1796: Focus Knob

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Focus Knob
Maybe if I spin it back and forth really fast I can do some kind of pulse-width modulation.
Title text: Maybe if I spin it back and forth really fast I can do some kind of pulse-width modulation.


The comic is a pun. Normally, a rotary control knob is used for adjusting parameters in instruments, and the parameter "focus" is used to adjust the focal length on microscopes, telescopes, and other lens-based equipment. Here, however, the "focus knob" is used for Randall's personal sense of focus -- that is, how focused he is on his work and productivity, with the extremes of focus being towards Detail-Oriented (small details) and the Big Picture respectively. (A similar knob was used in 1620: Christmas Settings).

The healthy balance, Randall suggests, is focusing mostly towards the Big Picture (two thirds of the way towards the Big Picture between ticks 24 and 25 out of 37), while keeping an eye on the details by still staying one third Detail-Oriented. Focusing too much on the big picture can ensure nothing gets done, leading to panic and existential paralysis. Unfortunately, the range of healthy balance appears to be vanishingly small and difficult to reach; additionally, if we assume the knob can only stop at the little ticks marked along the outside and that the boundaries are not inclusive, there is no way to set it in the window of Healthy Focus.

While performing any task (including your daily life as well as editing explainxkcd), it is easy to get so lost in the details that you forget the big picture. It is also equally easy to think too much about the big picture and make vague plans while missing out on the details.

It is clear that at the moment Randall is mainly focusing on the small details fiddling with his e-mail settings as the knob is set to the 13th tick only just past one third away from Detail-Oriented. He thus seems to try to avoid seeing the big picture right now, since it is his personal knob to set as he wishes.

The joke in the title text relates to Randall's use of an old fashioned analog control, probably a potentiometer, in the graphic versus a more electronically modern and efficient switching system. Randall imagines a replacement control using pulse-width modulation (PWM), which is a technique often used to control the regulation in electronic power supplies or the speed of electric motors with far greater power efficiency than simpler analog controllers. This technique consists of shifting between fully on and fully off states so that the average is the expected output, but no power is wasted by holding the control mechanism "partially on". For example switching back and forth between 0 and 1, spending half the time in each position will lead to a mean value of 0.5. To code 0.67 (the healthy balance), Randall would have to spend more time in the extreme big picture position (67% of the time) than in the detail-oriented position. In the real world of course, a person switching so radically and completely between attention states might get diagnosed with some sort of mania. But the knob might just be switched between the dividers bordering the healthy zone, creating the perfect balance.


[Caption above the drawing:]
Personal Focus
[A gray rotary control knob with the range of options divided by small ticks on a black semi. The knob has a black line that indicates that the knob's setting. At the bottom left and right where the semi circle begins and ends there are two labels in normal black text:]
Left: Detail-Oriented
Right: Big Picture
[Above and all along the black semi circle with the range, another semi circle is drawn in light gray. This has been divided into three sections, with two large sections left and right forming the actual semi circle with double arrow lines. There is a short section with no tick inside it between the two other sections. There are three labels for each of these section, with a line from the label down to the small section. All described here are drawn light gray color. Note that Randall has misspelled "existential".]
Left section: Fiddling with email settings
Right section: Panic and existental paralysis
Small section: Healthy balance
  • Click to expand for a more detailed image description without any more text:

[A gray rotary control knob with the range of options divided by 37 small ticks on a black semi circle that extends over 270 degrees from 45 degrees past "6 o'clock" and around to 45 degrees before that "time" on the other side. The first and last tick are a bit larger than the other 35. The knob has a black line that indicates that the knob's setting is on the 13th line from left. This also seem to indicate that the knob can only point to the ticks and not in between them. At the bottom left and right where the semi circle begins and ends there are two labels in normal black text.]
[Above and all along the black semi circle with the range, another semi circle is drawn in light gray. This has been divided into three sections, with two large sections left and right forming the actual semi circle which here consist of two double ended arrows pointing to four stopping lines orthogonal to the gray arrows pointing at them. The left and right stopping lines are above the larger left and right end ticks below. The other two stops are very near each other, the left just slightly past the 24th tick (from left) and the next is just short of the next 25th tick (but not as near as the other line was to the 24th tick). There is no line or arrow between these two very close stopping lines. There are three labels. The labels for the first section (spanning slightly more than 24 ticks) and the second section (spanning a bit more 13 ticks) have their labels written next to the arrows, which has been broken in order to have the text written next to the black semi circle. The remaining small space lies between the 24th and 25th tick, and it thus have no possible settings within it - i.e. no tick is inside this section, and it is the only part not encompassed by the two double arrows. It is labeled to the right of it, and a line goes from the label down to indicate this small section. All the above including the text is drawn in the same light gray color.]


  • Randall has misspelled existential as existental with only one "i"! This was later fixed.

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Too much existential paralysis can often lead to fiddling with email. Less frequently, too much time spent fiddling with email can lead to those existential crises. The knob can turn all the way around - there aren't stoppers on either side of the rotation... -- 14:20, 8 February 2017 (UTC)kb

Well since the two ticks at the end points are larger than the other 35 I would say that it cannot go past these. That would make sense and is also like on several knobs I have seen. This is also like the speedometer in my car, which does not shown anything below 0 or above 240 km/h... --Kynde (talk) 22:05, 8 February 2017 (UTC)

Maybe Randall is implying that he has issues with keeping the big picture in mind while doing detail work and gets lost in the details of implementation and vice versa. This means that for him the knob is more of an on/off or selection switch. Pulse Width Modulation would then allow him to use this on/off switch more like the knob in the picture shown. (... or whoevers voice Randall is speaking in as many people probably have issues with this, myself included.) I wonder if he obsessed over how to implement this comic: 1. As an on/off switch? 2. As a knob with limited none-usefull settings with "ideal" labeled between the actual settings available? 3. Like this, for simplicity, keeping the big picture in mind and not obsessing over the details of how it may under some circumstances be viewed? -- 10:19, 8 February 2017 (UTC)cdm

Since the knob clearly is set at the 13th tick he does not use it as an on/off which invalidates most of the arguments in this comment. But since he goes in e-mail mode left of the healthy balance and in panic to the right there is some kind of on/off behavior. But still he can focus more an more on the big picture even though he stays with his settings, until he goes past tick 25. --Kynde (talk) 22:05, 8 February 2017 (UTC)

If the knob only has discrete positions, none of which lies within the balanced region, he could use PWM to simulate that position. Let's say the focus variable goes from 0 to 10, the knob can only stay on integer values and the "sweet spot" is around 7,38. He can make a cycle that rests on 7 62% of the time and at 8 38% of the time, and repeat this cycle with a high enough frequency so that his mind wouldn't know the difference from actually being at the knob's focused on the approximate mirror location of the "healthy balance" section. I don't really have anything to suggest based on that though :/ 12:55, 8 February 2017 (UTC)

IMHO it's just a visual thing to balance the whole image. If you search for watch ads on google images, you'll see that the analogical ones pretty much always show an hour close to 10:10. Beside being balanced, I think those positions are chosen to look "random" (which is paradoxical), or "without a specific meaning", when a 0°, 45° or 90° would seem to have been chosen on purpose. 13:19, 8 February 2017 (UTC)
IMHO Randall has placed it there on purpose a long way from looking at the big picture because he do not wish a panic attack by reading the news on Trump. --Kynde (talk) 22:05, 8 February 2017 (UTC)

I noticed 2 things that are not already mentioned: 1) The dial is currently set to somewhere along the left side, which suggests that Randall is overly detail‐oriented. 2) Randall misspelled existential as existental. 16:55, 8 February 2017 (UTC)

An "existental" crisis is what happens when you are so focused on the big picture you forget details like how to spell "existential." 18:40, 8 February 2017 (UTC)
I have added explanation on where and why the knob is turned to tick 13, and also a trivia about the spell error, and thanks, I had corrected it in the transcript, but now turned it back, as it should be as in the comic. Maybe Randall updates it, as he has done so often when he makes bland mistakes like this, but that has not happened so far when I post here. If he does that should be noted in the trivia along with the reason why. --Kynde (talk) 22:05, 8 February 2017 (UTC)
Randall has indeed updated the comic with the correct spelling of existential - I have no idea how to update the comic graphic properly from this type of correction! --Ianrbibtitlht (talk) 06:03, 7 June 2017 (UTC)

There is no mention of the term "existential crisis" in the comic, and I don't see how any of this is related to "current world events". Existential paralysis means that when you only think about the biggest picture possible, nothing seems to matter anyway - it's just us tiny insignificant humans on this planet that will eventually turn barren wasteland when the sun expands etc. This doesn't help instill motivation to act, hence paralysis. 06:57, 9 February 2017 (UTC)

Could we please go back to simply explain what we see instead of trying to get our political views into the interpretation? I don't see any connection to "current world events", either. The theme of being paralyzed by seeing/realizing the big picture ist nothing new or even closely related any specific (current or past) event. Elektrizikekswerk (talk) 09:10, 9 February 2017 (UTC)
In any case focusing on the activities of Trump is NOT looking at the big picture 16:41, 9 February 2017 (UTC)
"Getting to deep into all this could cause ..." someone to level accusations of trolling. 23:42, 9 February 2017 (UTC)
Well I disagree. My reasoning is based on the the fact that Randall lately has included several comics that could be seen as being caused by a sad/negative state of mind. All these comics (five so far) have come out since Trump got elected, with no similar comics like these coming out in the year before that event! And that he did not wish Trump as president was made clear in I'm With Her, which I expect everyone agrees on! If Randall can only either be focusing on his e-mails (or Stardew Valley, see also Sad for that) or else panic and end up paralyzed because he reads the news and think about what may happen then that is quite a negative view of the world and your own level of sanity. And it is not just about Trump but also about the global warming we know for sure Randall fears (which Trump may increase with his executive orders, but which where already really bad before he entered the political scene) and all the other problems (wars, famine, pollution violence etc.) right now as he referred to indirectly in 2017. So maybe there is no mention of crisis, but I did not insert that link originally. (Actually I rather changed thew word crisis to paralyzed in the explanation). But it is not true that a existential paralysis would only come about because you see your self as a dot on a small insignificant planet. But that could also cause it though. Randall has been quite explicit in the comic by not mentioning Trumps name even once in any of his comics. That is not the same care he has taken with other politicians earlier in other elections. So in it self that could also be seen as a statement. And all these comics could be interpreted differently than this, which is goo. And had they appeared separately over a few years, rather than three months, I would have agreed with you. But there are already now as many comics with such a sad interpretation possible (or inevitable) during the last three months as there are sad Cancer comics over the two years where he posted 12 of these around the time his wife got cancer. Yes only five of those 12 could seriously be interpreted as being sad on Randall's behalf. (The other 7 only if you generally thought it was sad to joke about cancer, or a joke was sad because cancer was mentioned, even if it was the cure). So for sure something different has happened to the type of comics coming out on xkcd since Trumps election, and that is an important fact to behold on a site like this, just like we keep track of comics about the climate, and about time travel etc. --Kynde (talk) 15:42, 10 February 2017 (UTC)

A new what if?, Coast-to-Coast Coasting was released on the day this comic was released. There seems to have been no connection between it and the comics released before or after. --Kynde (talk) 14:07, 15 February 2017 (UTC)

Picture update
Help Wanted -
I downloaded the updated png image file from xkcd and visually confirmed it was the corrected image. However, I've tried to upload the new file twice now from two different systems using the File screen shown by clicking on the comic image, and both times the resulting file is still the original! I don't have a clue what I'm doing wrong but suspect it's 'cause I'm dumb!!! I obviously need help. :-( --Ianrbibtitlht (talk) 17:08, 8 June 2017 (UTC)
I don't know if an admin fixed the problem or it resolved itself with enough elapsed time. It's correct now, but I'd like to know if I was doing doing it incorrectly! --Ianrbibtitlht (talk) 20:51, 8 June 2017 (UTC)
Everything was fine and no admin has fixed anything. The problem is the damn cloud cache, you don't see such an update for a while. But after an hour or maybe more the cache is expired and everything is fine. I've also answered here: Ianrbibtitlht talk. --Dgbrt (talk) 12:41, 12 June 2017 (UTC)

"He thus seems to try to avoid seeing the big picture right now, since it is his personal knob to set as he wishes." - Haaa. Whoever wrote this does not have ADHD, as Randall clearly does. We who do, know it is essentially impossible to "set" our focus level as we wish - we are either easily pulled away from "big picture" things (like the flow of time or our own hunger) to hyperfixate on minor details, OR we freak out over the sheer number of tasks that are to be done without being able to concentrate on any of them, and also frequently feel the weight of existential dread that looms over everything we do like a giant dark cloud. --mezimm 16:51, 23 November 2021 (UTC)