Marble adding machine
Why Hacker News recommends it
HN cites it as the classic example of a mechanical binary adder and a source of inspiration for marble-based computers.
What it is
Matthias Wandel shows his wooden machine that adds binary numbers using marbles. It demonstrates computation with purely mechanical logic.
Recommended by 0 HN commenters across 0 different months, 2013 to 2021.
What Hacker News said
Cites fnordfnordfnord · 2013-04 · on “Tearable Cloth Simulation in JavaScript”
Without wishing to kick even more sand in your face, I thought it was pretty cool. I was as impressed with codepen (which I hadn't seen before) as I was with the demo (oh, they really can do some pretty neat stuff in javascript these days). It's like this video: [this video] Where a guy builds a binary adding machine out of wood and marbles. I've seen them before. I've even seen nicer ones (more expertly constructed). His little counter / adder isn't really a feat in any way. I could even show you how to build a vastly better one with a CPLD. Yet, I am still impressed, and amused when I see that someone has built one. Wood, Minecraft, Little Big Planet, anything else. But, don't stop being a hate
Cites gamegoblin · 2015-01 · on “K'nex Mechanical Computer (2011) [video]”
Seems like a slightly more complex (has a binary -> decimal decoder) of this [1] which was made around the same time but is a bit easier to see how it operates (since it isn't made of K'nex) [1] [this video] I guess the big difference is the ball-drop adders don't require electricity or motors for one calculation, but you need some method (human or otherwise) to move the balls back to the top. Also you can only carry out calculation downwards, so your CPU might wind up being a few hundred meters tall! Not to disparage the ball-drop adders at all, just pointing out the differences.
Cites monk_e_boy · 2016-05 · on “Paper Processor – What is fetch, decode, and execute?”
I'm not OP, but there are lots of mechanical logic out there. This uses levers to make a binary adder: [LINK] And this uses marbles to make an adder: [this video]
Cites donquichotte · 2016-11 · on “4-bit calculator made from cardboard and marbles”
As one of the comments on the bottom of the page points out, Canadian woodworker Mathias Wandel built a similar machine some time back: [this video]
Cites i336_ · 2017-05 · on “The Turing Tumble lets you and your kids build real mechanical computers”
PSA This webpage from 2007 is the first place I saw the same fundamental board design: [LINK] Direct video link: [this video] The design in the two links above is fairly simple (I'd hate to see the patent office decide it was unique[ly patentable], for example), and so I doubt that this person from 2007 was the first to build it. But I wouldn't be surprised if this particular design and video served as some serious inspiration for the linked product. To clarify, I recognize that this system far surpasses the basic wooden adder I've linked. But the similarities are there.
Cites bscphil · 2018-08 · on “Lego Axle Sorter [video]”
That Matthias video takes me back - one of the first channels I ever subscribed to back in 2007 because of this cool wooden marble adding machine: [this video]
Cites klibertp · 2021-11 · on “Ask HN: How did you learn math notation?”
> They do arithmetic's perfectly. So does abacus. Even something like this: [this video] is capable of doing arithmetic. Does that mean that the marbles somehow understand what addition is? > look them up and spit out answers, Wolfram Alpha does this, and let me tell you: things I couldn't understand listening to lectures and trying to work through handbooks (well, most of them were hand-me-downs from the '60s, so take that as you will), became clear in just a few days of work. I didn't cancel my subscription for 2 years after that, out of gratitude. But, most of the papers out there don't use interactive platforms for publishing. Even though they could. But as you said, that would be too much wo
Cites jasode · 2021-12 · on “DNA seen through the eyes of a coder”
>I find the coding analogy for DNA or cell biology in general to be rather problematic. It's fine as a very rough and oversimplified analogy, but if you try to apply it to the details I think it hurts more than it helps. [...] , but inevitably they will move out of the bounds of where the anlogy works unless they actually know the underlying biology. I think the author's "digital" explanation for DNA is more helpful than problematic because we can just understand where that knowledge can be appropriately applied. Focusing on the higher abstraction of DNA as "information" or "data" is important in bioinformatics: [LINK] And analyzing DNA as "information" and not just analog chemistry is also