[HN Gopher] Thermal Grill Illusion
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       Thermal Grill Illusion
        
       Author : ZeljkoS
       Score  : 58 points
       Date   : 2021-09-25 19:31 UTC (3 hours ago)
        
 (HTM) web link (en.wikipedia.org)
 (TXT) w3m dump (en.wikipedia.org)
        
       | stevep98 wrote:
       | There used to be a demo in Epcot ('The Body'?) which had two
       | coils, one cold and one heated.. they were separate at the ends,
       | so you could feel the difference. In the middle, they were
       | interleaved, and if you put your hand on it, it would feel
       | simultaneously hot and cold. Cool demo.
        
         | schoen wrote:
         | They have this at the Exploratorium, too!
        
       | goldenkey wrote:
       | Someone ought to make a thermoelectric/peltier toy version of
       | this illusion. Would be good for a Curiosity Box or something of
       | the sort.
       | 
       | I've used the Coolworks IceProbe, a peltier cooler with a
       | heatsink and fan, for cooling drinks at my desk and for the
       | custom cat fountain I made for my kitties [2] [3]
       | 
       | Email me (address in profile) if you'd like the plans for my
       | silver-infused (antibiotic) NSF-grade 0.5 micron filtered cat
       | fountain. I spent over three years perfecting it.
       | 
       | [1] https://en.wikipedia.org/wiki/Thermoelectric_cooling
       | 
       | [2] https://pentairaes.com/coolworks-ice-probe-reg.html
       | 
       | [3]
       | https://photos.google.com/share/AF1QipO871ejy0WcW85ACBSq8Ue8...
        
         | gregschlom wrote:
         | https://www.youtube.com/watch?v=otweN9sCSd8
        
       | canjobear wrote:
       | This article needs a rewrite. I can't understand what's going on
       | here:
       | 
       | > But if the person presses against only a cool bar, only
       | coolness is experienced; if the person presses against only a
       | warm bar, only warmth is experienced.
       | 
       | > Researchers have used the illusion to demonstrate that burning
       | pain sensation is in fact a mixture of both cold and heat pain
       | and that it is only the inhibition of the cold pain "channel"
       | that reveals the heat component.
       | 
       | How does the point about inhibition follow from the experiment?
       | Is the cold pain channel somehow inhibited by the grill, but
       | still active when only touching the hot part? idgi
        
         | GordonS wrote:
         | > burning pain sensation is in fact a mixture of both cold and
         | heat pain
         | 
         | Hmm, interesting. I know I'm off at a tangent here, but as an
         | aside, I have small fibre neuropathy and struggle to describe
         | the pain - sometimes I think it's more like a burning
         | sensation, other times I think it's more like a painfully cold
         | sensation.
        
       | kulor wrote:
       | Pretty good visual explanation of the "grill" and its effects:
       | https://www.youtube.com/watch?v=otweN9sCSd8
        
       | gzalo wrote:
       | I think I have experienced this when accidentally placing a
       | MacBook (after a few minutes of heavy CPU usage) in my belly
       | skin, below the belly button. The body of the notebook is a bit
       | hot, while the screen itself is cold (or it feels colder due to
       | the aluminum). If both parts touch the screen you feel like you
       | are burning, but if you only touch one of te two parts it's ok.
        
       | FeepingCreature wrote:
       | Tried out the finger version with three glasses of water. I could
       | only reproduce it partway - my middle finger felt like it was in
       | hot water, when it was actually in cold.
        
         | canjobear wrote:
         | I felt the correct temperatures in all fingers.
         | 
         | I'm starting to think this whole concept is bogus or at least
         | very variable across people.
        
           | zapt02 wrote:
           | I've tried this in a classroom settings (with the pipes) - it
           | definitely works.
        
         | tmm wrote:
         | Glad I'm not the only one! Since I was in the kitchen when I
         | read this, I had to try. Same result, all three fingers felt
         | like they were in warm water.
        
         | rootusrootus wrote:
         | Similar experience. And it wasn't foolproof, I could feel the
         | conflicting sensations, and detect that it was not quite right.
        
         | teeray wrote:
         | All three of mine felt like they were in a hot cup of coffee.
         | The faster you put your fingers in, the more intense the
         | sensation in my experiments
        
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       (page generated 2021-09-25 23:01 UTC)