Ikigai Daily
Menu
WonderFact

In an internal combustion engine, fuel burns inside the engine itself. The hot gases expand and push pistons, and the pistons turn a crankshaft that drives the wheels, so the fuel's chemical energy becomes motion.

Ikigai Daily

TechnologyScience

The story behind the card

'Internal' means the fuel burns inside the cylinders, unlike a steam engine, which burns its fuel outside to boil water. Most petrol engines work in four strokes: the piston moves down to draw in fuel and air, moves up to squeeze the mixture, is driven down when a spark from the spark plug ignites it, and rises again to push out the exhaust. Connecting rods turn this up-and-down movement into the turning of the crankshaft. The Belgian-born engineer Étienne Lenoir built a working gas engine in 1860, and Nicolaus Otto developed the first practical four-stroke engine in 1876. In 1886 Karl Benz patented his Motorwagen, widely regarded as the first practical car, which ran on a four-stroke engine. Even today, most of the energy in the fuel is lost as heat rather than turned into motion.

Türkçe oku
İçten yanmalı motorda yakıt, motorun kendi içinde yanar. Genleşen sıcak gazlar pistonları iter, pistonlar da tekerlekleri döndüren krank milini çevirir; böylece yakıttaki kimyasal enerji harekete dönüşür.

“İçten yanmalı” denmesinin nedeni, yakıtın silindirlerin içinde yanmasıdır; buhar makinesinde ise yakıt dışarıda, suyu kaynatmak için yakılır. Benzinli motorların çoğu dört zamanlıdır. Piston önce aşağı inerek yakıt-hava karışımını içeri çeker, sonra yukarı çıkarak onu sıkıştırır. Bujinin çaktığı kıvılcım karışımı ateşler ve yanan gazlar pistonu aşağı iter. Son olarak piston yeniden yukarı çıkar ve egzoz gazlarını dışarı atar. Biyel kolları bu aşağı yukarı hareketi krank milinin dönüşüne çevirir. Belçika doğumlu mühendis Étienne Lenoir 1860'ta gazla çalışan bir motor yaptı; Nicolaus Otto da ilk kullanışlı dört zamanlı motoru 1876'da geliştirdi. Karl Benz 1886'da, dört zamanlı bir motorla çalışan ve ilk kullanışlı otomobil sayılan Motorwagen'in patentini aldı. Bugün bile yakıttaki enerjinin büyük kısmı harekete değil, ısıya dönüşüp boşa gider.

Sources and further reading

Background reading: Internal combustion engine
Get the mobile appAbout our cards

Related cards

These cards share a subject or reading mode with the card above.

WonderHistory

When Neil Armstrong radioed “Houston, Tranquility Base here. The Eagle has landed” on 20 July 1969, his words reached Earth about 1.3 seconds later. Radio waves travel at the speed of light, and the Moon is about 384,000 km (239,000 miles) away.

Eagle was the lunar module that carried Armstrong and Buzz Aldrin down to the surface. Light, and so radio, travels at almost 300,000 km per second. At the Moon's average distance of about 384,400 km, a signal takes roughly 1.28 seconds each way, so every exchange with Mission Control in Houston had a built-in pause of about 2.6 seconds before an answer could arrive. Large dish antennas at Goldstone in California and at Honeysuckle Creek and Parkes in Australia picked up the signals; the clearest pictures of the first steps came through Australia and were watched live by an estimated 600 million people. Before leaving, the crew set up a panel of reflectors on the surface. Scientists still fire lasers at it and time the light's return, which is how we know the Moon is drifting away from Earth by about 3.8 cm a year.

Ikigai DailyRead card
WonderTechnology

Telomeres are stretches of repeated DNA that cap the ends of chromosomes, a little like the plastic tips on shoelaces. They get shorter as many of our cells divide, but their length cannot predict how long a particular person will live.

In the mid-1970s the Australian-born biologist Elizabeth Blackburn, working at Yale, found that chromosome ends carry a short DNA “word” repeated many times; in humans it is TTAGGG. She shared the 2009 Nobel Prize in Physiology or Medicine with Carol Greider and Jack Szostak for showing how telomeres, and an enzyme called telomerase that rebuilds them, protect chromosomes. Each time most body cells divide, the copying machinery cannot quite reach the very end, so a little telomere is lost; when it gets too short, the cell stops dividing, which is why telomeres are often called a clock. But it is a poor clock for comparing people or species: mice have much longer telomeres than humans yet live only two or three years, and telomere length varies widely between people from birth. Many scientists therefore doubt commercial tests that claim to read your “biological age” from them.

Ikigai DailyRead card
WonderTechnology

The atomic clocks on GPS satellites run about 38 millionths of a second a day faster than clocks on the ground, an effect predicted by Einstein's theories of relativity. Left uncorrected, the drift would put your position out by about 11 km within a single day.

A GPS receiver, such as the one in your phone, works out where it is by timing signals from several satellites orbiting about 20,200 km up. Radio signals travel about 300 metres in a microsecond, a millionth of a second, so even tiny clock errors matter. Relativity pulls the clocks apart in two ways. Special relativity says moving clocks run slow: travelling at almost 4 km a second, the satellite clocks lose about 7 microseconds a day. General relativity says clocks in weaker gravity run fast: high above Earth they gain about 46. The net gain is about 38 microseconds a day. So before launch, each satellite clock is set to run slightly slow, at 10.22999999543 million cycles a second instead of 10.23 million, and in orbit it keeps step with clocks on the ground.

Ikigai DailyRead card
WonderTechnology

The Apollo Guidance Computer that steered astronauts to the Moon had about 4 kilobytes of rewritable memory and 72 kilobytes of permanent memory. Its programs were woven by hand into “rope memory”: a wire threaded through a tiny magnetic ring stored a 1, and a wire passing it by stored a 0.

Designed at the MIT Instrumentation Laboratory and built by Raytheon, the computer was one of the first to use silicon chips (integrated circuits) and fitted into about 28 litres. Its memory was counted in “words” of 16 bits, or binary digits: 2,048 rewritable and 36,864 permanent. During Apollo 11's descent on 20 July 1969 it flashed 1202 and 1201 alarms: a radar left on in case the landing had to be abandoned was stealing processing time and overloading it. Its operating system, designed by J. Halcombe Laning, dropped less urgent jobs and restarted in a moment while the landing programs kept running, so Mission Control told the crew to carry on. The flight software was written by a team led by Margaret Hamilton, who received the Presidential Medal of Freedom in 2016. Its power was similar to that of the first home computers of the late 1970s.

Ikigai DailyRead card
WonderTechnology

In 1984 and 1985, John Clarke, Michel Devoret and John Martinis showed that a whole electrical circuit on a chip, cooled almost to absolute zero, can behave as a single quantum object, just like an atom. The discovery earned them the 2025 Nobel Prize in Physics.

The experiments were done at the University of California, Berkeley, in Clarke's group; Martinis was his doctoral student and Devoret a postdoctoral researcher. Absolute zero, −273.15 °C, is the lowest temperature possible. At the heart of the circuit was a Josephson junction: two superconductors, metals that carry current with no resistance when very cold, separated by an insulating layer only a few atoms thick. Vast numbers of electrons moved together as if they were one particle. The team saw two signs of quantum behaviour: the circuit escaped from a trapped state by tunnelling, slipping through an energy barrier it could not climb over, and it absorbed microwave energy only in fixed steps, or quanta, as an atom does. Circuits of this kind are now the qubits, the basic units of information, in the superconducting quantum computers built by companies such as Google and IBM.

Ikigai DailyRead card
Next card in the archiveThe Liverpool and Manchester Railway, opened on 15 September 1830, was the world's first inter-city railway. It was the first to use only steam locomotives, with no horse-drawn traffic, and the first to run entirely to a timetable. It cut the journey between the two cities to about two hours.Read next →