• Before video-chat and long-distance phone calls, written correspondence was used to exchange meaningful information. The goal was to write about the most important things that had happened since the last letter.
• Although the telephone was invented in the mid-19th century, it was on...

• Before electricity, people experienced bright, full-spectrum days of sunlight and dark nights. We slept in a different way than we do now.
• Everything changed when electric lighting was invented in the latter part of the 19th century. Since then there has been an ever-increasing ass...

Scientists identified 3.055 billion base pairs (“letters”) of our DNA code as they made the data public. However, the wait has been over two decades since the first draft was released in 2001. Scientists have known for decades that genes were spread across 23 pairs of chromosomes...