Plant Growth Stimulator
Marine animals are not the only things in nature which respond to sound. Some persons claim that sound can affect how fast plants grow! Here's a Project that will let you test this idea for yourself.
As you can see from the schematic, this is the same type of oscillator circuit we've used in many other Projects see Oscillator Section.
Current to the Transistor's base is supplied through the 100K resistor. Feedback to keep the oscillator going comes from the two 100 uF capacitors as they charge and discharge notice how they are connected to each other. What is this connection method called?
To see if this Project can actually speed up the growth of plants, you'll need to set up an experiment just like a scientist does. Take a dozen budding plants (such as beans) and divide them into two groups. Make sure each group gets the same amount of sunlight, water, fertiliser and keep both groups at the same temperature.
Let one group "hear" sound from the Project for a few minutes each day. At the end of two weeks compare the two groups. Has one grown faster than the other? Is the difference large or small? (Small differences in the growth rate might be due to chance)