Physical Chemistry podcasts

Melissa and Jam explain how evaporating water can cool a building and why the same approach works much better in dry climates than humid ones. They connect swamp coolers to older cooling techniques and examine newer ideas, including ice-based systems intended to reduce pressure on electricity grids.

Hosted by Melissa, Jam

Melissa and Jam trace the chemistry of refrigerants from early hazardous compounds to chlorofluorocarbons and their replacements. They explain why a substance that cools effectively can still create environmental problems, and discuss the tradeoffs among ozone protection, climate effects, flammability and regulation.

Hosted by Melissa, Jam

Melissa and Jam answer science questions drawn from Reddit, including why different metals produce different flame colors and why carbon has its own major branch of chemistry. The episode also considers the gap between discovering something that works and understanding its mechanism, with stories about laboratory mistakes.

Hosted by Melissa, Jam

Melissa and Jam unpack the chemistry inside an air conditioner. They explain how refrigerants, pressure changes and transitions between liquid and gas move heat out of a room, why the outdoor unit releases warmth, and what frozen coils reveal about the cooling process.

Hosted by Melissa, Jam

Melissa and Jam explain how hairspray combines a propellant, solvent and polymers to produce an aerosol that holds hair in place. The episode follows the formation of a fine mist, the behaviour of the polymer film and the formulation trade-offs involved, then compares hairspray with gels and mousses.

Hosted by Melissa, Jam

Mariana Kneppers, Mason Wakley and Frances Briggs reflect on 25 years of click chemistry and its spread into medicine and materials research. A second discussion examines covalent bonding in actinide elements and the experimental challenges of understanding how the heaviest atoms share electrons.

Hosted by Mariana Kneppers

Melissa and Jam examine how erasers remove graphite from paper. The episode connects the structure of graphite with the polymers and physical interactions that let an eraser lift a mark, contrasting absorption and adsorption and discussing what makes an everyday material effective for this purpose.

Hosted by Melissa, Jam

Melissa and Jam explain why graphite makes pencils useful for writing. The discussion follows carbon bonding into graphene sheets, conductivity and the weak interactions between layers, then connects these structures with paper, pencil hardness and clay mixtures.

Hosted by Melissa, Jam

Melissa and Jam recount Stephanie Kwolek’s discovery of Kevlar and explain the polymer chemistry behind its strength. The discussion covers rigid aromatic structures, hydrogen bonding and the organization of polymer chains into strong fibres. It connects these molecular features with protective equipment and other applications.

Hosted by Melissa, Jam

Melissa and Jam explore reverse osmosis through molecular motion, pressure and membrane separation. They also discuss limits and waste in water purification, questions about aluminium foil in dishwashers and sacrificial metals, and how mixtures of differently sized solid particles can separate through the Brazil-nut effect.

Hosted by Melissa, Jam

Melissa and Jam explain the colour-changing wetness indicator in diapers. The episode connects absorbent polymers with acid–base chemistry, conjugated molecular structures and interactions with light, showing how a change in chemical conditions can produce a visible shift in colour.

Hosted by Melissa, Jam

This episode examines water’s unusual physical properties and research testing whether liquid water can be understood through two distinct structural states. It also explores efforts to identify research misconduct, including image manipulation and fabricated publications, and the tools and post-publication review practices used by independent investigators.

Hosted by Mariana Kneppers

Melissa and Jam examine bird flight at the scale of air molecules. The discussion considers lift, momentum transfer, wing shape, angle and flapping, explains the limits of common Bernoulli-based accounts, and relates airflow to the molecular motion underlying the macroscopic behaviour of gases.

Hosted by Melissa, Jam

Rebecca Trager and Mason Wakley discuss themes from the AAAS annual meeting and developments in plasma chemistry. The episode places the scientific-policy discussions in their contemporary context and examines how plasma, the ionized state of matter, is being used to extend chemical research and applications.

Hosted by Mariana Kneppers

Melissa and Jam investigate why ice is slippery. They compare proposed explanations involving surface water, pressure and melting with experimental findings on ice surfaces, and discuss water’s unusual properties, amorphous structures and what these imply for skating and everyday slipping.

Hosted by Melissa, Jam

Sean Carroll and chemist Addy Pross examine how living systems maintain persistence despite constant internal activity. Pross introduces dynamic kinetic stability: a way for chemical systems to sustain themselves through continuing processes supported by an energy source. The discussion develops this chemical perspective on the transition from nonliving matter to life and considers its implications for understanding biological organization and, more speculatively, consciousness.

Hosted by Sean Carroll

Sara Imari Walker and Sean Carroll explore how life differs from other complex physical systems and whether information and computation help explain its emergence. Beginning around 6:38, Walker discusses biological homochirality: the preference for one molecular handedness, the roughly balanced mixtures produced without biology, and chemical symmetry breaking. Their wider conversation considers definitions of life, prebiotic chemistry, emergence, and the search for life beyond Earth.

Hosted by Sean Carroll