It's a common misconception, but in the context of electromagnetic waves, higher frequency doesn't necessarily mean more penetrating. The ability of electromagnetic waves to penetrate materials depends on various factors, including the wavelength and the interaction with the molecules of the material being penetrated.
Infrared waves and microwaves are both forms of electromagnetic radiation, but they have different characteristics and interact with matter in distinct ways.
Wavelength: Microwaves have longer wavelengths compared to infrared waves. Longer wavelengths tend to be more effective at penetrating certain materials, like certain types of glass or plastic, as they are less likely to be absorbed or scattered by the molecules in those materials.
Interaction with Water: One reason why microwaves are more effective at penetrating certain substances, like food, is because they interact strongly with water molecules. Microwaves are specifically designed to heat water-containing substances efficiently. When microwaves pass through food, the water molecules absorb the microwave energy and convert it into heat, effectively cooking the food from the inside out. Infrared waves, on the other hand, interact more with the surface of materials and are not as effective at heating water-containing substances from within.
Frequency and Energy: Higher frequency waves, such as X-rays and gamma rays, do tend to have more penetrating abilities through certain materials. However, this doesn't apply uniformly to all parts of the electromagnetic spectrum. Infrared waves have lower frequencies than microwaves, but they are still able to penetrate certain materials, especially those that are transparent to infrared radiation.
In summary, while infrared waves have higher frequencies compared to microwaves, the ability of electromagnetic waves to penetrate materials depends on various factors, including the wavelength and the interaction with the molecules of the material being penetrated. Microwaves, due to their longer wavelengths and strong interaction with water molecules, are more effective at penetrating and heating certain substances, especially those with high water content, like food.