Well. I had a program that drew hyper and hypo cycloids using the turtle but I seem to have misplaced it. Can't find my code anywhere.
But that means I get to write it again, and I could make it better this time.
One thing that bothered me about the old code is I didn't use the unique way that turtles can draw circles, I just used cartesian coordinates and goto commands.
Could there be a more elegant way?
Hyper/hypo cycloids are the fancy math words for "spirographs"
I guess a first step would be to find a new way of thinking about the sine and cosine curves since I was basically using those functions to calculate the motion of the interlocking circles.
hmmm...
@futurebird That sounds like a fun time. For some reason I'm writing COBOL right now? If I had any self respect at I would immediately stop and go make spirographs with Logo or something, but apparently I enjoy feeling pain lol
I kind of stumbled into teaching middle school CS (didn't want to do it, I thought it'd be boring, I was very wrong) but, in fact, it means part of my job is playing with fun code all day.
Most schools have endless desire to run such classes and no one to teach them.
@futurebird Oh! How delightful. I didn't realize middle schools even had a CS curriculum (well I'm in Canada, so I wouldn't, but I don't know if it's even a thing around here either tbh). That sounds like it'd be an interesting experience.
My CS teacher in grade 9 actually taught me a lot, despite my going into that class mostly just seeking an easy A, lol.
"I didn't realize middle schools even had a CS curriculum"
Strictly speaking they often don't it varies wildly from school to school. But, there are slowly emerging consensus ideas about the wide range of ideas a good curriculum ought to cover.
The worst ones teach students to be software operators, they are little better than job training.
The ideal curriculum teaches students to be critics and creators of software. Just as they are with literature, or historical texts.
And of course you need to teach students what computers are, their intrinsic mathematical nature, their potential and limitations.
Then add to all of this "online safety education" which is obviously important but can feel like something tacked on at the end... when it ought to grow more naturally out of the greater curriculum philosophy.
It can be very exciting and sometimes a little thankless to be a CS educator.
What could be a more important and neglected job?
I'm glad that I also teach math, since in mathematics our curriculum is ancient and its goals are clear and well debated, in math, the challenge is relevance, in CS we drown in too much relevance.
I assume that some day my students will make choices about what software we use, what networks we have and the rules that govern all of these things.
All of these things are designed and will be in their power.
I'm currently thinking about how to teach them about surveillance, its vast utility and potential for abuse.
My overall goal is that they never assume that these systems and software just exist and cannot be changed.
This can be difficult when a fair number of the well meaning adults I encounter don't really understand these things about computers or computer systems.
"Training young people for the jobs of the future!"
no no no no no we can do a lot more than that.
From time to time people get the idea that CS should be "integrated into the rest of the curriculum" rather than being its own subject.
You could take this integration approach with any subject, with math, or English... but 100s of years of experience show that this doesn't work very well unless you have an exceptional team of teachers with ample extra time to make such integration possible. Breaking education into subjects is a matter of effectiveness and efficiency.
Could you have an integrated project where a student learns about history, applies concepts from statistics and math and CS to analyze data, writes with expressive clarity about these topics and presents the work to their peers? Yes, and sometimes we can do that.
But you might not get the depth of understanding and technical competence possible if you have subjects.
Very few people will learn how a "for loop" works ... naturally.
@futurebird Aye. At school, our IT classes were literally just "how to use Microsoft Office". The final thing we did was mail merge using Excel and Word. I learned jack about how computers work.
To be fair... mail merges are kind of delightful in their own way. It's a kind of programing and very powerful.
My school had no real CS curriculum. But students who were interested could learn a great deal if we wanted to. I don't think that really cuts it anymore.
Oct 27, 2026, 10:22 AMIn the UK, when I was at school, we had 'IT' classes, which were terrible.
One of the few good things the Thatcher government did was to provide funding for the BBC to teach programming and funding for schools to buy computers with a bunch of requirements (including that they must support structured programming, which a lot of BASIC dialects at the time didn't).
When this curriculum started to be dated, companies like Microsoft pushed quite hard to turn it into a 'how to use office applications' course instead. When I was at school, this is what we were taught. There was some token programming around the edge but none of the theory was included.
A few years ago, the GCSE and A-level (national exams at 16 and 18) curricula were revised to properly introduce computer science. Unfortunately, this has made situations worse for universities offering computer science because now that there is a qualification that people arriving at university might have that covers about the first six months of what's typically tayght in a computer science degree. Wouldn't it be nice to make that a prerequisite of admissions? Except that it isn't available in all schools, isn't taught well in all schools where it is taught, and the ability to hire someone competent to teach computer science well correlates very strongly with the affluence of the area that contains the school.
@david_chisnall we face a similar problem here in France : some high school programs offer introductions to basic algorithmics, and some options include "digital sciences for the engineer" – which includes an intro to digital design, intro to programming (often through Arduino environments), etc. And then there's the others, who have seen none of that.
What "saves" us is that often they programmed in Python, and for now we stick to C.
1/2
We definitely did some BASIC in 7th grade but it was as an extracurricular.
@futurebird This was a problem we worked on using LEGO Robots. On some turtles that have good position or speed feedback on the motors, you can set the speed of the left and right motors independently.
Big circle is left motor slightly different speed than right - have fun and let the kids find out about differential steering!
@futurebird I doubt it would be especially elegant, but I think for the sake of variety you should use polar co-ordinates with local centers.
(the more I think about this, the harder it seems to make good choices about the locations of the local centers. )
Circle
Repeat 360 times
Forward 1
Left 1
Spiral in here. You change the side length each irritation
https://el.media.mit.edu/logo-foundation/what_is_logo/logo_primer.html
The spirals made with squares look a bit like cycloids, but it's not the same motion as the spirograph.
@futurebird it's frustrating because 14 year old me could actually help. C64 logo Lab aid
Oct 27, 2026, 1:44 AM@futurebird Used to do these and moires created by interference and pixelated diagonals on the Apple IIe machines all the time. I wonder if I still have hard copy code anywhere... So much fun!
@futurebird You could imagine the turtle rocking and spinning with the spirograph based on centripital force calculations.
I’d guess you’d need to calculate the second derivative of the hypocycloid. Might be easier in polar coordinates. Then you have the turtle always facing the opposite direction while flailing its arms. The magnitude of the vector should determine the turtle’s tilt.
The turtle isn’t walking, it’s riding the pen.
@futurebird The instantaneous velocity of a spirograph is a fairly simple function of time. From memory, the pen is inside a disk. The pen velocity is
disk's center velocity + pen velocity around center.
Tell the turtle to go in that direction.
@futurebird That's how I did it as a teen (although at the time I was using FORTRAN). My math wasn't up to doing it any other way, although I also had fun playing with the - I think it's called - evolute and involute of those curves?