How long does it take for one-half of everything we know about a subject to be proven wrong? Depends on the subject. 45 years, for example, if that subject is cirrhosis or hepatitis. Samuel Arbesman, applied mathematician and author of "The Half-Life of Facts: Why Everything We Know Has an expiration Date", joins Julia and Massimo to talk about the hidden patterns underlying how fast our understanding of science is changing.

If you're an ethically minded consumer, you should buy organic because it's better for the environment, right? Actually, the case isn't so clear-cut. But you should certainly buy fair-trade because it's better for foreign laborers, right? Well... that's complicated too. In this episode of Rationally Speaking, Julia and Massimo talk about how hard it is to know how much good you're accomplishing with your purchases, or whether you're even doing any good at all.

"Medicine is broken," warns Ben Goldacre, the British physician, academic, author of the Guardian's Bad Science column. In this live episode of Rationally Speaking, Massimo and Julia interview Ben about his new book, Bad Pharma, and how the evidence about pharmaceutical drugs gets distorted due to shoddy regulations, missing data, and the influence of drug companies.

In honor of the passing of Dear Abby columnist Pauline Philips, Massimo and Julia talk about the history and philosophy of advice. How do you rationally evaluate advice, and how do you give rational advice? Along the way they discuss some of Dear Abby's snarkiest moments, the origins of the advice column in 1680, and some of the worst advice ever given.

Can science denialism be blamed on a "Republican brain"? In other words: is there something about the psychology of Republicans that makes them inclined to reject the scientific consensus on topics like evolution and climate change? Special guest Chris Mooney argues there is, elaborating on the thesis in his popular book, "The Republican Brain: The Science of Why They Deny Science- and Reality." Massimo and Julia debate whether the evidence support Chris's thesis.

What's your IQ? Are you an ENTJ, or maybe an ISFP? What's your Openness score, your Conscientiousness score, your Neuroticism score? And just how seriously should you take all those test scores, anyway? In this episode of Rationally Speaking, Massimo and Julia discuss the science -- and lack thereof -- of intelligence and personality testing.

In this episode, Massimo and Julia discuss sociology and feminism, with special guest Victoria Pitts-Taylor, professor of sociology at the Graduate Center of the City University of New York. Victoria explains how feminists in sociology are dealing with results in neuroscience and evolutionary biology, especially regarding the question: How much inborn difference is there really between women and men? Massimo and Julia challenge Victoria on some academic feminist views, and investigate how the fields of sociology and academic feminism reach their conclusions -- what methods do they use, and how would we know if they were wrong?

What do Linux, Netflix, and the Oxford English Dictionary have in common? They've all benefited from the power of crowdsourcing, in which a task is outsourced to a group of hundreds or thousands of disparate people. In this episode of Rationally Speaking, Julia and Massimo discuss the phenomena of crowdsourcing, and ask: What makes it work? Is it ever unethical? And what are the limits to the wisdom of crowds?

We look to scientists to keep us informed about risks, such as: is this medicine effective? Is that level of toxicity harmless? How severe should we expect this upcoming storm to be? But when lives are at stake, tricky questions arise about how much responsibility falls on scientists' shoulders to get those estimations *right* -- and whether scientists should be punished if they fail. In this episode of Rationally Speaking, Massimo and Julia discuss a recent court case that shocked the world: A group of Italian scientists were sentenced to 6 years in prison for failing to effectively warn the public of an earthquake that killed over 300 people in 2009. Was this decision fair? And how should we decide where the boundaries of scientific accountability lie?

Massimo and Julia visit Indianapolis for a heated debate, in this live episode of Rationally Speaking. At a symposium organized by the Center for Inquiry (CFI), they join up with John Shook, Director of Education and Senior Research fellow at the CFI, and the author of more than a dozen books on philosophy and religion. Sparks fly as the three debate questions like: Should science-promoting organizations, like the National Center for Science Education, claim publicly that science is compatible with religion? And is philosophy incapable of telling us anything about the world?