In 1800, William Herschel discovered infrared radiation. [2] He was studying the temperature of different colours by moving a thermometer through light split by a prism. He noticed that the highest temperature was beyond red. He theorized that this temperature change was due to "calorific rays", a type of light ray that could not be seen. The next year, Johann Ritter, working at the other end of the spectrum, noticed what he called "chemical rays" (invisible light rays that induced certain chemical reactions). These behaved similarly to visible violet light rays, but were beyond them in the spectrum. [3] They were later renamed ultraviolet radiation. Exactly, Why have video's stating that doctors have said if they both lost weight it would help them conceive a baby, but make no effort in actually doing so. Emma maybe doing slimming world (I have no clue haven't watched her in the longest time!) but they have to be both at least 20/25 stone each. Their is nothing wrong at all with being over weight. I'm over weighted (Not as much as them but I am) but What annoys me is they're so desperate for a child and make videos about it, then why not do something to help improve the odds in their favour.

The electromagnetic waves in each of these bands have different characteristics, such as how they are produced, how they interact with matter, and their practical applications. There is no known limit for long and short wavelengths. Extreme ultraviolet, soft X-rays, hard X-rays and gamma rays are classified as ionizing radiation because their photons have enough energy to ionize atoms, causing chemical reactions. Radiation of visible light and longer wavelengths are classified as nonionizing radiation because they have insufficient energy to cause these effects. Near-infrared, from 120 THz to 400 THz (2,500–750nm). Physical processes that are relevant for this range are similar to those for visible light. The highest frequencies in this region can be detected directly by some types of photographic film, and by many types of solid state image sensors for infrared photography and videography. Whenever electromagnetic waves travel in a medium with matter, their wavelength is decreased. Wavelengths of electromagnetic radiation, whatever medium they are traveling through, are usually quoted in terms of the vacuum wavelength, although this is not always explicitly stated.

Feynman, Richard; Leighton, Robert; Sands, Matthew (1963). The Feynman Lectures on Physics, Vol.1. US: Addison-Wesley. pp. 2–5. ISBN 978-0-201-02116-5.

Creation of particle-antiparticle pairs. At very high energies a single photon can create a shower of high-energy particles and antiparticles upon interaction with matter. If radiation having a frequency in the visible region of the EM spectrum reflects off an object, say, a bowl of fruit, and then strikes the eyes, this results in visual perception of the scene. The brain's visual system processes the multitude of reflected frequencies into different shades and hues, and through this insufficiently-understood psychophysical phenomenon, most people perceive a bowl of fruit.Uses of Electromagnetic Waves | gcse-revision, physics, waves, uses-electromagnetic-waves | Revision World Electromagnetic radiation interacts with matter in different ways across the spectrum. These types of interaction are so different that historically different names have been applied to different parts of the spectrum, as though these were different types of radiation. Thus, although these "different kinds" of electromagnetic radiation form a quantitatively continuous spectrum of frequencies and wavelengths, the spectrum remains divided for practical reasons arising from these qualitative interaction differences. It’s challenging to avoid flying altogether, but some companies suggest low-carbon options where possible.