[HN Gopher] Want to Get Out Alive? Follow the Ants
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       Want to Get Out Alive? Follow the Ants
        
       Author : dnetesn
       Score  : 74 points
       Date   : 2021-02-03 11:54 UTC (1 days ago)
        
 (HTM) web link (nautil.us)
 (TXT) w3m dump (nautil.us)
        
       | DennisP wrote:
       | > In a room with six exits, it seems like the most logical course
       | of action would be for the crowd to divide evenly among all six.
       | Instead, we stampede to just one.
       | 
       | Something to watch out for if ever in that situation.
        
         | hombre_fatal wrote:
         | This gave me the mental image of an HNer patting himself on the
         | back for not following the crowd after finding himself burning
         | alive in the nightclub's broom closet as it burns down.
        
           | blablablerg wrote:
           | Yeah exactly this. If you know all the exits are safe, then
           | evenly splitting up is best. But I reckon in situations like
           | this, most of the time you don't know and then following the
           | rest seems like the best strategy to me.
        
             | DennisP wrote:
             | It seems like the best strategy because you figure other
             | people know something you don't know. But since they
             | _always_ pick just one exit, that 's not a valid
             | conclusion.
             | 
             | Since the crowd behaves the same way whether they picked
             | the best exit or a random one, you have no idea whether
             | it's the best way out, but you do know it has added risk of
             | delay and trampling.
        
               | thaumasiotes wrote:
               | The broom closet scenario isn't really possible; if the
               | door isn't an exit, it won't have the big EXIT sign over
               | it.
        
             | macintux wrote:
             | I attended some emergency training a couple of years ago,
             | and the instructor drove home one point in particular:
             | _always_ identify the exits when you're in an unfamiliar
             | building.
        
         | Jtsummers wrote:
         | In high school I got caught in the crowd once following a
         | release from some kind of pep rally, I was effectively crushed
         | against a wall while it passed. The gymnasium had plenty of
         | exits, but the field-side wasn't where anyone wanted to go.
         | Classes and the cafeteria were through three double-door exits
         | on the non-field-side. After that one mistake, I started going
         | toward the field and then walked around the exterior. I've kept
         | that pattern up whenever I'm in any crowded place with a lot of
         | people being released at once. I look specifically for the
         | reasonable exits that are away from most people's interest,
         | even if it takes me a bit longer (often it's faster because
         | there is no crowd jamming up the exit).
        
           | Skunkleton wrote:
           | Movie theaters (remember those?) usually have a door or two
           | up by the screen that no one uses. Most of the time I have
           | seen them lead out some weird hallway that goes directly
           | outside. They usually aren't emergency exits either. All
           | around pretty great.
        
             | Jtsummers wrote:
             | And many, in the US, don't alarm their emergency exits.
             | I've used those to good effect when I've opted to see a
             | particularly popular new release. You can usually park
             | behind/beside the theater, not just in the main lot, so
             | these exits are actually faster for accessing your car and
             | then you can use access roads behind the theater to exit
             | the parking lot as well.
        
             | macintux wrote:
             | Often they go directly outside. I once was seated near such
             | an exit when someone who had apparently left (and left
             | something behind) started hammering on the exit door.
             | 
             | This was years before the Aurora shooting, and after
             | looking around at everyone else who didn't want to make the
             | decision either, I let him in instead of letting him
             | continue to distract from the movie.
             | 
             | Bad decision, one I'd definitely not repeat.
        
               | sethammons wrote:
               | How many Aurora shootings have there been? How many
               | people have used those doors as entrances? I very much
               | suspect the odds suggest it was not a bad decision.
        
               | bluntfang wrote:
               | and this thought process is why we take off our shoes at
               | airports
        
               | corobo wrote:
               | > I once was seated near such an exit when someone who
               | had apparently left (and left something behind) started
               | hammering on the exit door.
               | 
               | Pretty sure you let in a freeloader, haha
        
               | macintux wrote:
               | Nah, he grabbed something in a seat and left.
        
             | KineticLensman wrote:
             | Ditto old theatre buildings in London's theatreland. These
             | alt routes help deconflict the people exiting the current
             | show from those coming in to see the next one.
        
       | virtualmachine7 wrote:
       | Ant death spiral: https://www.youtube.com/watch?v=N0HoqjxfvJ4
        
         | Lammy wrote:
         | https://en.wikipedia.org/wiki/Ant_mill
        
           | handol wrote:
           | I was really hoping that would be about using this ant
           | swirling phenomenon to drive machinery.
        
       | advisedwang wrote:
       | The mechanisms for ants and humans clumping behaviours are, I
       | expect, quite different. My understanding is that we are looking
       | and listening while ants are smelling and feeling. This means
       | that the actual architectural insights you get from ants - put a
       | column here and a door there - might not generalize to humans.
        
         | Jtsummers wrote:
         | In very crowded situations you end up with something closer to
         | the ant-like behavior. Your visibility is reduced to your
         | immediate neighbors, and theirs is similarly limited. This
         | prevents the deliberate movement you'd see in lower crowd
         | situations, or where people are very familiar with their
         | surroundings.
         | 
         | That is, a stadium exit is _not_ like the exit of a thousand
         | workers from a factory at the end of the shift. The factory
         | workers (ok, not always) know their path and may have an action
         | to perform on exit (punching out) which establishes a tempo. A
         | stadium exit is more freeform and people are less familiar with
         | their overall exit plan. So they jump into the stream and go
         | where it goes. They have to move as fast as the crowd behind
         | them pushes them or faster.
        
           | wpasc wrote:
           | Stadiums have signs though? Clearly lit pathways, signs, and
           | directions to all the exits. I'm pretty sure it's the law to
           | have those (at least for fire codes). I would be highly
           | surprised if people followed their nearest neighbor instead
           | of moving in a direction denoted by the signs and pathways
           | prescribed.
        
             | Jtsummers wrote:
             | Yes, but when you're in a _packed_ crowd even these may
             | become difficult to see for any individual. Think no real
             | room to move freely, maybe not even 1 ' in any direction
             | other than "forward", the direction in which the crowd is
             | _clearing_.
        
             | setr wrote:
             | I visited Venkateswara Temple in India, which gets some
             | 50~100k visitors daily. The main takeaway I got was that it
             | doesn't really matter what the path is -- you don't get a
             | say in the matter. The flow of the crowd moves you along,
             | and that's all there is to it.
             | 
             | You have people pushing from all around you (in a vague
             | general direction), and next to no space to actually
             | influence your movement -- and the lack of choice in the
             | matter is fairly incredible. The pushing stops coming from
             | any particular place, it just becomes some indeterminate
             | feeling of _pressure_ forcing you along.
             | 
             | I'm quite positive you could easily be crushed by it,
             | getting caught between a pole somewhere in the path, and
             | with no external factor to influence the crowd (a wall is
             | clearly visible, a pole is not), simply be pressed against
             | it indefinitely.
             | 
             | A stadium probably isn't an intense, but likely similar --
             | once you're in the stream, the only thing that matters is
             | stream.
             | 
             | Eventually, you're suddenly ejected from the stream and
             | have to figure things out for yourself again.
        
               | thaumasiotes wrote:
               | > the lack of choice in the matter is fairly incredible.
               | The pushing stops coming from any particular place, it
               | just becomes some indeterminate feeling of pressure
               | forcing you along.
               | 
               | You can experience this in total safety any day you want
               | by riding a subway during rush hour in a populous city.
        
       | thaumasiotes wrote:
       | The conclusion here seems off:
       | 
       | > Ants have been learning how to deal with congestion for
       | millions of years. They might just show us the way out.
       | 
       | But the research here doesn't involve studying ants to learn
       | their successful evacuation strategies. It involves noticing that
       | ants don't seem to have any special strategies, studying which
       | room layouts seem to make things easier for their strategyless
       | approach, and then using those same layouts for human rooms,
       | since humans, just like ants, have no particular evacuation
       | strategies.
        
         | LinuxBender wrote:
         | I think this is right. In my boredom, I have studied ants and
         | my observation was that they seem to send a small number of
         | ants in multiple directions, carving a room up into sections.
         | If an ant finds something of value, they change their pheromone
         | to something that attracts the other ants. With time, they all
         | eventually lock onto that pheromone trail, especially if it
         | involves food. On a side note, they especially like vodka and I
         | suspect they are disallowed from drinking it, as the bigger
         | ants come along and chop off their heads. I was taken aback and
         | never gave them alcohol again. Anyway, it seems this behavior
         | is how they manage to find food and then transport it back to
         | their nest. If you get this pheromone on your hands, the ants
         | will swarm you and run around in different directions very
         | chaotically. It seems to be a chemical based form of group
         | think. Perhaps their intelligence should be measured as a
         | group.
        
           | MPSimmons wrote:
           | You might be interested in this conference talk from a few
           | years ago:
           | 
           | https://www.usenix.org/conference/lisa16/conference-
           | program/...
        
       | bondarchuk wrote:
       | Does anyone know what's up with this account? They submit
       | nautil.us and phys.org articles in rigid alternation and they
       | seem to hit the frontpage with unlikely regularity, especially
       | for a religious organization like nautil.us.
        
         | hombre_fatal wrote:
         | The submitter isn't the one who upvotes it to the front page,
         | so what does it matter who submits what from where?
        
         | LilBytes wrote:
         | It's a religious site?
        
         | sli wrote:
         | I think you may have mixed up Nautilus Quarterly (this site)
         | with The Nautilus, a long defunct New Thought Movement
         | magazine.
        
           | bondarchuk wrote:
           | No I don't think so:
           | 
           | https://www.templeton.org/grant/nautilus-magazine
        
             | [deleted]
        
             | tzs wrote:
             | That they give grants to something doesn't mean that thing
             | is religious. For example, they give grants to PBS [1] [2]
             | for Nova and I doubt many would argue that Nova is a
             | religious program or PBS is a religious broadcaster.
             | 
             | [1] https://www.templeton.org/grant/nova-programming-on-
             | quantum-...
             | 
             | [2] https://www.templeton.org/grant/nova-programming-on-
             | the-cosm...
        
               | kevin_thibedeau wrote:
               | PBS broadcasts a lot of infomercials promoting quackery.
        
             | jrockway wrote:
             | Looking at Nautilus's about page, they seem to have many
             | other funding sources (including readers).
             | 
             | Wikipedia doesn't seem to think they are particularly
             | religious: https://en.wikipedia.org/wiki/Nautilus_Quarterly
        
         | ivanbakel wrote:
         | What makes nautil.us a religious organisation?
         | 
         | And their submission history looks to me to be full of whiffs,
         | rather than getting the frontpage with "unlikely regularity".
         | The user could be a bot, but both of those sources are well in
         | the curiosity-gratifying wheelhouse of the average HN reader.
        
         | [deleted]
        
         | Cthulhu_ wrote:
         | Probably a bot or marketing person on a schedule. The article
         | is from a few days ago too.
        
       | omginternets wrote:
       | I wonder, is this somehow a latency-throughput tradeoff in
       | disguise?
       | 
       | This seems roughly analogous to batch processing, where you
       | structure the dataflow to be mechanically sympathetic to the
       | machine doing the processing. Processing each item becomes more
       | efficient, so you process more items per unit of time, but each
       | item takes longer to process individually.
       | 
       | In the same way, it seems like we're structuring the crowd into
       | columns to optimize the layout of individuals with respect to the
       | floorspace. It takes less time to evacuate everybody, but each
       | person spends more time in the building.
       | 
       | I'm not sure what to do with this knowledge, if it is indeed
       | correct.
       | 
       | EDIT: I think the question I'm orbiting is whether or not this
       | strategy can generalize to people. In the realm of ants, things
       | like self-preservation and the value of the individual are very
       | different from humans.
        
         | thaumasiotes wrote:
         | It is definitely not a latency-throughput tradeoff in disguise,
         | since the metric is "time taken for everyone to leave the
         | enclosure".
         | 
         | > it seems like we're structuring the crowd into columns to
         | optimize the layout of individuals with respect to the
         | floorspace. It takes less time to evacuate everybody, but each
         | person spends more time in the building.
         | 
         | As stated, this is impossible. Everyone starts inside.[1] If
         | the time taken to empty the building is lower, it cannot be the
         | case that each person spends more time inside; at least one
         | person takes the full evacuation time, or else the evacuation
         | time would be lower.
         | 
         | [1] This is the core difference from the analogy you picked,
         | batch processing, in which jobs arrive at different times. If
         | all the jobs arrived at once, batch processing would be the
         | only possible kind of processing.
        
           | omginternets wrote:
           | >This is the core difference
           | 
           | Got it! Thanks for taking the time to point out my error.
        
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