Jonas Edward Salk (October 28, 1914 – June 23, 1995) was an American medical researcher and virologist, best known for his discovery and development of the first safe and effective polio vaccine. He was born in New York City to parents from Ashkenazi Jewish Russian immigrant families. Although they did not have much formal education, his parents were determined to see their children succeed. While attending New York University School of Medicine, Jonas stood out from his peers not just because of his academic prowess, but because he chose to do medical research instead of becoming a physician.

Until 1955, when the Salk vaccine was introduced, polio was considered the most frightening public health problem of the post-war United States. Annual epidemics were increasingly devastating. The 1952 epidemic was the worst outbreak in the nation's history. Of nearly 58,000 cases reported that year, 3,145 people died and 21,269 were left with mild to disabling paralysis, with most of its victims being children. The "public reaction was to a plague", said historian William O'Neill. "Citizens of urban areas were to be terrified every summer when this frightful visitor returned." According to a 2009 PBS documentary, "Apart from the atomic bomb, America's greatest fear was polio." As a result, scientists were in a frantic race to find a way to prevent or cure the disease. U.S. president Franklin D. Roosevelt was the world's most recognized victim of the disease and founded the organization that would fund the development of a vaccine.

"The Man" is a slang phrase that may refer to the government or to some other authority in a position of power. In addition to this derogatory connotation, it may also serve as a term of respect and praise.

The phrase "the Man is keeping me down" is commonly used to describe oppression. The phrase "stick it to the Man" encourages resistance to authority, and essentially means "fight back" or "resist", either openly or via sabotage.

The earliest recorded use^{[citation needed]} of the term "the Man" in the American sense dates back to a letter written by a young Alexander Hamilton in September 1772, when he was 15. In a letter to his father James Hamilton, published in the Royal Dutch-American Gazette, he described the response of the Dutch governor of St. Croix to a hurricane that raked that island on August 31, 1772. "Our General has issued several very salutary and humane regulations and both in his publick and private measures, has shewn himself the Man." ^{[dubious – discuss]} In the Southern U.S. states, the phrase came to be applied to any man or any group in a position of authority, or to authority in the abstract. From about the 1950s the phrase was also an underworld code word for police, the warden of a prison or other law enforcement or penal authorities.

Eckhart Tolle (German pronunciation: [ˈɛk.haʁt ˈtʰɔ.lə], English: /ˈɛ.kʰɑrt ˈtʰɒ.lə/; born 1948) is a German-born Canadian resident, best known as the author of the The Power of Now and A New Earth, which were written in English. In 2011, he was listed by the Watkins Review as the most spiritually influential person in the world. In 2008, a New York Times writer called Tolle "the most popular spiritual author in the [United States]."

Tolle says he was depressed for much of his life until he underwent, at age 29, an "inner transformation", then spent several years wandering and unemployed "in a state of deep bliss" before becoming a spiritual teacher. Later, he moved to North America where he began writing his first book, The Power of Now, which was published in 1997 and reached the New York Times Best Seller lists in 2000. Tolle settled in Vancouver, Canada, where he has lived for more than a decade.

The Power of Now and A New Earth sold an estimated three million and five million copies respectively in North America by 2009. In 2008, approximately 35 million people participated in a series of 10 live webinars with Tolle and television talk show presenter Oprah Winfrey. Tolle's books and teachings have stimulated much commentary from theologians and journalists. Tolle is not identified with any particular religion, but his work has been influenced by a wide range of spiritual teachings.