Texas A&M University (TAMU) GEOG 203 Planet Earth Exam 1 Practice Test

The Sun’s radiation peaks in the visible spectrum because its surface temperature is about 5800 K. According to Wien’s displacement law, a 5800 K blackbody emits most strongly at wavelengths around 500 nanometers, which lies in the middle of the visible range. So, even though solar energy spans ultraviolet and infrared as well, the highest intensity falls in the visible part of the spectrum, making daylight bright to human eyes and shaping how we perceive sunlight. The ultraviolet and infrared parts are present but not at the peak, and microwaves are far from the Sun’s strongest emission.