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100 explainers so far, 3 more already read. Four fields — Science, Technology, Engineering, Math. Filter or search; nothing here leaves the page.
| № | Explainer | Field | Source | Read |
|---|---|---|---|---|
| № 01 | Why adding noise can create imagesDenoising diffusion | Technology · Machine learning | Ho, Jain & Abbeel | 2:28 |
| № 13 | Why there is no largest primeInfinitude of primes | Math · Number theory | Mevstrović | 1:34 |
| № 14 | Hilbert's hotel: infinities of different sizesHilbert's hotel | Math · Logic & foundations | Salehi | 1:58 |
| № 15 | Euler's identity: e^(iπ) + 1 = 0Euler's identity | Math · Analysis | Inoué | 1:58 |
| № 16 | Chaos: the butterfly effect in a deterministic equationThe butterfly effect | Science · Physics | Maiocchi, Lucarini & Gritsun | 1:57 |
| № 17 | The Monty Hall problem | Math · Probability & statistics | Gill | 1:48 |
| № 18 | Why π turns up where there are no circlesBuffon's needle | Math · Probability & statistics | Bäsel | 2:04 |
| № 19 | Gödel: a true statement that cannot be provedGödel's incompleteness | Math · Logic & foundations | Gusfield | 1:50 |
| № 20 | Random walks: why you end up about √n awayRandom walks | Math · Probability & statistics | Kostinski & Amir | 1:58 |
| № 21 | The four-colour theorem | Math · Graphs & combinatorics | Robertson, Sanders, Seymour & Thomas | 2:18 |
| № 22 | Benford's law: why 1 leadsBenford's law | Math · Probability & statistics | Gauvrit & Delahaye | 2:26 |
| № 23 | Why the night sky is darkOlbers' paradox | Science · Physics | Arpino & Scardigli | 2:59 |
| № 24 | Why time runs one wayThe arrow of time | Science · Physics | Lebowitz | 2:50 |
| № 25 | Why the Sun needs quantum tunnelling to shineQuantum tunnelling in the Sun | Science · Physics | Adelberger et al. | 3:01 |
| № 26 | How we learned to hear spacetime rippleGravitational waves | Science · Astronomy | LIGO & Virgo Collaborations | 3:01 |
| № 27 | Why a magnet floats over a superconductorThe Meissner effect | Science · Physics | Osorio & Suderow | 3:01 |
| № 28 | One particle at a time, and still the stripesThe double-slit experiment | Science · Physics | Bach, Pope & Batelaan | 2:59 |
| № 29 | Why ice floatsWater's density anomaly | Science · Chemistry | Song et al. | 3:02 |
| № 30 | Why a spinning top does not fall overGyroscopic precession | Science · Physics | Bolina | 2:58 |
| № 31 | Hundreds of trillions of neutrinos a second, and you feel nothingSolar neutrinos | Science · Astronomy | Vitagliano, Tamborra & Raffelt | 3:00 |
| № 32 | Why hot things glowBlack-body radiation | Science · Physics | Passon & Grebe-Ellis | 3:02 |
| № 33 | Why a moving bicycle balances itselfBicycle self-stability | Engineering · Mechanical | Kooijman et al. | 3:03 |
| № 34 | Why no engine can turn all its heat into workCarnot efficiency | Engineering · Mechanical | Esposito et al. | 3:06 |
| № 35 | Why AC won: the transformerTransformers | Engineering · Electrical | Lotfifard | 3:00 |
| № 36 | Why power lines run at high voltageTransmission losses | Engineering · Electrical | EIA; OpenStax | 2:56 |
| № 37 | Why an arch standsMasonry arches | Engineering · Civil & structural | Block, DeJong & Ochsendorf | 2:58 |
| № 38 | Why the Tacoma Narrows bridge tore itself apartAeroelastic flutter | Engineering · Civil & structural | Billah & Scanlan | 3:03 |
| № 39 | How a wing makes liftLift | Engineering · Aerospace | Wild | 3:00 |
| № 40 | Why rockets drop stagesRocket equation | Engineering · Aerospace | Zimmerman (NASA) | 3:10 |
| № 41 | How cruise control holds a speed without knowing the car or the roadPID control | Engineering · Control & signals | Åström & Murray | 3:00 |
| № 42 | Why wagon wheels spin backwards on filmAliasing | Engineering · Control & signals | Shannon | 3:02 |
| № 43 | How attention lets a model look back at everythingAttention | Technology · Machine learning | Vaswani et al. | 3:02 |
| № 44 | Why adding the input back lets networks go deepResidual connections | Technology · Machine learning | He et al. | 3:07 |
| № 45 | Why switching neurons off makes a network learn betterDropout | Technology · Machine learning | Hinton et al. | 3:01 |
| № 46 | Why a noisy bottleneck can invent new dataVariational autoencoders | Technology · Machine learning | Kingma & Welling | 3:03 |
| № 47 | Why a small model learns more from a big model's wrong answersKnowledge distillation | Technology · Machine learning | Hinton, Vinyals & Dean | 3:08 |
| № 48 | Learning from preferencesLearning from human preferences | Technology · Machine learning | Christiano et al. | 3:05 |
| № 49 | Why bigger language models are predictably better, until they are notScaling laws | Technology · Machine learning | Kaplan et al. | 3:07 |
| № 50 | Why no comparison sort can beat n log nSorting's lower bound | Technology · Computing | MIT OpenCourseWare; Jeff Erickson | 3:05 |
| № 51 | Why a hash table finds things in constant timeHash tables | Technology · Computing | MIT OpenCourseWare | 3:01 |
| № 52 | Why 0.1 + 0.2 is not 0.3Floating point | Technology · Computing | Goldberg | 3:10 |
| № 53 | Why checking an answer can be easier than finding oneP versus NP | Technology · Computing | Scott Aaronson | 3:05 |
| № 54 | How compression shrinks a messageHuffman coding | Technology · Computing | Jeff Erickson | 3:07 |
| № 55 | Sharing a secret in publicDiffie-Hellman key exchange | Technology · Cryptography | Diffie & Hellman | 3:03 |
| № 56 | How RSA locks and unlocks a messageRSA | Technology · Cryptography | Rivest, Shamir & Adleman | 3:10 |
| № 57 | Why a hash can't be run backwardsCryptographic hash functions | Technology · Cryptography | NIST | 3:04 |
| № 58 | Trading speed for force: gears and leversGears and levers | Engineering · Mechanical | Urone & Hinrichs | 2:58 |
| № 59 | Storing energy in a spinning wheelFlywheel energy storage | Engineering · Mechanical | Amiryar & Pullen | 2:57 |
| № 60 | How an electric motor spinsElectric motor | Engineering · Electrical | Urone & Hinrichs | 2:51 |
| № 61 | Charging a phone without a wireInductive charging | Engineering · Electrical | Detka & Górecki | 2:55 |
| № 62 | Getting to Mars the cheap wayHohmann transfer | Engineering · Aerospace | Widnall & Peraire | 2:56 |
| № 63 | Why we have seasonsThe seasons | Science · Earth science | Fraknoi, Morrison & Wolff | 2:56 |
| № 64 | Why there are two tides a dayTides | Science · Earth science | Fraknoi, Morrison & Wolff | 2:59 |
| № 65 | Why the Moon shows us one faceSynchronous rotation | Science · Astronomy | Fraknoi, Morrison & Wolff | 2:47 |
| № 66 | Why hurricanes spinCoriolis and cyclones | Science · Earth science | NOAA/AOML Hurricane Research Division | 3:01 |
| № 67 | Why flames have coloursAtomic spectra | Science · Chemistry | Flowers, Theopold, Langley & Robinson | 3:06 |
| № 68 | Stealing speed from JupiterGravity assist | Engineering · Aerospace | H. Morales | 3:12 |
| № 69 | Trusting two liarsKalman filter | Engineering · Control & signals | Welch & Bishop | 3:01 |
| № 70 | The weight that fights the swayTuned mass damper | Engineering · Civil & structural | Mazzon, Frappa & Pauletta | 3:06 |
| № 71 | Why triangles hold a bridge upTrusses | Engineering · Civil & structural | D. W. Baker & W. Haynes | 3:04 |
| № 72 | Size buys hours, chemistry buys voltsCells and batteries | Engineering · Electrical | Flowers, Theopold, Langley & Robinson | 3:05 |
| № 73 | Cut the square, keep the areaPythagoras by dissection | Math · Geometry & topology | Rachel Morley | 3:01 |
| № 74 | A triangle with too many degreesSpherical triangles | Math · Geometry & topology | I. Todhunter | 3:11 |
| № 75 | You cannot comb a sphereHairy ball theorem | Math · Geometry & topology | Peter McGrath | 3:01 |
| № 76 | Every answer is rightCoastline paradox | Math · Geometry & topology | Husain, Reddy, Bisht & Sajid | 3:04 |
| № 77 | A strip with one sideMöbius strip | Math · Geometry & topology | Cartwright & González | 3:05 |
| № 78 | Seven bridges, no routeThe bridges of Königsberg | Math · Graphs & combinatorics | Donna Kirk | 3:41 |
| № 79 | Everyone is six steps awaySix degrees of separation | Math · Graphs & combinatorics | Lars Backstrom, Paolo Boldi, Marco Rosa, Johan Ugander & Sebastiano Vigna | 4:11 |
| № 80 | Who asks mattersStable matching | Math · Graphs & combinatorics | Eric Lehman, F Thomson Leighton & Albert R Meyer | 3:32 |
| № 81 | The number that can't be a fractionWhy √2 is irrational | Math · Number theory | Richard Hammack | 4:06 |
| № 82 | Arithmetic on a clockClock arithmetic and Fermat's little theorem | Math · Number theory | William Stein | 3:31 |
| № 83 | Primes never stop, but they thin outWhy the primes thin out | Math · Number theory | William Stein | 3:27 |
| № 84 | 0.999… is 1Why 0.999… equals 1 | Math · Analysis | D. O. Tall & R. L. E. Schwarzenberger | 3:33 |
| № 85 | The sum that never stops growingWhy the harmonic series diverges | Math · Analysis | Steven J. Kifowit & Terra A. Stamps; Jeffrey C. Lagarias | 2:52 |
| № 86 | Any shape from sinesFourier series | Math · Analysis | Jeremy Orloff | 3:36 |
| № 87 | The program that cannot be writtenThe halting problem | Math · Logic & foundations | Boaz Barak | 3:34 |
| № 88 | Twenty-three people, even oddsThe birthday paradox | Math · Probability & statistics | Charles M. Grinstead & J. Laurie Snell | 3:40 |
| № 89 | Prove you know it without saying itZero-knowledge proofs | Technology · Cryptography | Jean-Jacques Quisquater & Louis Guillou; Boaz Barak | 4:22 |
| № 90 | How a packet finds its wayPacket routing | Technology · Computing | J. Moy; E. W. Dijkstra; G. Malkin | 4:32 |
| № 91 | Why the network asks senders to slow downTCP congestion control | Technology · Computing | Van Jacobson & Michael J. Karels | 4:22 |
| № 92 | Fixing a flipped bitHamming codes | Technology · Computing | R. W. Hamming | 5:25 |
| № 93 | How a random surfer ranks the webPageRank | Technology · Computing | Sergey Brin & Lawrence Page; Lawrence Page & Sergey Brin | 4:24 |
| № 94 | How a nerve firesThe nerve impulse | Science · Biology | OpenStax Anatomy and Physiology 2e; A. L. Hodgkin and A. F. Huxley | 5:10 |
| № 95 | How bacteria outrun antibioticsAntibiotic resistance | Science · Biology | Michael Baym et al.; Julian Davies and Dorothy Davies | 4:13 |
| № 96 | Why an elephant's heart beats slowlyMetabolic scaling | Science · Biology | Geoffrey B. West, James H. Brown and Brian J. Enquist; Van M. Savage et al.; Craig R. White and Roger S. Seymour | 4:57 |
| № 97 | Herd immunity | Science · Biology | Paul Fine, Ken Eames and David L. Heymann; Paul L. Delamater et al.; Haley E. Randolph and Luis B. Barreiro | 4:46 |
| № 98 | How spots and stripes can draw themselvesTuring patterns | Science · Biology | A. M. Turing; Shigeru Kondo and Takashi Miura; John E. Pearson | 4:38 |
| № 99 | Why the sky is blue and sunsets are redWhy the sky is blue | Science · Earth science | Lord Rayleigh (John William Strutt) | 5:05 |
| № 100 | How a catalyst speeds up a reactionCatalysis | Science · Chemistry | Paul Flowers, Klaus Theopold, Richard Langley and William R. Robinson; Derek Cheung | 4:16 |
| № 101 | A reaction that ticks like a clockThe Belousov-Zhabotinsky reaction | Science · Chemistry | A. T. Winfree; Alexander Pechenkin; Anatol M. Zhabotinsky; Andrew Adamatzky et al. | 4:55 |
| № 102 | How we find planets around other starsTransit photometry | Science · Astronomy | David Charbonneau, Timothy M. Brown, David W. Latham and Michel Mayor; Joshua N. Winn | 4:02 |
| № 103 | How a transistor switches: the gate voltage opens the channelThe MOSFET | Technology · Computing | Chenming Hu | 4:35 |
| № 104 | Why an LED is one colour: the bandgap sets the photon energyLED colour | Technology · Computing | Chenming Hu; Class for Physics of the Royal Swedish Academy of Sciences | 4:20 |
| № 105 | How a touchscreen feels your finger: a grid of tiny capacitorsCapacitive touch | Technology · Computing | Gary Barrett and Ryomei Omote; Feargal Cleary | 4:36 |
| № 106 | Why GPS needs relativity: 38 microseconds a dayRelativity in GPS | Technology · Computing | Neil Ashby | 3:58 |
| № 107 | Why a few turns of rope hold so muchThe capstan equation | Engineering · Mechanical | Vlado A. Lubarda; Stephen W. Attaway | 4:36 |
| № 108 | The shape of a hanging chainThe catenary | Engineering · Civil & structural | Robert Osserman; Philippe Block, Matt DeJong, John Ochsendorf | 5:10 |
| № 109 | The sound barrier and the Mach coneThe sound barrier | Engineering · Aerospace | John D. Anderson, Jr.; Ames Research Staff; Harry W. Carlson; Jerry M. Seitzman; Domenic J. Maglieri et al. | 4:33 |
| № 110 | Balancing a stick on a cartThe inverted pendulum | Engineering · Control & signals | Bidhayak Goswami and Anindya Chatterjee; Karl Johan Astrom, Richard M. Murray | 6:38 |
| № 111 | Recovering a signal from too few samplesCompressed sensing | Engineering · Control & signals | Emmanuel Candes, Justin Romberg, Terence Tao; Ahmad Mousavi, Mehdi Rezaee, Ramin Ayanzadeh | 5:10 |
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