See your GP if you have: 1  persistent or worrying symptoms that could be caused by haemochromatosis â particularly if you have a northern European family background. 2  a parent or sibling with haemochromatosis, even if you don't have symptoms yourself â tests can be done to check if you're at risk of developing problems.
The reflection of light can be roughly categorized into two types of reflection: specular reflection is defined as light reflected from a smooth surface at a definite angle, and diffuse reflection, which is produced by rough surfaces that tend to reflect light in all directions (as illustrated in Figure 1).
Emission nebulae are usually red, because hydrogen, the most common gas in the universe, most commonly emits red light. Reflection nebulae are clouds of dust that simply reflect the light of a nearby star or stars. Reflection nebulae are usually blue, because blue light scatters more easily.