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.
Tips for painting the sky. 1  Vary the color of the sky. 2  When painting the sky with clouds wet-in-wet, remember that colors will lighten up as the paper dries. 3  Note that the sky appears warmer and lighter as it approaches the horizon.