-
| Data
| Most digital communications cables contain at least one wire that carries data. Typically there will be a more descriptive name if there are multiple data pins.
| 2
| TMDS Data2 Shield
|-
| -3.3V DC
| Negative voltages were used more frequently in the past, however modern systems typically generate any negative voltages they might require internally from the given positive voltages.
| 3
| TMDS Data2-
|-
| +5V
| Many actual pin configurations use +5 volts to supply power to a device. That's not what this means.
| 4
| TMDS Data1+
|-
| Tx
| "Tx" typically refers to pins used to transmit as opposed to "Rx"/receive
| 5
| TMDS Data1 Shield
|-
| +6VI
| V is usually used to represent volts, but here, VI represents the Roman numeral 6. (See Pin 4)
| 6
| TMDS Data1-
|-
| Wx
| "Wx" does not typically exist in the "Tx"/"Rx" scheme. In the weather forecasting community, Wx means "weather" .
| 7
| TMDS Data0+
|-
| +7VII
| V is usually used to represent volts, but here, VII represents the Roman numeral 7, continuing the pattern from above.
| 8
| TMDS Data0 Shield
|-
| Rx Only
| "Rx" typically refers to pins used to receive as opposed to "Tx"/transmit. In this case "Rx" is used as part of a pun on "Rx (prescription) only"
| 9
| TMDS Data0-
|-
| Antidata
| Some ports use differential signaling, where a signal and its inverse are sent over a pair of pins (e.g. D+ and D-). This mixes that practice with a humorous reference to the notion of matter versus antimatter. There is no such thing as antidata.
| 10
| TMDS Clock+
|-
| Unknown
| Occasionally extra pins will be included for future use, however they will typically be labeled "reserved" to point out that their usage is not yet defined.
| 11
| TMDS Clock Shield
|-
| Water
| Labs often have ports connecting to common supplies of various supplying (Oxygen, water, fuel, vacuum).
| 12
| TMDS Clock-
|-
| +240V DC
| High voltage DC is not typically used in small communications connectors. It would need to be low current to avoid generating excess heat.
| 13
| CEC
|-
| Vacuum
| Labs often have ports connecting to common supplies of various supplying (Oxygen, water, fuel, vacuum).
| 14
| Reserved (1.0-1.3a), Utility (1.4+, optional)
|-
| 5V AC
| Pins often supply low voltage direct current to devices. This pin supplies 5V alternating current, which is not typically supplied.
| 15
| SCL (I²C serial clock for DDC)
|-
| Amazon Copyright Pin
| HDMI can optionally be protected by a digital rights management (DRM) scheme, known as HDCP. This pin humorously implies the presence of a different DRM scheme specific to Amazon.com, as well as poking fun at the fact that copyright is an explicit part of the HDMI protocol (although it is not assigned to a specific pin).
| 16
| SDA (I²C serial data for DDC)
|-
| GND
| GND typically refers to "ground" on pinout diagrams. Remarkably, this is correct.
| 17
| DDC/CEC Ground
|-
| Decorative
| Decorative elements are pieces of an assembly that serve only an aesthetic purpose without any technical function. This would not be particularly useful inside a connector, as almost no one will ever see it--however, in HDMI, pin 14 was reserved for future use in versions 1.0–1.3a (and was only assigned an official use in 1.4).
| 18
| +5V
|-
| Ground
| Compared to Pin 17 ("GND"), this appears to be the same ground pin. However, the presence of both GND and Ground seems to imply that GND represents something other than the standard "ground" pin. Some systems have different grounds for analog and digital sections, but they would typically be disambiguated by terms like AGND.
| 19
| Hot Plug Detect
|}

HDMI uses four pairs of shielded twisted-pair connectors, along with seven other connectors. (Twisted-pair means a wire is wrapped with the other wire that returns the current to the original device, thus minimizing electromagnetic noise. Shielding refers to wrapping a cable with a conductor to absorb the energy of noise.) Three of these pairs are for data (TMDS Data0, Data1, and Data2) and the other is a clock. These pairs take up three pins as one of them is a ground pin for the shielding wrapped around each pair. TMDS stands for "[https://en.wikipedia.org/wiki/Transition-minimized_differential_signaling Transition-minimized Differential Signaling]" and is also used in the DVI standard.

DDC stands for "Display Data Channel" and is based on the [https://en.wikipedia.org/wiki/I%C2%B2C I²C] serial standard. It is used to allow the transmitting device to learn what formats of data the receiving device can accept.

CEC stands for "Consumer Electronics Control" and is supposed to allow a single remote control to control multiple devices.

"Hot Plug Detect" refers to hot-plugging, where a cable is connected to a device already turned on. The device should then ideally detect that the cable has been plugged in and respond appropriately.

=== Micro USB ===

A ground pin is commonly found on USB and other pin connectors. At least one ground is necessary to complete the circuit, and some cables use multiple ground lines to distribute current or to support {{w|twisted pair}}s. However, there is no purpose served by having many more ground pins than data pins. Therefore, it seems rather silly for the micro USB to have 4 ground pins and only 1 functional "USB" pin. It also does not give much information about what the "USB" pin would do, as opposed to a standard pinout diagram. This diagram also leaves out the +5V power pin that is present in the real micro USB connector, which would render most USB peripherals unable to function.

The ordering and count of the pins may be an allusion to {{w|Monty Python}}'s {{w|Spam (Monty Python)|"Spam"}} sketch, in which one of the many Spam-related menu items is "Spam, Spam, Spam, egg, and Spam".

{| class="wikitable" style="text-align: center;"
! Label !! Explanation
|-
| GND
| A ground pin
|-
| GND
| A second ground pin
|-
| GND
| A third ground pin
|-
| USB
| Apparently the only data pin in this connector.
|-
| GND
| A fourth ground pin. A real micro USB only has one ground pin.
|}

=== USB-C ===
{| class="wikitable" style="text-align: center;"
! Label !! Explanation
|-
| +5V DC
| A common electronics supply voltage.
|-
| +3.3V DC
| Another common electronics supply voltage. This pin is not present on USB type C, mostly because the voltage is too low to supply useful levels of power at the current limit of the pins.
|-
| +120V AC
| Residential supply voltage in the United States; its use on an electronics connector would be very unusual, as it would burn out any unguarded transistor-logic electronics.
|-
| Boobytrap Pin (Pure Solder)
| {{w|Solder}} is a metal alloy with a low melting temperature, used to bond electronic components together permanently. Making a connector pin out of it would likely result in the pin overheating and melting, thus bonding the connector to its receptacle, and thereby "trapping" the receptacle.
|-
| Mechanical
| All connectors include portions whose job is to ensure a solid connection between the cable and the port. This is typically not the job of the pins, however. In real USB type C connectors, this task is performed by the center tongue of the female connector.
|-
| +3.3eV/C
| {{w|Electron-volts}} per {{w|coulomb}} would be a very unusual unit to see in a pinout. It is equivalent to volts, however, so technically this pin would be a +3.3V pin.
|-
| Candlepin
| Randall is making a pun on the word ''pin'', which refers to a electrical connector pin as well as a thing to knock down in bowling. {{w|Candlepin bowling}} is a form of bowling.
|-
| Facebook use
| This would imply that Facebook had a hand in specifying USB type C, and had a pin dedicated to their use. This would be strange given Facebook's primary business is web technology and would have little need for a dedicated pin in the USB standard.
|-
| +5V (Positrons)
| {{w|Positron}}s are the antimatter counterparts to electrons. So this pin is supplying +5V, but does so by sourcing positrons into the device rather than sinking electrons out. NOTE: Positrons cannot be conducted through normal matter conductors as they would annihilate with the electrons.
|-
| Pin Roulette
| Presumably in the same vein as "Chat Roulette", this pin's purpose is not rigidly defined and is instead left to chance. According to the title text, this pin's counterpart on the other side of the connector is the "FireWire Tribute Pin", so this cable would only be truly rotationally symmetric (which is the whole point of the USB-C connector) when the pin roulette ball lands on that same function.
|-
| GND
| Ground pin. Typically denoted as "GND".
|-
| SKY
| Reference to the ground pin, which refers to the common grounding on the larger metal body. There is no corresponding "sky" pin, although sky is often thought as the opposite of ground.
|-
| FireWire Tribute Pin
| ''In Title text:'' {{w|FireWire}} is Apple's version of IEEE 1394 which is a 6 pin connector that has a ground pin a power pin and two pairs of data pins. It was something of a competitor to USB, and had faster data rates than USB 2.0, but is much less popular now. Presumably the writers of the USB-C standard (which far outpaces its data rates) wished to memorialize it somehow, although it's not clear how the pin actually works for that purpose.
|}

=== Coax ===

{| class="wikitable" style="text-align: center;"
! Label !! Explanation
|-
| Pin
| An {{w|RF connector|coaxial RF connector}} has two contacts - one pin, and the shield; typically the whole connector is labeled with whatever function/signal is carried by the pair.
|}

==Transcript==

:[Caption at top]
:Pinouts
:Quick Reference Guide

:[Four common connectors are depicted - vertically, rather than the usual horizontal orientation.]

:[The first connector is a 19-pin HDMI connector.]
:[The nine pins on the left are labeled:]
:*Data
:*+5V
:*+6VI
:*+7VII
:*Antidata
:*Water
:*Vacuum
:*Amazon Copyright Pin
:*Decorative
:[The ten pins on the right are labeled:]
:*+3.3V DC
:*-3.3V DC
:*Tx
:*Wx
:*Rx Only
:*Unknown
:*+240V DC
:*5V AC
:*GND
:*Ground

:[The second connector is a 5-pin Micro USB connector.]
:[The five pins are labeled:]
:*GND
:*GND
:*GND
:*USB
:*GND

:[The third connector is a 24-pin USB-C connector, with only the right side labeled.]
:[The twelve pins on the right are labeled:]
:*+5V DC
:*+3.3V DC
:*+120V AC
:*Boobytrap Pin (Pure Solder)
:*Mechanical
:*+3.3eV/C
:*Candlepin
:*Facebook Use
:*+5V (Positrons)
:*Pin Roulette
:*GND
:*SKY

:[The fourth and final connector is a 1-pin COAX connector.]
:[The one pin in the center is labeled:]
:*Pin

{{comic discussion}}
[[Category:Computers]]

2317: Pinouts

2020-06-09T00:46:25Z

162.158.78.50: /* HDMI */ Added Pin numbers and actual designations. This does need explanations added after the table.

{{comic
| number = 2317
| date = June 8, 2020
| title = Pinouts
| image = pinouts.png
| titletext = The other side of USB-C is rotationally symmetric except that the 3rd pin from the top is designated FIREWIRE TRIBUTE PIN.
}}

==Explanation==
{{incomplete|Created by a FIREWIRE TRIBUTE PIN. Should include a column for the actual purpose of the pin. Do NOT delete this tag too soon.}}
Electronics connecters are designed to transport both information and power. A {{w|pinout}} diagram describes the function of each pin such as to communicate data, transport power, physical function (keying), etc. In this comic there is an absurd alternative to the actual pins used in connectors.

The real life diagrams are as follows: [http://unitedtechnologies.com.pk/Nti/image/10ci.png HDMI], [https://www.arrow.com/en/research-and-events/articles/micro-connector-usb-pinout Micro USB], [https://www.allaboutcircuits.com/technical-articles/introduction-to-usb-type-c-which-pins-power-delivery-data-transfer/ USB-C].

=== HDMI ===

{| class="wikitable" style="text-align: center;"
! Label !! Explanation !! Pin No. !! Actual purpose
|-
| +3.3V DC
| 3.3V is a typical voltage in digital electronics. The "+" Indicates a
| 1
| TMDS Data2+
|-
| Data
| Most digital communications cables contain at least one wire that carries data. Typically there will be a more descriptive name if there are multiple data pins.
| 2
| TMDS Data2 Shield
|-
| -3.3V DC
| Negative voltages were used more frequently in the past, however modern systems typically generate any negative voltages they might require internally from the given positive voltages.
| 3
| TMDS Data2-
|-
| +5V
| Many actual pin configurations use +5 volts to supply power to a device. That's not what this means.
| 4
| TMDS Data1+
|-
| Tx
| "Tx" typically refers to pins used to transmit as opposed to "Rx"/receive
| 5
| TMDS Data1 Shield
|-
| +6VI
| V is usually used to represent volts, but here, VI represents the Roman numeral 6. (See Pin 4)
| 6
| TMDS Data1-
|-
| Wx
| "Wx" does not typically exist in the "Tx"/"Rx" scheme. In the weather forecasting community, Wx means "weather" .
| 7
| TMDS Data0+
|-
| +7VII
| V is usually used to represent volts, but here, VII represents the Roman numeral 7, continuing the pattern from above.
| 8
| TMDS Data0 Shield
|-
| Rx Only
| "Rx" typically refers to pins used to receive as opposed to "Tx"/transmit. In this case "Rx" is used as part of a pun on "Rx (prescription) only"
| 9
| TMDS Data0-
|-
| Antidata
| Some ports use differential signaling, where a signal and its inverse are sent over a pair of pins (e.g. D+ and D-). This mixes that practice with a humorous reference to the notion of matter versus antimatter. There is no such thing as antidata.
| 10
| TMDS Clock+
|-
| Unknown
| Occasionally extra pins will be included for future use, however they will typically be labeled "reserved" to point out that their usage is not yet defined.
| 11
| TMDS Clock Shield
|-
| Water
| Labs often have ports connecting to common supplies of various supplying (Oxygen, water, fuel, vacuum).
| 12
| TMDS Clock-
|-
| +240V DC
| High voltage DC is not typically used in small communications connectors. It would need to be low current to avoid generating excess heat.
| 13
| CEC
|-
| Vacuum
| Labs often have ports connecting to common supplies of various supplying (Oxygen, water, fuel, vacuum).
| 14
| Reserved (1.0-1.3a), Utility (1.4+, optional)
|-
| 5V AC
| Pins often supply low voltage direct current to devices. This pin supplies 5V alternating current, which is not typically supplied.
| 15
| SCL
|-
| Amazon Copyright Pin
| HDMI can optionally be protected by a digital rights management (DRM) scheme, known as HDCP. This pin humorously implies the presence of a different DRM scheme specific to Amazon.com, as well as poking fun at the fact that copyright is an explicit part of the HDMI protocol (although it is not assigned to a specific pin).
| 16
| SDA
|-
| GND
| GND typically refers to "ground" on pinout diagrams. Remarkably, this is correct.
| 17
| DDC/CEC Ground
|-
| Decorative
| Decorative elements are pieces of an assembly that serve only an aesthetic purpose without any technical function. This would not be particularly useful inside a connector, as almost no one will ever see it--however, in HDMI, pin 14 was reserved for future use in versions 1.0–1.3a (and was only assigned an official use in 1.4).
| 18
| +5V
|-
| Ground
| Compared to Pin 17 ("GND"), this appears to be the same ground pin. However, the presence of both GND and Ground seems to imply that GND represents something other than the standard "ground" pin. Some systems have different grounds for analog and digital sections, but they would typically be disambiguated by terms like AGND.
| 19
| Hot Plug Detect
|}

=== Micro USB ===

A ground pin is commonly found on USB and other pin connectors. At least one ground is necessary to complete the circuit, and some cables use multiple ground lines to distribute current or to support {{w|twisted pair}}s. However, there is no purpose served by having many more ground pins than data pins. Therefore, it seems rather silly for the micro USB to have 4 ground pins and only 1 functional "USB" pin. It also does not give much information about what the "USB" pin would do, as opposed to a standard pinout diagram. This diagram also leaves out the +5V power pin that is present in the real micro USB connector, which would render most USB peripherals unable to function.

The ordering and count of the pins may be an allusion to {{w|Monty Python}}'s {{w|Spam (Monty Python)|"Spam"}} sketch, in which one of the many Spam-related menu items is "Spam, Spam, Spam, egg, and Spam".

{| class="wikitable" style="text-align: center;"
! Label !! Explanation
|-
| GND
| A ground pin
|-
| GND
| A second ground pin
|-
| GND
| A third ground pin
|-
| USB
| Apparently the only data pin in this connector.
|-
| GND
| A fourth ground pin. A real micro USB only has one ground pin.
|}

=== USB-C ===
{| class="wikitable" style="text-align: center;"
! Label !! Explanation
|-
| +5V DC
| A common electronics supply voltage.
|-
| +3.3V DC
| Another common electronics supply voltage. This pin is not present on USB type C, mostly because the voltage is too low to supply useful levels of power at the current limit of the pins.
|-
| +120V AC
| Residential supply voltage in the United States; its use on an electronics connector would be very unusual, as it would burn out any unguarded transistor-logic electronics.
|-
| Boobytrap Pin (Pure Solder)
| {{w|Solder}} is a metal alloy with a low melting temperature, used to bond electronic components together permanently. Making a connector pin out of it would likely result in the pin overheating and melting, thus bonding the connector to its receptacle, and thereby "trapping" the receptacle.
|-
| Mechanical
| All connectors include portions whose job is to ensure a solid connection between the cable and the port. This is typically not the job of the pins, however. In real USB type C connectors, this task is performed by the center tongue of the female connector.
|-
| +3.3eV/C
| {{w|Electron-volts}} per {{w|coulomb}} would be a very unusual unit to see in a pinout. It is equivalent to volts, however, so technically this pin would be a +3.3V pin.
|-
| Candlepin
| Randall is making a pun on the word ''pin'', which refers to a electrical connector pin as well as a thing to knock down in bowling. {{w|Candlepin bowling}} is a form of bowling.
|-
| Facebook use
| This would imply that Facebook had a hand in specifying USB type C, and had a pin dedicated to their use. This would be strange given Facebook's primary business is web technology and would have little need for a dedicated pin in the USB standard.
|-
| +5V (Positrons)
| {{w|Positron}}s are the antimatter counterparts to electrons. So this pin is supplying +5V, but does so by sourcing positrons into the device rather than sinking electrons out. NOTE: Positrons cannot be conducted through normal matter conductors as they would annihilate with the electrons.
|-
| Pin Roulette
| Presumably in the same vein as "Chat Roulette", this pin's purpose is not rigidly defined and is instead left to chance. According to the title text, this pin's counterpart on the other side of the connector is the "FireWire Tribute Pin", so this cable would only be truly rotationally symmetric (which is the whole point of the USB-C connector) when the pin roulette ball lands on that same function.
|-
| GND
| Ground pin. Typically denoted as "GND".
|-
| SKY
| Reference to the ground pin, which refers to the common grounding on the larger metal body. There is no corresponding "sky" pin, although sky is often thought as the opposite of ground.
|-
| FireWire Tribute Pin
| ''In Title text:'' {{w|FireWire}} is Apple's version of IEEE 1394 which is a 6 pin connector that has a ground pin a power pin and two pairs of data pins. It was something of a competitor to USB, and had faster data rates than USB 2.0, but is much less popular now. Presumably the writers of the USB-C standard (which far outpaces its data rates) wished to memorialize it somehow, although it's not clear how the pin actually works for that purpose.
|}

=== Coax ===

{| class="wikitable" style="text-align: center;"
! Label !! Explanation
|-
| Pin
| An {{w|RF connector|coaxial RF connector}} has two contacts - one pin, and the shield; typically the whole connector is labeled with whatever function/signal is carried by the pair.
|}

==Transcript==

:[Caption at top]
:Pinouts
:Quick Reference Guide

:[Four common connectors are depicted - vertically, rather than the usual horizontal orientation.]

:[The first connector is a 19-pin HDMI connector.]
:[The nine pins on the left are labeled:]
:*Data
:*+5V
:*+6VI
:*+7VII
:*Antidata
:*Water
:*Vacuum
:*Amazon Copyright Pin
:*Decorative
:[The ten pins on the right are labeled:]
:*+3.3V DC
:*-3.3V DC
:*Tx
:*Wx
:*Rx Only
:*Unknown
:*+240V DC
:*5V AC
:*GND
:*Ground

:[The second connector is a 5-pin Micro USB connector.]
:[The five pins are labeled:]
:*GND
:*GND
:*GND
:*USB
:*GND

:[The third connector is a 24-pin USB-C connector, with only the right side labeled.]
:[The twelve pins on the right are labeled:]
:*+5V DC
:*+3.3V DC
:*+120V AC
:*Boobytrap Pin (Pure Solder)
:*Mechanical
:*+3.3eV/C
:*Candlepin
:*Facebook Use
:*+5V (Positrons)
:*Pin Roulette
:*GND
:*SKY

:[The fourth and final connector is a 1-pin COAX connector.]
:[The one pin in the center is labeled:]
:*Pin

{{comic discussion}}
[[Category:Computers]]

Talk:2313: Wrong Times Table

2020-06-01T18:08:29Z

162.158.78.50:

Such an illogical table. Smaller numbers multiply to larger answers than larger numbers? Even numbers multiply to odd numbers?! How?!?! What sort of illiterate alien declared this to be the multiplication table?! [[Special:Contributions/108.162.221.101|108.162.221.101]] 20:54, 29 May 2020 (UTC)

This is easily one of the worst XKCD comics, period. Not funny, nor clever. Just seems like noise. [[Special:Contributions/172.69.68.183|172.69.68.183]] 20:57, 29 May 2020 (UTC)
:I suspect Randall may have just been feeling random, perhaps after several months of mostly Coronavirus-related comics. [[User:Barmar|Barmar]] ([[User talk:Barmar|talk]]) 21:13, 29 May 2020 (UTC)
::That's fair, I'm being a bit harsh, but this just comes across as exceptionally meaningless and contrived, so much so that I felt the need to come here and comment immediately for the first time ever [[Special:Contributions/172.69.71.56|172.69.71.56]] 21:18, 29 May 2020 (UTC)
:I relate to certain mathematical facts not sounding right, like how 54 intuitively feels like it's divisible by 4. Nonsensical, but makes sense anyway. [[Special:Contributions/162.158.62.233|162.158.62.233]] 21:42, 29 May 2020 (UTC)

This seems like the multiplication equivalent of looking at a word and thinking it is spelled incorrectly. Sometimes I look at a simple word like "fish" and think: "That can't be right." Sometimes multiplication can feel that way, particularly 7's because those were tricky for some reason. The alt text confirms fishiness with 7's [[Special:Contributions/108.162.246.173|108.162.246.173]] 21:09, 29 May 2020 (UTC)
:Is it weird that I ''don't'' get this? I have this sense of "that is obviously wrong" when it comes to multiplication of small numbers like these, even with sevens and eights. If I read that 7 * 8 = 54, my brain screams "NOOOOOOOOO IT IS 56 YOU IDIOT!". [[Special:Contributions/108.162.221.101|108.162.221.101]] 21:14, 29 May 2020 (UTC)
::It's lucky for you! Careless errors [of all types] can be annoying, and sometimes difficult to locate... Some of us have ingrained this information better than others. (This comic seems less like a joke and more sharing a hindrance Randall suffers from when doing arithmetic. And speaking personally, I can certainly relate to that.)[[Special:Contributions/162.158.78.50|162.158.78.50]] 18:05, 1 June 2020 (UTC)

Well, 2,2 that's actually 2^3=8. 2,3 is addition instead of multiplication. 1,2 is division instead of multiplication. 1,1 is subtraction. 10,10 seems to be a visual gag, though most of the 10s row is either multiplication by 11 or 12... There's some logic to some of these, but it's different for each row, column, or cell. [[Special:Contributions/162.158.74.167|162.158.74.167]] 21:13, 29 May 2020 (UTC)
:Yeah, there is something going on. It looks like a lot of it is remembering the correct answer to a different problem. By my count 55 squares are the correct answer to a square next to it and 31 have a correct answer for somewhere else on the grid. Also, 2*2, 4*4 and 5*5 are double the correct answer.[[Special:Contributions/108.162.245.76|108.162.245.76]] 21:41, 29 May 2020 (UTC)

It's almost disappointing that he didn't hide one or two asymmetries in there just to throw us off! [[Special:Contributions/108.162.216.114|108.162.216.114]] 22:04, 29 May 2020 (UTC)

I get the idea that this is the sort of table you'd get if you tried to train an Adversarial AI from scratch to determine x*y purely by stocastic guessing and comparing to a co-evolving 'scorer' that also starts off naively but supports each answer according to the 'rightness' it thinks it has ''except'' for the real answer which is always hard-coded to be down-scored. (Also noting that DA reportedly came by his choice of 42 by asking people which numbers were 'funnier' than others, which can be said to be a similar kind of process but without the arrayed "original multiplication" element.) [[Special:Contributions/162.158.158.179|162.158.158.179]] 22:13, 29 May 2020 (UTC)

As someone who often confuses 7*8 as 54, I found the alt text very humorous. [[Special:Contributions/172.69.34.118|172.69.34.118]] 22:29, 29 May 2020 (UTC)

I'm disappointed to see that 6*9 isn't equal to 42. [[User:Probably not Douglas Hofstadter|Probably not Douglas Hofstadter]] ([[User talk:Probably not Douglas Hofstadter|talk]]) 23:01, 29 May 2020 (UTC)

This is just a collection of equations with the wrong answers. I'm not sure who finds this funny. [[Special:Contributions/108.162.219.96|108.162.219.96]] 00:33, 30 May 2020 (UTC)

https://www.explainxkcd.com/wiki/index.php/1210:_I%27m_So_Random[[User:Overlord of oddities|Overlord of oddities]] ([[User talk:Overlord of oddities|talk]]) 01:16, 30 May 2020 (UTC)

I have asked [https://codegolf.stackexchange.com/q/205425/67157 a Code Golf Stack Exchange question] with the goal of producing the shortest program that computes this function. [[User:Aaron Rotenberg|Aaron Rotenberg]] ([[User talk:Aaron Rotenberg|talk]]) 02:29, 30 May 2020 (UTC) @Aaron I had a similar thought, but was going to settle for the generator function for the main diagonal. If we can come up with one, we should submit it to https://oeis.org/ [[User:Cellocgw|Cellocgw]] ([[User talk:Cellocgw|talk]]) 13:30, 1 June 2020 (UTC)

I'm disappointed that 17 does not show up in any product cell, seeing as I've known since at least 1970 that 17 is the world's most random number. <-- a fact proved for a limited case here: https://www.youtube.com/watch?v=2JPSJL7Kvus [[User:Cellocgw|Cellocgw]] ([[User talk:Cellocgw|talk]]) 13:35, 1 June 2020 (UTC)

I too was unimpressed with this... unitl I got to the alt text. I'm in my sixties now, and for some reason, 8*7 has ALWAYS been difficult for me. I find myself always doube-checking to make sure I did it right. And 6*7 gave me problems too, but I got over that a few decades ago. I wonder what it is about those that gave us trouble. --[[Special:Contributions/162.158.62.75|162.158.62.75]] 14:35, 1 June 2020 (UTC)

I do not believe that the table was constructed rationally, but intuitively by Randall. He took the two factors (in both permutations) and thought, which resulting number he felt best about. It is more like a psychological experiment than a table constructed with a system or code in mind. Sebastian --[[Special:Contributions/162.158.89.193|162.158.89.193]] 16:27, 1 June 2020 (UTC)

Am I the only one who reads the author's intention slightly differently? I don't think that he intended that these values feel more correct than the real multiplication table. Rather, I thought he meant that from all possible ''wrong'' values, these feel ''most'' correct to him. In this way, I at least could sympathise with many values given here. [[Special:Contributions/162.158.238.216|162.158.238.216]] 17:34, 1 June 2020 (UTC)
:Agreed--he doesn't feel that the answers are incorrect, but rather, if he were given the problem on a test, "True or False: One times two equals one half.", he'd have to think for a minute. [[Special:Contributions/162.158.78.50|162.158.78.50]] 18:08, 1 June 2020 (UTC)

Talk:2313: Wrong Times Table

2020-06-01T18:05:02Z

162.158.78.50:

2313: Wrong Times Table

2020-06-01T17:59:47Z

162.158.78.50: /* Explanation */

{{comic
| number = 2313
| date = May 29, 2020
| title = Wrong Times Table
| image = wrong_times_table.png
| titletext = Deep in some corner of my heart, I suspect that real times tables are wrong about 6x7=42 and 8x7=56.
}}

==Explanation==
{{incomplete|Created by 6x7. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}
A "times table" (or {{w|multiplication table}}) is a table used to define multiplication between numbers. Typically, elementary school children are taught to memorize the table as part of learning arithmetic.

In this comic, [[Randall]] "feels" that some values in the table are incorrect and so he supplies his own alternate version of the times table, with incorrect values. It is unclear how his values are derived, as they don't follow a consistent pattern, but it could be that when calculating products, he sometimes has to correct his mental arithmetic, perhaps thinking along such lines as "8*4 is 36... Or, wait, is it 32?". Most of the values are transposed from their correct position (i.e. adding or subtracting one -- or two, or three -- from one or both multiplicands), some are "off by one" (or two, or by a factor of two), and some (mostly in the 1 row and column) could be created by adding, subtracting, or dividing the two factors instead of multiplying them. It is notable that some properties of mathematics are not followed, as sometimes smaller multiplicands multiply to a larger product than larger multiplicands, and sometimes two even multiplicands produce an odd product.

The times table is symmetric, indicating that Randall's form of multiplication is [[wikipedia:Commutative property|commutative]].

The title text (referencing Randall's suspicion that 6x7=42 may be wrong) may be an allusion to ''{{w|The Hitchhiker's Guide to the Galaxy}}'', in which the ultimate answer to life, the universe, and everything is said to be {{w|Phrases_from_The_Hitchhiker%27s_Guide_to_the_Galaxy#The Answer to the Ultimate Question of Life, the Universe, and Everything is 42|forty-two}}. However, this answer is meaningless without knowing the ultimate ''question'', and so a planet-sized computer is constructed to calculate the ultimate question, which later becomes Earth, but Earth is destroyed shortly before its calculation is complete. Arthur Dent, one of the last surviving humans, attempts to recreate the ultimate question (hoping it may be stored within himself somehow, as a remnant of Earth) by picking letter tiles from a bag, and produces the sentence "What do you get if you multiply six by nine". This leads him to remark "I always thought something was fundamentally wrong with the universe." (6x9 = 42 in base thirteen, but when asked about this, Douglas Adams replied, "I may be a sorry case, but I don't write jokes in base 13.") In this table, neither 6x7 nor 6x9 are said to result in 42, but 7x7. Note however that operation of said planet-sized computer was disrupted so it's also possible the universe is ok and just the question was computed incorrectly.

If we consider the smaller multiplicand to be ''a'' and the larger to be ''b'', then (one of infinitely many possibilities of) the formulas used by Randall are as follows:

{| class="wikitable" style="text-align: center;"
!
! scope="column" | 1 || 2 || 3 || 4 || 5 || 6 || 7 || 8 || 9 || 10
|-
! scope="row" | 1
| a-b || a/b || a+b ||a+b || a+b || a+b || a+b || a+b || a+b || a (b-1)
|-
! scope="row" | 2
| a/b || 2ab || a+b || a(b-1) || a(b+1) || a(b+1) || a(b-1) || b+10 || b+10 || a(b+1)
|-
! scope="row" | 3
| a+b || a+b || ab+1 || (a+1)b || a(b-1)+1 || (a-1)b || a(b+1) || (a+1)b || a(b-2) || a(b+1)
|-
! scope="row" | 4
| a+b || a(b-1) || (a+1)b || 2ab || (a+1)b || (a+1)(b-1) || ab+1 || a(b+1) || a(b-2) || a(b+2)
|-
! scope="row" | 5
| a+b || a(b+1) || a(b-1)+1 || (a+1)b || 2ab || (a-1)b || a(b+1) || a(b+1) || a(b-1) || (a+1)b
|-
! scope="row" | 6
| a+b || a(b+1) || (a-1)b || (a+1)(b-1) || (a-1)b || (a-2)(b+2) || a(b+1) || ab+2 || a(b+3) || a(b+2)
|-
! scope="row" | 7
| a+b || a(b-1) || a(b+1) || ab+1 || a(b+1) || a(b+1) || a(b-1) || (a-1)(b+1) || (a-1)(b+1) || a(b+2)
|-
! scope="row" | 8
| a+b || b+10 || (a+1)b || a(b+1) || a(b+1) || ab+2 || (a-1)(b+1) || a(b-2) || ab+2 || a(b-3)
|-
! scope="row" | 9
| a+b || b+10 || a(b-2) || a(b-2) || a(b-1) || a(b+3) || (a-1)(b+1) || ab+2 || a(b-1) || a(b-1)
|-
! scope="row" | 10
| a(b-1) || a(b+1) || a(b+1) || a(b+2) || (a+1)b || a(b+2) || a(b+2) || a(b-3) || a(b-1) || a(b+1)
|}

The "correct" times table for the numbers from 1-10 is below:
{| class="wikitable" style="text-align: center;"
! ×
! scope="column" | 1 || 2 || 3 || 4 || 5 || 6 || 7 || 8 || 9 || 10
|-
! scope="row" | 1
| 1 || 2 || 3 || 4 || 5 || 6 || 7 || 8 || 9 || 10
|-
! scope="row" | 2
| 2 || 4 || 6 || 8 || 10 || 12 || 14 || 16 || 18 || 20
|-
! scope="row" | 3
| 3 || 6 || 9 || 12 || 15 || 18 || 21 || 24 || 27 || 30
|-
! scope="row" | 4
| 4 || 8 || 12 || 16 || 20 || 24 || 28 || 32 || 36 || 40
|-
! scope="row" | 5
| 5 || 10 || 15 || 20 || 25 || 30 || 35 || 40 || 45 || 50
|-
! scope="row" | 6
| 6 || 12 || 18 || 24 || 30 || 36 || 42 || 48 || 54 || 60
|-
! scope="row" | 7
| 7 || 14 || 21 || 28 || 35 || 42 || 49 || 56 || 63 || 70
|-
! scope="row" | 8
| 8 || 16 || 24 || 32 || 40 || 48 || 56 || 64 || 72 || 80
|-
! scope="row" | 9
| 9 || 18 || 27 || 36 || 45 || 54 || 63 || 72 || 81 || 90
|-
! scope="row" | 10
| 10 || 20 || 30 || 40 || 50 || 60 || 70 || 80 || 90 || 100
|}

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}
:[Caption above table:]
:<big>Wrong Times Table</big>
:The incorrect answers that feel most right to me

{| class="wikitable" style="text-align: center;"
!
! scope="column" | 1 || 2 || 3 || 4 || 5 || 6 || 7 || 8 || 9 || 10
|-
! scope="row" | 1
| 0 || ½ || 4 || 5 || 6 || 7 || 8 || 9 || 10 || 9
|-
! scope="row" | 2
| ½ || 8 || 5 || 6 || 12 || 14 || 12 || 18 || 19 || 22
|-
! scope="row" | 3
| 4 || 5 || 10 || 16 || 13 || 12 || 24 || 32 || 21 || 33
|-
! scope="row" | 4
| 5 || 6 || 16 || 32 || 25 || 25|| 29 || 36 || 28 || 48
|-
! scope="row" | 5
| 6 || 12 || 13 || 25 || 50 || 24 || 40 || 45 || 40 || 60
|-
! scope="row" | 6
| 7 || 14 || 12 || 25 || 24 || 32 || 48 || 50 || 72 || 72
|-
! scope="row" | 7
| 8 || 12 || 24 || 29 || 40 || 48 || 42 || 54 || 60 || 84
|-
! scope="row" | 8
| 9 || 18 || 32 || 36 || 45 || 50 || 54 || 48 || 74 || 56
|-
! scope="row" | 9
| 10 || 19 || 21 || 28 || 40 || 72 || 60 || 74 || 72 || 81
|-
! scope="row" | 10
| 9 || 22 || 33|| 48 || 60 || 72 || 84 || 56 || 81 || 110
|}

{{comic discussion}}
[[Category:Math]]