Rubbish Physics

Some ideas for how we can develop the physics aspect of Rubbish Science are outlined below. Please feel free to add others in the comments section.

Teaching Physics Principles 

Here in no particular order are experiments that can be done using only rubbish

(1) Pinhole camera 

This was the idea that started rubbish science when I was searching for ideas to teach science in a school in a developing nation that literally had no equipment apart from a broken pair of scissors and a ball of string. I used a juice carton and a plastic bag as the screen

There are lots of different options – Pringle Cans work particularly well

(2) Cartesian Diver  – Classic density experiment you can use sealed straws, condiment packets etc as the diver

(3) Thermal Energy Transfer 

Lots of experiments that can be done here although they require thermometers

Make a Thermos flask using one or more bottles. Keeping vaccinations cool or maintaining the temperature of hot things .

(4) Thermodynamics – Air cooler 

This has caused a big stir. Does it work? How might you test it?


(5) Stoves – Solar Cookers 

Lots of potential to look at thermal energy transfer and efficiency. What is the physics that underpins these.  What are the ‘best ‘ designs. Can they be made portable? Or scaled up to be water heating etc.

DIY solar panels 

Using cans as solar panels – Could old car windscreens be used  in place of the plexiglass?



(6) Stoves – Rocket Stoves  –  Lots of variables to explore here as well as an exploration of fuels


(7) Plastic Bottle – Radioactive decay model

Simply by hanging a dripping plastic bottle and simply plotting the water level vs time. As the water leaks from the bottle, the rate of flow falls .  This produces a decent decay curve that the ‘half life’ can be calculated from. Increasing the flow, by making the hole bigger, represents a source with a higher activity and hence a shorter half life.

Another activity easily created using rubbish is here

(8) Lighting Options 

Litre of Light – Refraction. This is a brilliant and well established charitable project that installs plastic bottles in the roof of dwellings without electricity. Light is refracted and reflected and gives the equivalent  light of a 55 Watt incandescent bulb.

We could explore which bottles provide the best light – how far up/down to place the bottles etc

What gives huge scope for investigation is the night light and streetlight projects

The solar bottle streetlights can transform the safety for people walking at night in dark urban areas. Lots to investigate here . What is the most efficient design? Consider – Run time of bulbs, battery life, solar panels – type , size and positioning. Large arrays or single units?

Other Lighting Projects 

LED bulbs can transform lives as they are highly efficient, long lasting and now relatively cheap.

There are many Solar Projects that can be explored to harness the Sun’s light. What can we do when there is insufficient sunlight?

Gravitational Energy Stores 

Clocks have been powered for centuries by harnessing a falling mass – how can we use this with modern technology? Lots of experimentation opportunities

Gravitylight  – See TED Talk  uses the principle that we can fill a gravitational store by lifting a mass. As the mass then falls we can generate an electrical current that can light LEDs


Generating Electricity using bacteria may be an option in the future

(9) Generating Electricity using discarded materials

We can do small scale ones using plastic bottle vanes to investigate efficiency


(10) Electrostatic Experiments 


Or produce a Van Der Graaf !

Or a Capacitor