In Our Time

Megalosaurus

⏱ 56 min listen · ~2 min read 🎙 Steve Brusatte

Three working palaeontologists retell the birth of dinosaur science through one jawbone, one eccentric clergyman and a footprint site dug up in its 200th year.

Key takeaways

01William Buckland named Megalosaurus at the Geological Society of London on 20 February 1824, two decades before Richard Owen coined the word dinosaur.
02Buckland's 1824 reconstruction scaled a modern lizard up to about 40 feet on four legs, yet he correctly saw the legs held directly beneath the body.
03Megalosaurus lived about 166 million years ago, so T. rex at 66 million years ago is closer in time to us than to Megalosaurus.
04Oxfordshire trackways show a Megalosaurus speeding from about 4 to about 18 miles an hour, but no complete skeleton of the animal has ever been found.

Chapters

2:30 · Buckland's 1824 address and the Britain it shocked5:43 · William Buckland, Oxford's eccentric professor8:08 · Red Lady of Paviland and the Kirkdale Cave hyenas11:14 · The Oxford jawbone that defines the genus13:13 · Cuvier, Mary Anning and a lizard scaled up to giant size17:47 · Mantell, Iguanodon and the birth of dinomania+8 more

Read the full summary →

Archive: Citizen Kane

⏱ 54 min listen · ~2 min read 🎙 Ian Christie

Three film historians explain, scene by scene and dollar by dollar, how a first-time director's studio picture became the film every greatest-ever list is measured against.

Key takeaways

01Orson Welles was 25 and had never made a film when RKO gave him total control of Citizen Kane, which was released in 1941.
02Gregg Toland's deep focus and floor-level low angles let Citizen Kane tell Kane's rise and fall through camera position and decor.
03Citizen Kane cost RKO $686,000, cheap for Hollywood then, and stayed on budget partly by reusing sets and props from other RKO films.
04William Randolph Hearst turned his newspapers against the film, and cinema owners afraid of retaliation refused to screen it.

Chapters

2:14 · An archive pick about a 1941 classic4:25 · Welles before Hollywood: stage and radio years8:08 · Gregg Toland's deep focus and low angles8:33 · The Xanadu opening and the fake newsreel11:32 · William Randolph Hearst as the model for Kane13:46 · RKO's gamble on a $686,000 picture+8 more

Read the full summary →

Casablanca

⏱ 53 min listen · ~2 min read 🎙 Sheldon Hall

Three film historians take apart the industrial, political and personal machinery behind a film most people think they already know, and correct several of its favourite legends along the way.

Key takeaways

01Warner Brothers built Casablanca from Everybody Comes to Rick's, an unstaged play submitted the day after Pearl Harbor and bought for $20,000.
02Casablanca's script passed through the Epstein twins, Howard Koch, Lenore Coffee and Casey Robinson, and producer Hal Wallis supplied its final line.
03Ian Christie counted about 40 Europeans appearing in Casablanca, roughly half of them recent immigrants to America.
04The Office of War Information kept Casablanca out of North Africa on Robert Riskin's advice, fearing French reaction to its picture of Vichy.

Chapters

2:35 · A 1942 wartime hit discussed live in Sheffield5:39 · Warner Brothers buys an unstaged play for $20,0007:31 · European stars and refugees reach Hollywood9:50 · The plot and the many hands on the screenplay13:37 · Hollywood's slow build towards anti-fascist films18:02 · Casting Bogart and Bergman, and the Reagan myth+8 more

Read the full summary →

Archive: Dark Matter, the mysterious substance in space

⏱ 46 min listen · ~2 min read 🎙 Carlos Frenk

Three working physicists explain, in plain language, how astronomers can be sure that something invisible exists and why they still disagree about when it will be found.

Key takeaways

01Fritz Zwicky saw in the 1930s that galaxies in clusters move at about 1,000 km per second, too fast to stay bound without unseen mass.
02Dark matter is detected only through gravity: flat rotation curves, X-ray gas that should escape, and gravitational lensing that bends light into arcs.
03The microwave background fixes ordinary matter to within 1 per cent, and dark matter carries roughly five times as much mass as everything we can see.
04Neutrinos were ruled out because they move near light speed, and Carlos Frenk has spent some 35 years failing to rule out cold dark matter.

Chapters

3:28 · Melvyn Bragg sets out the problem of missing matter4:30 · Fritz Zwicky weighs galaxy clusters in the 1930s6:35 · Why matter that ignores light is so hard to find8:22 · Flat rotation curves in spiral galaxies11:01 · 1970s simulations and the stabilising dark halo12:55 · X-ray gas in clusters and the meaning of weighing+8 more

Read the full summary →

Particle Accelerators

⏱ 52 min listen · ~2 min read 🎙 Harry Cliff

Three specialists take you from a PhD student peering out of a lead-lined tea chest in 1932 to the open puzzles the Large Hadron Collider still cannot answer, in plain language.

Key takeaways

01CERN's Large Hadron Collider, a ring near 30 km long under France and Switzerland, is the latest of the machines that found 14 of 17 known fundamental particles.
02Victoria Martin explains that accelerators use electric fields to speed charged particles up and magnets to steer them, then smash beams so energy becomes new mass.
03Only about two in a billion LHC proton collisions make a Higgs boson, which decays at once and is spotted through products such as pairs of photons.
04Harry Cliff says the Higgs, confirmed on 4 July 2012, is still a fuzzy picture, and theory suggests such a particle should not exist in its observed form.

Chapters

2:18 · Why accelerators are the microscopes of matter4:53 · Ernest Rutherford and the hunt for controllable beams7:18 · Electric fields accelerate, magnets steer9:37 · Colliders as atom smashers, and their detectors12:57 · From Victorian discharge tubes to cathode rays14:57 · Cockcroft and Walton split the nucleus in 1932+8 more

Read the full summary →

Archive: Erasmus

⏱ 42 min listen · ~2 min read 🎙 Eamon Duffy

Three leading historians of Christianity argue over how much one restless scholar set off the Reformation without ever joining it.

Key takeaways

01Erasmus, born in 1467 the illegitimate son of a priest, invented the name Erasmus of Rotterdam and lived as a scholar with no fixed home in Europe.
02Erasmus's 1516 New Testament printed a fresh Latin translation beside the Greek, letting readers check Jerome's Vulgate against the original text.
03Eamon Duffy says Erasmus used fewer than ten Greek manuscripts, none earlier than the 11th century, and turned the end of Revelation from Latin back into Greek.
04Erasmus defended Martin Luther at first but broke with him over free will, holding that human effort cooperates with grace instead of counting for nothing.

Chapters

3:13 · Holbein's portrait and the panel's introductions4:20 · A priest's son and the monastery at Stein6:19 · Humanism and the escape to the bishop of Cambrai8:05 · Inward piety and the return to Greek sources11:09 · A loyal critic who attacked the Church with laughter14:04 · Pagan philosophers and the philosophy of Christ+8 more

Read the full summary →

Thomas More's Utopia

⏱ 54 min listen · ~2 min read 🎙 Laura Ashe

Three specialists show why a 500-year-old book coined a word for perfection yet keeps reading as a warning.

Key takeaways

01Thomas More was nearly 40 and idle in the Low Countries, after trade talks for Henry VIII stalled, when he began Utopia, published in 1516.
02Utopia's title is a Greek pun on 'good place' and 'no place', and More's working Latin title, Nusquama, simply meant nowhere.
03Book One's lawyer boasts of hanging 20 thieves at a time, and Hythloday answers that hunger and enclosed sheep pastures, not sin, drive men to steal.
04More's ideal island also runs on mutual surveillance, slaves, mercenaries and male-headed homes, flaws Cathy Shrank says the text raises and then undercuts.

Chapters

2:30 · A 1516 book, a new word and three Tudor scholars3:53 · More at 40: lawyer, MP and stranded diplomat5:37 · Erasmus, humanism and the ancient models for dialogue12:41 · A title built on a Greek pun14:47 · Prefatory letter, Book One and Book Two explained16:56 · A crescent island fortress modelled on England+8 more

Read the full summary →

Archive: The Measurement of Time

⏱ 42 min listen · ~2 min read 🎙 Jim Bennett

Three curators explain in under an hour why an hour has 60 minutes, why clockwise runs the way it does and why Greenwich became the world's zero line.

Key takeaways

01Babylonian mathematicians chose a base-60 system because 60 divides cleanly by so many numbers, and our hours and minutes still follow it.
02Jonathan Betts traces each gain in accuracy to the escapement and oscillator, the part that meters out time, from swinging bars to pendulums.
03Medieval iron clocks drifted about 20 minutes a day, while pendulum clocks after Huygens kept time to within a few seconds a day.
04Bristol ran about 20 minutes behind London until railway time arrived around 1847, and locals, clergy and some astronomers resisted the change.

Chapters

2:18 · Misha Glenny introduces the archive pick4:28 · Sun, moon and stars as the first calendars7:35 · Why the Babylonians counted in sixties9:09 · Water clocks timing speeches and military watches13:29 · Sundials and the geometry of moving shadows15:34 · Monastery clocks that rang the hours for prayer+8 more

Read the full summary →

Archive: Trinity

⏱ 44 min listen · ~2 min read 🎙 Janet Soskice

Three scholars untangle a doctrine most churchgoers recite every week without being able to explain, and show why one Latin word still divides East and West.

Key takeaways

01Christianity's Trinity claims one God in three persons, a belief Melvyn Bragg's panel says sets it apart from Judaism and Islam despite sharing their monotheism.
02Arius, a priest in Alexandria, taught that God made the Son out of nothing, and Constantine called the Council of Nicaea in 325 partly to settle the dispute.
03The filioque phrase is in none of the creeds of 325, 381 or 451, yet entered Western churches from about the 6th century, probably starting in Spain.
04Orthodox churches reject the filioque because a Spirit proceeding from Father and Son implies a ranked, derivative Spirit inside a Godhead meant to be equal.

Chapters

2:35 · The doctrine that sets Christianity apart5:10 · Jewish roots and Pliny's report of hymns to Jesus7:28 · From two divine figures to three at the baptism9:54 · Constantine, Arius and the Council of Nicaea14:37 · Nicene and Athanasian creeds on equality and rank26:48 · The filioque clause and the East-West divide+8 more

Read the full summary →

Megalosaurus

Archive: Citizen Kane

Casablanca

Archive: Dark Matter, the mysterious substance in space

Particle Accelerators

Archive: Erasmus

Thomas More's Utopia

Archive: The Measurement of Time

Archive: Trinity

▸Questions this show answers