Backyard scientist sizzles with ideas

Posted by Karen Driver
From: Nelson Mail

As I popped in to visit Peter Knowles at home in a quiet suburban street in Richmond and check out his biodigester system, I had no idea what I was in for!

Peter has set up a modest looking biodigester, which converts waste organic material into biogas, with a series of 5 storage tanks holding 400 litres of gas. Peter and his wife use the biogas to fuel their kitchen stove and their BBQ. I was suitably impressed with the simple system that provides free cooking fuel, but couldn’t help noticing the very large beam engine under construction standing next to the biodigester. Peter is building it for the Wakefield steam museum and explained that it is a model of the very first beam engine that uses steam to convert the vertical motion of the beam into rotational movement to drive machinery.

Behind the biodigester is Peter’s observatory, housing his large and powerful telescope, where he reveals the curiosities of the night sky to interested people. He and his wife are also proud of their 4,000 litre rainwater storage system for the garden and the 35 sq metres of solar panels that heat 35,000 litres of swimming pool water!

Thanking Peter for his time, I started to walk back to my car. “We haven’t got started yet”, said Peter “Come into the workshop and I’ll show you my models that I use to teach science in local schools.” Little did I know what I was in for!

Peter fired up his high-voltage generator and a 600,000 volt spark of electricity made me jump out of my skin. When he added a glass condenser to the top, sparks jumped inside the condenser, reminiscent of Frankenstein’s monster-making apparatus; when Peter lifted his arm up to the generator, electricity arced across into his arm. “Don’t worry, it’s harmless!” he shouted above the noise”. I was not so sure.

Inside Peter’s cloud chamber, alpha and beta sub-atomic particles ionise the isopropyl gas in a minus 40 degree temperature, creating silvery trails like spider webs. These trails allow you to see the effects of the particles that continuously bombard us from space, which otherwise go undetected.

A planetary simulator was next—a large 3d model of the sun, planets, stars, and how they all move relative to each other, a perfect way of showing children night and day, the seasons, tides and much more.

Something else unique that Peter has created is an electronic motor that, instead of requiring field magnets or field windings, uses the Earth’s magnetic field.

He then showed me his 3d models of atoms, including the hydrogen atom, which is the most basic atom, with just one proton as its nucleus and one electron that zooms around it. If the nucleus was the size of the ping pong ball Peter used in his model, then the electron of a hydrogen atom would be a staggering 500 metres distant from its nucleus. No one yet understands how atoms condense together to form solid objects.

Peter has made a siderial time clock, which demonstrates star time in a simple and visual way, is working on a boat that runs on electrolysis in seawater, and has countless other treasures, including a parabolic solar cookers and solar BBQ.

I asked Peter where he gets his ideas from. “From the internet mostly, but some are completely my own inventions, like the sidereal clock.”

The Nelson Science Society, recognising Peter’s genius and the enormous value of Peter’s working models to science teachers, has given Peter a van and pay for fuel so he can transport his models to deliver science workshops to schools. He charges a modest sum of $2 per student for his workshops, suitable for secondary schools as well as primary. “The kids are mesmorised said Peter, the teachers say that the kids will need a break after an hour but I find I can’t tear the kids away”.  I’m not surprised.

After a tasty cuppa made using Peter’s biogas, I took my leave and drove back to my office at Nelson Environment Centre, hoping to dodge being bombarded by alpha and beta particles. My mind was buzzing: so many things I never knew existed and such a fabulous resource right here in Nelson. Students who are lucky enough to experience Peter’s working models will gain true understanding of basic science principles in a way they will never forget.

Peter is keen to do more school visits: to make a booking, contact him at or phone: 03 544 6701.

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