5 Scientific Breakthroughs that Happened by Accident

5 Scientific Breakthroughs that Happened by Accident

Science Sometimes Cuts You a Break

Being a hard-working genius is probably nice and all that, but sometimes you simply can’t beat dumb luck. The history of humanity is filled with scientific advancements that were heavily influenced by random chance. Here are a few examples of serendipity at its finest.


Alexander Fleming

One of the most famous stories in science is how Scottish biologist Alexander Fleming discovered penicillin in 1928 by simply keeping an untidy lab. After leaving for a few weeks on vacation, Fleming returned to find that he had left one of his Petri dishes out by mistake. The sample containing Staphylococcus bacteria had developed mould, but Fleming also noticed something curious – the mould had inhibited bacterial growth. He correctly concluded that this new culture had antibacterial properties and named it Penicillium notatum.

Eventually, penicillin would kickstart the antibiotic movement which is now a cornerstone of medicine. However, that didn’t happen overnight. There was still a matter of finding a way to manufacture large quantities of penicillin which was no easy feat. It wasn’t until 1939 that a team of scientists including Howard Florey, Norman Heatley and Ernst Chain eventually turned penicillin into an efficient drug after much of the scientific world had given up on it.

Röntgen Rays


Unless you’re German, you probably know them better as X-rays. It was German physicist Wilhelm Röntgen who discovered them in 1895 by chance when he was doing some experiments with cathode rays. He noticed that the tube was lighting a piece of fluorescent cardboard that was sitting behind a black screen. At first, Röntgen simply tried to block the rays interfering with his experiment. However, nothing he tried seemed to work.

Hand x-ray taken by Rontgen

Hand x-ray taken by Rontgen

Intrigued by this new development, Röntgen continued experimenting in secret and became convinced of the potential of X-rays when he saw a flicker of his skeletal hand on screen. He later persuaded his wife Anna Bertha to assist him and scared her half to death when Röntgen produced an image showing the bones in her hand – the first x-ray or röntgenogram ever taken. Fast-forward a few years and Wilhelm Röntgen is awarded the first Nobel Prize in Physics in 1901.


henri becquerel

This next development was directly influenced by Wilhelm Röntgen’s discovery of x-rays. Unsurprisingly, other scientists wanted to get a better understanding of the concept. One French scientist, Henri Becquerel, suspected that phosphorescence was the phenomenon behind x-rays. He wanted to show that certain materials exposed to sunlight could be used to develop photographic plates.

Image of Becquerel's plate after exposure to uranium salts

Image of Becquerel’s plate after exposure to uranium salts

He tried various materials without success. Next up were uranium salts but, as luck would have it, on the day Becquerel was going to do the experiment, the sky was cloudy. He then grabbed his experiment components, stuck them in a drawer and waited for a sunnier day. When that day came, Becquerel took out the uranium salts and the photographic plates and noticed something strange – the plates showed signs of exposure even though they were kept in darkness and out of direct contact with the uranium salts. Clearly, this type of radiation was new – he had discovered radioactivity. Later on he also won a Nobel Prize for Physics which he shared with other scientists who pioneered work with radioactivity, Marie and Pierre Curie.

Vulcanized Rubber


Charles Goodyear usually gets the credit for discovering the vulcanization process of rubber. Although there is historical evidence to suggest that various cultures had their own techniques for centuries, it was certainly Goodyear who introduced the concept to the modern world after stumbling upon it by accident.

In the 1830s, rubber was becoming a popular material for footwear. At the same time, though, people were complaining that it wasn’t very durable. Rubber was regarded as not having a future – it was ok for the time being, but would soon be replaced by a more popular material.

1830s rubber shoes prior to vulcanization

1830s rubber shoes prior to vulcanization

Goodyear thought otherwise and was looking for ways of making rubber more durable. While tinkering with various concoctions, Goodyear spilled a mixture of rubber and sulfur onto a hot stove. He realized the resulting, leather-like material was stronger than before, as well as weather-resistant. He came up with vulcanization. Unfortunately, Goodyear spent the rest of his years in courts fighting for a patent on his process and never really made any money off his work.

Wearable Pacemaker

Photo: Steven Fruitsmaak

Photo: Steven Fruitsmaak

Wilson Greatbatch was one of the greatest inventors of our time, even though he isn’t remembered as such. Over the course of his life, Greatbatch held over 300 patents and the one that earned him the most recognition was the wearable pacemaker.

Pacemakers existed before Greatbatch’s work, but they were external and large and didn’t really offer a permanent solution. The version created by Greatbatch worked with a mercury battery that lasted for years and was small enough to be implanted inside the patient.

Photo: Sunzi99

Photo: Sunzi99

Greatbatch had his “Eureka” moment in 1956 while working on a heart rhythm recording device for the Chronic Disease Research Institute. He needed to install a resistor to complete the circuit. Greatbatch reached into a box of parts and pulled out one which was the wrong size. Once fitted, the circuit began emitting intermittent electrical pulses that Greatbatch immediately likened to the rhythm of the heart. He soon realized that such a device could be used to mimic the heart’s natural symmetry.