Build a CD spectroscope
Split light into its colours with a cardboard tube and an old CD, and discover how astronomers know what stars are made of.
●○○1 evening~£0Late Oct
The library
Hands-on experiments, books and tools for learning physics at home. Members can suggest new ones — every suggestion is checked before it appears here.
Experiments
Measure the speed of light with chocolate
Use a microwave oven, a bar of chocolate and a ruler to measure one of the fastest things in the universe.
●○○30 minutes~£2 (one chocolate bar)Nov
The double-slit experiment at home
See light behave like a wave using a laser pointer, a hair and some kitchen foil — the gateway to quantum weirdness.
●●○1–2 evenings~£5 (laser pointer)Nov
Find Planck's constant with LEDs
Different coloured LEDs switch on at different voltages. A multimeter and a little maths reveal the number at the heart of quantum physics.
●●○2 evenings~£15 (multimeter + LED kit)Late Nov – mid Dec
Weigh Jupiter
Track Jupiter's moons through binoculars over a few weeks, then use Kepler's third law to work out the mass of the largest planet.
●●●Several clear nights over 2–4 weeks£0 with binoculars you ownMid Dec – Jan
Track sunspots to time the Sun's spin
Project the Sun safely onto card, sketch its spots over a couple of weeks, and work out how fast our star rotates.
●●○10 minutes on each clear day, over ~2 weeks£0 with binoculars you ownMid Dec – Jan
Measure the Earth like Eratosthenes
A stick, its noon shadow and a little geometry — the same method used to measure the planet over 2,000 years ago.
●○○1 sunny day near the equinox£0Feb – Mar
Simulate an orbit in code
Start with PhET's ready-made simulations, then write a 30-line Python program that makes a planet orbit the Sun.
●●○2–3 evenings£0Feb – Mar
A charged particle in a magnetic field
Simulate the spiral path of a charged particle in Python — the motion behind auroras, particle accelerators and the Earth's radiation belts.
●●●2 evenings£0
Discover Hubble's law from real data
Look up real galaxies' distances and speeds, plot them in Python, and find out how fast the universe is expanding — and how old it is.
●●○2 evenings£0
Measure distance by parallax
Start with your thumb jumping as you blink, then measure the distance to a faraway landmark — the same idea astronomers use for the nearest stars.
●●○1 afternoon£0
Measure the Sun's diameter with a pinhole
Project a tiny image of the Sun through a pinhole and use similar triangles to work out how big our star is.
●○○1 sunny hour£0
Simulate a falling object, step by step
Your first physics simulation — a dozen lines of Python that drop a ball, then add air resistance and find its top speed.
●●○1–2 evenings£0
Simulate a particle in a box
Solve the simplest quantum system in Python — an electron trapped between two walls — and see why its energy comes in steps.
●●●2 evenings£0
Simulate an exoplanet transit
Extend your orbit code to make a planet cross its star, and see the tiny dip in starlight that astronomers use to find new worlds.
●●○2 evenings£0
The three-polariser puzzle
Two crossed polarising filters block all light — until you slip a third one between them. A tabletop doorway into quantum measurement.
●○○1 evening~£5 (polarising film)
Time a pendulum
A weight on a string and your phone's stopwatch — measure how the swing depends on length, then use it to measure gravity.
●○○1 evening£0
Why GPS needs relativity
A pen-and-paper calculation of how much GPS satellite clocks drift because of Einstein's relativity — and how far off your map would be without the fix.
●●○1 evening£0
Books
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Seven Brief Lessons on Physics — Carlo RovelliA very short, beautifully written tour of relativity, quantum mechanics, black holes and time.
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Quantum: A Guide for the Perplexed — Jim Al-KhaliliA clear, friendly guide to what quantum mechanics says — and why it's so strange.
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Astrophysics for People in a Hurry — Neil deGrasse TysonBite-sized chapters on the universe, from the Big Bang to dark matter.
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The Theoretical Minimum: Classical Mechanics — Leonard Susskind and George HrabovskyThe real physics, with only the maths you need: volume 1 of Susskind's series, on classical mechanics, with a free lecture series.
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Calculus Made Easy — Silvanus P. ThompsonThe famously friendly 1910 introduction to calculus — what a derivative and an integral actually mean, with no fuss.
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The Biggest Ideas in the Universe: Quanta and Fields — Sean CarrollQuantum mechanics and quantum field theory, with the real equations explained in plain language.
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The Biggest Ideas in the Universe: Space, Time and Motion — Sean CarrollThe real equations of classical physics and relativity, explained for curious readers rather than students.
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The Theoretical Minimum: Quantum Mechanics — Leonard Susskind and Art FriedmanQuantum mechanics as physicists actually do it — states, measurement and entanglement — with only the maths you need.
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The Theoretical Minimum: Special Relativity and Classical Field Theory — Leonard Susskind and Art FriedmanSpecial relativity and fields — the third volume of Susskind's series, with only the maths you need.
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Welcome to the Universe — Neil deGrasse Tyson, Michael A. Strauss and J. Richard GottAn astrophysical tour from the planets to the Big Bang, based on a Princeton course for non-scientists.
Tools and resources
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StellariumFree planetarium app: see what's in your sky tonight and identify Jupiter's moons.
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PhET Interactive SimulationsFree physics simulations from the University of Colorado — orbits, photons, atoms and more.
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ZooniverseDo real citizen science, such as classifying galaxies for research teams.
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OpenLearnThe Open University's free short courses, including introductions to astronomy and quantum physics.
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OpenStax Astronomy 2eA complete, free university astronomy textbook from Rice University — the place to look things up properly.
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The Feynman Lectures on PhysicsRichard Feynman's legendary lectures, free to read online from Caltech.
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AnkiFree flashcard app that uses spaced repetition, so what you read actually sticks.