PHYSICS BITES
Big ideas, in just minutes.
Watch a narrated animation, then try the experiment yourself.
Quantum Physics
9 bites
The strange rules of the very small.
ElectronMASS9.11×10⁻³¹ kgCHARGE · SPIN−1 · ½ProtonMASS1.67×10⁻²⁷ kgCHARGE · SPIN+1 · ½PhotonMASS0CHARGE · SPIN0 · 1Every electron is perfectly identical
01 · 57s · LAB
What Is a Quantum Particle?
The tiny building blocks — and why they’re wavy.
METALBRIGHT REDno electronsMETALDIM ULTRAVIOLETOne photon in → one electron out
02 · 55s · LAB
Photons: Particles of Light
Light comes in packets — and that changed physics.
ψ(x) · AMPLITUDE (can be negative)|ψ(x)|² · PROBABILITY (always ≥ 0)Square it → chance of finding the particle
03 · 1:15 · LAB
The Wave Function
ψ — the maths that describes a quantum particle.
Stripes = interference!
04 · 50s · LAB
Wave–Particle Duality
Electrons act like waves until you look.
n=1n=2n=3E = hfFalls back → emits a photon
05 · 47s · LAB
Energy Comes in Steps
Why atoms glow in exact colours.
Δx position spreadA PARTICLE’S WAVE PACKET
06 · 58s · LAB
The Uncertainty Principle
Nature keeps a little fuzziness.
|0⟩|1⟩06%194%Tilt sets the odds↻ turning = phase
07 · 1:28 · LAB
Superposition
Being two things at once — until measured.
ALICEUPBOBDOWN50% ↑ · 50% ↓Always opposite — instantly, at any distance
08 · 1:43 · LAB
Quantum Entanglement
Two particles, one shared state — at any distance.
BARRIERFADESA little leaks out!
09 · 46s · LAB
Quantum Tunnelling
Passing through walls — sometimes.
Space & the Universe
11 bites
From comets and stars to black holes and the Big Bang.
AN ORBIT→ moving sideways→ falling toward EarthAlways falling, never landing
01 · 57s · LAB
Orbits: Always Falling
Why the Moon never hits the ground.
you are hereTHE MILKY WAY~100,000 light-years across
02 · 55s · LAB
How Big Is Space?
Measuring the universe with light.
TAILS POINT AWAY FROM THE SUNpushed by sunlight and the solar wind
03 · 48s · LAB
Comets
Icy wanderers with tails that point away from the Sun.
MASS DECIDES EVERYTHINGRed dwarf0.2 Suntrillions of yearsSun1 Sun10 billion yearsBlue giant20 Suns10 million yearsheavier = hotter, bluer, shorter-lived
04 · 57s · LAB
How Stars Shine
Gravity, fusion and E = mc².
THEY ORBIT A SHARED BALANCE POINT+ centre of mass: m₁ r₁ = m₂ r₂heavy star: small, slow circle · light star: big, fast circle
05 · 50s · LAB
Binary Stars
Two suns, one orbit — and how we weigh stars.
A NEUTRON STAR~20 km1.4 Suns of mass, the size of a city
06 · 45s · LAB
Neutron Stars
A Sun’s worth of mass in a city-sized ball.
A COSMIC LIGHTHOUSEPULSE!beams from the magnetic poles sweep past Earthone flash every turn
07 · 46s · LAB
Pulsars
Spinning neutron stars that tick like clocks.
GRAVITY BENDS LIGHTtoo close → captured · the dark shadow
08 · 55s · LAB
Black Holes
Where escape needs more than light speed.
JETSparticles at~99% of light speedup to a millionlight-years long
09 · 48s · LAB
Quasars
Black holes that outshine whole galaxies.
THE BIG BANG’S AFTERGLOWcosmic microwave background2.7 K — just above absolute zerotiny hot and cold spots: seeds of galaxies
10 · 44s · LAB
The Big Bang
An expanding universe with a beginning.
ANNIHILATIONall the mass → two gamma rayseach photon: 511 keV · E = mc²
11 · 50s · LAB
Antimatter
Matter’s mirror twin — and a cosmic mystery.
Relativity
8 bites
Einstein’s rules for space, time and light.
A MOVING CLOCK TICKS SLOWERseen from outside, its light zigzags: a longer path→ 0.6 cat rest4moving clock3ticks so far
01 · 2:15 · LAB
Moving Clocks Run Slow
Why time passes slower when you move fast.
FAST THINGS ARE SHORTERat rest100 mflying past at 0.87 c50 mmeasured along its motion, from outside
02 · 1:17 · LAB
Moving Rulers Shrink
Fast objects are shorter — and so is the space ahead of them.
THE SAME FLASH, FROM THE PLATFORMtrain moving right at 0.5 cback door first……front door laterthe back door moves toward the light; the front door runs away
03 · 1:08 · LAB
Same Time? It Depends
Two events at once for you can be one after the other for me.
COUNT THE BIRTHDAYSlight-years →time ↑1025 years15 yearsthe straight path throughspacetime has the most timetested in 1971 with atomicclocks flown round the world
04 · 1:06 · LAB
The Twin Paradox
Why the twin who travels comes home younger.
E = mc²energymasslight speed²mass is a form of energyc² = 90,000,000,000,000,000 m²/s²(about ninety thousand trillion)
05 · 1:04 · LAB
E = mc²
Mass is energy — a lot of it.
YOUR LIGHT CONEyou, nowfuturewhat you can reach or affectpastwhat could have affected youelsewhereelsewhereevents “elsewhere” can’t affect you, or you them: not yet
06 · 1:08 · LAB
Spacetime
Space and time are one thing — drawn as a map.
MASS CURVES SPACETIMEa planet’s orbitit follows the straightest path through curved spacetime
07 · 1:09 · LAB
Gravity Bends Spacetime
Gravity isn’t a pull — it’s the shape of spacetime.
THE FIX+45 μs−7 μs= +38 μsper dayleft uncorrected, your position would drift11 kmso engineers tune the satellite clocksto tick slightly slow before launchevery map on your phone uses both of Einstein’s theories
08 · 1:06 · LAB
GPS Needs Relativity
Without Einstein, your map would drift 10 km a day.
Light & Optics
8 bites
How light bounces, bends, spreads and splits into colours.
A CURVED MIRROR GATHERS LIGHTfocustelescopes · satellite dishes · headlights
01 · 1:04 · LAB
Mirrors and Reflection
Angle in equals angle out — and that explains a lot.
WHY THE BEAM BENDSair (fast)glass (slow)the side that slows first makes the beam swing round
02 · 1:06 · LAB
Why Light Bends
Light slows down in glass and water — and changes direction.
WHY DIAMONDS SPARKLEdiamond: n = 2.42critical angle 24°light bounces inside and flashes back out of the top
03 · 1:02 · LAB
Trapping Light
How glass becomes a perfect mirror — and carries the internet.
A REAL, UPSIDE-DOWN IMAGEFFobjectimagecameras · projectors · your eye
04 · 1:04 · LAB
How Lenses Work
Bending light to make images — in cameras, glasses and your eye.
THE SECOND BOWsecond bow, 51°, colours reversedAlexander’s dark bandmain bow, 42°brighter sky inside
05 · 1:05 · LAB
How Rainbows Form
Sunlight, raindrops and a 42° angle.
TWO SLITS: STRIPESThomas Young, around 1801: light is a wave
06 · 1:04 · LAB
Light Spreads Out
Diffraction: the clue that light is a wave.
CROSS TWO FILTERSfirst filtersecond, turned 53°37%at 90°, no light gets through
07 · 53s · LAB
Polarised Light
The hidden direction of light — and why sunglasses cut glare.
WHY SUNSETS ARE REDyousun high: 1× airsunset: ~40× airalong the long path, the blue is scattered away
08 · 57s · LAB
Why the Sky Is Blue
Air scatters blue light — and steals it at sunset.
Electricity & Magnetism
9 bites
Charges, currents and magnets — and how together they make light.
THE RULES OF CHARGErepelrepelattractlike charges repel, opposites attract
01 · 50s · LAB
Electric Charge
Plus and minus: the force that holds atoms together.
FIELD LINESlines start on +…and end on −crowded lines = strong field
02 · 56s · LAB
Electric Fields
How charges reach across empty space.
VOLTAGE: THE PUSHPUMPbattery = pumplifts charge to higher energybulb = wheel: uses the energyvoltage = energy per unit of charge (volts)
03 · 1:00 · LAB
Voltage and Current
What actually flows in a wire — and what pushes it.
IN PARALLEL: SEPARATE PATHS+each branch gets the full voltage; currents add upthat’s how homes are wired
04 · 50s · LAB
Circuits and Ohm’s Law
Loops, switches, series and parallel.
A MAGNETIC FIELDSNcompass needles follow the lines, from N round to S
05 · 1:02 · LAB
Magnets
Poles, fields, and the giant magnet under your feet.
COIL IT UPSNa coil makes a field like a bar magnetadd an iron core: an electromagnet, far stronger
06 · 50s · LAB
Electromagnets
Currents make magnets — ones you can switch off.
WHERE ELECTRICITY COMES FROMSNalternating voltagespinning magnets past coils, 50 or 60 times a second
07 · 56s · LAB
Faraday’s Induction
Moving magnets make electricity.
A LOOP THAT SPINS: A MOTORNSthe two sides are pushed opposite waysso the loop turns
08 · 47s · LAB
How Motors Work
Magnets and currents that make things spin.
THE ELECTROMAGNETIC SPECTRUMradiomicrowaveinfraredvisibleUVX-raygamma← longer wavesshorter waves →visible light is a tiny slice of it
09 · 57s · LAB
Light Is an Electromagnetic Wave
Electricity and magnetism, travelling together at light speed.
Heat & Thermodynamics
8 bites
Temperature, heat, engines — and why time only runs one way.
TEMPERATURE IS MOTIONhotter: the molecules move faster
01 · 1:01 · LAB
What Is Temperature?
Hot and cold are really fast and slow.
CONVECTIONwarm fluid rises, cool fluid sinksit drives boiling pans, sea breezes and the weather
02 · 57s · LAB
How Heat Moves
Conduction, convection and radiation.
SQUEEZE IT: BOYLE’S LAW2.0× pressurevolume 50% → pressure ×2.0P × V stays the same
03 · 59s · LAB
The Gas Laws
Squeeze it, heat it: how gases push back.
GAS SPREADS OUTfar more ways to be spread out than bunched upnothing pushes them apart: it is just overwhelmingly likely
04 · 56s · LAB
Entropy
Why things spread out, mix up and run down.
▶ PLAYED FORWARDSthis looks normalyet each molecule’s laws work fine in reverse
05 · 57s · LAB
Why Time Has a Direction
Eggs break but never unbreak. Entropy is why.
CARNOT’S LIMITmax efficiency = 1 − T_cold / T_hottemperatures in kelvinhot side 900 K, cold side 300 Kat best 67%hotter engines can be more efficient
06 · 57s · LAB
Heat Engines
Turning heat into motion — and why some is always wasted.
STRANGE THINGS HAPPENsuperconductor:zero resistance, floating magnetssuperfluid helium:no friction, creeps up walls
07 · 57s · LAB
Absolute Zero
The coldest temperature possible — and why we can’t reach it.
COLD | HOT — FOR FREE?coldhotentropy went down: the second law broken?
08 · 59s · LAB
Maxwell’s Demon
Can a tiny sorter beat the second law?
Privacy
·
Terms