light is very important for the life on earth. It’s one of the most important world
energy resources used by plants and seaweeds to transform the nutrients to
grow. The oxygen we
breathe is released in the process.
The plants absorb water and minerals through the roots that end up in the leaves thanks to a network of small conducts. The leaves absorb Carbon dioxide from the air and, with the help of these 3 substances –water, minerals and Carbon dioxide– the plants build their tissues. To be able to do so they need energy, the same as we do for your foods. The energy the plants use is the solar energy they get and transform it through the process of Photosynthesis
The leaves of all plants have a green substance called chlorophyll that is used to retain light energy. This energy allows them to separate the Carbon and Oxygen from the Carbon dioxide and combine the carbon with the water and minerals stored in the leaves. The results of these combinations are the sugars and starches that are the majority of the nutrients of the plants. The oxygen is free and released during the process. This all together is the process of Photosynthesis. That’s why reforestation projects must be put in practice to help reduce carbon dioxide in our atmosphere.
The humans benefit from the solar light too
We need the light energy, among other things, to produce an essential vitamin for our growth and conservation of our bones and teeth: The vitamin D. Our body produces this vitamin, in the skin, through a similar process to the photosynthesis of the plants.
An excess of light can be dangerous
A part of the solar energy, the ultraviolet radiation, can seriously harm the living things but, luckily, the largest part of all the radiation doesn’t get to us. It is retained by the ozone of the outer layers of the atmosphere. The small portion that gets through can harm our skin if we do no take cautions when we expose ourselves to the sun for too long. A skin cancer specialist will recommend we should not expose ourselves for too long especially during the summer.
The balance of life
Without living things there is no oxygen, without oxygen there is no ozone, without ozone there are no living things…Life on Earth depends on the balance of many factors that must act in the right measure: with no solar radiation there is no life, but an excess of it could kill everything.
A short history review: Ozone Formation
About 4 billion years ago life started on Earth. However, for many million years there was no life on the land, because of the high amount of radiation from the sun that hit the Earth that made it impossible. The only living things were on the bottom of the oceans, and were mainly seaweeds. At some point, a new kind of seaweed appears, with chlorophyll that start occupying the shallow areas close to the shores. There they get enough light to be able to do photosynthesis and were safe from the excess of solar radiation. For million of years, these seaweeds released oxygen, than ended up in the atmosphere. So, the primitive atmosphere of the Earth began to change, reducing the proportion of carbon dioxide and increasing the oxygen to the levels of our time. From the atmospheric oxygen, ozone started to form, that accumulated in the outer layers of the atmosphere. The ozone prevents harmful solar radiation to go through, and, when the ozone layer had enough thickness, some organisms began living outside the water, on the mainland. It was the beginning of the conquering of the planet.
The ozone is not an especial or weird substance. The ozone is just oxygen in a tri-atomic molecular form, this means, 3 atoms instead of 2 of the “normal” oxygen molecules. This is the reason ozone is so unstable.
Stay tuned and will explain the Photosynthesis process in a chemical way ;)