100 Fun Facts About Energy

The SI unit of energy is named after which English physicist?

James Prescott Joule, a brewer and amateur scientist, let falling weights turn a paddle wheel in an insulated tank and showed that the work done always produced the same amount of heat.

The term 'horsepower' was adopted in the late 18th century by which engineer to sell his steam engines?

James Watt used horsepower to compare his engines with the draft horses they replaced; the unit of power that later displaced it, the watt, was named after him.

In which year did Einstein publish the paper establishing mass-energy equivalence, E = mc²?

It was one of his four 'miracle year' papers; the paper actually says a body giving off energy L loses mass L/c², rather than writing the famous formula.

In which city did Thomas Edison open Pearl Street Station, his first commercial power plant in the United States, in 1882?

New York: Pearl Street's six dynamos lit part of lower Manhattan until a fire in 1890 destroyed all but one of them, and the survivor is now a museum piece in Dearborn, Michigan.

The world's first nuclear power plant to feed electricity into a grid, in 1954, was in which country?

Soviet Union: its small Obninsk plant began supplying electricity in June 1954, three years after an American test reactor in Idaho had generated the first, trivial amount of nuclear electricity.

The world's largest power station by installed capacity, at 22,500 megawatts, sits on which river?

Yangtze: the Three Gorges reservoir is so vast that NASA scientists calculated its mass lengthens Earth's day by 0.06 microseconds.

The Chernobyl explosion of 26 April 1986 destroyed which of the plant's reactors?

Unit 4 blew up during a test of how its cooling pumps would cope with a power cut; the plant's other reactors kept running for years, the last until December 2000.

Besides Chernobyl, which nuclear accident was rated level 7 on the International Nuclear Event Scale?

Fukushima Daiichi (2011): three reactor cores melted after the tsunami from the Tōhoku earthquake swamped the plant, and Japan rated the accident lower at first, raising it to 7 a month later.

The 1973 oil embargo punished countries that backed Israel in which war?

The Yom Kippur War: Arab oil producers cut off the United States for resupplying Israel, the price of oil roughly quadrupled, and America adopted a national 55 mph speed limit to save fuel.

The first commercial oil well in the United States, drilled by Edwin Drake in 1859, is in which state?

Pennsylvania later voted Drake an annuity: he never patented his drilling method, lost his money and ended up poor while others made fortunes from oil.

How deep was Edwin Drake's pioneering 1859 oil well?

Modern wells routinely go down several kilometres; Drake's success mattered because it prompted enough drilling nearby to supply real businesses.

Which Italian scientist built the first electric battery around 1800 from a stack of zinc and copper discs?

Alessandro Volta built his pile to settle an argument with Luigi Galvani, who believed the twitching of frogs' legs revealed an 'animal electricity'; the volt is named after him.

John B. Goodenough became the oldest Nobel laureate at 97 by sharing the 2019 chemistry prize for what?

Lithium-ion batteries: Goodenough's 1980 cobalt-oxide cathode lifted the first lithium cell from about two volts to four, and Akira Yoshino built on it to make the first commercially viable version in 1985.

Which fish delivers the strongest electric shock of any animal, up to 860 volts?

Electric eel: despite the name it is a knifefish, not a true eel, and the 860-volt record belongs to a species that scientists only told apart from its relatives in 2019.

ITER, the giant international fusion experiment, is the world's largest example of which type of reactor?

Tokamak: ITER's is designed to release 500 megawatts of fusion power from 50 megawatts of heating, and the project grew out of a 1985 summit between Ronald Reagan and Mikhail Gorbachev.

The Sun shines by fusing hydrogen in its core into which element?

Helium: the Sun has been making it for about 4.6 billion years, and when its core hydrogen runs low in roughly five billion more it will swell into a red giant.

How long does light from the Sun take to reach Earth?

About 8 minutes: sunlight takes roughly 8 minutes 20 seconds to cross the 150 million km to Earth, so we always see the Sun as it was eight minutes earlier.

A calorie is the heat needed to warm one gram of what by one degree Celsius?

Water: the energy in food was first measured by burning a sample in a sealed 'bomb calorimeter' surrounded by water and reading how far the water's temperature rose.

Which process powers every commercial nuclear power station today?

Nuclear fission was discovered in 1938 by Otto Hahn and Fritz Strassmann and explained by Lise Meitner and her nephew Otto Frisch, yet only Hahn received the Nobel Prize for it.

In which country does geothermal energy heat roughly nine in ten homes?

Iceland sits on a volcanic rift that is among the most geologically active places on Earth, and it pipes the heat to buildings through district-heating networks.

Which French physicist first demonstrated the photovoltaic effect in 1839, aged 19?

Edmond Becquerel was experimenting with metal electrodes in a conducting solution in his father's laboratory when he found that light made a current flow, the principle behind every solar cell.

The first practical silicon solar cell was publicly demonstrated in 1954 at which research institution?

Bell Laboratories' silicon cell, by Daryl Chapin, Calvin Fuller and Gerald Pearson, succeeded where Charles Fritts's selenium cells of 1883 had not: those turned only about 1 percent of sunlight into electricity, too little to be practical.

In which country did James Blyth build a wind-powered machine to light his holiday home in July 1887?

Scotland: Blyth's windmill charged batteries that lit his cottage at Marykirk, and a later design is said to have powered the home for 25 years; that winter Charles Brush built a far larger machine in Ohio.

The first artificial nuclear reactor went critical in 1942 under a football stadium at the university of which city?

Chicago Pile-1, built by Enrico Fermi's team in a rackets court under the stands of Stagg Field, was held to about half a watt on its first run and shut down after a few minutes.

Hoover Dam impounds Lake Mead on the border between Nevada and which other state?

Arizona: built in the Black Canyon of the Colorado between 1931 and 1936, the dam was called Boulder Dam under the Roosevelt administration until Congress restored Hoover's name in 1947.

Which pigment do plants mainly use to capture light for photosynthesis?

Chlorophyll absorbs most colours of sunlight but green least, so green is the light that leaves bounce back to our eyes.

Which law of thermodynamics says energy can be transformed but neither created nor destroyed?

The first law is why a machine that puts out more energy than it takes in can never work, and why the US Patent Office refuses perpetual-motion patents without a working model.

Under the third law of thermodynamics, a system's entropy approaches a constant value as what approaches zero?

Its temperature: absolute zero, −273.15 °C, can be approached but never reached, so even the coldest laboratory experiments stop a tiny fraction of a degree short.

In the 1880s 'war of the currents', which company's AC system did Edison's DC oppose?

Westinghouse underbid General Electric to light the 1893 World's Columbian Exposition, and later that year won the contract to build the generators at Niagara Falls.

Household electricity bills are charged in which unit?

Kilowatt-hours measure energy, not power: one is a kilowatt used for an hour, so a 100-watt television takes ten hours to use one.

Japan's 2011 nuclear disaster began when a tsunami flooded and disabled the plant's what?

Emergency diesel generators: the tsunami put nearly all of them out of action, leaving no power to pump away the heat still building in the shut-down reactors, and three cores melted.

The first full-scale test of a thermonuclear device, in November 1952, was code-named what?

Ivy Mike yielded about 10 megatons, hundreds of times the Hiroshima bomb, but it was no usable weapon: its fuel was liquid deuterium that had to be kept at extremely low temperatures.

Which scientist discovered electromagnetic induction in 1831 and built the first electric generator?

Michael Faraday, a former bookbinder's apprentice with little formal schooling, could not express his ideas in mathematics; James Clerk Maxwell later turned them into the equations of electromagnetism.

Which temperature scale is named after the title taken by thermodynamics pioneer William Thomson, from a river in Glasgow?

Kelvin: Thomson, knighted for his work on the transatlantic telegraph cable, became Baron Kelvin in 1892, taking the name of the river that runs past Glasgow University.

Which English polymath possibly first used 'energy' in its modern sense, in 1807?

Thomas Young used the word in his 1807 lectures for what is now called kinetic energy; his experiments also challenged Newton's view that light is made of particles.

Which of these countries was one of OPEC's five founding members in Baghdad in 1960?

Venezuela, the only founder from outside the Middle East, was a driving force: its oil minister Juan Pablo Pérez Alfonzo helped call the Baghdad meeting.

Who proposed the name 'watt' in an 1882 address to the British Association?

Siemens, the German-born engineer behind the Siemens Brothers cable firm, was the association's president that year; the SI formally adopted the watt in 1960.

As of 2024, which country generates about two-thirds of its electricity from nuclear power?

France: in 1974, just after the first oil shock, its government launched a crash programme of reactor-building to cut the country's reliance on imported fuel.

What do physicists call the energy stored in a raised weight or a stretched spring?

Potential energy: a lake held high behind a dam is a store of it, which turns into motion and then electricity as the flow drops through the turbines.

Which country mines about half of the world's coal?

China mines about half of the world's coal, and is also both the largest consumer and the largest importer of it.

What is the highest rank of coal, a hard, glossy black variety that is up to 97 percent carbon?

Anthracite is the coal that heat and pressure have worked on the most over millions of years; lignite, the lowest rank, is the youngest.

Which oilfield services company performed the first two commercial fracking treatments on 17 March 1949?

Halliburton's pressurised fluid did a job that drillers since the 1860s had done by exploding nitroglycerin 'torpedoes' down their wells to shatter the rock.

Ghawar, by far the largest conventional oil field in the world, is in which country?

Saudi Arabia: American geologists surveying the desert spotted the uplift that hides Ghawar years before its first well struck oil in 1948, and state-owned Saudi Aramco runs the field.

Which country gets the highest proportion of its electricity from wind, 59 percent in 2024?

It pioneered commercial wind power in the 1970s and is home to Vestas, the world's largest turbine maker.

The 2014 Nobel Prize in Physics went to the inventors of an efficient LED of which colour?

Blue was the missing colour: red and green LEDs had existed for decades, and only with blue could they be combined into the white light of today's low-energy lamps.

The EPA's Energy Star label, created in 1992, first appeared on which products?

Computers and monitors came first: the EPA launched the label for office equipment, added printers and fax machines a year later, and only afterwards moved on to home heating and whole buildings.

Which rival of Isaac Newton proposed 'vis viva', a living force equal to mass times velocity squared?

Gottfried Leibniz argued that vis viva, not the 'quantity of motion' Descartes favoured, was what nature conserves, and his 1686 attack on Descartes set off a famous dispute among natural philosophers.

Which French engineer, studying how machines do work, described kinetic energy in its modern sense?

Gaspard Coriolis introduced 'work' and 'kinetic energy' in their modern senses while studying machines; his famous force also came from analysing rotating machinery such as waterwheels, not the weather.

Which Danish physicist proposed quantised energy levels in atoms in 1913?

Niels Bohr pictured electrons confined to fixed orbits, giving off light only when they jump to a lower one, which explained why atoms emit only certain colours.

Which mathematician's 1918 theorem ties energy conservation to symmetry in time?

Emmy Noether proved it at Göttingen, where the faculty refused to appoint a woman, so for years her lectures were advertised under David Hilbert's name.

Which organ, only about 2% of body weight, uses roughly a fifth of the human body's energy?

The brain is a hungry organ: it uses up to 20% of the body's energy and takes about 15% of the blood the heart pumps.

Which type of light bulb, glowing from a white-hot tungsten filament, turns under 5% of its energy into light?

Incandescent bulbs release more than 95% of their energy as heat, so a 'light' bulb of this kind is really a small heater that happens to glow.

Brent Crude, a benchmark for world oil prices, takes its name from an oil field under which sea?

The North Sea field was named after the brent goose, because Shell called its UK oil fields after seabirds in alphabetical order: Auk, Brent, Cormorant.

Which odourless gas makes up about 95% of the natural gas burned in home stoves and boilers?

Methane has no smell of its own, so suppliers add an odorant that reeks of rotten eggs to make leaks easy to notice.

In Albert Einstein's famous equation E = mc², what does the letter c stand for?

The speed of light is so large, and squared in the equation, that a tiny amount of mass corresponds to an enormous amount of energy.

Which measure did Germany adopt nationwide in April 1916 to save coal during the First World War?

Daylight saving time was meant to ease wartime coal shortages by shifting an hour of light to the evening. Germany and Austria-Hungary both began on 30 April 1916.

Which heavy metal, pressed into small pellets, is the usual fuel in nuclear power stations?

Uranium packs astonishing energy: a single fuel pellet produces more heat than burning a ton of coal.

The world's first large-scale AC power plant, opened in 1895, drew its energy from which waterfall?

Niagara Falls drove the Adams Power Plant, and one building from it still stands beside the river as a National Historic Landmark.

Tidal power stations harvest the rise and fall of the sea, caused mainly by the pull of what?

The Moon does most of the lifting: the Sun's tidal force is only about 46% as strong, and the regular lunar orbit makes tidal power highly predictable.

Which Houston energy-trading company collapsed in 2001 in what was then the largest bankruptcy in US history?

Enron had been named 'America's Most Innovative Company' by Fortune for six years running before its accounting fraud unravelled.

Which simple sugar do green plants make from air, water and sunlight to store the Sun's energy?

Glucose made in photosynthesis is fuel for nearly all life: every living organism can use it as a source of energy.

In a hydroelectric dam, water rushing down the penstock spins which bladed machine to make electricity?

A turbine does not need a giant dam: small ones can light a few homes from a drop of only one metre.

Which gas, released when coal and oil burn, is the primary cause of modern climate change?

Carbon dioxide is only a trace of the air, yet burning fossil fuels has lifted it from about 280 parts per million before industry to more than 420.

Which invisible rays did William Herschel find in 1800 when a thermometer warmed up beside a spectrum of sunlight?

Infrared rays turned out to carry slightly more than half of the Sun's energy that arrives on Earth, though no human eye can see them.

Gram for gram, which nutrient in food supplies the most energy, about 9 kilocalories?

Fat holds about 9 kilocalories per gram against roughly 4 for protein and most carbohydrates; only alcohol comes close, at 7.

The word 'energy' comes from energeia, a Greek term traced back to which philosopher of the 4th century BC?

Aristotle's energeia meant 'activity', a notion broad enough to include happiness and pleasure.

Which reaction, discovered in 1938 and named after the way living cells divide, powers every nuclear power station?

Fission got its name from physicist Otto Frisch, who borrowed the biologists' word for a cell dividing in two after he and Lise Meitner explained the discovery.

A drawn bow and a compressed spring both store which kind of potential energy until released?

Elastic energy is held in any object stretched, squashed or bent out of shape, which is how a catapult flings its load.

Which tiny charged particles carry the electric current along the metal wires in a home?

Electrons actually drift the opposite way to the 'conventional current' drawn on circuit diagrams, which follows the direction positive charges would flow.

Which US nuclear plant on the Susquehanna River suffered a partial meltdown in March 1979?

Three Mile Island is the worst accident in US commercial nuclear power history, yet its small releases had no detectable health effects on workers or the public.

The ruined Chernobyl nuclear power plant, beside the abandoned city of Pripyat, lies in which present-day country?

Ukraine holds the plant in its far north, only 16 km from the border with Belarus and about 100 km north of Kyiv.

The Lucas gusher at Spindletop, which blew in January 1901, launched the oil boom in which US state?

Texas changed overnight: the Spindletop well near Beaumont blew for nine days at an estimated 100,000 barrels of oil a day.

Which oil giant, built by John D. Rockefeller from 1870, was ordered broken up by the US Supreme Court in 1911?

Standard Oil's pieces lived on under new names, among them Exxon, Chevron and Amoco.

A large share of the world's seaborne oil squeezes through which narrow waterway between Iran and Oman?

The Strait of Hormuz is the only sea exit from the Persian Gulf, and in 2023–2025 it carried a quarter of all oil traded by sea.

The word petroleum joins the Latin for 'oil' to the Latin word petra, which means what?

Rock is the first half of the name, so petroleum is literally 'rock oil', a label coined in medieval Latin.

Which fuel, registered as a trademark by geologist Abraham Gesner in 1854, is now widely burned in jet engines?

Kerosene takes its name from the Greek for 'wax', and a highly refined grade called RP-1 burns in some rocket engines.

Which bottled gas became a favourite for barbecues and camping stoves because it boils at −42 °C?

Propane's low boiling point lets it turn to vapour inside a pressurised tank even on a cold day, sitting as gas above liquid.

Which hydrocarbon gives its name to the rating on petrol pumps that shows how well a fuel resists engine knocking?

Octane numbers compare a fuel with a test blend of two chemicals: iso-octane is assigned a rating of 100 and n-heptane a rating of 0.

Which alcohol fuel made from sugarcane is blended into the gasoline sold for cars across Brazil?

Ethanol is so established in Brazil that no light vehicles there run on pure gasoline, and blending it in has been mandatory since 1976.

Which mountainous European country gets almost nine-tenths of its electricity from hydropower stations?

Norway runs more than 1,700 hydropower plants, so its electricity sector relies predominantly on falling water.

Itaipu Dam, among the world's most productive hydroelectric plants, sits on Brazil's border with which country?

Paraguay and Brazil built the dam on the Paraná River under a 1973 treaty, and in 1994 American civil engineers named it one of the seven modern Wonders of the World.

Grand Coulee Dam, the largest power station in the United States, spans which river in Washington state?

Columbia water does double duty at Grand Coulee: the dam was built both to produce hydroelectric power and to supply irrigation.

Prudhoe Bay, the largest oil field in North America, feeds an 800-mile pipeline across which US state?

Alaska's North Slope field originally held about 25 billion barrels, and its oil flows south through the Trans-Alaska Pipeline to the tanker terminal at Valdez.

Which Serbian-American inventor's 1888 induction motor patents became the cornerstone of alternating-current power?

Nikola Tesla earned a considerable sum licensing the patents, and since 1960 the SI unit of magnetic flux density has carried his surname.

Which German physicist proposed in 1900 that energy is emitted in packets called quanta, launching quantum theory?

Max Planck's Nobel Prize citation honoured 'his discovery of energy quanta': the supposition that energy is given out only in multiples of an elementary unit.

Which physicist showed in 1865 that light is a travelling wave of electric and magnetic fields?

James Clerk Maxwell's equations are counted as the second great unification in physics, after Isaac Newton's, and he also presented the first durable colour photograph.

Which marquise, translator of Newton's Principia, dropped balls into clay to show energy grows with speed squared?

Émilie du Châtelet's Principia, published after her death, remains the only complete translation of Newton's book into her language.

Which German physician stated the conservation of energy in 1847 and later invented the ophthalmoscope?

Hermann von Helmholtz came to physics through medicine: his treatise 'On the Conservation of Force' grew out of his medical studies.

Which engineer's only book, 'Reflections on the Motive Power of Fire', made him the 'father of thermodynamics'?

Sadi Carnot died in relative obscurity at 36, long before his theory of the ideal heat engine made his name.

Which molecule, found in all known life, is nicknamed the 'molecular unit of currency' for energy inside cells?

ATP is spent and rebuilt so quickly that an average adult recycles around 50 kilograms of it every day.

Which radioactive metal's slow decay provides the heat that powers the Voyager probes and the Curiosity rover?

Plutonium-238 gives off steady heat that is converted into electricity; the first such unit sent into space, in 1961, carried just 96 grams of it.

Which cell structures were nicknamed the 'powerhouse of the cell' in a 1957 Scientific American article?

Mitochondria earn the name by using oxygen to release the chemical energy in food, and they even carry their own small genome, similar to a bacterium's.

In the rainbow of visible light, which colour's photons each carry the most energy?

Violet sits at the short-wavelength end of the visible spectrum, and a photon's energy rises as its wavelength shrinks.

In physics, which quantity equals a force multiplied by the distance moved in the force's direction?

Work has a tidy everyday example: when a ball is dropped, gravity's contribution equals the ball's weight times the height it falls.

Which measure, always below 100% for a real engine, compares a machine's useful output with its energy input?

Efficiency depends on what you count as useful: the output may be motion, light or heat, so one machine can score differently for different jobs.

Which form of heat transfer, the only one that crosses a vacuum, brings the Sun's warmth to Earth?

Radiation can be gathered as well as felt: mirrors at the PS10 solar tower focus sunlight to heat water to 285 °C.

Which soggy fuel, cut from bogs and dried for burning, is the first step in the formation of coal?

Peat is mostly half-rotted bog plants such as mosses and sedges, and over geological time it can turn into lignite, a low-grade coal.

Which lightweight black fuel is made by strongly heating wood with very little oxygen?

Charcoal is what remains once the water and volatile compounds are driven off, and it was widely used in place of coke in blast furnaces.

Which English ironmonger built a steam-driven 'atmospheric engine' in 1712 to pump water out of flooded mines?

Thomas Newcomen, a Baptist preacher by calling, created the first practical device to harness steam for mechanical tasks, and hundreds were built in the 1700s.

Which US Navy submarine, launched in 1954, was the world's first vessel powered by a nuclear reactor?

USS Nautilus went on to make the first submerged transit of the North Pole, on 3 August 1958.