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Chaotic Stirrer

Mixes better. Or not.
  [vote for,

Because of my unfounded and unproven belief that randomly stirring something into solution is more efficient than the boring circular method, I propose this device for the testing.

It is a double pendulum mounted horizontally below a round non-magnetic surface, driven by a variable speed motor. This is a modification of the standard lab stirrer, but it uses the chaotic motion of the double pendulum to move the magnetic end (or ends) of the pendulum arms beneath the vessel the solution is being made in, imparting chaotic motion to the stirrer in the solution.

The shape and character of the stirrer itself can be modified as to weight, center of gravity, shape, etc.

This idea should provoke turbulent comment.

minoradjustments, Mar 27 2024


       Lab stirrers, it would be nice if they did what you think they do. In practise, they sometimes stir in a nice even way, but often you increases the speed and the drag becomes too much and the stirrer decouples from the rotating magnetic base and it dances around chaotically driven by a combination of the magnetic influence and the (now) rotating liquid. So you slow the stirring down and the stir bar re-aligns with the base.   

       What's needed is VERY powerful magnets. If I ever get around to it, I'd like to make my own rare-earth stir bars and then tear down a magnetic stirrer to see what level of magnets they're using. Maybe I could repurpose the coils from a brushless motor? Add an RC electronic speed control and a PWM servo controller and I might be onto something.
bs0u0155, Mar 27 2024

       There are some shaker trays which can run a figure-8 motion to improve aeration (of small volumes like a millilitre or so in multiwell plates). Does that help?
Loris, Mar 27 2024

       [Loris] Sounds like DNA-volume mixing. I had more in mind a liter or two. But the chaotic motion could be imparted non-magnetically by chaotically moving around a thing like the paint can shakers they use. At the scale of a liter or two it would be a very violent sight, with the liquid sloshing while the stirrer(s) fly around too fast to follow. I don't doubt that it would be very well mixed.   

       [bs] I see that the 'decoupling' could be a problem at higher speeds. The horizontal double pendulum would have fine bearings and an embedded permanent or electromagnetic magnet somewhere along the length of the second pendulum arm. It should run as expected at very low speeds if the bearings are good enough. Now I'm wondering what effect the magnet arm would feel coming back from the stirrer. When you just want to spin the stirrer there's no problem but when stuff interacts and moves freely who can tell? It's magnets...
minoradjustments, Mar 28 2024

       Mr. Bond rejects this martini and asks for one chaotically shaken.   

       The idea only proposes chaotic movement in two dimensions
pocmloc, Mar 28 2024

       [poc] I don’t know how you would create ONLY 2-dimensional chaotic movement in a vessel full of fluid with something spinning around in it. And what would it look like if it was possible?   

       With some more development I think we’ve got the successor to the Lava Lamp here.
minoradjustments, Mar 28 2024

       From the title thought this might be an idea about "he who's name cannot be spoken on the Halfbakery" hahaha
xenzag, Mar 28 2024

       I suppose when you belong to the Trump cult anything reminds you of the center of your universe.   

       "Hey, look at that cute puppy. Trump would probably want to bite its head off. He's on record saying he likes biting puppies heads off.”   

       "Hey, this sandwich is really good! Trump bites the heads off of puppies."   

       "Nice day. Except that Trump bites the heads off of puppies."
doctorremulac3, Mar 28 2024

       Horrible thought. (Nothing about puppies, though.)   

       You can’t have any kind of pendulum if you don’t have a down force: gravity, magnetism, etc. so this idea is fun, it might get a bun but the physics is wrong. Mods coming... thanks [bu]
minoradjustments, Mar 28 2024

       //You can’t have any kind of pendulum if you don’t have a down force://   

       Can't you? What about those sprung flywheel thingamies in mechanical watches that spin one way, winding up a spring, then spin back the other direction unwinding and rewinding a coil in the opposite orientation. They seem like close analogs of pendulums to me, maximum force at minimum velocity at the ends, passing through 0 force with maximum velocity.
bs0u0155, Mar 28 2024

       //He's on record saying he likes biting puppies heads of."//Oh calm down - you’re like a snapping turtle with a boil in its bum.
xenzag, Mar 28 2024

       Maybe not a down force, but something that acts instead of gravity. If you start slinging around the double pendulum without it the arms will line up and you won't get that chaos you're looking for. You might get a replacement for that force by alternating clockwise and anticlockwise impulses, simulating the cyclical pendulum motion by forcing the driven horizontal arm to change direction. The spring winds down, just like the kinetic energy of a normal gravity-driven pendulum. An escapement could regulate speed to the most chaos-producing.   

       I like it better as a wind-up device like a music box than as a shiny electrified lab appliance with knobs.   

       As a wind-up device you eliminate the problem of the chaos only happening on the gravity side of its activity. With a wind-up you can ratchet around and cover the entire 360.° Great mod.
minoradjustments, Mar 28 2024

       //you’re like a snapping turtle with a boil in its bum.//   

       You talking to the mirror? That sounds about right. ExplaIns the whole cult thing.
doctorremulac3, Mar 28 2024

       If the end goal is truly random stirring, I don't think any arrangements of pendulums or simple vibrator/shaker would be unpredictable enough.   

       But radioactive decay is truly a random process*. You could set up a scintillation counter to read specific regions on a plate coated with a slightly radioactive material**, and use that to generate random numbers. The sequence of numbers could be used to 'kick' any number of solenoids or motors around your stirring shaft or shaking plate.   

       * so is Brownian motion, but Douglas Adams already used that in describing the invention of the Infinite Improbability Drive.   

       ** this method occured to me while on my way in to work this morning. turns out to be not very original, lots or prior art, and there are other ways to use radiation measurements for random number generation.
a1, Mar 29 2024

       // shiny electrified lab appliance with knobs.//   

       You don't get budget for equipment like that. A million dollar microscope to enable a new line of investigation, sure. A fancy computer to process that info, sure. Then there's "consumables" plastic ware, common chemicals media for cell culture, that kind of thing.   

       So there's a hole in the middle for equipment like stirrers, hot blocks, clamp stands, glassware etc. There's no official way of paying for it. So, in the wild, the lab stirrer has two phenotypes: 1. Beige, bought by someone who retired 20 years ago in the early 80's when it was a 15yo design. Several mystery stains and encrusted salt(s), worrying levels of rust underneath. At least three asset tags from 2 universities derived from failed attempts by administrators to achieve anything. 2. Blue, cheapest possible, bought from a chemical company (see budget) in the last 5 years, works just well enough to avoid being thrown out.   

       This really needs to be sorted out. There's no way of budgeting for what should be fundamental: labeling, organization, storage. Huge amounts of time and resources are lost because one tube from an experimental set goes missing because the ink from the cheapest possible pen wipes off with a little freezer condensation. No provision for data storage, which can be a huge problem, my microscopes generate ~1TB/week, 3d or cryo EM is 10x that. No motivation, money or training for managing that. The NIH should have an upload server and a lab supply web store. /rant.   

       //radioactive material**, and use that to generate random numbers.//   

       My first thought was "just use background radiation". Then I realized that if you need random numbers, you need a sufficient amount of them per unit time for your application. Background radiation giving between 10-80 counts on a GPM tube doesn't cut it at the second-by-second range, it becomes 0 to, maybe 4. So random numbers are a consumable resource of some value. I've carefully designed experiments to measure various things that, for some unknown reason, when looked at statistically were random number generators, quite good ones. One 96-well plate experiment gave 96 values from 500-50,000 in about 10 minutes.. Maybe I should have published that instead of giving up and trying another method.
bs0u0155, Mar 29 2024

       I think chatGPT predicted this.   

       You see, some time ago there was a claim made on here that AI couldn't be inventive, and in particular wouldn't ever be able to make creative poems, or something like that - and I said it already could.
So of course a challenge was made, and I went to chatGPT and said "Please write a poem in the style of Jabberwocky, on the theme of halfbaked inventions."

       And it gave me a lovely, inventive, /clever/ poem, featuring a competition between halfbaked inventors, with things going hilariously wrong. A little rough around the edges... maybe needing a bit of tidying up - but an amazing first draft.
Unfortunately it seems to have been deleted now.
There were four inventions featured; here are the verses covering my favourite:

       Then there was the WhizBangSpork,
A utensil of chaotic torque.
It diced and spliced, a culinary dream,
A marvel in the kitchen scene.

       But as it diced with fervent might,
It sliced through tables, chairs, and light.
The WhizBangSpork, a wild invention,
Leaving destruction in its direction.

       ...So there you are, you see; chaotic torque.
Loris, Apr 02 2024


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