Whether white is cooler than black depends on the context. While our perception and some simplified explanations suggest white is cooler, the reality, especially when considering infrared radiation, is more nuanced.
Understanding the Question
To accurately answer, we need to clarify what "cooler" means:
- Perceived Temperature: How hot something feels to the touch.
- Actual Temperature: The objective measurement of heat, often in degrees Celsius or Fahrenheit.
- Context: Is this about clothing, buildings, or another application?
White vs. Black: A Breakdown
Visible Light
White reflects most visible light, while black absorbs most visible light. This is the basis of the common understanding that white is cooler because it reflects sunlight away.
Infrared Radiation
According to research, white and black clothes look very similar in the infrared spectrum and reflect roughly the same amount of thermal radiation. (Reference: 09-Jul-2019)
Implications
- Clothing: While white may feel cooler due to reflecting visible light, both white and black clothing radiate similar amounts of heat in the infrared spectrum. Therefore, the color difference may not be significant for heat radiation.
- Buildings: Similar principles apply. White buildings might reflect more sunlight, but the ability to radiate heat is crucial for overall cooling.
Conclusion
While white reflects more visible light, leading to a perception of coolness, black and white surfaces often radiate heat similarly in the infrared spectrum, especially regarding clothing. The "cooler" choice depends on the specific context and the factors being considered (visible light reflection vs. infrared radiation).
