The Science of Putting Sunglasses on The Sun
Summary
Hosts Michael Stevens and Hannah Fry explore the physics of making the Sun appear to wear sunglasses, calculating the massive scale required for such an illusion from Earth to space. They discuss angular diameter, safe solar viewing, and the engineering challenges of positioning giant opaque discs at various orbital distances. The episode concludes by connecting this absurd premise to real-world geoengineering proposals, such as space sunshades to mitigate climate change and mirrors to reflect light at night.
Topics discussed
Introduction: Putting sunglasses on the sun
Sponsors: Cancer Research UK, Toyota, and Banks
Calculating the sun's angular size
The dangers of looking at the sun
Binocular vision and parallax issues
Scaling up: From skyscrapers to London-wide views
Global scale: Geostationary orbit and Lagrange points
Space sunshades and climate change mitigation
Space mirrors and the Reflect Orbital controversy
Physics of light pressure and momentum
The Arago spot and petal-shaped starshades
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