Nov 12: Rocket debris falling to Earth, non-compostable plastic, animal vocalization and more…

On this week's episode of Quirks & Quarks with Bob McDonald:

Proliferation of rockets raises fears that the sky is falling.

Recently the uncontrolled re-entry of a Chinese rocket booster closed airspace above Spain – and it wasn't an isolated incident. The growing number of rocket launches around the world has increased the risk that eventually people will be killed or injured by re-entry debris. Bob talks to astronomer Aaron Boley about evaluating the danger, and strategies for reducing the risk.

Quirks and Quarks9:21Proliferation of rockets raises fears that the sky is falling

Compostable plastics may not be compostable, and likely aren't being composted

A new study looking at plastic waste marketed as "home compostable" in Europe indicates that in reality the material mostly doesn't break down in homeowners' compost heaps. They also observed that when compostable plastic goes into the waste stream for municipal industrial compost, it was separated out and treated as normal trash. Mark Miodownik, Professor of Materials & Society at University College London, was part of the research team, who published their work in the journal Frontiers in Sustainability

Quirks and Quarks8:31Compostable plastics may not be compostable, and likely aren’t being composted

Many more animals make vocal sounds than we thought – which means its very ancient

A new study shows a range of widely diverse animals from turtles to lungfish to exotic legless amphibians called caecilians produce noises like squeaks, grunts and burps through their mouths. Gabriel Jorgewich-Cohen, recorded sounds from 53 animals previously thought not to have acoustic vocalization, which suggests the capacity to make these sounds arose in a common ancestor as long as 407 million years ago. His research was published in Nature.

Quirks and Quarks7:36Many more animals make vocal sounds than we thought – which means its very ancient

Tracking illegal fishing by watching when ships go into stealth mode

Researchers have been trying to get a better picture of the problem of illegal fishing by tracking when commercial fishing vessels deactivate their satellite location transponders. By using global databases, they've identified illegal fishing hot spots where ships suspiciously go dark. Bob speaks with ecologist Heather Welch, author of a new paper in Science Advances investigating when and where illegal fishing is happening. 

Quirks and Quarks9:01Tracking illegal fishing by watching when ships go into stealth mode

Next week there will be 8 billion of us, and that's already too many

According to the UN, the world's 8 billionth person will arrive any day now, on a planet whose resources are being overtaxed by managing with just 7,999,999,999 of us. To mark The Day of 8 Billion on November 15, we look at what scientists are most concerned about when it comes to population growth, how population impacts are inextricably linked with consumption, and how to 'flatten the curve' without trampling over human rights. We hear from:

• Bill Rees, population and human ecologist and professor emeritus and former director of the UBC School of Community and Regional Planning 
• Nandita Bajaj, executive director of Population Balance, and adjunct instructor at Antioch University in New England
• Céline Delacroix, Senior Fellow at the Population Institute and director of the FP/Earth project

Quirks and Quarks17:19Next week there will be 8 billion of us, and that’s already too many