Why do we need the sun?

+37 votes
asked Apr 5, 2015 in Science by Demi (860 points)
I have to do an essay on the benefits of the sun. I am looking for different takes and ideas, as well as scientific truths. I know the obvious but think there may be more to it.

1 Answer

+30 votes
answered Apr 14, 2015 by Cortney (660 points)

In short, the sun provides the necessary energy that all living things on Earth require to live. The sun is also required by Earth, and other planets, to stay in their own orbit because of its gravitational pull.

Here are the details:

  • The sun provides heat, or we would all freeze to death, and the sun provides light so we can see. Although most areas of the Earth are inhabited by humans (because we are able to provide our own heat and food sources when needed), only certain living organisms can live in certain places. Living creatures require different amounts of sun energy in order to survive.
  • Plants need sunlight for photosynthesis, which allows them to make their own food, as well as become food for other living creatures. All plants need sunlight but some plants need more sunlight, and some plants need less sunlight. For example, I have many house plants. I have two cacti and one tropical plant. These plants require as much sunlight as I can get them, so they are in the windows of my home that receive the most sunlight. I have many philodendron that do not like direct light at all. They thrive being hung from places that only receive indirect light. The same works for flowers and produce in a garden. A gardener has to be careful where they place each type of plant. Some plants will wilt and die if they receive too much sun, and others will not survive if they do not have full sun.
  • Animals need sunlight for warmth, as well as to feed the other creatures and plant life that they need to eat. Even nocturnal animals need the sun for this reason. Nocturnal land creatures feed off animals and plants that receive sunlight, in order to thrive, during the day. Ocean animals that dwell on the bottom (with very little sunlight) usually eat dead organic matter that once needed the sun to live.
  • Humans need sunlight for many reasons, including sight and warmth. Another reason some people do not know, is Vitamin D. We all need Vitamin D but, without the sun, we would not have it. Vitamin D is only found in the sun, and in other animals; however, even meat eating humans would lack in Vitamin D if the sun were not there to allow their food to absorb this much needed nutrient. Not only do our bodies need this particular vitamin for energy, and for certain brain hormones, we need Vitamin D to absorb Calcium. If you are lacking in Vitamin D, your body cannot absorb Calcium. Most of our minerals and vitamins require each other for absorption. One example is Vitamin C and Iron! Without the sun providing us with Vitamin D, we could not absorb Calcium and our bodies would just not work the same. Calcium is needed for muscle contraction and nerve function, as well as for building teeth enamel and strong bones.

Sunlight is vital to our existence. Without the sun, we would most likely not survive. You may watch this video on the same topic – Why do we need the sun?

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