Saturday: Hili dialogue and some space tweets amongst others

November 2, 2019 • 5:19 am

by Matthew Cobb

Hili is on the po-mo prowl:

A: What do you see there?
Hili: I’m afraid it’s a postmodernist again.
In Polish:
Ja: Co tam widzisz?
Hili: Obawiam się, że znowu jakiegoś postmodernistę.
Duck report [JAC}: The Secret Duck Farmer reports that duck numbers are back up:
7 ducks at the pond today, three females, including one who looked a lot like Honey and chased all of the other ducks just like Honey.  However, she didn’t want me to photograph her, though I have included the photo of her shifting to warp speed as I tried to take a picture.
Sadly, I can’t post the photo. Now back to Matthew:
On this day:
And you thought things were bad on planet Earth…

Lovely film of a glorious shark, now seen increasingly in UK waters, although its numbers are declining. This was shown on BBC’s Autumnwatch last night:

 

Physics is weird dept:

https://twitter.com/_beyondgalaxies/status/1189544448851693569?s=11

 

Autumn duck:

https://twitter.com/Duck_page/status/1190008434818789376

 

Be more cow:

 

And, from PCC(e), somewhere on the High Seas, this good news item, the story of a pet ‘turtle’ (tortoise to the English-speaking world) which went missing: ‘A tortoise that disappeared for a week was reunited with its owner after it was found 5 miles away at the house where it had lived a decade previously.’ More here!

(My cat Spizz did a similar thing – I once lived in Sheffield, then moved to London; when I moved to France in 1984 Spizz went to live with my pal Malcolm, in a different part of Sheffield. After a few months Spizz then went missing, and Malcolm eventually got a phone call from the person who lived in my old house saying ‘Your cat has come into our house and won’t go away…’)

 

11 thoughts on “Saturday: Hili dialogue and some space tweets amongst others”

  1. 5 miles in one week? Hmm. 0.03mph, but assuming the beast spent half the time feeding or sleeping, we’ll give it double the speed, 0.06mph. Since 0.06 of a mile is 316 feet, that creature travels practically one hundred yards in an hour! Pretty damn quick, and likely an underestimate as there probably wasn’t a straight line route back to the old house.

  2. The chain mountain is surprising. My intuitive feeling is that the beads are initially directed upward by the edge of the cylinder. The upward trend is increased because each bead adds inertia to the one following in the same direction.

    1. CHAIN FOUNTAIN [or Mould effect]: Your intuition is close to that of Steve Mould’s, but it’s more complicated than that! It’s Newton’s 3rd law of action/reaction.

      https://youtu.be/_dQJBBklpQQ

      [1] If the beads are connected less stiffly [by string say] there’s no effect at all
      [2] If the chain is allowed to fountain to any depth with no hindrance [you do it off a balcony] the container empties quicker than if the chain drop stops at a table or the like

      Thus we know the bead connectors can be free, but they must be stiffish, to allow forces to act in BOTH directions along the chain.

      WIKI:

      A variety of explanations have been proposed as to how the phenomenon can best be explained in terms of kinematic physics concepts such as energy and momentum. The scientific consensus has shown that the chain fountain effect is driven by upward forces which originate inside the jar. The origin of the upward force is related to the stiffness of the chain links, and the bending restrictions of each chain joint. When a link of chain is pulled upward from the jar, it rotates like a stiff rod being picked up from one end. This rotation produces a downward force on the opposite end of the link, which in turn generates an upward reactive force.

      It is this upward reactive force that has been shown to drive the chain fountain phenomenon. Furthermore, because the beads of the chain can drag laterally within the jar across other stationary links, the moving beads of the chain can bounce or jump vertically when they strike the immobile links. This effect contributes to the effect, but is not the primary driver

      1. All that is hard to wrap your head around ( or should it be…wrap around you head?). I’d almost chock it up to mystery and say it’s magic (The physicists are just pulling our chain, so to speak). But I have faith they understand it.

  3. Here’s Steve Mould going into more detail about the effect (from about 5 minutes in):
    http://www.youtube.com/watch?v=wmFi1xhz9OQ

    and the paper on it:
    http://www.youtube.com/watch?v=-eEi7fO0_O0

    I can follow the arguments and ‘understand’ it, but I still find it counter-intuitive.

    I think a fully-flexible chain should not show the effect. However, a slightly stiff rope or a length of plastic garden hose, for example, I think probably should. — and on reflection, maybe not. Any hysteresis will probably kill the effect. The special thing about Steve Mould’s chain – one of those little chains of metal balls used for attaching to sink plugs – is that it will bend with no resistance down to a certain radius then ‘locks’ and refuses to bend further. A garden hose or similar has a fairly constant resistance to bending. (This became apparent to me in trying to stuff a length of electrical extension cord into a bucket…)

    cr

      1. Yes, I’ve seen that. My comment takes that into account. It seems to me the prerequisite for this behaviour is to have components that rotate freely to a certain degree then resist further rotation. Such as the balls and intermediate links on Steve’s bathroom chain. When a ball has rotated a certain angle, the link to the next ball ‘locks up’ and won’t go any further, thus providing the leverage to kick the ball into the air. As noted somewhere, string won’t work.

        cr

        1. “as noted somewhere” you little fecker. T’was me who pointed out that string is KNOT going to work. Anyway you’re missing an ingredient from your recipe – ie you haven’t ‘got’ it yet. *hands to sides of head, wiggles fingers at infinite*

          2. The cat is not missing. The cat is in the right place. It’s your hoomin misunderstanding of where the cat “ought” to be that is at fault.
            I heard an old astronmical cat joke badly mangled a week or two back, and it deserves repeating correctly :
            Q : why are cats like comets?
            A : they both have tails and do what they want to.

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