Knotty Analog Oscilloscope Art

[@samuelflath3202]

i think i just witnessed the most nerdy thing on this channel and i like it

[@martink9785]

I’m a professional laser display artist with 30 years experience, this is one technique in how laser shows were made. Even now the signal from controller through to the galvanometers (scanners) is 100% analogue. Plenty of us still play with lissajous these days but we are down to 12 or 16 bit resolution digital to analogue converters.

[@colethecollector6742]

I'm convinced that being successful on youtube is 50% skill and 50% how nice your voice sounds

[@MicheleLimon]

When I was a graduate student we used the "crazy contraption" to take polaroids of the scope showing our measurements and then tape them in the lab handwritten logbook.

[@delsen]

Profoundly fascinating, thank you, Matthias, for sharing your process! Though I have a minimal understanding of math and electronics, you and Henry made this dark art surprisingly intuitive. And as a musician, once you described a voltage controlled oscillator, my first thought was: that's FM synthesis! I also dig the concept of knotty analog scope art on polaroid. Prost!

[@simonlinser8286]

a piece of string walks in to a bar and tries to order. the bartender says, sorry buddy we don't serve pieces of string in this bar. upset, the string leaves, and around the corner he straightens himself up, ties himself into a knot and parts his hair. when he walks back in the bartender says hey aren't you that piece of string from earlier? to which the string responds: I'm a frayed knot!

[@256byteram]

Awesome stuff. This makes me want to resurrect an old project I had going years ago which was this sort of thing, but more like a modular synth. Endless fun!

[@Kram1032]

The knots drifting out of phase over time almost looks like a 3D rotation of sorts, revealing that they aren't actually knots. I wonder how much harder this becomes if you basically make this "drifting out of phase" motion be *actual* 3D rotation projected to 2D, and it simply looks like you look at the knot from different perspectives.

[@murk1e]

Fundamentally, I don’t see how that’s possible with analogue as there’s nothing stopping an interception (one “string” through another). You could get the perspective with digital control, but that was not allowed by self constraint - and even there you’d manage it in software. As is often the case, it’d be very interesting if I were shown to be wrong!

[@whatelseison8970]

@@murk1e There's already nothing stopping the lines self-intersecting; he's just modulating the brightness. The figures being drawn are necessarily continuous, closed loops. As for the 3D rotations, you'd need to apply a rotation matrix, which is ultimately multiplying X(t) and Y(t) by more sines and cosines of the desired viewing angles (Euler angles). I can't se why it _wouldn't_ be possible actually, but don't ask me for a circuit diagram. haha.

[@3DIYOriginal]

Awesome !! Stunning material, well done 👏🏻👏🏻👏🏻

[@derderrr7220]

THIS IS AWESOME i'd love to understand further the inner workings of how oscilloscopes transpose an electron to visual display now.

[@whatelseison8970]

Analog scopes work similarly to the old CRT TV's (actually identically for B&W). A heated filament in the back of the tube is brought to 10 kV or so (Big TV's use up to 30kV) and electrons start coming off as a result. They are repelled from the filament (the electron gun) and attracted to the positive of the supply which is connected to a grid behind the screen. The signals to be viewed are amplified and applied to coils or plates above and below and to either side of the beam path. If coils are used the ones on either side deflect up and down and if plates are used the beam will be deflected directly toward/away from them.

[@neon_Nomad]

I enjoy the sounds of the shapes

[@wrOngplan3t]

More fun and educational than I thought! Appreciate the short intro to the integrator circuit (is it that easy? I suspect not :p I need to look more into that!).

[@romanb.6528]

Looks great

[@simonlinser8286]

this is cool as hell... crazy circuits im sure.

[@Circondi]

Because i teach some morpholocal and basic topological stuff in Paris Arvhitecture school some times ago… and because i am an artist too… this sounds crazy good !!!

[@pies32]

love you Henry!!!

[@lewisanesa1223]

Chapeau l'artiste!

[@murk1e]

It’d be helpful to see the circuit diagram with the clamping diode etc - block diagrams are in the description, and the standard integrator in the video; but it’d be nice to see the nitty gritty level, connecting the dots - i.e. the black boxes! (I can probably work it out… but it’s a nice thing to have it linked to. I’m wondering if I’m missing a trick as it seems to be one adjustment for speed in the unknot example…. But that would mean the two integrators being changed together?… easy enough with a dual-ganged variable - but if I’m missing something clever there, I’d like to know). Analogue computing is a very cool thing - you can do a nice A-level demo of resonance and damping with an LC network.

[@mgoerner]

As for the black box: all the potentiometers are a dual-gang. The circuit isn't clever and I was a bit disappointed that the amplitude isn't as stable over the whole frequency range than I wanted it to be. But since you asked for it, I am putting it up anyway, just follow the link in the description. For the positive feedback, I am doing the typical thing. To clamp the voltage, I saw people put a pair of Zener diodes (in series, anti-parallel) parallel to one of the integrating capacitors instead. Maybe I should have stuck to that.

[@murk1e]

@@mgoerner thanks - I was hoping I’d missed a clever trick with the adjustments - always nice to be surprised. Nevertheless, I’m sure that it’ll fill a gap for people who want to follow along without much electronic experience!

[@DanDart]

This adjustment makes me think of the Star Trek TNG episode "Where No One Has Gone Before"...

[@beefchicken]

I think the analogue multiplier he’s talking about uses Gilbert’s linearized transconductance technique, also know as a Gilbert Cell.

[@mgoerner]

Yes, that's exactly how the chips work internally. TL;DR Four of the multipliers are AD633 (for the geometry). And two multiplications are done on a LM13700 (for beam brightness - requiring less precision).

[@Thrustmaster64]

Only the unknot and the trefoil worked through the video, and even the trefoil was somewhat distorted. Looks more like eq than audio compression to my eyes though. I recall playing that oscilloscope art piece with mushrooms through youtube to my scope, and that worked better while also being more complicated.

[@tonysfun]

Thank you for this video - very nice! But the schematics aren't enough for me, I need more detail and exact diagram, since I'm new to electronics. I can assemble just about any circuit as long as I have exact instructions. Is there a way to provide better instructions - possibly put it on instructional website? And we can start with a simple generator and build upon that?

[@lumotroph]

So cool 🎉

[@Diogenes-archiv]

Wow I am really impressed by all of your works watching every video in my free time! Are you really Escher on streoids???

[@MrMcCoyD4]

if you re-shot this on film as well you could do analog showings!

[@Aotearoa.]

3 dimension in a 8 dimension reflecting cone that give off vibration not sure why

[@truefiasco2637]

I had a laser running off audio/analogue signals to draw 4d objects, starting with a loop of 4 channels running though the x,y,z,w coordinates of a hypercube and doing projection calculations to convert them into x,y screen space using analogue synths. it's not knots but thought it was relatable. and can you have knots that exist in either 3D or 4D but knot the other? kzbin.infoBrJyTqH5izQ

[@truefiasco2637]

PS how would you go about calculation f(x)=1/x using analogue circuitry?

[@PeterBarnes2]

Subtraction of exponentials seems more plausible for division, but if you had to, I'd think trying to take a geometric construction of division, like one of those straight-edge and compass constructions, would be promising.

[@massimookissed1023]

Say y = 1/x, then x•y = 1 You have an amplifier outputting some value z, then feed x and z into a multiplier. That product is introduced as negative feedback to the amplifier, reducing output z, until x•z = 1 at which point z is your y answer. A multiplier can output the square of an input easily by making both inputs the same. Effectively x•x A combination of multiplier and amplifier can also be used to find the square root of an input by using the square of the output as negative feedback. When the amp output is the square root, the square of the square root provides just the right amount of negative feedback for the amp output to be the square root.

[@CoughSyrup]

There is only the unknot in 4D.

[@drdca8263]

@@CoughSyrup While that’s true if you are only dealing with S^1 as the thing being knotted, it is possible to knot 2d surfaces in a 4D space.

[@massimookissed1023]

I managed to get a TV picture on an oscilloscope. My electronics teacher didn't know that was possible. He even dragged two other teachers in to show them.

[@tiagotiagot]

I'm surprised electronics teachers don't know how analog TVs work...

[@neon_Nomad]

Suprise now you're the teacher

[@bannerpunk]

knottiest video on youtube

[@iblesbosuok]

Those analog multiplier, are they AD633?

[@mgoerner]

Yes.

[@pauljs75]

With enough time he'll either make up an excuse to have a Euro-rack setup put together in the lab, or perhaps be doing similar work to that of Jerobeam Fenderson?

[@waldemar.golebski]

Matthias looks like a Hans Zimmer brother :)

[@joho0]

What's crazy is that 40 years ago, analog tech would have been the only way available to produce this. We're not that far removed from the analog world, but digital has overtaken nearly every technology since.

[@Aotearoa.]

Coolies. Colour and vibr9

[@landsgevaer]

"The knotty professor"

[@SashaPlatte]

This guy is like matthias wandel.

[@VEC7ORlt]

Why do you do premiers if all of it was recorded in advance? Also yes, it works even after YT compression.

[@confuseatronica]

I agree about the "premiers", they only make sense to marketing people at google, not real people.

[@henryseg]

The idea of a premiere is to get a bunch of people together to watch at the same time and discuss what's going on or ask questions. The YT compression comment was about taking the audio from this video and feeding it into your own oscilloscope to draw the knot there.

[@VEC7ORlt]

@@henryseg So in other words we have to shout in the chat, bicker for attention, wait for it to start and end, instead of watching it on my own time, taking my time to ask questions, scrolling through the video when needed. Yep, sounds like a great idea.

[@mostlyokay]

@@VEC7ORlt it's not mandatory!

[@Canyon_Lark]

@@VEC7ORlt certainly you can still watch in on your own time…. Some people enjoy watching things live with other folks at the same time. Why so bitter?

[@anarcocapitalista3700]

I want to see a Heavy Metal song in this.

[@aidanhasaknife]

knot😈

[@aaaaaaaaaaaaaaaaaaaaaaaaaa-ffs]

Hey doctor the things acting up

[@livieira7907]

🇧🇷

[@aldovk6681]

Too young to understand half of it, but it looks awsome

[@JakHart]

I'm going to go ahead and value the photograph at $15,582 USD.

[@shokdj1]

You can tell the camera man is struggling to understand this lol

[@JakHart]

This video is definitely just a prelude. I've seen how Henry works.. watch out @jerobeamfenderson1