The Rest Is Science

Why does the cartoon Sun always wear sunglasses? And how big would a real pair need to be?

Hannah Fry and Michael Stevens investigate space mirrors, Reflect Orbital and solar eclipses to find out.

Starting with a pencil held at arm’s length, they use the Sun’s angular diameter to calculate how big a pair of solar sunglasses would need to be for one eye, two eyes, everyone in London and eventually the entire planet.

Their hypothetical answer is a strange structure more than a million kilometres wide, positioned deep in space. Entirely practical. They compare its extraordinary scale with NASA’s Parker Solar Probe, the real spacecraft flying closer to the Sun than anything ever built, before using Lagrange points to work out where their creation could possibly go.

But could putting something between Earth and the Sun ever be useful?

Real proposals for space sunshades and climate geo-engineering suggest that blocking a small fraction of sunlight could help cool the planet. Moving from shade to reflection, they revisit Soviet attempts to reflect sunlight onto Earth at night and explore how Reflect Orbital’s Earendil 1 space mirror experiment might one day extend solar energy beyond daylight hours.

That leads them to the strange physics of light itself. Photons can push solar sails despite having no rest mass, revealing why E=mc² is only part of the full energy momentum equation from special relativity.

Finally, there is the optical phenomenon known as the Arago spot to contend with. It helps explain why NASA’s starshade concepts, future technology designed for hunting exoplanets, look like enormous sunflowers.

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For more information about Cancer Research UK, their research, breakthroughs and how you can support them, visit https://www.cancerresearchuk.org/our-research/rest-is-science

Cancer Research UK is a registered charity in England and Wales (1089464), Scotland (SC041666), the Isle of Man (1103) and Jersey (247). A company limited by guarantee. Registered company in England and Wales (4325234) and the Isle of Man (5713F). Registered address: 2 Redman Place, London, E20 1JQ.

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Find The Rest Is Science all over the internet by ⁠⁠clicking here.⁠⁠

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Video Producer: Adam Thornton + Oli Oakley + Jack Meek

Animator: Sam Benson

Video & Social: Bex Tyrrell

Assistant Producer: Lucy Lipscombe

Producer: Simona Rata

Senior Producer: Lauren Armstrong-Carter

Chief Digital Officer: Samuel Oakley

Exec Producer: Neil Fearn
Learn more about your ad choices. Visit podcastchoices.com/adchoices

Colour wheel or colour line? Light itself runs in a straight line from red to violet, yet every colour theory chart bends that spectrum into a circle and the reason has nothing to do with physics.

Professor Hannah Fry and Michael Stevens (VSauce) dig into why human vision refuses to see colour the way light actually behaves, tracing the visible light spectrum from one end to the other and asking where all the "missing" colours, like magenta and purple, actually come from if they don't exist on that spectrum at all.

It turns out the colour wheel is less a description of light and more a diagram of a workaround your brain performs constantly.

Send your questions to therestofscience@goalhanger.com or find us at r/TheRestIsScience on Reddit.

Find the wetter water Michael discusses at - https://winsol.com/products/wetter-water

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For more information about Cancer Research UK, their research, breakthroughs and how you can support them, visit ⁠⁠https://cancerresearchuk.org/restisscience⁠⁠

Cancer Research UK is a registered charity in England and Wales (1089464), Scotland (SC041666), the Isle of Man (1103) and Jersey (247). A company limited by guarantee. Registered company in England and Wales (4325234) and the Isle of Man (5713F). Registered address: 2 Redman Place, London, E20 1JQ.

-------------------

Find The Rest Is Science all over the internet by ⁠⁠clicking here.⁠⁠

-------------------

Video Producer: Adam Thornton + Oli Oakley + Jack Meek

Animator: Sam Benson

Video & Social: Bex Tyrrell

Assistant Producer: Lucy Lipscombe

Producer: Simona Rata

Senior Producer: Lauren Armstrong-Carter

Chief Digital Officer: Samuel Oakley

Exec Producer: Neil Fearn
Learn more about your ad choices. Visit podcastchoices.com/adchoices

Can Hannah convince Michael that the lithium-ion battery is one of our most overrated inventions to ever happen?

Hannah makes her case using a surprising energy source hidden in your fridge, a bell in Oxford that's been ringing since 1840, and a metal that is useful… but prone to bursting into flame from the inside out.

Tracing the battery's strange history, from a twitching dead frog to the executed man who helped inspire Frankenstein.

But the real point runs deeper: we don't have an energy problem, we have a storage issue, and until we crack it, the clean energy future stays just out of reach.

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For more information about Cancer Research UK, their research, breakthroughs and how you can support them, visit ⁠⁠https://cancerresearchuk.org/restisscience⁠⁠

Cancer Research UK is a registered charity in England and Wales (1089464), Scotland (SC041666), the Isle of Man (1103) and Jersey (247). A company limited by guarantee. Registered company in England and Wales (4325234) and the Isle of Man (5713F). Registered address: 2 Redman Place, London, E20 1JQ.

-------------------

Find The Rest Is Science all over the internet by ⁠⁠clicking here.⁠⁠

-------------------

Video Producer: Adam Thornton + Oli Oakley + Jack MeekAnimator: Sam BensonVideo & Social: Bex TyrrellAssistant Producer: Lucy LipscombeProducer: Simona RataSenior Producer: Lauren Armstrong-CarterChief Digital Officer: Samuel OakleyExec Producer: Neil Fearn
Learn more about your ad choices. Visit podcastchoices.com/adchoices

What grows in the spaces humans are forced to abandon?Hannah brings Michael an actual piece of barbed wire from the Korean Demilitarised Zone, one of the most heavily fortified and forbidden borders on Earth, and it sends them somewhere unexpected.

From deserted no man's land and radioactive exclusion zones to remote islands that most of humankind has quietly agreed to leave well alone, they explore the surprising ways life adapts to the damage we leave behind.Plus your questions: the scientific fact that scared Michael most, where tectonic plates actually go when they collide, and a very good would you rather.

Send questions of your own to therestofscience@goalhanger.com or find us at r/TheRestIsScience.

-------------------

For more information about Cancer Research UK, their research, breakthroughs and how you can support them, visit ⁠⁠https://cancerresearchuk.org/restisscience⁠⁠

Cancer Research UK is a registered charity in England and Wales (1089464), Scotland (SC041666), the Isle of Man (1103) and Jersey (247). A company limited by guarantee. Registered company in England and Wales (4325234) and the Isle of Man (5713F). Registered address: 2 Redman Place, London, E20 1JQ.

-------------------

Find The Rest Is Science all over the internet by ⁠⁠clicking here.⁠⁠

-------------------

Video Producer: Adam Thornton + Oli Oakley + Jack MeekAnimator: Sam BensonVideo & Social: Bex TyrrellAssistant Producer: Lucy LipscombeProducer: Simona RataSenior Producer: Lauren Armstrong-CarterChief Digital Officer: Samuel OakleyExec Producer: Neil Fearn
Learn more about your ad choices. Visit podcastchoices.com/adchoices

Did the world really end in 2012?

Not with fire, meteors or an ancient Mayan prophecy, but Professor Hannah Fry and Michael Stevens ask whether something just as profound took place instead.

Together they unravel how one of the biggest myths in history took hold and why the Maya were unable to accurately predict the apocalypse. But they also delve into why, according to Michael, 2012 was the year an old world was discarded and a new one began to emerge.

It was, afterall, the year a novel technology became unavoidable and we began to abandon a shared culture for millions of fragmented realities.

Along the way they also explore the science of confirmation bias, why humans are fascinated by the end of the world, and whether technology has made us less connected...or reconnected us in a different way.

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For more information about Cancer Research UK, their research, breakthroughs and how you can support them, visit https://www.cancerresearchuk.org/our-research/rest-is-science.

Cancer Research UK is a registered charity in England and Wales (1089464), Scotland (SC041666), the Isle of Man (1103) and Jersey (247). A company limited by guarantee. Registered company in England and Wales (4325234) and the Isle of Man (5713F). Registered address: 2 Redman Place, London, E20 1JQ.

-------------------

Find The Rest Is Science all over the internet by ⁠⁠clicking here.⁠⁠

-------------------

Video Producer: Adam Thornton + Oli Oakley + Jack Meek

Animator: Sam Benson

Video & Social: Bex Tyrrell

Assistant Producer: Lucy Lipscombe

Producer: Simona Rata

Senior Producer: Lauren Armstrong-Carter

Chief Digital Officer: Samuel Oakley

Exec Producer: Neil Fearn
Learn more about your ad choices. Visit podcastchoices.com/adchoices