Mordecai Mark Mac-Low

Last year, New York City's 4th and 8th graders scored below both the state and national averages on a nationwide science exam. Just 13% of eighth-graders were deemed proficient in science on the National Assessment of Educational Progress. Every day over the next week, we'll take a few minutes to get to the bottom of some common science questions.

Today's scientist is Mordecai Mark Mac Low, astronomer and chair of the division of physical sciences at the American Museum of Natural History.

Today: Astronomy

Please Explain is all about matter, anti-matter, and dark matter. Lisa Randall, Professor of Theoretical Physics at Harvard University; Michael Tuts, Professor of Physics at Columbia University and Mordecai Mark Mac-Low, Chair of the Department of Physics at the American Museum of Natural History tell us all about what it is and what it means.