[HN Gopher] Bridge spiders build webs that double as acoustic ar...
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Bridge spiders build webs that double as acoustic arrays
Author : pseudolus
Score : 83 points
Date : 2021-11-01 10:53 UTC (1 days ago)
(HTM) web link (www.the-scientist.com)
(TXT) w3m dump (www.the-scientist.com)
| sandbx wrote:
| the web allows the spider to be small, like the hot servers and
| powerplants allow your phone to be a cool glass object
| SeanFerree wrote:
| Amazing!
| scubakid wrote:
| Maybe I missed it, but from the spider's perspective do we / can
| we know if sensing the web vibrations actually feels the same as
| hearing shorter-range sounds they could pick up naturally? Or is
| it possible they're just reacting to the web vibrations as more
| of a touch stimulus?
| BurningFrog wrote:
| Since the web is much bigger than whatever serves as spider
| ears, it should pick up much lower frequencies, if my physics
| intuition is working this morning.
| samplenoise wrote:
| Tom Waits had a nice thing about a spider strumming its web in
| one of his live shows
|
| https://www.youtube.com/watch?v=VOC6pOaIUSE
| bestouff wrote:
| Not really the same but I've been doing paragliding since a long
| time, and my wing is definitely a giant sensor for 'air movements
| shape'. Kind of a part of me when in the sky.
| amelius wrote:
| How can that work without a giant Eustachian tube?
| CapmCrackaWaka wrote:
| Reminds me of the sci-fi book Children of Time. It follows the
| cultural evolution of a species of intelligent spiders. When
| they're angry, they vibrate and shake the web a certain way. In
| larger meetings, the spiders all share a single web, and private
| "whispers" are subtle plucking of private strands between two
| members.
| KineticLensman wrote:
| If one enjoys reading SF that involves intelligent spiders,
| then A Deepness in the Sky [0] is worth a look. Although the
| arachnoids in 'Deepness' are spider-like aliens, rather than
| evolved Earth-spiders, as in Children of Time. The latter also
| has evolved ants, as well. Both books are highly recommended.
|
| [0] https://en.wikipedia.org/wiki/A_Deepness_in_the_Sky
| Kiboneu wrote:
| Crawling insects (let's call them 2D navigation specialists) on
| land are prey to flying insects (3D navigation specialists). But
| these 3D specialist predators require more energy to navigate and
| maintain flying ability.
|
| Spiders invert this relationship -- they are 2D specialists that
| slice a 3D space with a trap, capturing 3D specialists without
| expending energy to navigate their prey's space.
|
| Not quite a free lunch -- it takes some prep work in the lifetime
| of a spider to survive. Losing your web makes you suspect to
| getting wrecked by robber flies until you build a new one.
|
| On a more science fiction note, I've wondered about generalizing
| this 2D/3D existence relationship into humans interacting with a
| hyper-dimensional entity. Will we also have to evolve to build
| traps against the perception weaknesses of our 4-dimensional
| invaders?
|
| Anyway, I've thought about the level of fidelity of information a
| spider could get from vibrations on a web. It's probably a
| function of nervous system ability and sensitivity for the spider
| to discern frequencies of forces impacted unto it by the web, as
| well as the frequencies filtered by the web itself. Looking
| forward to reading the paper.
| recuter wrote:
| _We_ are the 4-dimensional invaders of this planet. :)
| fleddr wrote:
| "Spiders invert this relationship -- they are 2D specialists
| that slice a 3D space with a trap, capturing 3D specialists
| without expending energy to navigate their prey's space."
|
| I think that's a great way to put it, although "spiders" really
| should say "orb weaving spiders".
|
| Jumping spiders don't build a web, they are active hunters in
| the 3D space with the ability to plan several steps ahead.
| Although they can't fly, they definitely hunt in 3D and don't
| really conserve energy.
|
| Huntsman spiders are also active hunters, but mostly in 2D and
| waiting from an ambush position. They don't build a web.
| Neither do crab spiders, but I'd agree that these two families
| of spiders are trap-based and largely passive, even if the trap
| is not a web.
|
| Labyrinth spiders (funnel web spiders) are a fun anomaly due to
| the complexity of their trap, which is 3D, but arguably it's a
| still a passive way to hunt.
|
| My favorite would be the net-casting spider, which builds a
| tiny web that it holds, and then casts on its prey. The timing
| and coordination of that is mind blowing:
| https://www.youtube.com/watch?v=QyRPrax9MJU&t=19s
| Gravityloss wrote:
| What a cool thought!
|
| What if it takes so much energy to move in the fourth dimension
| that the entities have to be vulnerable? They might be even
| easy to catch, or destroy by accident.
| dTal wrote:
| Not all spiders are 2d specialists who hunt with webs. Jumping
| spiders display extraordinary spatial reasoning in conjunction
| with excellent vision, which they use to stalk prey. Jumping
| spiders have been known to sit motionless for up to half an
| hour, scanning the landscape to plan the best route to
| something they can see (the FOV of their hi-res front-facing
| eyes is quite narrow, so this scanning is necessary to gather
| the required information).
| egfx wrote:
| https://arstechnica.com/science/2021/10/spiders-are-much-
| sma...
| linguistbreaker wrote:
| let's amplify that signal and use it for music?
| mhb wrote:
| Is the spider's reaction to "hearing" a sound different than its
| reaction when an insect lands on the web? You'd expect it to
| react when the web vibrates.
| TeMPOraL wrote:
| > _You 'd expect it to react when the web vibrates._
|
| I imagine if I were to set up a parabolic reflector, my
| reaction to sounds I hear would be different from my reaction
| of something hitting the reflector itself.
| mhb wrote:
| Is your reaction to crouch, flatten out, or otherwise give a
| startled response?
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