Our garden depends on light for growth, for it to be seen at all, and for its colours. We are now converting sunlight energy into electricity with our solar panels.
Light is either particles (photons) or a wave. Which is confusing as how can anything take two forms? But this is the realm of the sub atomic and they do things oddly there. The light particle has no mass and has a maximum speed of 300,000 kms per second. Nothing can travel faster. It was this limit to light’s speed that was one of the factors that caused Albert Einstein to develop his Theory of Relativity.
The light in our garden comes from the sun. Green plants have chlorophyll in their leaves which utilise the light’s energy to create sugar from water and carbon dioxide. Very simplified:
6CO2 + 6H20 + light energy = C6H12O6 + 6O2
Or in words: carbon dioxide + water + light energy = glucose + oxygen
This is photosynthesis. Nearly all our food crops are dependent on this process, The actual pathway is exceedingly complex with many steps. If humanity could do this itself, without plants, then we could solve the worlds food problem, as sugar can be converted into starch, which is the food found in wheat, rice, maize and potatoes, the most important food crops worldwide. Many scientists are working on it. A major problem is that even if you have devised the process, it has to be cheaper than sugar and starch from plants, or economics would rule it out.
All the food we eat gets its energy from photosynthesis. Plant food directly or meat which comes from animals fed on plants. If the sun went out, we would starve.
Note the oxygen created by photosynthesis, as well as sugar. Underwater plants in our pond such as hornwort and Canadian pond weed give off oxygen when they photosynthesise. And this oxygenates the pond water, allowing pond animals to thrive in the pond.
On a global scale, billions of years ago the first plants oxygenated the world, allowing oxygen breathing animals to evolve. Oxygen is very reactive and so must be continually created. We breathe it in (oxygen is 21% of air) and after going through our complex metabolism, we breath it out as carbon dioxide. Oxygen is needed so our cells can break down food to produce energy for the body’s systems. Without oxygen, the body can’t perform normal functions like movement, digesting food, growth, reproduction or even thinking.
The plants in our garden need oxygen for growth and seed production. They are utilising some of the oxygen that they have produced via photosynthesis.
Another aspect light is colour. The beauty of a garden is dependent on colour, most specifically those of flowers. The more light, the more the colour is enhanced. Colour though doesn’t actually exist in nature. Our eyes and brain respond to light of a specific wavelength, for example grass looks green because it reflects light of a certain wavelength, which our eyes and brain interpret as green. But someone else may see green differently from you. And who is right?
On the roof of our container we have two solar panels. They consist of banks of photovoltaic cells which turn the energy of sunlight into electrical energy which we store in two batteries. We can use that for any uses of electricity we require, such as heating a kettle, lighting, for electrical tools or powering an amplifier for music.
Photography utilizes the energy of light too. Pre-digital photography employed the fact that certain silver salts are altered by light. In digital cameras light is converted into an electrical charge, the camera’s processor turns that into image data.
I see our iron bird, its shadow on the Fothergill panel. And snap it. Just the right angle at 11.30 in the morning on a winter’s day. Light and shade.
what is light
To see
Photosynthesis
Colours
Light and dark
Shade
winter and summer light
Solar panels