Chemist and Intel co-founder Gordon Moore predicted in 1965 that the speed and processing power for computer technology would double every two years. This idea came to be known as Moore's Law.
Moore's theory was daring for its time but appears less so when looked at in the context of the massive scientific and technological breakthroughs of the decades prior. Starting in 1927, Stacker has done just that: By combing through the archives of science's highest achievements, we've selected some of the top scientific breakthroughs of the last 93 years. Because of these milestones, humans today are capable of things earlier generations would have chalked up to be pure science fiction. Scientists have extended and improved human life, cured seemingly incurable illnesses, uncovered previously unknown worlds and creatures, and unearthed fascinating discoveries about our world and the solar system beyond.
Keep reading to discover major scientific breakthroughs of the last century.
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1927: Matter found to be wavelike
In 1925, Clinton Davisson and Lester Germer of Bell Telephone Laboratories experienced a fortunate accident. A botched experiment ended up showing that particles of matter can act like waves and that electrons scatter from a crystal the same way an X-ray does. In 1927, they published two papers describing their findings. Their work eventually earned Davisson a Nobel Prize.
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1928: Discovery of penicillin
Alexander Fleming, a bacteriologist at St. Mary’s Hospital in London, returned to the lab from a trip and discovered something had changed in his petri dishes of Staphylococcus aureus. A particular mold had invaded and prevented normal growth. This soon resulted in the discovery of penicillin, one of the world’s first antibiotics (still used widely today) and a game-changer in the field of medicine.
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1929: Hubble’s Law of the expanding universe
In 1929, Edwin Hubble published one of the most famous scientific papers of all time. He detailed what would later be known as Hubble’s Law, which explains how the universe is continually expanding, a postulation that changed humankind’s understanding of space.
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1930: Absolute geological timescales developed
Geologic time is divided into eras (such as the Mesozoic) and epochs (such as Pleistocene). This measure, which is based on rock layers, had been theorized about for centuries, but, in 1930, British geologist Arthur Holmes established the first absolute timescale.
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1931: First electron microscope created
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1932: Discovery of the neutron
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1933: Concept of neutron stars developed
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1934: Sonoluminescence discovered
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1935: Magnitude scale for earthquakes developed
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1936: First nerve agent discovered
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1937: Citric acid cycle discovered
Many high school biology students will have heard of the Krebs cycle, named for Sir Hans Adolf Krebs, a German biochemist. He was awarded the Nobel Prize for discovering how living organisms break down and convert sugars, fats, and protein to carbon dioxide, water, and other energy-rich compounds.
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1938: Nuclear fission discovered
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1939: 1DDT first used as an insecticide
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1940: Plutonium first synthesized
Plutonium, the radioactive metal used to create nuclear weapons, was first created at UC Berkeley in December of 1940. Researchers didn’t publicize this finding until the conclusion of WWII, in to keep its existence secret from enemy forces.
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1941: Hormonal treatment of cancer developed
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1942: Race-based blood typing debunked
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1943: DNA proved to be genetic material of chromosome
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1944: Echolocation discovered
While still a student, animal behaviorist Donald Griffin caused a stir in the scientific community when he and a colleague realized that bats reflect sound off objects in order to detect their location. He named this “echolocation.” Today, we know that dolphins, shrews, and other animals also use this method of tracking, and it’s inspired technology like sonar detection.
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1945: First atom bomb test
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1946: Fluoride water study begins
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1947: Invention of the transistor
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1948: The introduction of the Big Bang theory
In 1948, American cosmologist Ralph Apher, as well as Robert Herman and George Gamow, first predicted “cosmic microwave background,” or the heat left from what would later be known as the Big Bang. The Big Bang theory transformed human understanding of the history of the solar system.
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1949: First bone marrow transplant
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1950: Leukemia drugs developed
Chemist Gertrude Elion experienced immense discrimination as a female researcher, but defied expectations by becoming the first to discover a breakthrough drug to treat leukemia. In 1950, she created a purine chemical that disrupted the formation of leukemia cells. It soon became the foundation for drugs used for those suffering from childhood leukemia, previously a fatal diagnosis.
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1951: HeLa cancer cells harvested
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1952: Polio vaccine created
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1953: Discovery of the structure of DNA
We know about the double-helix, twisted-ladder shape of DNA thanks to James Watson and Francis Crick. This groundbreaking development served as a foundational discovery of molecular biology, and made Watson and Crick one of the most famous scientific duos of all time.
[Pictured: James Watson.]
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1954: First organ transplants
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1955: The placebo effect identified
Harvard Medical School’s Henry K. Beecher published his paper “The Powerful Placebo” in 1955, which identified the placebo effect and the need for double-blind, placebo-controlled clinical pharmaceutical trials. Though there had been talk of the placebo reponse in the scientific community before, Beecher was the first to quantify it through experiments. Today, double-blind tests are standard in the research community.
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1956: Theory of free-radical aging developed
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1957: Invention of the birth control pill
Enovid, the first FDA-approved oral form of birth control, was released in 1957. Though it was prescribed for menstrual disorders, one of its side effects was effective contraception. In 1960, Enovid was officially branded as a birth control pill.
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1958: Researchers link hormones and cancer
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1959: Float glass invented
Window panes created in the 1950s or earlier had a “fun-house effect,” because they were made by rolling sheets of hot glass. This type of glass was inexpensive to manufacture, but uneven. In 1959, British engineer Alastair Pilkington created float glass , made by floating hot glass on a bath of molten tin, which is completely flat. Most plate glass today is still produced with his method.
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1960: First laser demonstrated
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1961: The first human goes to space
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1962: Launch first active communications satellite
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1963: Discovery of quasars
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1964: Research from the Great Alaska Earthquake
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1965: Kevlar developed
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1966: ELIZA published
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1967: Handheld calculator invented
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1968: Intel founded
Chemist Gordon Moore and physicist Robert Noyce founded microprocessor company Intel in 1968. The chips made by the company became foundational for computer science and can still be found in most electronics today.
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1969: First man on the moon
"That's one small step for man, one giant leap for mankind." Those words from Neil Armstrong became immortal during the first moon walk . Armstrong, Buzz Aldrin, and Michael Collins were all aboard the iconic Apollo 11 flight, which entranced viewers around the world and changed the possibilities for space travel forever.
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1970: The Exeter stem first used for hip replacement
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1971: First PC goes on sale
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1972: CAT scan developed
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1973: Invention of recombinant DNA
The first genetically modified organisms were created in 1963 , when Stanley Cohen and Herbert Boyer cut open a plasmid loop from one bacteria, inserted a gene from a different bacteria, then inserted the gene into a third organism. GMO technology has paved the way for new crops, medicines, and even “chimeric” animals. This breakthrough has also been key for developments in cloning.
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1974: Discovery of “Lucy”
Donald Johanson and Tom Gray were traveling through Ethiopia searching for fossils when they stumbled upon human bones . These were the remains of “Lucy,” an early hominin who lived 3.2 million years ago. This partial skeleton has been studied extensively, and has changed our understanding of early human species.
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1975: Cancer linked to genes
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1976: The Viking 1 lands on Mars
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1977: First complete DNA sequencing
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1978: First baby born using in-vitro fertilization
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1979: Biologists investigate thermal vents
Thermal vents are not very hospitable to life: these underwater fissures, usually found near volcanically active areas, are incredibly hot. A great deal of marine life exists there, nevertheless, from certain species of shrimp to giant worms. In 1979, scientists from Rutgers, the University of Miami and other institutions got their first peek at this strange, deep-sea world in the Galapagos Islands, a major step for the field of marine biology.
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1980: Smallpox eradicated
Smallpox was among humanity’s most devastating diseases. About 300 million people died from it over the course of the 20th century —which is why the World Health Organization targeted it with a global immunization program . Their efforts were successful, and in 1980, they declared the highly contagious disease eradicated.
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1981: First fetal surgery
UC San Francisco clinical surgeon Michael R. Harrison was the first to complete fetal surgery, which is now used regularly to fix abnormalities or other conditions in unborn babies. He made two attempts to unblock urinary tract obstructions in fetuses in 1981; the second surgery resulted in a healthy baby. Today, many more surgical procedures are available to treat fetuses.
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1982: First artificial heart transplant
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1983: AIDS virus identified
In the 1970s and 80s, rare types of pneumonia, cancer, and other diseases were being reported around the country. By 1982, scientists were beginning to use the term “acquired immunodeficiency syndrome” (AIDS) to describe it. It wasn’t until 1983 that scientists discovered the virus that causes AIDS. Though an estimated 35 million people have died as a result of contracting AIDS, treatment options are now readily available and many people can effectively fight infection for many years.
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1984: DNA fingerprinting uncovered
University of Leicester geneticist Alec Jeffreys analyzed DNA to discover that certain repetitive patterns are present in all humans, but vary in length . This discrepancy was specific to each individual, and could be used to link biological samples to out someone’s identity. He coined the term “genetic fingerprinting,” a development which contributed to paternity testing, crime scene analysis, and more.
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1985: Hole in the ozone layer discovered
In 1985, Joe Farman, Brian Gardiner, and Jon Shanklin published an alarming paper in the journal Nature: Ozone levels above the Antarctic had fallen 40 percent over the previous decade. This would become known as the “hole” in the ozone layer. This became one of the most important discoveries in the history of climate science.
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1986: High-temperature superconductor created
Today, high-temperature superconductors—material that, even at high temperatures, can conduct energy with no resistance—are used in medical and physics research. One such experiment resulted in the discovery of the Higgs boson . In 1986, IBM's Johannes Bednorz and Karl Mueller discovered that copper oxide ceramics can conduct currents without resistance at higher temperatures, which earned them a Nobel Prize and set off a worldwide race to develop superconductors.
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1987: Prozac hits the market
Prozac hit the market in 1987 . A new antidepressant with fewer side effects than other drugs of its time, it soon became the most-prescribed psychiatric drug in American history and later inspired the pop-culture film Prozac Nation .
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1988: Hawking publishes “A Brief History of Time”
Theoretical physicist Stephen Hawking’s “A Brief History of Time” was not only a defining book in the field, it appealed to a worldwide audience. In it, the famed scientist answered questions about the origin of the universe , the nature of time, and much more.
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1989: Hepatitis C identified
Though hepatitis C has plagued humans throughout history, the particulars about how the disease works were largely unknown until 1989 . Researchers at the California biotech company Chiron and the Centers for Disease Control and Prevention identified a new virus separate from known forms of hepatitis, a discovery which led to methods for testing individuals and screening blood donations.
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1990: The “Pale Blue Dot” photographed from space
On Valentine’s Day of 1990, NASA’s Voyager 1 spacecraft took one of the most famous photographs in the world: the “Pale Blue Dot.” The picture features Neptune, Uranus, Saturn, Jupiter, Earth, and Venus, with our home planet appearing as nothing more than, as the name would suggest, a blue speck. The idea to take the photograph came from renowned astrophysicist Carl Sagan, who would go on to write his 1994 book of the same name.
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1991: Carbon nanotubes discovered
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1992: First pulsar planets observed
Aleksander Wolszczan used a high-powered radio telescope and found three planets in 1992. These weren’t just any planets, though: They were the first ever discovered outside our solar system . These planets were circling a pulsar—a rotating neutron star. In the years since, more than 160 planets have been found outside of our solar system.
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1993: Microprocessor-controlled prosthetic released
Prosthetics were once incredibly restrictive for amputees. In the 1990s, engineers began to integrate microprocessors into prosthetics, which were life-changing for many patients. The Endolite Intelligent Prosthesis Plus was released in 1993 : the first artificial knee with a microprocessor to adjust its motion according to its wearer’s walking speed.
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1994: Breast cancer gene discovered
Oncologists knew that breast cancer often ran in families, so that’s where they looked to hunt down the hereditary link in breast cancer. In 1994, they found BRCA 1 , named for being the BReast CAncer gene. In 1995, a second such gene was found, making huge strides in cancer prevention.
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1995: First exoplanet identified
It comes with a whimsical name: The 51 Pegasi b, or “Dimidium.” Found by Swiss astronomers Didier Queloz and Michel Mayor , it was the first exoplanet found to be orbiting a star similar to Earth’s sun. The impact on our understanding of the universe was huge: For the first time, we could confirm that Earth-like planets might exist elsewhere.
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1996: Cloning of Dolly the sheep
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1997: KLOTHO aging gene discovered
Clotho one of the mythical Greek fates who acts as a “spinner” of life. A disambiguation of this figure was a fitting title for a longevity-related genetic enzyme . Discovered by Japanese-born researcher Makoto Kuro-O and his colleagues in 1997, degenerations or mutations in this gene are linked to skin atrophy, osteoporosis, bone loss, and other signs of early aging.
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1998: Genetic sequencing completed
The parasitic roundworm had its 15 minutes of fame in 1998 when Human Genome Project researchers at the Washington University School of Medicine in St. Louis and the Sanger Centre in Cambridge sequenced its 97-million base genome . This was the first time such a sequence was conducted for a “complete animal.” This was a huge step toward eventually completing the human genome.
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1999: Cell phone miniaturization
Peter Gammel and his peers at Bell Labs and Lucent Technologies got one step closer to creating the small, super-thin cell phones on the market today. The team used micromachining to reduce the size of three phone parts , allowing them to all fit on a single chip.
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2000: Tau neutrino discovered
Though Wolfgang Pauli first proposed that neutrinos might exist in 1930, it wasn’t until 2000 that his theory was proven. A neutrino is a neutral subatomic particle with a mass close to zero, which rarely reacts with normal matter. An experiment called DONUT was designed to search for tau neutrinos, and found evidence of them in 2000, opening up new pathways in the study of physics.
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2001: Draft of the Human Genome Project released
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2002: Anthrax toxin structure revealed
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2003: Commercial gene therapy approved
Gene therapy remains an experimental medical technique, using genes to target complex disorders. In 2003, the China State Food & Drug Administration approved Gendicine, a gene therapy medicine for head and neck squamous cell carcinoma. It’s hoped that someday doctors may treat patients by introducing genes into a patient’s cells rather than using drugs or surgery.
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2004: The Mars rovers discovers remnants of water
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2005: First partial-face transplant
Though doctors have done transplants of organs, skin grafts, and other body parts, facial transplants have been among the most difficult procedures to refine. In 2005, a French woman lost her mouth and nose in a dog attack. Surgeons were able to complete a partial face transplant—a huge breakthrough. Since then, dozens of similar procedures have been performed.
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2006: Evolutionary link discovered between fish and land animals
The average person may not have heard of Tiktaalik roseae, a now-extinct creature with fish-like scales and the long body of an alligator. Discovery of its fossils changed our understanding of evolution forever. University of Chicago paleontologist Neil Shubin made the discovery, which showed the first evolutionary link between fish and the animals that evolved to live on land 375 million years ago.
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2007: Skin cells used for stem cells
Though stem cells had proven to be one of the greatest scientific discoveries of the 20th century, its use was controversial, as the cells were usually obtained from embryos. This changed in 2007, when researchers at Kyoto University and the University of Wisconsin used skin cells to form muscle , fat, heart, and nerve tissues. Today, there are several alternative sources for stem cells.
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2008: The Large Hadron Collider begins its proton beam tests
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2009: First extinct animal cloned
Though dreams of cloning wooly mammoths or saber tooth tiger are still the stuff of science fiction, humans succeeded in cloning the first extinct animal in 2009 . Spanish researchers used frozen skin from a Pyrenean ibex to create a clone. Though the ibex had only been extinct since 2000 and the clone died shortly after birth, this was still considered a substantial advancement.
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2010: Nanorobotic spiders created
Arachnophobes need not fear: Nanorobotic spiders have nothing to do with insects. In fact, they’re 100,000 times smaller than the diameter of human hair , impossible to see with our naked eye. These microscopic “robots,” made from DNA, were created by a team at Columbia University. It’s hoped that someday nanorobots may be deployed inside the human body to crawl across our DNA and perform medical procedures.
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2011: First artificial organ transplant
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2012: Discovery of the Higgs boson
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2013: 3D printing makes massive strides
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2014: Stem cells cure paralysis
After being paralyzed by an attacker brandishing a knife, Darek Fidya regained the ability to walk in 2014, thanks to stem cell treatment . In 2012, doctors transplanted cells from the patient’s nose to the gap in his spinal cord, using nerve tissue from his ankles as a “bridge” to help the nerves grow. It worked: After several years, Fidya was mobile, with the help of a walker.
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2015: Traces of water discovered on Mars
Though NASA rovers had shown that there was likely once water on Mars, the Mars Reconnaissance Orbiter presented strong evidence that water may, in fact, currently flow on the planet. This could influence our knowledge of whether life may exist there.
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2016: First space-time ripples detected
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2017: First mammals incubated in an artificial womb
In 2017, scientists at the Children’s Hospital of Philadelphia grew eight fetal lambs in “biobags,” artificial wombs. Some compared them to the “rebirth pods in The Matrix. Others said they looked like Ziploc bags . However you view it, it was a massive leap forward for science. This development could be a precursor to being able to bring prematurely born babies to term outside of the uterus.
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2018: CRISPR babies
In a monumental—if highly controversial—moment for science, CRISPR babies—gene-edited infants—were allegedly created in 2018 in China. Scientist He Jiankui claimed to have successfully deactivated the CCR5 gene in two infant girls, theoretically offering them protection from several strains of HIV.
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2019: First image of a black hole
Capturing an image of a black hole was once considered totally impossible. To prove that assumption wrong, a team of international astronomers set up a series of tightly synchronized telescopes in a process called Very Long Baseline Interferometry, or VLBI.
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2020: Open public access to COVID-19 research