Highlights. 1  Acute myocardial infarction is the medical name for a heart attack. 2  A number of different factors may increase your risk for a heart attack, including high blood pressure, high cholesterol, and diabetes.  Call 911 immediately if you believe you or someone you know may have had a heart attack.
The blue color of the sky is due to Rayleigh scattering. As light moves through the atmosphere, most of the longer wavelengths pass straight through. Little of the red, orange and yellow light is affected by the air. However, much of the shorter wavelength light is absorbed by the gas molecules.
This is why light scattered by clouds takes on the same color as the incoming light. For example, clouds will appear white or gray at midday and orange or red at sunrise or sunset. In this way, clouds act as a screen on which natureâs colors are painted. This is why sunsets or sunrises are so much prettier when some clouds are available to show us the colors.