The Threshold of Human Sensation
Summary
Hosts Michael Stevens and Hannah Fry investigate the smallest physical sensation humans can detect, debunking unsourced internet myths about sensory thresholds. They analyze the molecular requirements for hearing, taste, and smell, noting that while taste and smell involve millions of molecules, the vestibular sense and touch rely on detecting minute structural differences. The episode culminates in the discovery that a single cosmic ray particle can trigger a visual flash by directly interacting with brain neurons, challenging the definition of "feeling" through direct neural stimulation r…
Topics discussed
Introduction: What is the smallest thing you can feel?
Sponsors: Cancer Research UK and Wegovy
Critiquing Wikipedia's poetic thresholds for senses
The molecular complexity of emotions and Lisa Feldman Barrett
Hearing: Calculating the energy of a single proton
Taste: The sensitivity of Luganin and sweet receptors
Smell: Anatomy of olfactory nerves and detection limits
Sponsors: Cancer Research UK and Uber Eats
Vestibular sense and the phenomenology of self-touch
Touch: Texture differences between DVD and Blu-ray
Cosmic rays and the sensation of flashes of light
Vision: How rod cells detect single photons
Subconscious awareness of single photon detection
Conclusion and sponsor: Anthropic
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