# ­xkcd thread **URL:** \ **Category:** Cafe Society\ **Tags:** comic-strips\ **Created:** [May 28, 2020, 12:57am UTC](https://boards.straightdope.com/t/xkcd-thread/854574 "2020-05-28T00:57:03Z")\ **Posts on this page:** 20\ **Page:** 34
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [April 15, 2021, 11:19pm UTC](https://boards.straightdope.com/t/xkcd-thread/854574/662 "2021-04-15T23:19:21Z")
I’m surprised we’re not seeing any single-dose vaccines, there. There are some who only have one dose marked on the graph before they’re done, but those doses are all marked “2”, and are preceded by dotted lines, not the solid gray line used for undosed individuals. And I’m not sure what’s supposed to be computationally difficult about this problem, with or without vaccines. It might get difficult if social events are so frequent that they often overlap, but these events appear to all be at least days apart. ---
**Author:** ![BigT](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bigt/32/12044_2.png) [@BigT](https://boards.straightdope.com/u/BigT)\ **Post date:** [April 16, 2021, 12:07am UTC](https://boards.straightdope.com/t/xkcd-thread/854574/663 "2021-04-16T00:07:49Z")
> [@Chronos](#): > > And I’m not sure what’s supposed to be computationally difficult about this problem, with or without vaccines. It might get difficult if social events are so frequent that they often overlap, but these events appear to all be at least days apart. I don’t think any of the dates were originally there. The problem included figuring what events you could do with whom at what time. There could easily be other events that were omitted. I also think the NP-hard joke is just another self-deprecating joke about how bad Randal is in social situations. Also, deciding it would be okay to watch the movie with person 3 is interesting. I presume they are counting on shot 1 immunity because this movie is something they’ve really been looking forward to, knowing the two other participants would be fully vaccinated. They’re taking a calculated risk. That’s also what makes me think this might be an actual schedule for Randall’s real life. It would also explain why no single-shot users were included. ---
**Author:** ![dtilque](https://avatars.discourse-cdn.com/v4/letter/d/d6d6ee/32.png) [@dtilque](https://boards.straightdope.com/u/dtilque)\ **Post date:** [April 17, 2021, 4:54am UTC](https://boards.straightdope.com/t/xkcd-thread/854574/664 "2021-04-17T04:54:55Z")
> **[AI Methodology](https://xkcd.com/2451/)** > > We've learned that weird spacing and diacritics in the methodology description are apparently the key to good research; luckily, we've developed an AI tool to help us figure out where to add them. ---
**Author:** ![SCAdian](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/scadian/32/3292_2.png) [@SCAdian](https://boards.straightdope.com/u/SCAdian)\ **Post date:** [April 17, 2021, 5:04am UTC](https://boards.straightdope.com/t/xkcd-thread/854574/665 "2021-04-17T05:04:24Z")
> [@BigT](#): > > I also think the NP-hard joke is just another self-deprecating joke about how bad Randal is in social situations. What’s “NP-hard”? ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [April 17, 2021, 5:41am UTC](https://boards.straightdope.com/t/xkcd-thread/854574/666 "2021-04-17T05:41:11Z")
It’s a computer science term. There’s a certain class of problems where it is easy to check your answer, but hard to come up with a correct answer. For example, if I give you a set of objects of different weights, is there some subset that adds up to 100 lbs? Once you come up with a solution, it’s easy to verify. But there’s no known way to solve it other than trying all possible combinations. That and other problems are called NP-hard. Informally, computer science types tend to use “NP-hard” as a kind of joke label for any difficult problem (like dealing with social anxiety). Also, it’s not possible for something to be “NP-hard enough”; it’s a binary classification. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [April 17, 2021, 12:10pm UTC](https://boards.straightdope.com/t/xkcd-thread/854574/667 "2021-04-17T12:10:35Z")
Two fully-vaccinated people meeting with one partially-vaccinated person is probably safe enough… if it was just those three. Was the movie they were watching at home, or was it at a theater? If a theater, then yes, that one partially-vaccinated person was a non-negligible risk. Once all people involved are vaccinated, though (as is the case in all but that one interaction), the risk should be very small in all cases. That doesn’t make for hard problems. ---
**Author:** ![SCAdian](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/scadian/32/3292_2.png) [@SCAdian](https://boards.straightdope.com/u/SCAdian)\ **Post date:** [April 17, 2021, 3:11pm UTC](https://boards.straightdope.com/t/xkcd-thread/854574/668 "2021-04-17T15:11:18Z")
Thanks. ---
**Author:** ![puzzlegal](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/puzzlegal/32/3827_2.png) [@puzzlegal](https://boards.straightdope.com/u/puzzlegal)\ **Post date:** [April 19, 2021, 12:11pm UTC](https://boards.straightdope.com/t/xkcd-thread/854574/669 "2021-04-19T12:11:37Z")
I was looking at some data that suggested that most of the people who took the J&J shot were younger adults. People whose lives are busy, and for whom “one shot, less protection” seems like a good trade-off. Randall is a little older, and my guess is that he and most of his friends got the 2-shot vaccines. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [April 19, 2021, 8:51pm UTC](https://boards.straightdope.com/t/xkcd-thread/854574/670 "2021-04-19T20:51:33Z")
I think there’s a simpler explanation for an age bias in which shot people got. When older folks became eligible, the mRNA vaccines were the only ones available. Now, when young people are eligible, J&J is available, and due to its much easier logistics (easier to make, store, and transport), most vaccines are J&J. Old people can also get J&J now, of course, but many of those who would be interested already got Moderna or Pfizer, so they don’t need it. ---
**Author:** ![puzzlegal](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/puzzlegal/32/3827_2.png) [@puzzlegal](https://boards.straightdope.com/u/puzzlegal)\ **Post date:** [April 19, 2021, 9:45pm UTC](https://boards.straightdope.com/t/xkcd-thread/854574/671 "2021-04-19T21:45:25Z")
Last week, most of the vaccine that entered my state was mRNA, despite us getting a big batch of J&J. I would guess other states are similar. ---
**Author:** ![dtilque](https://avatars.discourse-cdn.com/v4/letter/d/d6d6ee/32.png) [@dtilque](https://boards.straightdope.com/u/dtilque)\ **Post date:** [April 20, 2021, 2:05am UTC](https://boards.straightdope.com/t/xkcd-thread/854574/672 "2021-04-20T02:05:03Z")
> **[Aviation Firsts](https://xkcd.com/2452/)** > > Mile High Club membership \[✓\] \[\] Discovery of parts of Amelia Earhart's skeleton \[\] \[\] Mid-flight incident that results in safe landing on the Hudson River \[✓\] \[\] Flight incidents due to mix up of SI/non-SI units [✓] [✓] ---
**Author:** ![Civil\_Guy](https://avatars.discourse-cdn.com/v4/letter/c/d78d45/32.png) [@Civil\_Guy](https://boards.straightdope.com/u/Civil_Guy)\ **Post date:** [April 20, 2021, 3:07am UTC](https://boards.straightdope.com/t/xkcd-thread/854574/673 "2021-04-20T03:07:13Z")
This could be a fun game! Passenger delivered half-way around the globe by mistake Through experimentation: ‘open-bracket’ ‘x’ ‘close-bracket’ gives the checked box ‘open-bracket’  [semicolon] ‘close-bracket’ gives the unchecked box ---
**Author:** ![smithsb](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/smithsb/32/12107_2.png) [@smithsb](https://boards.straightdope.com/u/smithsb)\ **Post date:** [April 20, 2021, 3:45am UTC](https://boards.straightdope.com/t/xkcd-thread/854574/674 "2021-04-20T03:45:43Z")
Smoke alarm in lavatory disabled Passenger(s) dragged kicking and screaming from aircraft ---
**Author:** ![dtilque](https://avatars.discourse-cdn.com/v4/letter/d/d6d6ee/32.png) [@dtilque](https://boards.straightdope.com/u/dtilque)\ **Post date:** [April 20, 2021, 4:01am UTC](https://boards.straightdope.com/t/xkcd-thread/854574/675 "2021-04-20T04:01:37Z")
Even more enormous non-wooden, double fusilage aircraft built by non-reclusive billionaire that’s flown exactly once ---
**Author:** ![Ponderoid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ponderoid/32/19221_2.png) [@Ponderoid](https://boards.straightdope.com/u/Ponderoid)\ **Post date:** [April 20, 2021, 4:35am UTC](https://boards.straightdope.com/t/xkcd-thread/854574/676 "2021-04-20T04:35:33Z")
Airbag-cushioned landing after atmospheric entry: Rocket-assisted sky-crane landing: ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [April 20, 2021, 4:40am UTC](https://boards.straightdope.com/t/xkcd-thread/854574/677 "2021-04-20T04:40:59Z")
Foam-cushioned landing absent atmospheric entry: Rocket-assisted wingborne flight: Ramjet powered rotor-borne flight: Speaking Jive onboard: Asking Jimmy about Turkish prisons: ---
**Author:** ![GreenWyvern](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/greenwyvern/32/2834_2.png) [@GreenWyvern](https://boards.straightdope.com/u/GreenWyvern)\ **Post date:** [April 20, 2021, 5:18am UTC](https://boards.straightdope.com/t/xkcd-thread/854574/678 "2021-04-20T05:18:33Z")
> [@Civil\_Guy](#): > > Through experimentation: > ‘open-bracket’ ‘x’ ‘close-bracket’ gives the checked box > ‘open-bracket’  [semicolon] ‘close-bracket’ gives the unchecked box You don’t need the non-breaking space. ``` [x] [] ``` ---
**Author:** ![dtilque](https://avatars.discourse-cdn.com/v4/letter/d/d6d6ee/32.png) [@dtilque](https://boards.straightdope.com/u/dtilque)\ **Post date:** [April 22, 2021, 9:51pm UTC](https://boards.straightdope.com/t/xkcd-thread/854574/679 "2021-04-22T21:51:49Z")
> **[Excel Lambda](https://xkcd.com/2453/)** > > Extremely rude how Turing's later formulations of the halting problem called me out by name specifically. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [April 22, 2021, 10:01pm UTC](https://boards.straightdope.com/t/xkcd-thread/854574/680 "2021-04-22T22:01:52Z")
I laughed. Although I bet this one will leave many of his readers scratching their heads. ---
**Author:** ![jsc1953](https://avatars.discourse-cdn.com/v4/letter/j/5daacb/32.png) [@jsc1953](https://boards.straightdope.com/u/jsc1953)\ **Post date:** [April 22, 2021, 10:53pm UTC](https://boards.straightdope.com/t/xkcd-thread/854574/681 "2021-04-22T22:53:54Z")
I have no idea what he’s talking about, and i do IT for a living. [Previous page](https://boards.straightdope.com/t/xkcd-thread/854574.md?page=33) [Next page](https://boards.straightdope.com/t/xkcd-thread/854574.md?page=35)