Today's Health/Science: optimism, next tech, aging, disease fighter (and singer)

Humans have a natural bias toward a positive outlook. Its prevalence suggests that optimism has a biological basis, which scientists are beginning to identify in the brain, and is beneficial from an evolutionary standpoint.

Five MIT faculty members answer the question: What technologies do you predict will change our lives over the next few decades as dramatically as personal computers, the Internet, and cellphones have over the last few?

E. coli used to be immortal. But recent research has found that E. coli does not enjoy eternal youth. Over time, some of the bacteria become decrepit and lose the ability to make quick, flawless copies of themselves. The discovery suggests that aging is a universal property of life.

Dr. Joia Mukherjee (left) really wants to be a singer. That, she has already decided, will be her second career, and she just has to finish her first career, this minor business of "getting all the world's HIV and poverty squared away," before she can get started in earnest.

Also, couldn't the probiotic bacteria in yogurt actually be dangerous and how does helium make your voice high-pitched?