The sun is merely one of hundreds of billions of stars in our galaxy, and by stellar standards, it is a fairly ordinary star—neither particularly large nor bright. Yet, to us, it is profoundly special. The sun makes life on Earth possible, and cultures across the world and throughout the ages have rightly worshipped it.
The Science and Psychology of Sunlight
In the developed world, we now spend up to 90% of our time indoors, yet the sun remains a powerful force underpinning our lives, even influencing our perception of beauty. The "golden hour"—the time just before sunset—is a real phenomenon. The sun is not actually yellow, orange, or red; it is all colors mixed together. As the sun rises or sets, the shortwave colors (green, blue, and violet) are scattered by the atmosphere, leaving only the yellow and red parts of the spectrum to create that amazing glow. When the sun is high, its blue waves bounce around, which is why the sky looks blue. A rainbow is simply the sun's light separated into all its magnificent colors.
The sun's perceived movement across the sky is deeply embedded in our biology, even though it is the Earth that rotates on its axis. When sunlight enters the eye, it sends signals to a master clock in our brain called the suprachiasmatic nucleus. This internal clock regulates everything from when we sleep to how we digest a meal.
Messing with this finely tuned circadian rhythm—whether through working night shifts or traveling across time zones—can make us feel rough. Even the bluish light from a mobile phone late at night is enough to disrupt and confuse our internal body clock. Being out of step with the sun affects our mood and our ability to think clearly, and there is evidence that this kind of disruption can lead to higher rates of obesity, heart disease, diabetes, and even cancer, suggesting that living out of step with the sun may be causing a public health crisis.
A Force of Power and Peril
The sun is an immense, dynamic, and sometimes violent force. Every hour, enough sunlight falls on the Earth to power the entire world for a year. Deep in its core, at around 15 million degrees Celsius, the sun constantly fuses hydrogen to make helium, releasing vast amounts of energy in the form of sunlight.
Fortunately, we are getting better at harnessing this power. It is estimated that a significant portion of the world's energy now comes from renewables, with solar growing faster than any other source.
However, the sun is not without its threats. The sun's surface looks like a raging sea of fire with huge eruptions, and it periodically blasts massive clouds of charged particles toward Earth—known as solar storms or coronal mass ejections (CMEs)—which can potentially wreak havoc on our technology. In 1859, a gigantic solar storm hit the Earth, creating auroras that covered the entire planet, knocking out the telegraph network, and sending sparks flying from electrical equipment. If a similar storm were to strike today, the consequences for our way of life could be devastating, potentially knocking out electricity grids, s
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