explain xkcd - User contributions [en]

Talk:2324: Old Days 2

2020-06-25T06:54:54Z

141.101.69.33: Comparison with false etymologies about the 1500s.

I've gotta try that, see how the ice cream truck guy reacts. Wonder where I can find an ice cream truck though? [[Special:Contributions/172.69.71.16|172.69.71.16]] 23:42, 24 June 2020 (UTC)
: The above is me, wasn't logged in, would I get in trouble for fixing the signature? [[User:Mikemk|Mikemk]] ([[User talk:Mikemk|talk]]) 23:44, 24 June 2020 (UTC)
(@Mikemk, I recon you sorted it by adding what you did. If you'd have just changed things, probably no crime if you explained it in the edit Summary. But I'm just an IP Address, so no authority.) Anyway. The bit about a phone-call stopping all electronic business is obviously rooted in dial-up needing exclusive use of a POTS line, something that only went out with broadband piggy-backing alongside voice-calls, the respective carrier-signals now microfiltered at each end of the house-to-exchange copper cabling to let them coexist over the same circuit without blocking/overwhelming each other. Though, in this comic, it's hyperbole, overly fuzzy memory, leg-pulling and/or an alternate-history being described. [[Special:Contributions/141.101.98.130|141.101.98.130]] 02:06, 25 June 2020 (UTC)

In the early days (of the ARPAnet) there was actually something that today would be classed as a "cloud service" (before the term was invented) although limited. It was a computer (in Cambridge, MA) funded by ARPA with massive amounts of storage and anybody on the ARPAnet could use it for storage (primary access was through FTP). So, cloud storage but not cloud computing. If you wanted to do something with the data you had to copy the whole file to your local disk, edit it there, and then send it back. The actual bits were stored on magnetic tape and there was an elaborate X/Y mechanism to select a tape and mount it on a tape drive, and later return it to its cubby. [[User:MAP|MAP]] ([[User talk:MAP|talk]]) 02:38, 25 June 2020 (UTC)

"State landline" is reminiscent of the old sailing joke where you'd ask a n00b to bring you 100 feet of shoreline. -- brad

Hm, I'd think that "state landline" is a pun on "state line". [[User:Gvanrossum|Gvanrossum]] ([[User talk:Gvanrossum|talk]]) 04:19, 25 June 2020 (UTC)

Also, while mainframes didn't exactly knit sweaters when they ran your code, they *did* produce physical artifacts -- reams of line printer paper. [[User:Gvanrossum|Gvanrossum]] ([[User talk:Gvanrossum|talk]]) 04:21, 25 June 2020 (UTC)

"It's not even likely that any punch patterns used in computer coding would be interpretable as valid sweater-creating instructions." Is anyone up to the challenge? [[User:Barmar|Barmar]] ([[User talk:Barmar|talk]]) 05:04, 25 June 2020 (UTC)

Wouldn't a loom produce woven textiles rather than knit garments like sweaters? Seems like an additional layer of tall tales. [[Special:Contributions/172.68.189.179|172.68.189.179]] 06:46, 25 June 2020 (UTC)

It seems to me that the comic is having fun with false etymologies. There is especially one article that 'explains' a lot of idiom (in the sense of making up a fanciful story), which has been debunked by Snopes
https://www.snopes.com/fact-check/life-in-the-1500s/ and the comics seems to allude to a similar situation in computer science, which is now old enough that early days are shrouded in a bit of mist out of which selective trivia is remembered (punch cards had something to do with looms) and then put together into a semi-coherent story that no longer reflects reality. (With part of the joke being that many people here will actually still know or even remember what it was really like in the 'early years', but the fewer those become, the more likely it will be that made-up 'origin stories' become accepted as true.

[[Special:Contributions/141.101.69.33|141.101.69.33]] 06:54, 25 June 2020 (UTC)

Talk:2307: Alive Or Not

2020-05-16T07:44:29Z

141.101.69.33:

I'm pretty sure high-pressure fire hoses belong on this scale[[User:60sRefugee|60sRefugee]] ([[User talk:60sRefugee|talk]]) 21:47, 15 May 2020 (UTC)
:What about wacky waving inflatable tube guy? [[Special:Contributions/172.68.38.124|172.68.38.124]] 00:41, 16 May 2020 (UTC)

Funny, for once viruses are said to be alive. That's new... [[Special:Contributions/141.101.107.138|141.101.107.138]] 22:01, 15 May 2020 (UTC)
:Definitely new, and extremely angering! I could scream... [[Special:Contributions/172.68.143.30|172.68.143.30]] 22:47, 15 May 2020 (UTC)
::Jup. The nex disgusting piece of antiscience after Wednesday´s nonsense about handwashing helping against respirational diseases. I think Monroe has caught a bug from Potus Donald. --[[Special:Contributions/141.101.69.33|141.101.69.33]] 07:44, 16 May 2020 (UTC)

Do we want to bicker over the placement of the line (like "Why is it below viruses"), or the order things are placed in (like "Why are slime molds below plants")? [[User:GreatWyrmGold|GreatWyrmGold]] ([[User talk:GreatWyrmGold|talk]]) 22:06, 15 May 2020 (UTC)
: Oh, go on. If you insist. You go first, unless you already have. ;) [[Special:Contributions/162.158.154.31|162.158.154.31]] 22:46, 15 May 2020 (UTC)

True fossils have remineralised so generally do not have DNA left. They are merely the shadow of a previous life.

Surprised no one has noticed the typo yet. It's 'archaea', not 'archea'
:(Sign yourself(/ves), "True fossils" and "Surprised"?) I disagree. It's 'archæa'... [[Special:Contributions/162.158.154.31|162.158.154.31]] 22:46, 15 May 2020 (UTC)

356: Nerd Sniping

2018-12-15T21:41:31Z

141.101.69.33: /* Explanation */ grammar

{{comic
| number = 356
| date = December 12, 2007
| title = Nerd Sniping
| image = nerd sniping.png
| titletext = I first saw this problem on the Google Labs Aptitude Test. A professor and I filled a blackboard without getting anywhere. Have fun.
}}

==Explanation==
{{w|Nerd}}s have a way of getting distracted easily and focusing on one thing and ignoring the rest, when they feel their specific skills are challenged by an interesting problem. [[Black Hat]] has decided to make this into a disturbing game of getting nerds, in this case a physicist, to stop in the middle of a street and get crushed by traffic by showing them an interesting problem to solve. (This may be based on a real event—see the [[#Trivia|trivia]] section).

The problem Black Hat shows is an electronics engineering thought experiment to find the resistance between two points. In normal wiring, a one-ohm resistor would result in one ohm of resistance. Two resistors connected in a series, where electricity has to go through each, has two ohms of resistance. Two one-ohm resistors in parallel give the circuit only half an ohm since you average the resistance of the path (1 ohm of resistance over 2 paths). With an infinite grid of equal resistors, you have an infinite number of paths to take, and for each path an infinite number of both series and parallel paths to consider, so much more advanced methods are needed. The exact answer to the question is 4/π − 1/2 ohms, or about 0.773 ohms. See [http://www.mathpages.com/home/kmath668/kmath668.htm Infinite Grid of Resistors].

Black Hat explains the concept of his new sport, '''Nerd Sniping''', to [[Cueball]] while killing the physicist, but Cueball is appalled and will have no part in this sport, which doesn't make Black Hat give up on him as he suggest it would be fun if he made his own sign. Black Hat finally suggest that "physicists are two points, mathematicians three." This may indicate that he considers a mathematician to be a more difficult target for his game than a physicist would be. It is unclear whether this is meant as a dig on physicists or on mathematicians; it might be because physicists are interested in a wider range of problems, or because mathematicians require a higher-quality problem to hold their interest. Alternatively he just dislikes mathematicians more, and is thus willing to award more points for sniping one of them.

In the title text [[Randall]] explains that he saw this problem in a [http://googleblog.blogspot.com/2004/09/pencils-down-people.html Google Labs Aptitude Test]. This is a collection of puzzles published by {{w|Google}} as a parody of tests such as the {{w|SAT}}. Google is known for using logic & math puzzles in their job interviews.

Randall explained in [http://www.youtube.com/watch?v=zJOS0sV2a24 a speech at Google] five days before this comic was released, that he was nerd sniped, in a way, by that problem in this test (see problem 10 on [https://3.bp.blogspot.com/_Ap14FtNN91w/Rll5oF8Px0I/AAAAAAAAAHo/cHG6a83cmlI/s1600-h/GLAT_3.jpg page 2]), and got quite irritated when he ultimately found that it was actually a modern physics research problem, requiring very advanced math, far more complicated than the other puzzles. Putting such a problem in an aptitude test, can be a way of testing if someone might realize when they cannot solve a problem and remember to move along to the other problems. If they fail to do this, they will never reach the easier problems that come later, and will fail due to their inability to realize when they will come up short. This is also an important knowledge to have about yourself. Seen in this context it is not necessarily a bad idea to have such an impossible problem in an aptitude test, as it is not interesting to have someone who is easily nerd sniped working for you.

Note that the truck should have stopped no matter what since the nerd was walking on a zebra crossing. However, the driver may have seen him walking, then estimated that he would be safe before reaching him, and realized too late that he had stopped in the street. Alternatively, the truck driver is part of Black Hat's sport.

Randall has later referred back to the concept of ''Nerd Sniping'' several times in the past, such as in the title text of [[730: Circuit Diagram]], and in the [[what if?]] blog. In [http://what-if.xkcd.com/113/ Visit Every State] (7 years after this comics release) the entire comic was shown at the top and the truck again further down the post—Randall has again been nerd sniped by a paper he read. This also happens to him in [https://what-if.xkcd.com/124/ Lunar Swimming]—see the title text for the second to last picture.

==Transcript==
:[Black Hat is sitting on a chair, Cueball is standing next to him. Across the street another Cueball-like guy is coming from a building walking towards the zebra crossing across from Black Hat.]
:Black Hat: There's a certain type of brain that's easily disabled.
:Black Hat: If you show it an interesting problem, it involuntarily drops everything else to work on it.

:[The Cueball-like man across the street is about to enter a crosswalk, which is seen from right behind Black Hat in his chair, holding on to the sign which is still pointing down. Cueball is looking on.]
:Black Hat: This has led me to invent a new sport: Nerd Sniping.
:Black Hat: See that physicist crossing the road?

:[Black Hat lifts up the sign when the physicist is in the middle of the street, halfway across the zebra crossing.]
:Black Hat: Hey!

:[A close up of Black Hat's sign is shown in a frame less panel. There is text above and below an image of a four by five grid of nodes with resistors (shown as wiggly lines) between every node and also continuing away from the 16 outer nodes. A total of 5 columns with 5 and 4 rows with 6 resistors for a total of 20 nodes and 49 resistors. Two nodes, a knight's move apart, are marked with red circles in the 3rd row 2nd column and the 2nd row 4th column.]
:Sign: On this infinite grid of ideal one-ohm resistors,
:Sign: what's the equivalent resistance between the two marked nodes?

:[The Cueball-like physicist has stopped pondering the questions a hand to his chin.]
:Physicist: It's... Hmm. Interesting. Maybe if you start with... No, wait. Hmm... You could—

:[In another frame less panel a ten wheeled truck is zooming past from the right, apparently going through the spot where the physicist just stood.]
:Truck: <big>''Foooom''</big>

:[Cueball looks down on Black Hat who looks back up from his chair at the curb, again holding the sign down. He lifts one hand up while replying.]
:Cueball: I will have no part in this.
:Black Hat: C'mon, make a sign. It's fun! Physicists are two points, mathematicians three.

==Trivia==
*It could be that Randall was inspired by a story from {{w|John Horton Conway|John H. Conway}} about when he was involved in a "near" nerd snipe event that was a perfect match for this comic.
**The story can be read in the book ''[https://books.google.ca/books?id=aFHyUfFUVIwC&printsec=frontcover&hl=da#v=onepage&q&f=false Candid Science Five]'' from 2005 (two years before this comics release), specifically on [https://books.google.ca/books?id=aFHyUfFUVIwC&pg=PA22&lpg=PA22&dq=Coxeter+came+to+Cambridge+and+he+gave+a+lecture,+then+he+had+this+problem+...++Ileft+the+lecture+room+thinking.+As+I+was+walking+through+Cambridge,+suddenly+theidea+hit+me,++but+it+hit+me+while+I+was+in+the+middle+of+the+road.++When+the+ideahit+me+I+stopped+and+a+large+truck+ran+into+me+...++So+I+pretended+that+Coxeter+hadcalculated+the+difficulty+of+this+problem+so+precisely+that+he+knew+that+I+would+getthe+solution+just+in+the+middle+of+the+roa&source=bl&ots=CgmxTG2n0w&sig=ohqqBGtJrpuQFeiCPPusMVsQUV4&hl=en&sa=X&ved=0CB0Q6AEwAGoVChMIy4KdnPakyAIV0ZeICh2OGghP#v=onepage&q=%22in%20the%20middle%20of%20the%20road%22&f=false page 22]:
::"{{w|Harold Scott MacDonald Coxeter|[Donald] Coxeter}} came to Cambridge and he gave a lecture, then he had this problem ... I left the lecture room thinking. As I was walking through Cambridge, suddenly the idea hit me, but it hit me while I was in the middle of the road. When the idea hit me I stopped and a large truck ran into me ... So I pretended that Coxeter had calculated the difficulty of this problem so precisely that he knew that I would get the solution just in the middle of the road ..."

{{comic discussion}}

[[Category:Comics with color]]
[[Category:Comics featuring Black Hat]]
[[Category:Comics featuring Cueball]]
[[Category:Multiple Cueballs]]
[[Category:Math]]
[[Category:Physics]]

Talk:2040: Sibling-in-Law

2018-09-03T09:09:45Z

141.101.69.33:

Unless you want to go completely nuts on this topic, avoid reading Jane Austen, where the the term "X-in-law" is used to mean, roughly, "someone to whom you are related for legal reasons". It can be used to refer to, for example, what we today might refer to as step/half-siblings, adopted siblings, etc. [[User:Arcanechili|Arcanechili]] ([[User talk:Arcanechili|talk]]) 15:51, 31 August 2018 (UTC)

> The title text refers to incestual relationships, which are generally frowned upon in Western culture.
How on earth this refers to incest if persons are only legally, not genetically related??? It's just that Randall doesn't know how to call new relatives but cannot stop their arrival. {{unsigned ip|162.158.91.251}}

Yes, I also don't think it refers to incest. {{unsigned ip|172.68.94.40}}

:I'm not sure if that is right or not, but that was my interpretation of that text, based on the "a reason why these two should not be wed." Unless there is a different issue with this, also involving marriage? [[Special:Contributions/162.158.59.190|162.158.59.190]] 16:44, 31 August 2018 (UTC)

::I read the title text as... the reason he is objecting has nothing to do with the couple getting married, it's simply the selfish reason that Randall doesn't want the confusion of having to figure out what to call the new extended-family members. [[User:N0lqu|-boB]] ([[User talk:N0lqu|talk]]) 17:37, 31 August 2018 (UTC)

Somehow I don't have this problem whatsoever...as I'm a single child who married a single child. I have zero siblings-in-law. In fact, my future kids won't even have (regular) cousins... {{unsigned ip|162.158.74.231}}

Am I the only one that thinks there's an error in this comic? Shouldn't spouse's sibling be the sibling-in-law of Cueball's *sibling*? But then, maybe I'm also making Randall's point... [[User:Sspenser|Sspenser]] ([[User talk:Sspenser|talk]]) 18:28, 31 August 2018 (UTC)

^ Sspenser I honestly think this is a poorly constructed diagram because it invites this type of confusion -- I was also tripped up at first, but I think all relationships are meant to be labeled *with respect to "Me"/cueball*. My initial assumption was that each double-headed arrow was intending to label *pairs* of siblings-in-law; in fact I think it is trying to label individuals who are each independently siblings-in-law of cueball's (or assumed siblings-in-law of cueball's). The different double-headed arrows represent different levels of confidence in claiming this relationship between Cueball and the individuals in that "layer." I think it would have been more clear if he kept the arrows basically the same, but labeled as "*My* Siblings-in-law"/"Also *My* Siblings-in-law, I think?"/etc. ~clukes [[Special:Contributions/162.158.63.238|162.158.63.238]] 00:28, 1 September 2018 (UTC)
:'''''I''''' was initially confused by the black border surrounding the image, which connects the heredity lines of ''all'' the people in the chart as if they shared a parent by different matings. This image really ought not to have a border the same color as the chart lines... [[User:ProphetZarquon|ProphetZarquon]] ([[User talk:ProphetZarquon|talk]]) 01:21, 1 September 2018 (UTC)

The Russian language actually has different words for both "types" of brothers in-law (spouse's brother vs. sister's husband), also for parents and children in-law on either side: https://ru.wikipedia.org/wiki/Свойство_(родство) .
But all these in-law distinctions are based on the respective spouse's sex, so it won't work for same-sex marriages. {{unsigned ip|162.158.234.58}}

:In German, they even have a word for "spouse of sibling in-law" and similar situations: "Schwippschwager" https://de.wikipedia.org/wiki/Schwippschwager [[User:Polyfier|Polyfier]] ([[User talk:Polyfier|talk]]) 23:41, 31 August 2018 (UTC)

The way this is defined, you and your spouse both have the same set of siblings and siblings-in-law. In other words, if someone is your spouse's sibling or sibling in law then that person is your sibling in law if that person is not your sibling. The relationship chains across a maximum of one sibling relationship. [[User:Probably not Douglas Hofstadter|Probably not Douglas Hofstadter]] ([[User talk:Probably not Douglas Hofstadter|talk]]) 18:56, 31 August 2018 (UTC)

Off topic but I can't resist:
:DARK HELMET: I am your father's brother's nephew's cousin's former room-mate.
:LONE STARR: What's that make us?
:DARK HELMET: Absolutely nothing....
Spaceballs (1987) parody Star Wars --[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 19:51, 31 August 2018 (UTC)

Anyone else think this comic is a form of "Wedding Gift" Randal is giving to a sibling who's getting married (presumably today)? {{unsigned|JamesCurran}}

People actually complain cousins removed is hard to understand? When I first learned about it, my thought was actually: Wow, that is so much clearer than what we use in Dutch. In Dutch we use a prefix for each step its is removed so it can get wordy. A cousin would be "neef" a cousin once removed would be "achterneef" a 2nd cousin "achterachterneef". I think a 2nd cousin removed would then be "achterachterachterneef" and third cousins "achterachterachterachterneef". I'm not even sure that's how confusing it is. The English system is easy. Simply count up to the common ancestor (A), then down to the relative (R). Then you're (R-2)th cousins (A-R) times removed. Fun fact, your siblings are your zeroth cousins and you are your own negative first cousin. [[User:Tharkon|Tharkon]] ([[User talk:Tharkon|talk]]) 22:32, 31 August 2018 (UTC)
:That is awesome & I'm totally using it from now on; except I'm going to call anyone 2nd cousin or beyond "altachterneef" & see how long it takes for a Dutch-speaker to give me a quizzical look. [[User:ProphetZarquon|ProphetZarquon]] ([[User talk:ProphetZarquon|talk]]) 01:21, 1 September 2018 (UTC)

Sooo... Maybe you can help me with this:
My half-sister from my Mother's first marriage has 3 half-sisters from her Father's second marriage. My half-sister adopted her youngest half-sister, becoming her legal guardian or "parent". So is that person my niece? Half-sister? Half-sister in-law? Sister? Half-sister's half-sister? Half-sister's daughter in-law? Niece in-law once removed? None? [[User:ProphetZarquon|ProphetZarquon]] ([[User talk:ProphetZarquon|talk]]) 01:21, 1 September 2018 (UTC)
:She's your adopted half-niece. She had no named relationship to you prior to adoption. [[User:LtPowers|LtPowers]] ([[User talk:LtPowers|talk]]) 12:49, 1 September 2018 (UTC)
::That sounds about right! We all refer to each other as brother & sisters though. [[User:ProphetZarquon|ProphetZarquon]] ([[User talk:ProphetZarquon|talk]]) 15:35, 2 September 2018 (UTC)

I've never heard of a spouse's sibling's spouse being called your sibling-in-law before. That usage seems weird to me. But then, none of my siblings or siblings-in-law are married. [[User:LtPowers|LtPowers]] ([[User talk:LtPowers|talk]]) 12:50, 1 September 2018 (UTC)

;Ray Steven's song
If he thinks that's confusing, he should follow Ray Steven's ''I'm My Own Grandpa'' song. [[Special:Contributions/172.68.150.76|172.68.150.76]] 14:12, 1 September 2018 (UTC)
:When I was growing up, I did know some kids where the younger one was claimed as the other's uncle... [[User:ProphetZarquon|ProphetZarquon]] ([[User talk:ProphetZarquon|talk]]) 15:35, 2 September 2018 (UTC)

;Zaphod Beeblebrox character
Zaphod is described as a "semi-half-cousin" of Ford Prefect, with whom he "shares three of the same mothers". Because of "an accident with a contraceptive and a time machine", his direct ancestors from his father are also his direct descendants. He has referred to himself as Zaphod Beeblebrox the First, but is called Zaphod Beeblebrox the Nothingth by his great-grandfather.
:[[User:ProphetZarquon|ProphetZarquon]] ([[User talk:ProphetZarquon|talk]]) 15:35, 2 September 2018 (UTC)

Accidentally deleted yesterday, sorry for that: --[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 16:11, 1 September 2018 (UTC)
:The Merriam-Webster and Oxford dictionaries both give a simple list of people who can be considered a sibling-in-law. Your sibling's spouse, your spouse's sibling, and your spouse's sibling's spouse. It does not include your sibling's spouse's siblings. So the questionable "sibling-in-law" on the left is not a sibling-in-law, while the one on the right is. Why does two marriage and a sibling relationship count for more than two sibling and a marriage relationship? Because married people generally spend a lot of adult time together, while siblings gradually drift apart. A cause to gather siblings can easily sweep multiple spouses into the gathering, while a cause to gather one side of the family only rarely gathers the other side. These differences become more pronounced in with large numbers of siblings.[[Special:Contributions/162.158.186.12|162.158.186.12]]

I'm just noting, I looked at Wikipedia, and the best I can find as a solution to it, starting at "Also siblings-in-law, I think?" are "First Cousins-in-law", and the numbers increase as they radiate out. --[[Special:Contributions/172.68.58.89|172.68.58.89]] 07:33, 2 September 2018 (UTC)

Um, the description of the title text seems to have a lot of supposition in it. All it really says is that the reason isn't good enough - not that anyone actually tried it, was shot down etc, or even that it refers to banns. My reading of it before I came here was actually similar to the incest train of thought, where not having that relationship clarified could cause issues down the road in regards to inheritance, future marriages etc.
Also, 'traditional wedding in most English-speaking regions' isn't entirely accurate - banns are generally a Christian thing, sure, but Christianity extends to non-English-speaking areas as well and has done for quite some time, and a requirement for notice and swearing that no legal impediments to the marriage exist are now part of many secular, legal processes for marriage (e.g. part of the process of obtaining a licence, or via registration of intent). I'd recommend this be changed to something a little less interpretative. e.g:
"The title text states that not knowing whether a marriage would create an in-law relationship between one of the parties and a third person doesn't constitute an objection to a marriage significant enough to stop it from happening. The phrase "reason why these two should not be wed" comes from the historical practice of announcing a marriage in advance so that people could raise any objections - such as one of the parties already being married - prior to the wedding. This process is now often handled by notice requirements or a signed declaration by the parties that no impediment exists."
: In-law are awefully (intended) simple : exactly one marital and one blood link. I fail to understand how anyone could possibly be confused by that.

2035: Dark Matter Candidates

2018-08-20T11:37:32Z

141.101.69.33: Brief descriptions from Wikipedia.

{{comic
| number = 2035
| date = August 20, 2018
| title = Dark Matter Candidates
| image = dark_matter_candidates.png
| titletext = My theory is that dark matter is actually just a thin patina of grime covering the whole universe, and we don't notice it because we haven't thoroughly cleaned the place in eons.
}}

==Explanation==
{{incomplete|Every section needs to be filled and explained. Do NOT delete this tag too soon.}}
This comic gives a set of possibilities of what dark matter could possibly be. In cosmology, {{w|Dark_matter| dark matter}} is an unknown type of matter thought to account for 85% of the total matter in the universe. The joke in this comic is that the range of the mass of the possible particles and objects stretch over 81 powers of ten. Randall filled the gap between small candidate particles and large candidate objects with highly absurd suggestions.

'''{{w|Axion|Axion}}'''
An hypothetical elementary particle that might be a component of dark matter.

'''{{w|Sterile_neutrino|Sterile neutrino}}'''
An hypothetical particle interacting only via gravity. It's an actual candidate for dark matter.

'''{{w|Electron|Electrons}} painted with space {{w|camouflage|camouflage}}'''

'''{{w|Neutralino|Neutralino}}'''
A hypothetical particle from {{w|Supersymmetry|Supersymmetry}}. It's an actual candidate for dark matter.

'''{{w|Q-ball|Q-ball}}'''
In theoretical physics, a Q-ball is a stable group of particles. It's an actual candidate for dark matter.
In billiards, a cue ball is the white (or yellow) ball hit with the cue in normal play.

'''{{w|Pollen|Pollen}}'''

'''{{w|Ceratopogonidae|No-See-Ums}}'''
Also called Ceratopogonidae, a family of small flies (1–4 mm long) who can pass through most window screens.

'''{{w|Pool (cue sports)|8-balls}}'''
In billiards, the 8-ball is a black ball numbered 8. It's a pun with Q-ball/cue ball.

'''Space {{w|Cow|Cows}}'''

'''{{w|Obelisk|Obelisks}}, {{w|2001: A Space Odyssey (film)|Monoliths}}, {{w|Pyramid power|Pyramids}}'''

'''Black Holes ruled out by:'''
** Gamma Rays
** GRB lensing
** Neutron Star Data
** Mirco lensing
** Solar System Stability
** Buzzkill Astronomers

'''Maybe those oribt lines on space diagrams are real and very heavy'''

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

{{comic discussion}}

Talk:2034: Equations

2018-08-17T20:13:01Z

141.101.69.33: T

Is the joke that all of the equations are actually wrong/malformed/meaningless but they sort of look like typical equations for that field? {{unsigned ip|172.68.133.66}}
:Sort of. A bit of dimensional analysis would have helped. ;-) --[[Special:Contributions/162.158.91.221|162.158.91.221]] 07:28, 17 August 2018 (UTC)

Should we add a column with examples of similar correct equations from the respective fields? Sebastian --[[Special:Contributions/172.68.110.4|172.68.110.4]] 09:33, 17 August 2018 (UTC)
:That would definitely tidy up my attempts to provide context for Randall's versions. The challenge then is working in explanations for the correct equations as well as arguing over which examples should be used. [[User:Exxi|Exxi]] ([[User talk:Exxi|talk]]) 09:45, 17 August 2018 (UTC)

I don't think the part in parentheses about OH in the Chemistry equation explanation is correct. OH- would mean that it's negatively charged and has nothing to do with unpaired electrons of Oxygen. It would add another horror to the equation, though, as it wouldn't be charge preserving anymore. [[Special:Contributions/162.158.88.230|162.158.88.230]] 09:58, 17 August 2018 (UTC)

"Redshit". Best typo ever. Please keep it. [[Special:Contributions/172.69.54.177|172.69.54.177]] 10:13, 17 August 2018 (UTC)

;Deep physics equations
The transcript is wrong here, the last letter is not a <math>\mu</math>, but a "u" with a cedilla: u̧. The math parser refuses to render it, though. [[Special:Contributions/162.158.88.230|162.158.88.230]] 05:54, 17 August 2018 (UTC)
:Looks like it. But I don't think that letter exists even. --[[Special:Contributions/162.158.91.221|162.158.91.221]] 07:28, 17 August 2018 (UTC)
:Is this equation a sort of nod to a Theory Of Everything which unifies quantum mechanics and gravity... H-hat (a Hamiltonian, which in quantum mechanics describes the total energy of a system, and usually runs in to problems describing large systems - such as the entire universe - where gravity or spacetime curvature effects matter) *minus* u0 (the relativistic mass of the whole system at time zero ie. the big bang) gives 0 (no energy everywhere always). Since mass is energy (e=mc^2) and mass is also the sole cause of gravity the two theories cleanly collapse together when mass is zero, and figuring out how to extend the theory to other less clean points on the mass axis is obviously a job for less profound physics? I've no ideas to explain the cedilla. [[Special:Contributions/141.101.98.28|141.101.98.28]] 08:49, 17 August 2018 (UTC)
:It looks to me a little like a parody of the {{w|Wheeler-DeWitt_equation#Hamiltonian_constraint|Wheeler-DeWitt equation}} which (in theory) describes a wavefunction for the entire Universe. [[User:Exxi|Exxi]] ([[User talk:Exxi|talk]]) 09:06, 17 August 2018 (UTC)一
: I'm just thrilled someone found the right character for it. I spent 20 minutes looking for the right u symbol without any luck at all. {{unsigned ip|172.68.143.132}}
Is this poking fun at equation-filled blackboards in movies and cartoons? {{unsigned ip|172.68.254.42}}
:Doesn't seem like it. These equations actually do look like the kinds of equations you would see in these fields. On blackboards in movies you tend to get equations that are pure nonsense. {{unsigned ip|172.68.143.132}}
I think this may also be a reference to Feynman's unworldliness equation, http://www.feynmanlectures.caltech.edu/II_25.html#Ch25-S6 . [[Special:Contributions/108.162.219.220|108.162.219.220]] 17:02, 17 August 2018 (UTC)

;Table layout at the explanation
That oversized table is really bad layout. We've had this discussion many times before - tables should only be used for small contents. Right now I would run into too many edit conflicts but I'll change it to a proper floating text with small headers for each section. --[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 11:51, 17 August 2018 (UTC)
:Done, looks much more like a real paper... --[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 12:58, 17 August 2018 (UTC)

;All number theory equation
The explanation for math doesn't seem entirely correct. You can in fact extend the ring of integers (as well as rational and real numbers) with positive and negative infinity, but it won't be a ring anymore. Specifically, the infinities don't have an additive or multiplicative inverse (but 1/infinity = 0); and addition of positive and negative infinity, as well as the product of 0 and either infinity is undefined. However, these properties are not used in the above equation. What we ''can'' use is that <math>\forall n < \infty: n - \infty= -\infty </math>. We would thus have <math>K_n = \sum_{i=0}^{\infty}\sum_{\pi=0}^{\infty}(n-\pi)(i-e^{\pi-\infty}) = \sum_{i=0}^{\infty}\sum_{\pi=0}^{\infty}(n-\pi)(i-0) = \sum_{i=0}^{\infty}\sum_{\pi=0}^{\infty}(n-\pi)i= \sum_{i=0}^{\infty}i\sum_{\pi=n}^{\infty}-\pi= \sum_{i=0}^{\infty}i\cdot(-\infty)=-\infty</math>. Also, how often does one use e and pi in number theory? --[[User:Ycthiognass|Ycthiognass]] ([[User talk:Ycthiognass|talk]]) 12:11, 17 August 2018 (UTC)
:Pi (or any other number) minus infinite is just absurd. You can use the infinite symbol only as a limit but NOT as number in calculations. --[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 12:33, 17 August 2018 (UTC)
::It is not absurd. Adding the rules <math>n+\infty=\infty\text{ for }n>-\infty,n-\infty=-\infty\text{ for }n<\infty, \pm n\cdot\infty = \pm\infty\text{ for }n>0, \pm n\cdot(-\infty) = \mp\infty\text{ for }n>0,\frac1{\pm\infty}=0</math> gives you a consistent theory that is especially useful when talking about infinite sums and integrals. Would you say the term <math>n-\sum_{i=1}^\infty i</math> is absurd? --[[User:Ycthiognass|Ycthiognass]] ([[User talk:Ycthiognass|talk]]) 14:35, 17 August 2018 (UTC)
:::Of course it's absurd. It is <math>\infty-\infty \neq 0</math> because it could be everything between <math>\infty</math> and <math>-\infty</math>. {{w|Infinity}} is a concept describing something without any bound... And, as you can't divide by zero you can't do the same for infinity. --[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 17:24, 17 August 2018 (UTC)
:::One more: It is
::::<math>\sum_{i=1}^\infty a_i = \lim_{n\to\infty} \sum_{i=1}^n a_i.</math>
:::When this limit exists, one says that the series is ''convergent'' or ''summable''. Otherwise it's called ''divergent'' and has no solution like this one:
::::<math>\sum_{i=1}^\infty i</math>
:::Infinite is NO number! --[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 17:33, 17 August 2018 (UTC)

Completely separate from the above, it's probably worth noting that i is also a constant, and as such has the same misconception as <math>\pi</math>. Computer scientists are happy using i for loops/summations, but mathematicians prefer using n. Based off that, it's probably another misconception/joke that n is treated as a constant, while known-constants are used as variables. [[Special:Contributions/108.162.246.149|108.162.246.149]] 17:28, 17 August 2018 (UTC)
:There is nothing non-standard about using i as an index variable. Often as part of the series i,j,k.
Searching for summation convention will give plenty of examples.

There are fewer letters than mathematical concepts in need of letters, so most letters are used for multiple purposes. Occasionally this causes difficulty. You can be halfway through a linear algebra problem before you discover you need i for an imaginary number despite already using it as an index. Hilarity ensues. [[Special:Contributions/162.158.74.105|162.158.74.105]] 19:57, 17 August 2018 (UTC)

;Chemistry equation
OH should have a charge symbol: OH-. The actual reaction would be:

CH4 + OH- + heat -> CH3- + H2O

The methyl group can dissolve in water, and this is presumably happening in water, so this equation can work, just not the one provided by Randell. Reacting longer alkanes with bases is a way to make soaps, but the methyl group would be too reactive to be used this way. [[User:Nutster|Nutster]] ([[User talk:Nutster|talk]]) 13:13, 17 August 2018 (UTC)

;Fluid Dynamics equation
I believe the fraction 8/23 in the Fluid Dynamics equation is a Randallesque reference to the fractional approximation of pi = 22/7. It's probably not a coincidence that you get 8/23 from 22/7 if you invert it and add 1 to both the numerator and denominator. [[User:Ianrbibtitlht|Ianrbibtitlht]] ([[User talk:Ianrbibtitlht|talk]]) 15:19, 17 August 2018 (UTC)

;Gauge theory equation
<s>I think the transcript is missing a left superscript 0 before the turned xi. [[Special:Contributions/172.68.226.16|172.68.226.16]] 16:50, 17 August 2018 (UTC)</s> Ah no, sorry. False alarm. It's just that Randall writes the xi with a funny tail. The same tail is on the non-turned xi earlier. [[Special:Contributions/172.68.226.10|172.68.226.10]] 16:52, 17 August 2018 (UTC)

If explainxkcd.com is to make XKCD comics more understandable then this explanation is failing that. I assumed from the beginning that the joke was about the equations being wrong, but the description of the joke is making my head hurt.

;All truly deep physics equations
In the description paragraph, the last sentence starting "The principle of least action says allows..." does not scan. If someone can fix this (copy&paste?) error, please delete this comment. [[Special:Contributions/162.158.58.171|162.158.58.171]] 19:33, 17 August 2018 (UTC)

Note that this comics also emphasizes that Randall is more familiar with physics than with chemistry : while most of the equations here require college-level education to grok, the chemistry one is at the very most high-scool-grade.

Talk:2027: Lightning Distance

2018-08-02T08:39:31Z

141.101.69.33: It's bunk

All this is complete nonsense.

The radio burst is in the hundreds of kHz, a few Mhz at best,
and cannot possibly be timed to a nanosecond.

Also the lightning path would have to be a circle
centered on the observer to within 30 cm, aka one nanosecond.

OTOH locating lightning strokes to about a kilometer (or a microsecond)
by the radio burst is quite practical. (to about 1000 kilometer)

See <www.blitzortung.org> for the practical results.
Triangulation with more than three stations improves the accuracy.

Jan

Talk:1925: Self-Driving Car Milestones

2017-12-09T19:16:27Z

141.101.69.33:

This page is, without offense to the creator, a mess. We're gonna need a table for this. [[Special:Contributions/172.68.47.78|172.68.47.78]] 19:14, 6 December 2017 (UTC)
* Or at least a list. I have created one, but it could use fleshing out.[[User:WingedCat|WingedCat]] ([[User talk:WingedCat|talk]]) 19:55, 6 December 2017 (UTC)
::List is fine. You don't need a table for everything - especially if this table had only one or two columns...
: none taken, it's my first time (I only wrote the first three points from a blank page) [[Special:Contributions/162.158.111.61|162.158.111.61]] 09:08, 7 December 2017 (UTC)

I'm going to go with a [citation needed] on that "sex in a self-driving has probably already happened." Are there stats suggesting the amount of coitus per vehicle in the relevant counties?

"This a joke about Boolean satisfiability, as evaluating an arbitrarily complex bumper sticker and determining whether to honk is NP-complete." What? Determining whether to honk has nothing to do with the satisfiability problem; this is more of a joke about getting a computer to evaluate the truth of Boolean expressions that it may have no information about. [[User:Checkmate|Checkmate]] ([[User talk:Checkmate|talk]]) 22:07, 6 December 2017 (UTC)Checkmate

I believe the "Autonomous canyon jumping" is related to the self-loathing; a self-loathing is likely to autonomously jump off a cliff. [[Special:Contributions/108.162.212.179|108.162.212.179]] 22:30, 6 December 2017 (UTC)

"As of 2017, self-driving s require a human to be able to take over just in case, but any such trip where the human never actually took control would qualify for this milestone."
I seems like not all places require a human backup driver: https://www.theverge.com/2017/11/7/16615290/waymo-self-driving-safety-driver-chandler-autonomous [[Special:Contributions/172.69.22.146|172.69.22.146]] 23:19, 6 December 2017 (UTC)

Time to start printing "Honk if this statement evaluates as 'do not honk!'" bumper stickers! [[Special:Contributions/162.158.63.28|162.158.63.28]] 01:24, 7 December 2017 (UTC)

Is this related to the Vsauce Mind Field video about self-driving s and the trolley problem the literally released today, or is it just a weird coincidence?[[Special:Contributions/162.158.74.225|162.158.74.225]] 05:13, 7 December 2017 (UTC)

The likelihood of trolley-like problems is no lower for an autonomous car than a human-driven one, since it depends on external factors. It might be true that if a significant number of the ''other'' cars on the road were replaced with self-driving ones, that would reduce the occurrence of conflicts, and therefore the likelihood and severity of these problems would be lower, but it would be lower for self-driven and human-driven cars alike. The real issue with such debates is that they tend to make a false assumption that existing human drivers are good at solving these problems, when the whole thrust of these thought experiments is to demonstrate that there are no generally accepted solutions to these problems.[[Special:Contributions/141.101.104.239|141.101.104.239]] 09:33, 7 December 2017 (UTC)
:I don't think anyone would argue that human drivers are good at handling trolley-problem situations, and we don't tend to expect humans to make good decisions under pressure. The problem is that a self-driving car would need to be programmed to make decisions in these scenarios in advance, which would involve assigning absolute values to the different options in a trolley-problem scenario. As you said, there's no generally accepted solution to these problems, so the controversy arises from deciding how self-driving cars should be programmed to handle these situations. [[Special:Contributions/162.158.79.161|162.158.79.161]] 21:05, 7 December 2017 (UTC)
"Given the nature of human sexuality, it is possible this has already happened, but there has not been a public documentation of this milestone."
Rule 34 applies. --[[Special:Contributions/162.158.89.133|162.158.89.133]] 12:44, 7 December 2017 (UTC)
:that part after the but is an edit from me, because the previous wording was even less plausible:
:"but no one recorded the incident." - I changed that to "but there has not been a public documentation of this milestone."
:because I didn't find any recording with a quick search on one of the more famous free sites for videos like that (not car videos...) [[User:Lupo|Lupo]] ([[User talk:Lupo|talk]]) 16:58, 7 December 2017 (UTC)

"An empty car wandering the highways" - that doesn't seem so ridiculous; a car costs what, $9000/year? That's like an EC2 instance and not even the biggest one. [[User:Sabik|Sabik]] ([[User talk:Sabik|talk]]) 13:22, 7 December 2017 (UTC)
: Plus you have to factor in the potential for the cost of letting the car wander becoming cheaper than paying for a parking space, in which case it may become a deliberate choice.[[Special:Contributions/141.101.104.239|141.101.104.239]] 13:24, 7 December 2017 (UTC)
: Some stops will provide free electricity so an electric car could keep going that way. Its owner will notice it's missing but they could be sick in hospital or even dead - they may even die in the car from a medical issue if that then counts as an empty car. Why the car's journey never ends is a different question. Maybe it drives the deceased owner to work and back every day. Maybe it's searching for a parking space and charging point but cannot reach the former from the latter before it has to go back and charge again. Robert Carnegie rja.carnegie@excite.com [[Special:Contributions/141.101.105.6|141.101.105.6]] 16:09, 7 December 2017 (UTC)
::My first thought was of a woman who had died in her house, but wasn't found for many years because her bills were all auto-paid.[[Special:Contributions/162.158.122.12|162.158.122.12]] 14:49, 8 December 2017 (UTC)

Added a bit more to the explanation and formatted everything into a table so it's more organized. --[[User:JayRulesXKCD|'''JayRules''XKCD''' ]][[User talk:JayRulesXKCD|what's up?]] 13:26, 7 December 2017 (UTC)

Are there any researchers working on cars that can find a parking space? (Instead of just park in one that the human driver finds?) [[Special:Contributions/162.158.111.145|162.158.111.145]] 14:53, 7 December 2017 (UTC)
: There is a parking space app and parking payment apps. I don't know if smart cars are allowed to use these without human supervision. Robert Carnegie rja.carnegie@excite.com [[Special:Contributions/141.101.105.6|141.101.105.6]] 16:11, 7 December 2017 (UTC)
:Tesla already has software to allow a Model S or X to park itself after dropping off human occupants at their destination. It's not yet released to owners but Tesla is testing it. ----

The first three milestones all come under the heading of recently achieved. 1.Volvo has an auto breaking system on imminent collision detection 2.lane keeping/warning systems are now relatively common. 3.Several models have automatic parking assist.[[Special:Contributions/162.158.165.16|162.158.165.16]] 04:28, 8 December 2017 (UTC)

Perhaps commenters here are to young to remember Evel Knievel https://en.m.wikipedia.org/wiki/Evel_Knievel but I feel very confident Randall was thinking of Evel and his Snake River Canyon jump when he wrote the "Autonomous Canyon Jumping" milestone----

The table seems to miss the fact that the comic starts with things which have all been implemented in vehicles and have become commonplace, spending a lot of time talking about hypothetical problems which don't really change the fact that these things are all "done". Automatic emergency braking is available on new cars and appears to be a fairly simple collision-avoidance system. Highway lane-keeping is also definitely "solved" in the current batch of self-driving cars and is a selling point for some mainstream cars and trucks too (and the difficulties with faded lines or whatever is fairly irrelevant to the comic as a whole). Self-parking is also available in a lot of standard cars these days. "Full highway autonomy" is more or less solved now, though of course there are legal issues with it. Without doing any research I think we can all agree that "First sex..." has definitely been done by now. The first milestone that is probably in our future, now, is the "no input" line (though I can't be sure... can a user really just get into the car, give and address and do nothing else to help until it parks at its destination?).[[Special:Contributions/141.101.69.33|141.101.69.33]] 19:16, 9 December 2017 (UTC)

Talk:1925: Self-Driving Car Milestones

2017-12-09T19:04:19Z

141.101.69.33:

This page is, without offense to the creator, a mess. We're gonna need a table for this. [[Special:Contributions/172.68.47.78|172.68.47.78]] 19:14, 6 December 2017 (UTC)
* Or at least a list. I have created one, but it could use fleshing out.[[User:WingedCat|WingedCat]] ([[User talk:WingedCat|talk]]) 19:55, 6 December 2017 (UTC)
::List is fine. You don't need a table for everything - especially if this table had only one or two columns...
: none taken, it's my first time (I only wrote the first three points from a blank page) [[Special:Contributions/162.158.111.61|162.158.111.61]] 09:08, 7 December 2017 (UTC)

I'm going to go with a [citation needed] on that "sex in a self-driving has probably already happened." Are there stats suggesting the amount of coitus per vehicle in the relevant counties?

"This a joke about Boolean satisfiability, as evaluating an arbitrarily complex bumper sticker and determining whether to honk is NP-complete." What? Determining whether to honk has nothing to do with the satisfiability problem; this is more of a joke about getting a computer to evaluate the truth of Boolean expressions that it may have no information about. [[User:Checkmate|Checkmate]] ([[User talk:Checkmate|talk]]) 22:07, 6 December 2017 (UTC)Checkmate

I believe the "Autonomous canyon jumping" is related to the self-loathing; a self-loathing is likely to autonomously jump off a cliff. [[Special:Contributions/108.162.212.179|108.162.212.179]] 22:30, 6 December 2017 (UTC)

"As of 2017, self-driving s require a human to be able to take over just in case, but any such trip where the human never actually took control would qualify for this milestone."
I seems like not all places require a human backup driver: https://www.theverge.com/2017/11/7/16615290/waymo-self-driving-safety-driver-chandler-autonomous [[Special:Contributions/172.69.22.146|172.69.22.146]] 23:19, 6 December 2017 (UTC)

Time to start printing "Honk if this statement evaluates as 'do not honk!'" bumper stickers! [[Special:Contributions/162.158.63.28|162.158.63.28]] 01:24, 7 December 2017 (UTC)

Is this related to the Vsauce Mind Field video about self-driving s and the trolley problem the literally released today, or is it just a weird coincidence?[[Special:Contributions/162.158.74.225|162.158.74.225]] 05:13, 7 December 2017 (UTC)

The likelihood of trolley-like problems is no lower for an autonomous car than a human-driven one, since it depends on external factors. It might be true that if a significant number of the ''other'' cars on the road were replaced with self-driving ones, that would reduce the occurrence of conflicts, and therefore the likelihood and severity of these problems would be lower, but it would be lower for self-driven and human-driven cars alike. The real issue with such debates is that they tend to make a false assumption that existing human drivers are good at solving these problems, when the whole thrust of these thought experiments is to demonstrate that there are no generally accepted solutions to these problems.[[Special:Contributions/141.101.104.239|141.101.104.239]] 09:33, 7 December 2017 (UTC)
:I don't think anyone would argue that human drivers are good at handling trolley-problem situations, and we don't tend to expect humans to make good decisions under pressure. The problem is that a self-driving car would need to be programmed to make decisions in these scenarios in advance, which would involve assigning absolute values to the different options in a trolley-problem scenario. As you said, there's no generally accepted solution to these problems, so the controversy arises from deciding how self-driving cars should be programmed to handle these situations. [[Special:Contributions/162.158.79.161|162.158.79.161]] 21:05, 7 December 2017 (UTC)
"Given the nature of human sexuality, it is possible this has already happened, but there has not been a public documentation of this milestone."
Rule 34 applies. --[[Special:Contributions/162.158.89.133|162.158.89.133]] 12:44, 7 December 2017 (UTC)
:that part after the but is an edit from me, because the previous wording was even less plausible:
:"but no one recorded the incident." - I changed that to "but there has not been a public documentation of this milestone."
:because I didn't find any recording with a quick search on one of the more famous free sites for videos like that (not car videos...) [[User:Lupo|Lupo]] ([[User talk:Lupo|talk]]) 16:58, 7 December 2017 (UTC)

"An empty car wandering the highways" - that doesn't seem so ridiculous; a car costs what, $9000/year? That's like an EC2 instance and not even the biggest one. [[User:Sabik|Sabik]] ([[User talk:Sabik|talk]]) 13:22, 7 December 2017 (UTC)
: Plus you have to factor in the potential for the cost of letting the car wander becoming cheaper than paying for a parking space, in which case it may become a deliberate choice.[[Special:Contributions/141.101.104.239|141.101.104.239]] 13:24, 7 December 2017 (UTC)
: Some stops will provide free electricity so an electric car could keep going that way. Its owner will notice it's missing but they could be sick in hospital or even dead - they may even die in the car from a medical issue if that then counts as an empty car. Why the car's journey never ends is a different question. Maybe it drives the deceased owner to work and back every day. Maybe it's searching for a parking space and charging point but cannot reach the former from the latter before it has to go back and charge again. Robert Carnegie rja.carnegie@excite.com [[Special:Contributions/141.101.105.6|141.101.105.6]] 16:09, 7 December 2017 (UTC)
::My first thought was of a woman who had died in her house, but wasn't found for many years because her bills were all auto-paid.[[Special:Contributions/162.158.122.12|162.158.122.12]] 14:49, 8 December 2017 (UTC)

Added a bit more to the explanation and formatted everything into a table so it's more organized. --[[User:JayRulesXKCD|'''JayRules''XKCD''' ]][[User talk:JayRulesXKCD|what's up?]] 13:26, 7 December 2017 (UTC)

Are there any researchers working on cars that can find a parking space? (Instead of just park in one that the human driver finds?) [[Special:Contributions/162.158.111.145|162.158.111.145]] 14:53, 7 December 2017 (UTC)
: There is a parking space app and parking payment apps. I don't know if smart cars are allowed to use these without human supervision. Robert Carnegie rja.carnegie@excite.com [[Special:Contributions/141.101.105.6|141.101.105.6]] 16:11, 7 December 2017 (UTC)
:Tesla already has software to allow a Model S or X to park itself after dropping off human occupants at their destination. It's not yet released to owners but Tesla is testing it. ----

The first three milestones all come under the heading of recently achieved. 1.Volvo has an auto breaking system on imminent collision detection 2.lane keeping/warning systems are now relatively common. 3.Several models have automatic parking assist.[[Special:Contributions/162.158.165.16|162.158.165.16]] 04:28, 8 December 2017 (UTC)

Perhaps commenters here are to young to remember Evel Knievel https://en.m.wikipedia.org/wiki/Evel_Knievel but I feel very confident Randall was thinking of Evel and his Snake River Canyon jump when he wrote the "Autonomous Canyon Jumping" milestone----

The table seems to miss the fact that the comic starts with things which have all been implemented in vehicles and have become commonplace. Automatic emergency braking is available on new cars and appears to be a fairly simple collision-avoidance system. Highway lane-keeping is also definitely "solved" in the current batch of self-driving cars and is a selling point for some mainstream cars and trucks too (and the difficulties with faded lines or whatever is fairly irrelevant to the comic as a whole). Self-parking is also available in a lot of standard cars these days. "Full highway autonomy" is more or less solved now, though of course there are legal issues with it. Without doing any research I think we can all agree that "First sex..." has definitely been done by now. The first milestone that is in our future, now, is the "no input" line.[[Special:Contributions/141.101.69.33|141.101.69.33]] 19:04, 9 December 2017 (UTC)