What are far-infrared rays which have a good effect on health?
Far infrared rays are initially part of solar rays. The sun radiates electromagnetic waves of a different wavelength from gamma rays to electric waves. Electromagnetic waves refer to waves that electric field and magnetic field alternately surge ahead.
Ultraviolet rays and infrared rays are well known among the solar rays. Ultraviolet radiation is used for medical and dietary applications including sterilization. On the other hand, infrared ray is characterized by its strong hyperthermia effect and also used for medical application. X-ray is also applied for medical use.
Infrared ray is an invisible electromagnetic wave that has a longer wavelength than the red in the visible ray among the solar rays. Its wavelength band is within the range from 0.75 to 1000 μm (micron).
A British astronomer, William Hershel found that there was an invisible ray having the power to warm materials. When Hershel was measuring the temperature of visible rays dispersed into seven colors by passing the solar rays through a prism, he found that the temperature outside the red was the highest and invisible ray was present there. Since it exists outside the red color, it is called an infrared ray.
Infrared ray is divided into three based on the wavelength, and far-infrared ray refers to wavelength from 3 μ to 1000 μ.
The research conducted in 1981 by the National Aeronautics and Space Administration (NASA) clarified the effect of far-infrared rays on the human body, which is a far-infrared wave with longer wavelengths among infrared rays is vital to the survival of all the creatures.
If the far-infrared is exposed to the human body, it is conversed into heat energy to promote blood circulation. You may take thermal sensing when it reaches the sensory nerve. Near infrared ray also warms the body, but it has demerit to cause a moderate-temperature burn. If the purpose is just warming, microwave gives a stronger effect. However, we cannot use the microwave to warm up our body because it injures cells or genes if directly exposed to human body.
It is a far infrared ray that gives no harm to human body and warms the body most efficiently. Among the solar ray, it is a far-infrared ray whose wavelength most conforms to humans.