President Trump explained early Tuesday why he has so far avoided a return to full-scale war with Iran — even after Iran downed a US military helicopter. When we ask for reasons in speaking, we can use the phrase why is that? In informal conversations we often say why’s that?: … Why Is the Sky Blue? The Short Answer: Sunlight reaches Earth's atmosphere and is scattered in all directions by all the gases and particles in the air. Blue light is scattered more than the other colors because it travels as shorter, smaller waves. This is why we see a blue sky most of the time. Find definitions for over 300,000 words from the most authoritative English dictionary. Continuously updated with new words and meanings. Human activities are driving the global warming trend observed since the mid-20th century. The greenhouse effect is essential to life on Earth, but human-made emissions in the atmosphere are trapping and slowing heat loss to space. Five key greenhouse gases are carbon dioxide, nitrous oxide, methane, chlorofluorocarbons, and water vapor. Thinking and discourse on the topic is sought in the English language through questions such as—but not limited to— What is the meaning of life? , What is the purpose of existence? , and Why are we here?. Search the world's information, including webpages, images, videos and more. Google has many special features to help you find exactly what you're looking for. The meaning of WHY is for what cause, reason, or purpose. How to use why in a sentence. Some philosophers conclude 'Why is there something rather than nothing?' is unanswerable. They think the question stumps us by imposing an impossible explanatory demand, namely, 'Deduce the existence of something without using any existential premises'. Why is the US attacking Iran? The United States and Israel began strikes on Iran early on Feb. 28, in a campaign that killed the nation's supreme leader, Ayatollah Ali Khamenei, and dozens of.