Pneumonia can be more severe if you are pregnant. Tell your health care provider if you have signs of pneumonia during pregnancy. If you are pregnant, check with your health care provider before taking any medicine.
The visible spectrum is the portion of the electromagnetic spectrum that is visible to the human eye.Electromagnetic radiation in this range of wavelengths is called visible light or simply light. A typical human eye will respond to wavelengths from about 390 to 700 nm.In terms of frequency, this corresponds to a band in the vicinity of 430â770 THz.isible wavelengths pass through the  optical window , the region of the electromagnetic spectrum that allows wavelengths to pass largely unattenuated through the Earth's atmosphere. An example of this phenomenon is that clean air scatters blue light more than red wavelengths, and so the midday sky appears blue.
Sources of Visible Light Visible light comprises only a tiny portion of the entire electromagnetic spectrum of radiation. The wavelengths that the human eye can typically visualize lie between 400 and 700 nanometers in length, as illustrated in Figure 1.ources of Visible Light Visible light comprises only a tiny portion of the entire electromagnetic spectrum of radiation. The wavelengths that the human eye can typically visualize lie between 400 and 700 nanometers in length, as illustrated in Figure 1.