Amazing work!
Gears
91–100 of 230 posts
Re: Gears
#92Earlier quoted context omitted.
Having been down this road, yes, it does take time, but you can save some time by using SVG and some DOM library. Although canvas is faster, most diagrams don't really need it, so I use SVG unless I really need to switch to canvas. SVG also adjusts for screen dpi automatically. The things I like: 1. Reactivity (ObservableHQ, Vue.js, hyperactiv.js, etc.). There's usually some underlying data and then a corresponding v…
Observable is amazing! Some time ago, I prototyped half of the 2.0 version of a company's product in it in a scope of a few days; that's how nicely the notebook interface and reactive programming fit together. I didn't realize Vue can work without a build step; that's actually great. While I so far avoided using any JS on my tiny little blog, I'd really like to do some interactive explanations. I'll check this workfl…
Observable's templating is directly inspired by lit-html, which also works without a built step, and works great with SVG.
Re: Gears
#93I have heard that it is good practice to always chose the number of teeth of two gears to be relatively prime. This is because there can be impurities in the metal, and if you have a small part of a tooth that is harder than the rest it will erode the opposing gear (there is always some friction going on). By choosing the number of teeth to be relatively prime, the wear and tear is distributed uniformly on the gears,…
That's also what I was taught as a best practice, but it's not always possible. Otherwise, best practice is to index the gears (ie mark a specific tooth on each). That way, when you disassemble the gearbox (it's bound to happen sometime for maintenance), you can make sure it's reassembled so that the same teeth will continue to mesh, preserving the wear pattern. Otherwise, wear is substantially increased.
Re: Gears
#94If someone ever makes the creation process for this type of visualization accessible to the average university professor, it could blow the lid of the digital textbook market. Most digital textbooks I've seen are basically just putting the text and images on a web page, and maybe integrating multiple choice quizzes. That's seriously under-utilizing the medium. They need to be interactive , and encourage the student t…
I'm a professor currently writing an online textbook. I can assure you that writing a textbook, without anything interactive, is extremely challenging. I find it hard to imagine a time when my book will be good enough that adding interactive explorables will be the best educational return on time invested. (Though I'm thinking about it!)
Re: Gears
#95This is beautiful. Great explanations, and a really powerful interactive website. A really impressive and engaging page to pull it all together.
Re: Gears
#96For me, nothing beats the mechanical calculator used to calculate torpedo firing solutions in WWII. It was a sophisticated differential equation solver that kept a real-time updated firing solution using ... gears. There's a whole maintenance and operations manual beautifully scanned here[1]. I've wanted to build one forever, but lack the time and expertise. 1. https://maritime.org/tech/tdc.htm
I am interested in differential analyzers too, especially after the anecdotes in Richard Hamming's Learning to Learn (aka Hamming on Hamming)[1] about re-purposing "gun directors" to solve engineering problems.
Some of the mechanisms involved are really elegant, like the torque amplifier[2] which wasn't invented until the 1920s. A tabletop demo of one is on my to-do list.
[1] https://www.youtube.com/playlist?list=PL2FF649D0C4407B30
Re: Gears
#97The illustrations are what draws attention and they are very nice and informative. In context of parallel HN discussion¹ on merits of animated SVG, I consider it a loss for open standards that these animations are not made in SVG. If you try to inspect this page, the design and animation is hidden behind canvas and some (nicely written BTW) imperative javascript. It is hard to replicate, and hard to compose with othe…
> The author is not to blame here, as we lack decent tools for declarative graphics/animations. Please show me the pure SMIL declaration for a pixel-exact replica of the example from the wonderful article: number and size of teeth on a spinning gear scales based on the horizontal position of a draggable slider. On a related note: this wonderful article is an article. The next time an HN article about web complexity t…
Can you explain what is it that you win? Because the current state where it takes a talented programmer + mathematician + designer to create this kind of content is loss for everyone.
No, SMIL on its own cannot replicate these illustrations. I hope that some future standard for declarative reactive graphics will be able to.
Re: Gears
#98Earlier quoted context omitted.
So the force generated by the torque is completely unaffected by the mass of the lever? Then, why does applying the force on a longer portion of the lever create more torque? I had thought it was because there is more mass acting on the point of rotation (longer lever = more mass).
> So the force generated by the torque is completely unaffected by the mass of the lever? Yes, that's right. > Then, why does applying the force on a longer portion of the lever create more torque? Most of the answers to this question reduce, upon examination, to "that's how we define torque". We define the torque of 100 newtons at a lever distance of one meter as the product of 100 newtons and a meter, which we can…
A generalization which applies to levers, pulleys, and hydraulics is mechanical advantage while conserving energy. You have a system with input work and output work (energy) that are the same, ignoring frictional losses.
Recall that work is force over distance. The mechanical system relates the input and output distances by a scalar coefficient. Since the working distances are related by a ratio, the working forces are related by the reciprocal of that ratio.
You can find the lever and fulcrum ratio with simple geometry. The input and output lever segments are radii, and the travel is distance along two arcs. Since the arc length is directly proportional to radius, the ratio of lever radii translates directly to the same ratio of arc lengths, and the reciprocal ratio is the force multiplier. Your 10:1 lever sweeps 10:1 arc lengths and balances with 1:10 opposing forces.
Re: Gears
#99If someone ever makes the creation process for this type of visualization accessible to the average university professor, it could blow the lid of the digital textbook market. Most digital textbooks I've seen are basically just putting the text and images on a web page, and maybe integrating multiple choice quizzes. That's seriously under-utilizing the medium. They need to be interactive , and encourage the student t…
I'm a professor currently writing an online textbook. I can assure you that writing a textbook, without anything interactive, is extremely challenging. I find it hard to imagine a time when my book will be good enough that adding interactive explorables will be the best educational return on time invested. (Though I'm thinking about it!)
I think it definitely is more appropriate in some domains than others. Sometimes you can replace 1000 words with a picture, 100 pictures with a video, and 10 videos with an interactive visualization. In that case, it might not actually be more work. I think the problem is that it's very different work, that professors aren't trained for. Again, it's not easy, maybe impossible. But if it could be done...
PS - I see you're at U as well. I work on a datavis team (iobio) in the genetics department (Steph says hi!). If you ever want to meet up I'd be interested in talking more about this.
Re: Gears
#100I have heard that it is good practice to always chose the number of teeth of two gears to be relatively prime. This is because there can be impurities in the metal, and if you have a small part of a tooth that is harder than the rest it will erode the opposing gear (there is always some friction going on). By choosing the number of teeth to be relatively prime, the wear and tear is distributed uniformly on the gears,…
That's also what I was taught as a best practice, but it's not always possible. Otherwise, best practice is to index the gears (ie mark a specific tooth on each). That way, when you disassemble the gearbox (it's bound to happen sometime for maintenance), you can make sure it's reassembled so that the same teeth will continue to mesh, preserving the wear pattern. Otherwise, wear is substantially increased.
That's also what I was taught as a best practice, but it's not always possible.