When staying warm is a matter of survival, they use this tried-and-true strategy.
The United States has the highest level of economic inequality of any developed country. Professor Joseph E. Stiglitz, winner of the 2001 Nobel Prize in Economics, explains why he thinks the American economy is rigged, and what that means for future generation. To learn more about America's rigged economy and what we can do to fix it, click here.
The answer lies in the tiny shifts we see in a star's position as Earth revolves around the sun.
Researchers programmed a computer to compare structures and toxic effects of different chemicals, making it possible to then predict the toxicity of new chemicals based on their structural similarity to known ones.
To understand tau, you need to understand pi. Watch how mathematicians from Archimedes on have wrapped their heads around the math of circles.