Here comes the sun
We are living in a time when solar energy is frequently touted as the prospective solution for powering our communities. But we rarely link it to the source, the centre of our solar system — the sun. As such, today we look into the sun itself.
Humanity has long been captivated by the sun, its brilliance, and its life-giving energy, inspiring awe, mythology, and scientific exploration throughout history. Ancient civilizations worshiped the sun, from the Ra cult in Egypt, the Incas in Peru, to the “Sun King” Louis XIV in France. Amaterasu, the Sun Goddess, holds a significant place in Japanese mythology and is considered the ancestor of the Japanese imperial family. In the modern era, this star is the inspiration behind The Beatles' song Here Comes the Sun or Rammstein’s Sonne. But many of us just love the sun and can’t wait for the first rays after a series of gloomy grey months.
But what is the sun?
In the 16th century, Giordano Bruno’s stated that the Sun is a star, which ended in his execution by burning at stake for such unorthodox cosmological beliefs. Today we know that the sun is indeed a star, composed of 74% hydrogen and 24% helium. It is around 4.6 billion years old and it is classified in the yellow dwarf star category. Its gravitational pressure triggers nuclear fusion generating energy in the form of light and heat. As such, many forget that solar energy is just nuclear energy — from a distance.
It is estimated that the sun’s core (of 15 million°C) rotates as rapidly as once a week, four times faster than its surface. When the magnetic field from the core bubbles to the surface, it creates concentrated and inhibits convective heat transfer, resulting in cooler, darker regions on its surface. These phenomena of sunspots are observable even by laic astronomers. Sunspots' magnetic fields can become unstable and release enormous amounts of energy during solar flares, causing sudden powerful bursts of radiation and particles into space. Solar flares have the potential to disrupt communication systems, power grids, and satellite operations on Earth due to their impact on the Earth’s magnetosphere and ionosphere. The concept of solar flare apocalypse was the element of a few apocalyptic Hollywood movies…
But let’s look at the bright, sunny side, living in proximity of a burning star has its perks. The gravitational pull of this hot ball of plasma means our planet remains in orbit and we get to enjoy the light and heat arriving from the sun. Without this, life on Earth would not be possible as the planet would freeze, and there would be no wind, ocean, or clouds. The Sun provides the essential energy through a process known as photosynthesis, driving the growth of plants and the subsequent food chain that sustains all ecosystems.
As far back as the 7th century B.C., humans harnessed solar energy by reflecting the Sun’s rays onto shiny objects to create fires. In 1839, French physicist Edmond Becquerel (at the age of 19) discovered the photovoltaic effect during his experimentation. Today, we are harnessing sun energy through photovoltaic panels for electricity and heat to power our everyday life. With the global race to net zero, solar is expected to play a pivotal role but it has some limitations due to its intermitted nature but this is a topic for another time.
Final thoughts
Up until around 1980, variations in Earth’s temperature could be attributed to fluctuations in solar activity and volcanic events, but since then, the Earth’s temperature has continued to increase even as solar output remains consistent. It has been said before and we will say it again … it is now evident that human activities are the primary drivers of global warming.
The sun remains a constant in our lives as we float through the cosmos on a spinning planet orbiting this burning ball of plasma that provides us with life force.
