Rune Elmqvist forwent practicing medicine to invent the first inkjet printer

Samuel O’Reilly patented the tattoo gun in 1891

Before the tattoo gun's invention, recipients sweated while artists slowly tapped or sliced designs into their flesh. The tattoo gun changed the field, helping artists ink clients’ skin at incredible speeds. Inventor Samuel O’Reilly applied the basic idea of an electric pen invented by Thomas Edison to his tattoo gun.

Watch the engineering challenges overcome in turning a 3D printer into a tattoo machine

The DIY project required reprogramming the printer to operate on a curved, 2D surface rather than making flat layers in 3D, editing replacement firmware to bypass temperature safety checks, and developing a rapid system to stop the tattoo in case of an emergency. The final product printed "LEG" on a volunteer's leg.

The first 3D printing patent was filed in 1967

Wyn Swainson, an English literature graduate student, filed a patent in Denmark for a system that scans an object and uses the scanning data to rebuild it using lasers that harden light-sensitive plastic. However, he never developed a working prototype. The idea originated from wanting to produce recreations of sculptures.

Harvard and MIT researchers are developing life-saving tattoos

Tattoos aren’t just a fashion statement. Scientists are trying to find life-saving applications for them. Harvard and MIT researchers are developing tattoo inks that react to body chemicals, alerting diabetics to blood sugar fluctuations or athletes to dehydration. Someday, patients may observe their body chemistry with tattoos that change colors.

Pig heart valves have been placed in humans since 1965

The first successful use of a pig heart valve in a human was reported in 1965. This 2015 video details why humans have been able to use pig animal valves for so long with good results and how that differs from what's needed for whole organ transplants.

Read more about the backstory on the 2025 Nobel Prize for immune system work

A trio of scientists won the Nobel in Physiology or Medicine that year, but they performed their award-worthy work beginning about two decades before winning the prize. This announcement includes details about the science and notes that the three scientists will equally share the 11 million Swedish kronor (almost $1.2M).

Microgravity environments improve the success of 3D bioprinting

Gravity can cause gaps, such as those in the chambers of a 3D-printed heart, to collapse before stem cells, hydrogels, and biochemicals bind together during the bioprinting process. Rather than Earth's surface, some bioprinting is done on the International Space Station, where defective organs are also printed to test treatment methods.

How the heart achieves its first beat

Scientists observed zebrafish embryos as they grew and isolated the several-second-long initial heartbeats to better understand this crucial moment in every heart's life. The zebrafish's heart starts beating 20 hours into their existence. Each heart cell activates electrically at random, without rhythm. As these cells mature, they become more sensitive to electrical charges; as they all fire, a rhythm is established and a pulse is born.

With no textbooks or antibiotics, this WWI surgeon pioneered facial reconstruction

New Zealand surgeon Dr. Harold Gillies made extraordinary advances in the field of reconstructive surgery during World War I and after. This 36-minute NPR podcast interviews historian Lindsey Fitzharris, author of Gillie's biography, The Facemaker, charting how the good doctor reconstructed the faces of numerous soldiers in an age before antibiotics and plastic surgery as we know it today.

In a first, eye prosthesis has restored sight to macular generation patients

In a clinical trial, 27 of 32 participants with advanced macular degeneration regained enough vision to read books, food labels, and subway signs about a year after receiving a prosthetic retina device. This is the first device to restore functional vision to patients with incurable vision loss, though in this case they can only see in black and white, with no shades in between.

A dispute about the origin of twitching frog legs led to the invention of the first battery

Experiments by Luigi Galvani on exposed frog leg nerves showed activity when they were hung from iron railings and brass hooks, suggesting the existence of "animal electricity" that discharged when connected to metals. Alessandro Volta's voltaic pile, which stacked metals with an inorganic electrolyte, showed that electricity originates from chemical reactions.

Elon Musk's Neuralink's N1 chip can wirelessly read brain signals from over 2,000 electrodes

The device is a battery-powered brain implant that transmits data via Bluetooth. Neuralink's near-term objectives for the device focus on unlocking new treatments for paralysis, neurological disorders, and some psychiatric conditions.

Read the original 1907 paper on the first known Alzheimer's patient

Alzheimer's disease was first identified by Dr. Alois Alzheimer in 1901, following a postmortem brain examination of a patient experiencing memory loss and other symptoms. Alzheimer's original paper was largely lost until 1995, when an English translation was published in a medical journal.

The Juke 8 was the world's first karaoke machine

Daisuke Inoue invented the machine in 1971 by combining an amplifier, microphone, and 8-track machine, though he never patented it and, as a result, never collected royalties from the billion-dollar industry.

The unexpected origin story of the snow globe

In 1900, a Vienna tradesman named Erwin Perzy I was attempting to invent an inexpensive way to improve light amplification in hospital operating rooms. After experimenting with a glass globe filled with water, the idea for the snow globe struck. Industrious as well as inventive, Perzy eventually turned his idea into a successful business. Read the full article to learn how the invention grew to become recognized globally.

How Mary Cassatt pioneered printmaking

In 1890, the artist attended an exhibition in Paris featuring a vast collection of 725 Japanese woodblock prints. Inspired by the work, she told a friend she could not stop thinking about "color on copper," and eventually used a metal plate "intaglio" technique to execute her vision. This video recreates how she made it happen.

Lasers, semiconductors, medical imaging, and atomic clocks rely on quantum mechanics

Semiconductors, crucial in electronics, operate based on quantum superposition. Lasers use stimulated emission, a quantum process, and MRI machines leverage the quantum spin of hydrogen atoms for imaging. Atomic clocks measure time with unprecedented precision using quantum transitions.

Computer pioneer Alan Turing was also an elite runner

Alan Turing is credited with helping to found modern computer science, in addition to cracking the Nazi code known as Enigma. Beyond these world-historical achievements, the British mathematician also nearly represented his country in the Olympics in the marathon, running just 11 minutes slower than the eventual gold recipient at the 1948 games. Read more on this lesser-known aspect of the man here.

Laser-etched electric charges guide toner during laser printing

When sending a print job, the file data generates an image that a laser maps positively charged regions onto a drum separately for each color toner. Once the negatively charged toner is applied where it was electrically attracted, heat and pressure fuse it onto the paper.

The Bauhaus designer who predicted the future of graphic design

László Moholy-Nagy believed that technology would eventually turn typesetting into a process that allowed fonts to be easily modified rather than manually constructed. This history from the American Institute of Graphic Arts digs into how Moholy-Nagy arrived at those prescient theories.

English mathematician Ada Lovelace wrote the first computer algorithm a century before computers existed and hypothesized that computing devices would one day be able to compose music—foreseeing the generative AI systems of today.

The Google Doodle honoring Jan Ingenhousz, who discovered oxygenic photosynthesis

Born in 1730, the Dutch scientist expanded on existing knowledge that plants produce and absorb gases in his 1779 paper, which detailed that light was necessary for the biochemical processes that produce oxygen in plant leaves. He also identified that all parts of plants produce carbon dioxide at night.

How Gleevec transformed leukemia treatment and cancer research

An outline of the discovery of imatinib (Gleevec), a ground-breaking drug that transformed the treatment of chronic myelogenous leukemia and sparked the beginning of precision medicine.

A life measured on the backs of coffee receipts

Years ago, a storyteller doodled on the back of a receipt. Hundreds of doodles later, Odding Wang has created a digital diary with a tactile feel. Click through the project's website to peruse the portals into Wang's life and mind. Hovering over a comic will reveal the receipt on the other side.

The history of many kitchen appliances involves unexpected discoveries and applications, including wartime radar turned hamster defroster and replacing an 'ice king' with heat-stealing boxes.

The printing press spread novels widely

Johannes Gutenberg's invention of the printing press in 1440 changed how writing was reproduced. It allowed multiple manuscripts to be copied via movable type rather than by hand, making more literature more widely available. Over time, that change caused literacy rates to rise, creating a market for even more literature.

Merck developed MDMA in the early 1900s as part of its effort to create a blood clotting drug

The company's chemists were attempting to synthesize a substance that could compete with an existing patent for the best clot medicine of that time, hydrastinine. MDMA was the byproduct of that effort.

The first line of 'immortal' human cells, which can divide indefinitely and are used in scientific research, was nonconsensually taken from a Black woman.

Sony set the standard for cylinder-shaped batteries when it repurposed manufacturing equipment used to make rolls of magnetic recording tape.

The concept of phantom limbs, the perception that amputated limbs are still present, dates back to a French military surgeon in the 16th century.

Learn more about the history of fireworks, which dates back to an accidental invention during an alchemist's quest for information about immortality.

Tattoos remain visible on your skin thanks to immune cells called macrophages

Clever Hans was a 1900s horse that was believed to be able to solve math equations, tell time, and read and comprehend German, until a psychology student discovered how he got his answers.

See images of medical cases of firework injuries shared on this 'Instagram for doctors.' (Warning: Graphic content)

Elk Cloner, the first computer virus to spread in public, was written as a practical joke by Richard Skrenta, a Pittsburgh high school student.

As of 2025, the most cited papers in science include a review of graphene, methods to improve image recognition, streamlining electron density calculations, and optimizing protein studies.

Double world record holder Hunter Ewen helped conquer his fear of balloons, called globophobia, by training to win Guinness World Record titles for balloon inflation.

Mid-century modern graphic designers, known for their bright colors and bold lines in advertising, also found success with children's books.

Against his wishes, Albert Einstein's brain was removed before his cremation, and the pathologist responsible stored it for decades in mason jars within a beer cooler.

Visualize how CRISPR-Cas9—a type of immune system used by single-celled organisms to attack invasive viruses—targets and makes precise changes to a gene's DNA.

Objects can be 3D printed with light by projecting 2D computerized tomography (CT) scans onto rotating cylinders of resin, which solidify upon exposure.

Experimental hantavirus vaccines and therapies, still under development, have long been funded by the US military.

Graffiti dates back to at least ancient Pompeii, where citizens scrawled messages to one another on public walls

Studies suggest when you sleep is as important as how much you get, and syncing with your circadian rhythms may lead to less fatigue and improved long-term health outcomes

The Ramones' 'Pet Sematary,' the theme song for the Stephen King novel of the same name, was written while the band was admiring the writer's collection of horror memorabilia.

This site reaches millions of visitors who are tired of AI chatbots and seeking human connection. Pretend to be an AI chatbot and ask questions, provide answers, and draw for people in real time.

Mark Twain spent decades feuding with the US Postal Service, convinced its costs and regulations were bureaucratic overreach.

The first image of a black hole was captured by creating an Earth-sized virtual observatory from a network of eight radio telescopes.

Some coin denominations have ridges etched on their sides, partly to prevent counterfeiting, in a practice called 'reeding.'

See a ranking of the best (and worst) Federal Reserve Chairs since 1914 out of the 16 men and women who have held the office since.