Stepping into the (not-so-lime) light!

The Centre for Life’s forthcoming live science show In a Spin is being produced in collaboration with Think Physics. Today, therefore, has involved much sketching, planning and calculating, as Joe and Duncan from Life build props and set-pieces for the show.

Don’t be fooled by the cobbled-together appearance of the strip of lightbulbs above. Oh, no. That is a very rough-around-the-edges prototype. What it shows, however, is that we’ve done our sums more-or-less correctly, and we can indeed switch a bunch of lamps with a controller and a relay without blowing anything up unintentionally. Which would have been embarrassing.

Tomorrow, Joe’s world will revolve around a pile of laser-cut arrows, and new intern Callum will hopefully show us how to draw up a PCB which we can get fabricated by Northumbria’s magnificent milling machine.

I’d say ‘watch this space,’ but really, don’t: watch the show at the Centre for Life, from 16th June.

Tinkering Thursday: March 5th “Turn it off!” edition

Andrew has invented the ANNOY-O-TRON!! It’s in block capitals and has two exclamation marks, to be particularly annoying. A development of the previous instrumented pendulum, the ANNOY-O-TRON!! features several key advances:

  • Annoyingly many ‘compile / wait / upload / wait / fail / turn off / wait / turn back on / wait’ cycles.
  • Annoying choice of annoyingly loud GarageBand synthesised instrument.
  • Annoyingly flaky MIDI interface from the TouchBoard to GarageBand…
  • …which turned out to be caused by an annoyingly obvious-in-hindsight bug. Who knew that unless you turn a note off before playing a new one, GarageBand spawns a new instrument for each, topping out at 64 instruments? Harrumph. Annoying.
  • Annoyingly not-very-tremendous result in the end.
Andrew does battle with the less annoying parts of his code.

Andrew does battle with the less annoying parts of his code.

Annoyances aside: Andrew’s now turned the instrumented pendulum into something wholly more whimsical and ridiculous than, er, the sampled sine wave of previous weeks. He’s also had two sensors being synthesised at once, which obviously doubles the annoyance factor.

Next up: further exploring the MIDI controller aspect of this, to see how much flexibility there is to manipulate instruments rather than simply trigger notes. Then there’s building a frame, rigging a dozen pendulums, working out what and how we want to turn into what sort of sound, and thinking about what else we can drive with the data. Sound is only part of the excessive annoying extravaganza that will be this installation.

Tune in next Tinkering Thursday for tales of triumph over annoying adversity!

Andrew would like to make it clear that the annoyingly frequent use of the word ‘annoying’ in this update is not his responsibility.

Tinkering Thursday: 19th Feb “In the swing of it” pendulum edition

Our charmingly softly-spoken volunteer Andrew is filling in some time before his own physics degree by… actually, I’m not entirely sure why he’s here, but he didn’t seem to mind when I dropped a Bare Conductive Touchboard set in front of him and said ‘Here, get that working.’ We always have things going on we can rope people into.

Touchboard is a nifty little circuit board which integrates an Arduino controller, an audio engine, and a multi-channel capacitance sensor. If you’ve seen Makey-Makey, it’s a bit like one of those only with a whole raft of other bits bolted on. It’s more expensive, but much more capable.

Andrew fettles an instrumented pendulum

Andrew fettles an instrumented pendulum

I have a bit of a masterplan to build an installation piece for Maker Faire UK that involves generating sounds (or maybe light, we’ll work that out as we go) which respond to pendulum movement. Creeping ever higher on my list of ‘Things I really should have done before now’ has been powering up a Touchboard and seeing how we might use it to extract data from a moving pendulum, which was the task I set Andrew on today.

There he is at right trying different approaches, attaching foil-plate electrodes to the Touchboard and logging the raw sensor output over a serial link. As far as I can tell he’s never done this sort of thing before, so it’s a testament to Bare’s tutorials, the approachability of this sort of tinkering, and particularly Andrew himself that he produced this:

pendulum-trace-1

…which is a pretty clean trace. That’s with one electrode stuck to the bottom of the pendulum bob (my water bottle – the blue thing in the photo) and the other resting on the floor.

It took us a while to work out why there’s a double peak on each swing. We think that’s about the geometry of how the plates face each other as the pendulum swings past dead-centre.

The photograph shows a different arrangement, where we attached the plates up by the pivot point of the pendulum. There are several reasons we thought this might work:

  • The capacitance sensor has a limited range, so the smaller motion at the top of the pendulum is beneficial.
  • The electrode plates are quite large, so the one attached to the pendulum presents a large surface area for air resistance. Along with smaller displacement goes lower speed, so there should be much less damping from the plate up at the top than if it were attached lower down the string.
  • There’s less of an effect from the natural decay of the pendulum amplitude anyway.

pendulum-trace-2Happily, the trace from there looked like the one to the right: much more sinusoidal. At the bottom of the waveform you can see where the sensor plates are furthest apart, and noise starts to creep in. It’s not bad, though – there’s clearly something there we can work with.

Next steps include exploring the audio capabilities of the board, and we talked a little about Fourier techniques and processing the data to extract frequency information.

I’m excited to be underway with this at last. I’m absolutely unsure if where we’re heading is physics or kinetic sculpture, and I’m entirely happy about that: there’s something very appealing to me about taking simple objects and mechanisms, instrumenting them, and using the data collected in creative and interpretive ways.

We’ll see where the investigation goes, and we’ll keep you posted with progress.

 

 

bubbles-mid-35h

Tinkering Thursday – Feb 5th 2015

Tinkering Thursday is back. It’s taken us a couple of weeks to shake off the post-Christmas blues and carve out some time, but at last there’s been some activity in the lab. OK, so some of this happened yesterday: ‘Tinkering Thursday’ is more a state of mind than a requirement.

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The university Physics Society is running a high-altitude balloon project, and they’re getting properly stuck into their sensor and tracking package. Or at least, they’ve got the different sensors out of their plastic pouches and have run some electricity through them. LEDs have flashed, coffee has been consumed: all the required conditions have been met for programming to happen.

Meanwhile, volunteer Andrew gleefully seized on one of the Lego Mindstorms kits we found gathering dust on a store-room shelf. They’re legendary kits in education circles, and we’re keen to explore and think how we might use them.

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At the sticky-tape-and-straws end of the scale, this afternoon we tried making some eardrum models with students at Cramlington Learning Village. Not with complete success, it seems: the recommended route we followed led to the weird contraption you see in front of the speaker.

It didn’t work very well. Or at all, in fact. The idea is that you float the ping-pong ball in a tray of water and look for the ripples it makes, but we saw no movement. However, we had better luck with a long straw sticking out sideways, as you’ll recognise in the other picture. So the right sorts of things are happening, we just need to fine-tune a little to see the effect we want. Sometimes progress is like that.

— That was Tinkering Thursday for the first week of February. We’re still finding our feet, but it’s good to see activity. Next challenge: turning ‘activity’ into ‘progress.’

Tinkering Thursday: 18th December, a tale of two wave types

A simple Tinkering Thursday this week as we start to – let’s be honest – tidy the office so it’s not quite such a heap when we return in early January. Carol produced a lovely little ripple tank which had apparently been in one of the many cardboard boxes strewn around the office, and we proceeded to set it up.

Joe and Carol set up our new ripple tank

Joe and Carol set up our new ripple tank

We’ve more testing to do with different depths of water, but we managed to get some pretty decent-looking wave patterns and interference effects, as you can see at the top of the post (click the image to expand it). It’s a nice piece of kit, and we look forward to playing with it experimenting further.

I outsourced my tinkering for the week, taking my car to the garage to treat it to a new wheel bearing for Christmas. This post is late because I had to run out of the office early to collect it, which you really don’t need to know but hey, human detail and open communication are the keys to being approachable. I’m sure I read that somewhere.

Joe, meanwhile, had a busy afternoon. Yes, that’s our camera strap around his head to hold his normal desk phone in place so he can continue to monitor a conference call on mute, whilst talking on his mobile. Who needs a bluetooth earpiece?

Joe goes hands-free so he can operate a second phone for multi-tasking conversations.

Joe goes hands-free so he can operate a second phone for multi-tasking conversations.

Tinkering Thursday: 11th December

In the photograph above, Joe is pointing a telescope at the sun. Two things about this are remarkable:

  1. It’s December, we’re in Newcastle, and we actually saw the sun today.
  2. Joe can still see.

We all know – obviously – that looking at the sun through telescopes, binoculars, even cameras is, in general, a really really bad idea. But let’s be clear, just in case this is news to you:

Looking at the sun through a telescope, pair of binoculars, or indeed any sort of optical instrument is a really, really bad idea. You’re quite likely to blind yourself.

Don’t do it.

…unless you have a solar telescope. Oh heck yes, we have one of those. It has a very, very precise and very, very dark filter, and through it the sun looks like this:

The sun’s disc, with a little cloud, as seen through the solar telescope. December 11th 2014.

The sun’s disc, with a little cloud, as seen through the solar telescope. December 11th 2014.

So that was fun. We’ve some work to do getting the best performance out of the solar telescope, but the good news is that we’ve managed to extract the weird bits of material that were floating around in the eyepiece, so the whole thing doesn’t have to go back to the manufacturers. In California. Phew.

Back in Think Lab, we continued Tinkering Thursday with Joe making rather more smoke than he’d intended. He was attempting to make a lightbulb from scratch, but since we haven’t yet worked out how to isolate the smoke detectors in the Lab, we packed that in sharpish. We’ll come back to it.

Our attention turned, therefore, to the more careful (and less combustible) pursuit that is trigonometry. There is, it turns out, good reason you learn sines, cosines, and (in this case) inverse tangents in school: so you can make adorable little robots draw not-quite-lined-up Christmas trees:

This sort of thing makes us happy. If you look closely you might catch a glimpse of some extremely rough-looking code – the main output of the afternoon was, perhaps, a bug report filed with the lovely Mirobot team. We continue to be big fans of our dinky little robot friend, and as the software settles down it’s proving even more capable than we’d hoped.

More Tinkering next Thursday!

Tinkering Thursday: 4th December

This week Think Lab has been playing host to a delegation of Chinese architects – hey, it’s all go here – so we set to work in our office instead. We already have a hundred snow globes strewn around the place, what harm is there in adding a little craft mess?
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Tinkering Thursday: Soap Bubble Viewing

Joe observes soap bubbles on a prototype viewer

Prototype soap bubble viewer, with Joe for scale

We’ve been exploring a novel way of viewing the colour fringes created by curved soap films, with fairly dramatic results. This is a quick test time-lapse with only very minor processing – the camera really did see colours this dramatic.

In a week or two we’ll write up an activity based around this, but if you’re particularly keen you can probably work out how we’re doing this from the photo alongside.

You might like a hint: Melodi (£5).

We only had video lights to hand but standard desk lamps are fine, and if you stick your head where the camera is you should see a view as spectacular as the animation above. Or – quite likely – a place where bubble was until a fraction of a second earlier. So it goes.

…or perhaps you might like to try your hand blowing some giant soap bubbles?