100 Fun Facts About Energy

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

One joule is the work done when a force of one newton moves something one metre; a joule of energy will lift a small apple about a metre.

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

He needed a figure customers could picture: how many draft horses an engine replaced. One imperial horsepower is about 745.7 watts.

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 was Edison's Pearl Street Station, the first US commercial central power plant, opened in 1882?

On its first day it powered just 400 lamps for 82 customers in lower Manhattan; two years later it served 508 customers and more than 10,000 lamps.

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

Obninsk, about 110 km from Moscow, produced only about 5 megawatts of net electricity, but it ran until 2002.

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

China's Three Gorges Dam displaced more than a million people and slightly slowed the Earth's rotation by shifting so much water uphill.

The Chernobyl explosion of 26 April 1986 happened in which of the plant's four reactors?

It blew up during a test simulating how the reactor's cooling would behave in a blackout; the other reactors kept running for years, the last closing in 2000.

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

Fukushima was triggered by the Tōhoku earthquake and a tsunami up to 14 metres high that knocked out cooling for the emergency diesel generators.

During the 1973 oil embargo, the price of a barrel of oil rose from about $3 to nearly what?

Arab exporters cut off countries that had backed Israel in the Yom Kippur War, a rise of nearly 300 percent that brought petrol rationing and 55 mph speed limits to the US.

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

The well beside Oil Creek near Titusville was only 69.5 feet deep, but it set off the first American oil boom.

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.

The first continuous-current battery, built around 1800, stacked zinc and copper discs with cloth soaked in what?

Alessandro Volta's pile gave the world the volt; he had been arguing with Luigi Galvani about whether frogs' legs twitched from 'animal electricity'.

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

He shared it with Stanley Whittingham and Akira Yoshino; his cobalt-oxide cathode from 1980 is still the basis of the battery in most phones.

Roughly what voltage can a South American electric eel deliver in a single shock?

Despite the name they are knifefish, not true eels, and they use weaker pulses as a kind of radar to navigate murky water.

How much fusion heat is ITER designed to produce from 50 megawatts of input?

That tenfold gain would run for pulses of 400 to 600 seconds; the whole site needs more than 300 MW of electricity to make it happen.

Roughly how much hydrogen does the Sun's core fuse into helium every second?

About four million tonnes of that mass becomes pure energy each second; the light produced takes 8 minutes 19 seconds to reach Earth.

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

8 minutes 19 seconds at the average distance; 1.3 seconds is the trip from the Moon, and 4 hours gets you to Neptune.

The 'Calorie' on a US food label is really a kilocalorie. How many small calories is that?

A small calorie heats one millilitre of water by one degree Celsius and equals exactly 4.184 joules, so a 200-Calorie snack is about 837 kilojoules.

One thermochemical calorie is defined as exactly how many joules?

The definition rests on the energy needed to warm a millilitre of water by one degree Celsius; the other numbers are the electron charge, gravity and Avogadro's number in disguise.

In which country are at least 90 percent of homes heated with geothermal energy?

Sitting on the Mid-Atlantic Ridge helps; in 2020, 99.94 percent of the country's electricity came from hydro and geothermal sources.

Who first demonstrated the photovoltaic effect in 1839, aged 19, in his father's laboratory?

His son Henri would later share a Nobel Prize with the Curies for discovering radioactivity; the family produced four generations of physicists.

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

Calvin Fuller, Daryl Chapin and Gerald Pearson's cell was far more efficient than Charles Fritts's 1883 selenium device, which converted about 1 percent of sunlight.

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

Blyth offered surplus power to light the main street of Marykirk, but locals refused it as 'the work of the devil'; Charles Brush built a larger automatic turbine in Cleveland months later.

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

Enrico Fermi's team built Chicago Pile-1 under the west stands of Stagg Field; the leaders trusted his calculations enough to run it in the middle of a city.

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

Built between 1931 and 1936 in the Black Canyon of the Colorado River, it was called Boulder Dam by the Roosevelt administration until Congress restored Hoover's name in 1947.

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

Carbon dioxide and water plus photons become carbohydrate and oxygen, which is where every calorie in your food and nearly all of the air you breathe comes from.

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

The second law says entropy in an isolated system never decreases, and the third says entropy approaches a constant as temperature approaches absolute zero.

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

Absolute zero itself, -273.15 °C, cannot be reached in a finite number of steps, which is why the coldest labs get within billionths of a degree and no closer.

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

Westinghouse underbid GE to light the 1893 World's Columbian Exposition in Chicago, a showcase that won it the contract for the Niagara Falls power station.

The kilowatt-hour on your electricity bill equals how many megajoules?

A kilowatt for an hour is 1,000 joules per second times 3,600 seconds; utilities bill in kWh because it maps neatly onto appliances rated in watts.

The 2011 Fukushima Daiichi accident began when a tsunami knocked out cooling for the plant's what?

The wave arrived about 50 minutes after the Tōhoku earthquake and disabled 10 of the 13 cooling systems for the backup generators, leading to meltdowns in three reactors.

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

It proved the Teller-Ulam design and yielded more than 10 megatons, vaporising the Pacific islet of Elugelab.

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

He was a bookbinder's apprentice with little formal maths; it took nearly 50 years for generators and Joseph Swan's light bulbs to come into common use.

Which physicist, later ennobled and remembered for an absolute temperature scale, coined 'kinetic energy' c. 1850?

Thomson became Lord Kelvin; the word comes from the Greek kinesis, 'motion', and the energy of a moving object is half its mass times the square of its speed.

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

Young also helped decipher the Rosetta Stone and showed that light behaves as a wave; the word itself goes back to Aristotle's energeia.

OPEC was founded in 1960 in Baghdad by five countries. Which of these was one of them?

Iran, Iraq, Kuwait, Saudi Arabia and Venezuela signed up first; the organisation moved its headquarters from Geneva to Vienna in 1965 after Switzerland declined to extend diplomatic privileges.

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.

Which country generates about two-thirds of its electricity from nuclear power?

Nuclear has been its largest source since the mid-1980s; the share peaked above 71 percent in 2018 and the country exports tens of terawatt-hours to its neighbours.

Which Scottish engineer coined the term 'potential energy' in 1853?

Rankine also gave his name to an absolute temperature scale in Fahrenheit-sized degrees, still used by some American engineers.

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

India is second at about a tenth. Coal forms when plants decay into peat that is cooked by heat and pressure over millions of years; anthracite is the hardest, highest-ranked type.

What is the highest rank of coal, a hard, glossy black variety used mainly for space heating?

Lignite is the softest and youngest; anthracite burns hottest and cleanest, which is why it was prized for home stoves.

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

The jobs were in Stephens County, Oklahoma and Archer County, Texas; the technique pumps water, sand and thickeners into rock at high pressure so oil and gas can flow.

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

Discovered in 1948 and producing since 1951, it is wholly owned by the state company Saudi Aramco.

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?

Red and green LEDs had existed for decades; blue light plus a phosphor makes white, and LED bulbs use a fraction of the energy of incandescents.

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

The label spread to appliances, homes and whole buildings; the original targets were PCs that idled at full power all night.

Which 17th-century thinker proposed 'vis viva', or living force, defined as mass times velocity squared?

He believed total vis viva was conserved and that heat was the motion of matter's tiny parts, an idea accepted only a century later.

Which French engineer described 'kinetic energy' in its modern sense in 1829?

Thomas Young had possibly been first to use the word 'energy' in its modern sense in 1807.

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

Schrödinger and Heisenberg supplied the modern quantum-mechanical explanation in 1926.

Noether's theorem, linking symmetries to conservation laws, dates from which year?

It generalises constants-of-motion results from Lagrangian (1788) and Hamiltonian (1833) mechanics.

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.