Susan Gaidos' Articles
Since the 1950s, some portions of Antarctica have cooled (as denoted in faint blue tones), but many areas, including West Antarctica, have warmed substantially (red tones). The stronger the tone, the larger the warming or cooling.
Not all math skills are learned in the classroom. Some of them come naturally. Consider the split-second calculations you make when you estimate the number of empty seats on the school bus or gauge the number of cookies in a cookie jar.
These ballpark estimates can often be done without counting. That’s because humans are born with the ability to approximate, or closely guess, the number of items in a group. Researchers refer to this trait as a person’s “number sense.”
For most mammals, puberty is marked by an increase in aggression. As animals reach reproductive age, they often have to establish themselves in their herd or social group. In species where males compete for access to females, signs of aggressive behavior
Fake medicine, such as a pill filled with sugar, can sometimes make the people taking it feel better.
Rapideye / iStockphoto
Feeling sick? You wouldn’t want to take fake medicine for an earache or major illness. But in some cases, the fake stuff can help.
At left is Peru’s Qori Kalis glacier in 1978, when it was still healthy. At right is the much-reduced glacier in 2000. A lake of meltwater now occupies what 22 years earlier had been a deep field of flowing ice.