Physics Trivia
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8correct to beat the crowd
This physics trivia quiz runs 110 free questions with answers across the whole subject: the SI units and who they are named after, the constants that hold the universe together, the classic experiments from Cavendish's torsion balance to the LIGO detectors, and the people behind quantum and particle physics. It starts with things most people half-remember from school, such as the speed of light, absolute zero and why the sky is blue, and climbs to questions for real enthusiasts: which metal superconductivity was first seen in, what is carved on Boltzmann's tombstone, and who quipped 'Who ordered that?' when the muon turned up. It works as a science round for a pub quiz, a classroom warm-up or a solo test of how much physics you actually retained. Every answer has been checked against an encyclopaedia or primary source, and each question shows its explanation and citation once you have answered, so a disputed fact can be settled on the spot.
30 of 110 questions with answers and explanations. Play the quiz
Q 01Roughly how fast does light travel through empty space?
About 300,000 km per second
Light travels at about 300,000 km per second through empty space, exactly 299,792,458 metres per second; since 1983 the metre has been defined from that speed.
Q 02Whose three laws of motion were first published in the Principia in 1687?
Isaac Newton
Isaac Newton set out the three laws in Philosophiae Naturalis Principia Mathematica, written in Latin and published in 1687, alongside universal gravitation.
Q 03Which SI unit, symbolised by the Greek letter omega, measures electrical resistance?
Ohm
The ohm honours the German physicist Georg Ohm, whose 1827 law links voltage, current and resistance; one ohm passes one ampere under one volt.
Q 04What phenomenon makes the daytime sky look blue?
Rayleigh scattering
Rayleigh scattering by air molecules affects short blue wavelengths far more than long red ones, so scattered blue light fills the sky; the low Sun turns orange as its blue is scattered away.
Q 05At 20 °C, how fast does sound travel through air?
About 343 metres per second
Sound moves at about 343 metres per second in air at 20 °C, roughly a kilometre every three seconds, which is why you count between lightning and thunder.
Q 06Absolute zero corresponds to which temperature on the Celsius scale?
−273.15 °C
Absolute zero is −273.15 °C, or 0 kelvin, the point to which an ideal gas's pressure would extrapolate to nothing; Johann Lambert had estimated about −270 °C in 1779.
Q 07Which SI unit of power is named after a Scottish inventor?
Watt
James Watt improved the steam engine, and Werner von Siemens proposed naming the unit after him. The absolute watt formally joined the SI in 1960.
Q 08Who received the very first Nobel Prize in Physics, in 1901?
Wilhelm Röntgen
Wilhelm Röntgen won the first physics Nobel in 1901 for discovering X-rays, known as Röntgen rays in German and other languages; he never patented them.
Q 09Ignoring air resistance, by roughly how much does a falling object's speed increase each second?
9.8 m/s
A falling object's speed grows by about 9.8 m/s every second; the figure is about 0.5% larger at the poles than at the Equator, so you weigh slightly more in Helsinki than in Singapore.
Q 10In the name of CERN's Large Hadron Collider, what is a hadron?
A particle made of quarks
A hadron is a particle made of quarks bound by the strong force; the proton is the best-known example, and the LHC's 27 km ring near Geneva collides protons.
Q 11Which British physicist is credited with discovering the electron in 1897?
J. J. Thomson
J. J. Thomson showed in 1897 that cathode rays were particles over a thousand times lighter than a hydrogen ion; his son George later won a Nobel for showing electrons diffract like waves.
Q 12Which SI unit is defined as one cycle or event per second?
Hertz
It honours Heinrich Hertz, the first person to prove conclusively that electromagnetic waves exist. Like all units named after people, it is lower-case when written out in full.
Q 13In which year did the ATLAS and CMS experiments at CERN announce the discovery of the Higgs boson?
2012
ATLAS and CMS announced the Higgs boson on 4 July 2012, nearly half a century after Peter Higgs and others proposed it in 1964; the particle weighed about 125 GeV.
Q 21Which SI unit of energy is named after an English physicist born in 1818?
Joule
James Prescott Joule was a brewer's son who worked out how much mechanical work it takes to heat water. One of these units is the work done pushing with a force of one newton over one metre.
Q 22Which physicist led the first self-sustaining nuclear chain reaction at Chicago Pile-1 in 1942?
Enrico Fermi
Enrico Fermi led the team that took Chicago Pile-1 critical on 2 December 1942 in a squash court under the west stands of Stagg Field, proving a controlled chain reaction possible.
Q 23Which particle did James Chadwick discover in 1932, earning him a Nobel Prize three years later?
The neutron
Q 14In which year did Erwin Schrödinger describe his famous cat thought experiment?
1935
Schrödinger published the cat paradox in 1935, the year of the EPR paper, after correspondence with Einstein; it was a critique of the Copenhagen interpretation, not an endorsement.
Q 15Whose principle says buoyant force equals the weight of fluid displaced?
Archimedes
Archimedes' principle, from the Greek mathematician of Syracuse in the third century BC, explains why steel ships float: the displaced water weighs as much as the ship.
Q 16Christian Doppler first proposed his famous effect in an 1842 treatise about the coloured light of what?
Binary stars
Doppler's 1842 paper was titled 'On the coloured light of the binary stars'; his idea that the effect explains star colours was wrong, but the effect itself was right.
Q 17Which SI unit of pressure is named after a French mathematician who experimented with barometers?
Pascal
The pascal honours Blaise Pascal, who in 1648 had a barometer carried up the Puy de Dôme to show that air pressure falls with altitude; weather maps quote hectopascals.
Q 18Albert Einstein's Nobel Prize in Physics was awarded specifically for his work on which phenomenon?
The photoelectric effect
The 1921 prize, announced in 1922, cited Einstein's law of the photoelectric effect; the committee judged relativity too controversial to reward.
Q 19Marie Curie won the 1903 Nobel Prize in Physics and a second Nobel in 1911 in which field?
Chemistry
Her 1911 Nobel was in Chemistry, for discovering radium and polonium; she was the first person to win Nobel Prizes in two different sciences.
Q 20The Planck constant links a photon's energy to which property of the light?
Its frequency
E = hν: a photon's energy is the Planck constant times its frequency, which is why ultraviolet photons carry more punch than red ones; since 2019 h is fixed at exactly 6.62607015 × 10⁻³⁴ J·s.
His letter to Nature was titled 'Possible Existence of a Neutron' after only about two weeks of experiments. The discovery made it possible to create elements heavier than uranium.
Q 24In the acronym LASER, what does the letter S stand for?
Stimulated
The full phrase is light amplification by stimulated emission of radiation. Physicists have joked that LOSER, for light oscillation, would have been more accurate.
Q 25Superconductivity was discovered in 1911 in which metal, cooled to a few degrees above absolute zero?
Mercury
Heike Kamerlingh Onnes saw the resistance of mercury vanish at about 4.2 K in 1911, having liquefied helium three years earlier; he won the 1913 Nobel Prize for low-temperature work.
Q 26Léon Foucault's famous pendulum of 1851 was the first simple, direct demonstration of what?
The rotation of the Earth
Foucault's pendulum, hung first at the Paris Observatory and then under the Panthéon's dome in 1851, swung in a slowly turning plane, showing the rotation of the Earth directly; he repeated the feat with a gyroscope in 1852.
Q 27Which of the four fundamental interactions is by far the weakest at the atomic scale?
Gravity
Gravity is weaker than the other three by dozens of orders of magnitude: a fridge magnet lifting a paperclip beats the pull of the whole planet; it dominates at large scales only because it is always attractive.
Q 28Murray Gell-Mann took the word 'quark' from which novel?
Finnegans Wake
The line 'Three quarks for Muster Mark' in James Joyce's Finnegans Wake appealed to Gell-Mann because he had proposed three such particles; George Zweig preferred the name 'aces'.
Q 29How many flavours of quark are there in the Standard Model?
Six
There are six quark flavours: up, down, charm, strange, top and bottom; only up and down occur in ordinary matter, the rest appear briefly in accelerators and cosmic rays.
Q 30In which year did LIGO make the first direct detection of gravitational waves?
2015
LIGO recorded GW150914 on 14 September 2015, the signal of two merging black holes; the detection was announced in February 2016.