"Quantifying the Sun's Immense Energy Output"

The Sun's energy output is a crucial factor for life on Earth and has been measured to be approximately 4 × 10^26 watts. This measurement was historically achieved through a combination of understanding the Sun's physical properties, such as its size and distance from Earth, and the development of instruments like the actinometer. William Herschel's discovery of infrared radiation and subsequent experiments by his son John Herschel and others led to the ability to calculate the Sun's power output by measuring the energy incident on Earth. These findings have paved the way for modern solar power technologies, harnessing the Sun's energy for various applications.