(playful music) - [Narrator] Nature's webs come in all shapes and sizes, from dense shrouds to silken curtains, from creative chaos to perfect symmetry.

They can look like waves and nets, slings and deadly funnels.

Of course, these intricate creations are useful for catching prey, but that's not their only purpose.

- [Ross] Spiders that weave webs often have very poor eyesight, and so, they understand the world through the vibrations in their webs.

I've always been fascinated by spiders, and I was looking at how does the whole web vibration communicate information to the spider?

- [Narrator] While this might sound like an inquiry into biology and nature, for Ross Hatton of Oregon State University, it starts with robots.

- I study snakes and spiders and how they move, and how we can use those ideas from how they move to make better robots.

- [Narrator] So how do you get from web-weaving spiders to engineering robots?

- [Ross] We started off by building computer models of how vibrations travel through complex networks of strings.

And in order to validate those models, we built the spider web.

- [Narrator] The web needed to translate how a spider senses the world into a form humans can understand.

- [Ross] And our closest understanding of vibrations as humans is sound.

And so, how can we translate the vibrations that are happening in the web into sound?

- [Narrator] This process is known as bioinspiration.

- [Ross] Bioinspiration is looking at animals and saying, what are the things that an animal does we might want to use as a starting point for engineering?

- [Narrator] For example, real spiders use very stiff, strong silk for their web's radial lines, and stretchier silk for the spiral lines.

To duplicate this 10-to-1 ratio, the team used parachute cord for the radial lines and shock cord for the spiral lines, the stuff hair elastics are made of.

One of the next decisions was how large the web should be.

- The clear answer for that was eight feet, but that was a little bit too big to build.

And so, we cut that in half to about a four-foot diameter.

- [Narrator] Adjustable tuning pegs pull all the web strings into a uniform tension.

Then, along came a spider.

- A live spider can feel vibrations through its legs.

And so, when the web shakes, that shakes the foot.

And so, it's almost like we have an ear listening to each of these radial strands.

- [Narrator] The team began exploring cues, like direction, loudness, and pitch to get a sense of how spiders collect information.

(bright music) For direction, the model suggested spiders might do it pretty much like we do.

- If you hear a sound and you look at it, you're balancing the sound between your ears.

And we can use that to center where the source is coming from.

(spider pops) - [Narrator] Ross's spider looks for that balance between its feet.

(fly buzzing) - [Ross] With eight feet, and you can figure out which pairs of feet are centered on the sound.

Once we've done that, we can combine that with the loudness to determine is it coming from in front of you or behind you?

That gives us direction information.

- [Narrator] But to find out exactly where the prey is, simulated here by a pluck, the spider shows that it has a musical side.

- We have made it so that the big long strings play low notes, and the short little strings play high notes.

From that, we can tell, did I pluck it far away or did I pluck it close to the spider?

(gentle harp music) - [Narrator] The model may seem whimsical, but the complex mathematics behind it prove another instance where engineering and biology make good partners.

(people chattering in the distance) - [Person On Porch] I've never seen anything like that.

- No, this is the only one in the world.

- Oh, it is?

- Really?

- Really?

- Oh my God.

- [Person Wearing Blouse] Is somebody gonna play it pretty soon?

- Ah, yes.

From very early on in the project, I knew we were gonna build the physical spider web.

And I said, you know, when we string this up, it's gonna look a lot like a harp.

But I didn't have someone who could take on the musical aspects of the project.

- [Narrator] Enter Chet Udell, another OSU engineer with an extensive background in music.

- My PhD is in music composition and electrical engineering.

I saw a news broadcast of this really cool four-foot spider web.

Perfect.

And I was like, this would be a really cool musical instrument.

- Chet and Ross ran into each other at a university event and- - Ross was like, "Yeah, like, I think it would be a really cool harp.

Let's do it."

- Welcome and thank you all for coming to the SpiderHarp concert.

I'm Ross Hatton, and this is Chet Udell.

(audience clapping) - I am simultaneously the best spider harp player in the entire world, and I'm also the world's worst spider harp player.

So thanks for coming out to see it.

(gentle harp music) Every instrument has a trade-off.

In order to do a few things really well, it can't do other things really well.

Where the spider harp has a lot of advantages is that circular pitch layout.

There we go.

If you have a melody for, like.

♪ The itsy bitsy spider ♪ (Chet humming) So there's, like, a shape to that melody.

And you could play that same melody up a very high octave or a very low octave, but it's still the same shape.

(energetic harp music) But it is a bit limited.

You know, when I first walked up to the spider harp, I could pluck a spot on the web, and the spider could tell about once every five seconds where that vibration was coming from.

And I was like, it's not fast enough, it's not accurate enough.

You know, and let's fix this thing and really buckle down.

And we spent a whole year collaborating and we actually ended up optimizing the algorithm to detect five events per second.

(bright harp music) (bright harp music continues) (bright harp music continues) - [Narrator] It's an improvement, but you still gotta play kind of slow.

Still, this novel harp is not only unwrapping the secrets of a spider's senses, it also made it to the finals of the Guthman Musical Instrument Competition at Georgia Tech in 2019.

- So, you put the cool back in spiders, is basically what you're telling us.

Okay, awesome.

(audience laughing) (gentle harp music) - I feel like this medium is ripe with opportunities.

And the music that you hear really is only the very tip of that experiential iceberg.

This really frivolous desire to transform this physical model of how spiders detect vibrations in their web into a instrument that you could play on stage, you know, I think that this collaboration between the arts and the sciences, you know, can improve engineering.

That's a very exciting thing for me.

- [Narrator] It's also a good example of how an intriguing scientific inquiry can lead to a pretty cool way to spend a summer afternoon.

(audience clapping) (wind blowing gently) (no audio) (no audio) - Getting inspiration for your next adventure, it's kinda why you're here, right?

Well, you can support more of what we do on "Oregon Field Guide" and everything else you see on OPB by going to opb.org/video and becoming a Sustaining member.

(upbeat music)