Who Discovered Weak and Strong Forces and What is the difference between the Weak Force and the Strong Force?

For several centuries scientists thought that gravity and electromagnetic forces governed the universe. Then twentieth-century physicists found atomic nuclei composed of positively charged protons. Why didn’t they fly apart since positive electrical forces repel each other? Further, why did some atoms naturally radioactively decay while others did not? Many physicists proposed that two new forces … Read more

Who Discovered that an Ecosystem is a given place where plants, animals, and environment are all interdependent?

Many scientists over the centuries had studied the relationship of various species to their climate and environment. They studied elements of ecology. However, it wasn’t until 1935 that Arthur Tansley realized that all species in a given environment were interconnected. Grasses affected top carnivores and the bugs that decomposed dead animals, and fallen trees affected … Read more

Who Discovered the Function of Genes and How do Genes control individual cells?

Genes are strung along chromosomes and contain directions for the operation and growth of individual cells. But how can a molecule of nucleic acid (a gene) direct an entire complex cell to perform in a certain way? George Beadle answered this critical question and vastly improved our understanding of evolutionary genetics. Beadle discovered that each … Read more

Who Discovered Blood Plasma and How does separating red blood cells and plasma extended the shelf life?

Whole blood can be safely stored for only a few days. That had always meant that blood donations had to come from local sources and be given at the time of need. Blood couldn’t travel long distances. People with unusual blood types often had to do without during surgery and suffered accordingly. Charles Drew discovered … Read more

Who Discovered the Semiconductor Transistor and How does a semiconductor turn into superconductor?

John Bardeen won his first Nobel Prize for discovering the transistor effect of semiconductor materials. Most materials either conduct electric flow (conductors) or block that flow (insulators). But a few materials sometimes permitted some electric flow (semiconductors). Though they had been identified by the late 1800s, no one knew the value of semiconductors until Bardeen … Read more

Who Discovered Jumping Genes that are not permanently fixed on chromosomes and When?

Every researcher in the world accepted that genes were strung along chromosomes in fixed positions like pearls on a necklace. Working alone in a small, windswept cornfield at Cold Springs Harbor, Long Island, Barbara McClintock proved every other genetic scientist in the world wrong. Carefully studying wild corn, Barbara McClintock found that genes not only … Read more

Who Discovered Quarks and Where do the subatomic particles that make up protons and neutrons come from?

First scientists identified plant fibers, then individual cells. Then scientists conceived of atoms and molecules. In the early twentieth century, scientists discovered electrons and then the existence of protons and neutrons. In each case, scientists believed that they had finally discovered the smallest possible particle of matter. Each time this belief proved wrong. The discovery … Read more

Who Discovered Quasars and Pulsars and Where do the super dense, distant objects in space come from?

Quasars and pulsars represent a new class of objects in space, a new kind of massive, extraordinarily bright object. Massive, exceedingly dense, and producing powerful radio and light transmissions, quasars and pulsars radically expanded and altered scientists’ view of space and space structures. Quasars are some of the brightest and most distant objects in the … Read more

Who Discovered that Evolution is driven by symbiotic relationships and mergers between cooperating species?

Charles Darwin was the first to conceive that species evolved, changed, over time, and the first to identify a driving force for that change, survival of the fittest. Darwin’s theories instantly became the bedrock of biological thinking and survived unchallenged for a century. Lynn Margulis was the first to discover and prove modification to Darwin’s … Read more

Who Discovered Chaos Theory and Why is long term weather impossible to predict and forecast?

Ed Lorenz uncovered a non-linear, complex, interdependent system of equations that describe the real movement of the atmosphere. He showed that atmospheric models are so dependent on initial and boundary conditions (starting data supplied to the model) that even seemingly infinitesimal changes in them create major changes in the system. In other words, when a … Read more

Who Discovered that the Seafloor is Spreading which confirms continental drift theory by Alfred Wegener?

We now know that Earth’s continents move. Over hundreds of millions of years, they drift across Earth’s surface. You have likely seen pictures of what Earth looked like 500 million years ago. But just 60 years ago, no one believed that it was possible for massive continents to move. There was no force great enough … Read more

Who Discovered DNA and Where does the DNA molecule come from?

British biochemist Francis Crick, and his American partner, James Watson, created the first accurate model of the molecular structure of deoxyribonucleic acid, or DNA, the master code to the building and operation of all living organisms. That discovery has been called by many “the most significant discovery of the century.” This discovery of the details … Read more

Who Discovered the Origins of Life on Earth and What was the first laboratory re-creation of amino acids?

One of the greatest mysteries has long been: How did life first form on this planet? Theories abound. Bacteria not naturally found on Earth have been found in meteorites recovered in Antarctica. Possibly life here came from some other planet. For over a hundred years, the most popular scientific theory has been that DNA molecules … Read more

Who Discovered Nuclear Fusion and How does fusing two atomic nuclei into one atom release energy?

Fusion energy is the power of the sun. It is a virtually unlimited power source that can be created from hydrogen and lithium, common elements in the earth’s crust. Fusion is clean, environmentally friendly, and non-polluting. Fusion was theorized in the late 1910s and the 1920s. It was mathematically described in the 1930s. It was … Read more

Who Discovered Dark Matter and Where does Dark Matter come from?

Calculations of the expansion of the universe didn’t work. Calculations of the speed of stars in distant galaxies didn’t match what astronomers observed. Calculations of the age of the universe (based on the speed of its expansion) didn’t make sense. Something had to be wrong with the methods used for these calculations. With these major … Read more

Who Discovered Continental Drift theory and Why do the Earth’s continents drift and move over time?

Before Alfred Wegener’s discovery, scientists thought that the earth was a static body, never changing, now as it always has been. Alfred Wegener’s discovery that Earth’s continents drift across the face of the planet led to modern tectonic plate theories and to a true understanding of how Earth’s crust, mantel, and core move, flow, and … Read more

Who Discovered Penicillin and Where does Penicillin come from?

Penicillin has saved millions of lives, tens of thousands during the last years of World War II alone. The first antibiotic to successfully fight bacterial infections and disease, penicillin was called a miracle cure for a dozen killer diseases rampant in the early twentieth century. Penicillin created a whole new arsenal of drugs in doctors’ … Read more

Who Discovered the Function of Chromosomes and What is the relationship between Chromosomes and Genes?

T. H. Morgan’s discovery that genes were linked into groups and strung along chromosomes was the second major step in peeling back the mystery of heredity and evolution. Morgan’s discovery formed much of the foundation for later discoveries of how genes and chromosomes do their work as well as the structure of the DNA molecule. … Read more

Who Discovered Antimatter and Where does Antimatter come from?

Antimatter are particles of the same mass and composition as protons and electrons, but with an opposite electrical charge. Science fiction space ships are regularly powered by antimatter drives. Futuristic bombs are designed around antimatter. Yet neither you nor anyone you’ve ever met has even once seen a particle of antimatter. Antimatter does not come … Read more

Who Discovered Isotopes and Why do some chemical elements have different atomic weights?

Isotopes of an element are slightly different forms of that element. Isotopes have the same chemical, physical, and electrical properties as the original element, but have a different number of neutrons in their nucleus. The discovery of isotopes created a new dimension and concept for physics and chemistry. This discovery answered baffling problems that had … Read more

Who Discovered Superconductivity and How do some materials lose all resistance to electrical current at super low temperatures?

Superconductivity is the flow of electrical current without any resistance to that flow. Even the best conductors have some resistance to electrical current. But superconductors do not. Unfortunately, superconductors only exist in the extreme cold of near absolute zero. Even though the practical application of this discovery has not yet been realized, superconductivity holds the … Read more

Who Discovered that Earthquakes occur along Fault Lines and Where do Earthquakes come from?

Scientists now know that they can predict the locations of future earthquakes by mapping the locations of fault lines. However, just a century ago this simple truth was not known. Harry Reid’s discovery that earthquakes happen along existing fault lines provided the first understanding of the source and process of earthquakes. This discovery laid the … Read more

Who Discovered the relationship between matter and energy and What is the most famous equation in the history of humankind?

For all of history, matter was matter and energy was energy. The two were separate, unrelated concepts. Then Albert Einstein established the relationship between matter and energy by creating the most famous equation in the history of humankind, E = mc2. (The second most famous is the Pythagorean Theorem for a right triangle, A2 = … Read more

Who Discovered Neutrons and Where do Neutrons come from?

A neutron is a subatomic particle located in the nucleus of an atom with the mass of a proton but no electrical charge. The discovery of neutrons has been hailed as a major landmark of twentieth-century science. First, this discovery completed our understanding of the structure of atoms. Second, because they have no electrical charge, … Read more

Who Discovered Hormones and How do the chemical messengers trigger action in various organs in the body?

At the dawn of the twentieth century, scientists thought that all control signals in the human body were sent electrically along nerve fibers. Then William Bayliss and Ernst Starling discovered that chemical messengers (called hormones) as well as electric signals trigger body organs to function. This startling discovery started a whole new field of medical … Read more

Who Discovered Atmospheric Layers and What is the difference between the troposphere and the stratosphere?

What could be more basic to understanding planet Earth than to know what lies between the surface and Earth’s center, or between the surface and outer space? Yet the twentieth century dawned with science having virtually no concept of what the atmosphere was like more than two miles above the earth’s surface. Teisserenc de Bort … Read more

Who Discovered Mitochondria and What does the word Mitochondria mean in Greek?

Mitochondria are tiny energy producers in every cell. One of many tiny structures floating in the cell’s cytoplasm (fluid) that are collectively called organelles, mitochondria are considered the most important of all cell parts, besides the nucleus. Amazingly, mitochondria have their own separate DNA. You depend on them. They depend on you. And yet they … Read more

Who Discovered Cell Structures and What was the first accurate map of the structures that make up a living cell?

Albert Claude was the first scientist to develop procedures for isolating and studying individual structures within a cell. He is the one who mapped the inner organization and activity of a cell and its many components. He is rightly called the founder of modern cell biology. Although he never graduated from high school, Claude pioneered … Read more

Who Discovered the Theory of Relativity and How does space and time merge to form the fabric of the universe?

Albert Einstein is one of only three or four scientists in history who have changed the fundamental ways in which humans view the universe. Einstein’s theory of relativity changed humankind’s core assumptions concerning the nature of the universe and of Earth’s and of humans’ place in it. The twentieth century’s developments in technology, science, and … Read more

Who Discovered Antibiotics and How do Antibiotics kill infectious organisms without harming the human host?

The word “antibiotic” comes from the Greek words meaning “against life.” Early folk medicine relied on some natural compounds that cured certain diseases, the ground bark of a tree, certain cheese molds, certain fungi. Doctors knew that these natural compounds worked, but had no idea of how or why they worked. Paul Ehrlich conducted the … Read more

Who Discovered Quantum Theory and How does the mathematical system describe the behavior of the subatomic world?

In the first 20 years of the twentieth century, physics buzzed with the incredible discovery of the subatomic world. Long before microscopes were powerful enough to allow researchers to see an atom, scientists used mathematics to probe into the subatomic world of electrons, protons, and alpha and beta particles. Albert Einstein, Werner Heisenberg, Max Planck, … Read more

Who Discovered Atomic Bonding and How do electrons gain, lose, and hold energy?

Marie Curie opened the century by proving that there was a subatomic world. Einstein, Dirac, Heisenberg, Born, Rutherford, and others provided the new theoretical descriptions of this subatomic world. But proving what lurked within an atom’s shell, and what governed its behavior, lingered as the great physics challenges of the early twentieth century. It was … Read more

Who Discovered Neurotransmitters and How do they transmit nerve impulses between individual neuron fibers?

Like cracking the genetic code, like the creation of the atomic bomb, the discovery of how the brain’s system of neurons communicates is one of the fundamental science developments of the twentieth century. Nerves signal sensations to the brain; the brain flashes back commands to muscles and organs through nerves. But how? Otto Loewi’s discovery … Read more

Who Discovered the Electron and When was the first subatomic particle discovered?

Atoms had never been seen before. Defined as the smallest particles possible and the basic building blocks of all matter, they were invisibly small, in the late nineteenth century still more theoretical than real. How could someone claim to have found something smaller? How could particles get any smaller? J. J. Thomson discovered the electron … Read more

Who Discovered that the Universe is Expanding and millions of galaxies move away from its center?

Edwin Hubble’s twin discoveries (that there are many galaxies in the universe, not just the Milky Way, and that all of those galaxies are traveling outward, expanding the universe) rank as the most important astronomical discoveries of the twentieth century. These discoveries radically changed science’s view of the cosmos and of our place in it. … Read more

Who Discovered that the Earth is shaped by erosion and geologic forces over millions of years?

In the eighteenth century scientists still believed that Earth’s surface had remained unchanged until cataclysmic events (the great flood of Noah’s ark fame was the most often sited example) radically and suddenly changed the face of our planet. They tried to understand the planet’s surface structures by searching for those few explosive events. Attempts to … Read more

Where does Heat come from and Who Discovered that friction causes heat?

Scientists once believed that heat was an invisible, weightless liquid called caloric. Things that were hot were stuffed with caloric. Caloric flowed from hot to cold. They also believed that fire (combustion) came from another invisible substance called phlogiston, a vital essence of combustible substances. As a substance burned, it lost phlogiston to air. The … Read more

Who Discovered the Uncertainty Principle and Why is it impossible to know the position and motion of a particle?

Werner Heisenberg is famed worldwide for discovering the Uncertainty Principle, which states that it is impossible to determine both the position and momentum (motion) of an elementary particle at the same time since the effort to determine either would change the other in unpredictable ways. This pivotal theorem marked a fundamental turning point in science. … Read more

Who Discovered the Speed of Light and How was the universal constant measured accurately?

In the late 1800s discovering the true the speed of light had only minor importance because astronomers were the only ones who used this number. Distances across space are measured in light-years, how far light travels in one year’s time. Since their measurements were only approximations anyway, they could accept a 5 percent (or even … Read more

Who Discovered Blood Types and How Humans have different types of blood that are not all compatible?

Blood was blood, or so the world thought. Then Austrian physician Karl Landsteiner discovered that there were four types of blood. Some could be safely mixed and some could not. That discovery has saved millions of lives. The day that Karl Landsteiner’s results were published, blood transfusions became a safe and risk-free part of surgery. … Read more

Who Discovered Electromagnetism and How does an electric current create a magnetic field?

Before 1820, the only known magnetism was the naturally occurring magnetism of iron magnets and of lodestones, small, weak direction finders. Yet the modern world of electric motors and electric generating power plants is muscled by powerful electromagnets. So is every hair dryer, mixer, and washing machine. Our industry, homes, and lives depend on electric … Read more

Who Discovered Heredity and How does Heredity pass traits and characteristics from one generation to the next?

Gregor Mendel conducted the first serious study of heredity. His findings, his methods, and his discoveries laid the foundation for the field of genetics and the study of genes and heredity. The discoveries of genes, chromosomes, DNA, and the decoding of the human genome (completed in 2003) are all direct descendents of Mendel’s work. The … Read more

Who Discovered the Existence of Molecules and How different atoms are attached to form a Molecule?

If atoms are the basic building block of each element, then molecules are the basic building blocks of each substance on Earth. Scientists were stalled by their inability to accurately imagine, let alone detect, particles as small as an atom or a molecule. Many had theorized that some tiny particle (that they called an atom) … Read more

Who Discovered Electrochemical Bonding and How Molecular Bonds between chemical elements are electrical in nature?

Humphry Davy discovered that the chemical bonds between individual atoms in a molecule are electrical in nature. We now know that chemical bonds are created by the sharing or transfer of electrically charged particles, electrons, between atoms. In 1800, the idea that chemistry somehow involved electricity was a radical discovery. Davy’s discovery started the modern … Read more

Who Discovered Infrared and Ultraviolet Radiation and When?

Infrared and ultraviolet radiation are key parts of our scientific development over the past 200 years. Yet until 1800 it never occurred to anyone that radiation could exist outside the narrow band that human eyes detect. The discovery of infrared and ultraviolet light expanded science’s view beyond the visible light to the whole radiation spectrum, … Read more

Who Discovered Vaccination and What does the word Vaccination mean in Latin?

Have you had smallpox? Polio? Typhoid? Probably not. However, such infectious diseases used to plague humankind. The word plague comes from one of these killer diseases, the bubonic plague. Throughout the fourteenth and fifteenth centuries, the plague killed nearly half of the population of Europe. Smallpox killed over 100,000 people a year for a century … Read more

Who Discovered Cell Division and How do chromosomes split so that cells can divide to produce new cells?

Chromosomes carry genes that hold the blueprints for building, operating, and maintaining the cells of your body. Genetics and heredity research could not advance until these physical structures inside the nucleus of each cell had been discovered and studied. Our basic understanding of biology also depends, in part, on our knowledge of how cells divide, … Read more

Who First Discovered Oxygen and When was the gaseous element isolated?

Joseph Priestley’s discovery of oxygen sparked a chemical revolution. He was the first person to isolate a single gaseous element in the mixture of gasses we call “air.” Before Priestley’s discovery, scientific study had focused on metals. By discovering that air wasn’t a uniform thing, Priestley created a new interest in the study of gasses … Read more

Who Discovered the Nature of Electricity and that all forms of electricity are the same?

Electricity is one of our greatest energy resources and one of the few natural energy sources. Benjamin Franklin’s electricity experiments were the first scientific ventures into the nature and use of electricity and uncovered its true nature. They set the stage for much of the scientific and engineering development in the nineteenth century and for … Read more

Who Discovered Conservation of Matter and the law of conservation of mass and When?

Antoine Lavoisier was the first chemist to believe in measurement during and after experiments. All chemists before had focused on observation and description of the reactions during an experiment. By carefully measuring the weight of each substance, Lavoisier discovered that matter is neither created nor destroyed during a chemical reaction. It may change from one … Read more

Who Discovered Taxonomy and How are organisms grouped and organized into a simple hierarchy?

Until the eighteenth century, nature was viewed as a wild profusion of life. Carl Linnaeus discovered order and organization in that seeming randomness. His system for naming, grouping, and conceptually organizing plants and animals provided insights into botany, biology, ecosystems, and biological structure that scientists still rely on almost 300 years later. For his discovery, … Read more

Who Discovered the Theory of Evolution and the concept of survival of the fittest and When?

Darwin’s theory of evolution and its concept of survival of the fittest is the most fundamental and important discovery of modern biology and ecology. Darwin’s discoveries are 150 years old and are still the foundation of our understanding of the history and evolution of plant and animal life. Darwin’s discovery answered countless mysteries for anthropology … Read more

Who Discovered Atomic Light Signatures and How each element radiates light at specific frequencies?

Twenty new elements (beginning with the discovery of cesium in 1860) were discovered using one chemical analysis technique. That same technique allows astronomers to determine the chemical composition of stars millions of light years away. It also allowed physicists to understand our sun’s atomic fires that produce heat and light. That same technique allows other … Read more

Who Discovered Ice Ages and that the Earth’s climate was radically different millions of years ago?

It was a revolutionary idea: Earth’s climate had not always been the same. Every scientist for thousands of years had assumed that Earth’s climate had remained unchanging for all time. Then Louis Agassiz discovered proof that all Europe had once been covered by crushing glaciers. Earth’s climate had not always been as it was now. … Read more

Who Discovered the First Dinosaur Fossil proving that giant dinosaurs once walked the earth and When?

Most people and scientists assumed that the world and its mix of plants and animals had always been as it was when these scientists lived. The discovery of dinosaur fossils destroyed that belief. This discovery represented the first proof that entire groups of ancient, and now extinct, animals once roamed Earth. It was the first … Read more

Who Discovered that the absolute volume and pressure of a gas are inversely proportional at a constant temperature?

The concept Robert Boyle discovered (now called Boyle’s Law) laid the foundation for all quantitative study and chemical analysis of gasses. It was the first quantitative formula to describe the behavior of gasses. Boyle’s Law is so basic to understanding chemistry that it is taught to every student in beginning chemistry classes. A genius experimenter, … Read more

Who Discovered Electromagnetic Radiation, Radio Waves, and Electromagnetic Spectrum?

Throughout most of the nineteenth century, people thought that electricity, magnetism, and light were three separate, unrelated things. Research proceeded from that assumption. Then Maxwell discovered that they are all the same, forms of electromagnetic radiation. It was a startlingly grand discovery, often called the greatest discovery in physics in the nineteenth century. Maxwell did … Read more

Who Discovered how the Human Circulatory System works and When?

The human circulatory system represents the virtual definition of life. No system is more critical to our existence. Yet only 400 years ago, no one understood our circulatory system. Many seriously thought that the thumping inside the chest was the voice of the conscience trying to be heard. Most thought that blood was created in … Read more

Who Discovered that other planets in the Solar System besides Earth have Moons and When?

Galileo discovered that other planets have moons and thus extended human understanding beyond our own planet. His careful work with the telescopes he built launched modern astronomy. His discoveries were the first astronomical discoveries using the telescope. Galileo proved that Earth is not unique among planets of the universe. He turned specks of light in … Read more

Who Discovered that all Objects fall at the same speed regardless of their weight and When?

It seems a simple and obvious discovery. Heavier objects don’t fall faster. Why does it qualify as one of the great discoveries? Because it ended the practice of science based on the ancient Greek theories of Aristotle and Ptolemy and launched modern science. Galileo’s discovery brought physics into the Renaissance and the modern age. It … Read more

Who Discovered Human Anatomy and created the first scientific guide to the structure of the human body?

The human anatomy references used by doctors through the year A.D. 1500 were actually based mostly on animal studies, more myth and error than truth. Andreas Vesalius was the first to insist on dissections, on exact physiological experiment and direct observation, scientific methods, to create his anatomy guides. His were the first reliable, accurate books … Read more

Who first Discovered that the Sun Is the Center of the Solar System and the earth rotates around it and When?

Copernicus measured and observed the planets and stars. He gathered, compiled, and compared the observations of dozens of other astronomers. In so doing Copernicus challenged a 2,000-year-old belief that the earth sat motionless at the center of the universe and that planets, sun, and stars rotated around it. His work represents the beginning point for … Read more

Who Discovered the Three Laws of Motion which are the foundation of physics and engineering and When?

Newton’s three laws of motion form the very the foundation of physics and engineering. They are the underlying theorems that our physical sciences are built upon, just as Euclid’s basic theorems form the foundation of our modern geometry. For the creation of these laws, combined with his discovery of gravity and his creation of calculus, … Read more