Quirks & Quarks has been taking your burning questions for 50 years. And while we thought we might have answered every question there is, our listeners proved there are always more science questions for us to tackle. Including:

• What does the black hole orbit?
• What do you sweat out in a sauna?
• Why are robins' eggs blue?
• What if we no longer had a moon?
• Did dinosaurs produce milk?
• Were there ever giant humans?

From doubting our doubts to sleuthing out scientific fraud, this week we revisit some of our favourite stories about humans.

For our 50th anniversary celebration last October, we spoke with some of Canada's top scientists about their predictions for the future. We revisit our conversations with:

• Evan Fraser, director of Arrell Food Institute and professor of geography at the University of Guelph
• Katie Mack, Hawking Chair in Cosmology and Science Communication at the Perimeter Institute for Theoretical Physics
• Luke Stark, assistant professor in the faculty of information and media studies at Western University
• Laura Tozer, assistant professor of environmental studies at the University of Toronto
• Ana Luisa Trejos, professor in the department electrical and computer engineering and the school of biomedical engineering and Canada Research Chair in wearable mechatronics at Western University in London, Ont.
• Yvonne Bombard, professor at the University of Toronto and scientist and Canada Research Chair in Genomics Health Services and Policy

From filming a black hole to flaming hot water ice on Neptune, we revisit some of our favourite space-related stories from the past season.

On this week’s best of Quirks & Quarks, we revisit our annual holiday listener question show, with fascinating queries like:

• Why did a Canadian astronaut's eyesight change when she went to space?
• How is the dust inside our homes changing?
• Why do some professional athletes stick out their tongues when they play?
• Why are most fruits round, but bananas and pineapple are not?
• What would have happened if the dino-killing asteroid never struck Earth?

We'll satisfy all these scientific curiosities and many more!

From the science of how we sweat to solving golf's greatest mystery, we revisit some of our favourite summery segments from the past season.

From elephant whiskers to Arctic rhinos and even science programming in prisons, we revisit some of our producers’ favourite stories from this season. Including:

• One of the world's earliest plant-eaters discovered in Nova Scotia
• Elephant trunk whiskers increase their sensitivity to better 'feel' their surroundings
• Yogurt with a creepy-crawly secret ingredient
• Rhinos roamed Arctic Canada 23 million years ago
• Bringing science education to the incarcerated

We revisit our conversations with authors of some of the year’s most fascinating science books in our annual holiday book show. Featuring:

• Questioning the purpose of whale song — for love or echolocation?
• Journeying through deep geological time to better tackle problems of the future
• Biological sex is complicated, but that's what helps animals like humans thrive

Plus, science journalist and BookLab podcast co-host Dan Falk reviews The Martians by David Baron, Dinner With King Tut by Sam Kean and The Mind Electric by Pria Anand.