50 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.