Greatest discoveries

Life-Changing Science Discoveries

Try to imagine life without antibiotics. We wouldn’t live nearly as long as we do without them. Here’s a look at some discoveries that have changed the world. It’s impossible to rank their importance, so they’re listed in the order they were discovered.

Gravity

Isaac Newton, an English mathematician and physicist, is considered the greatest scientist of all time. Among his many discoveries, the most important is probably his law of universal gravitation. In 1664, Newton figured out that gravity is the force that draws objects toward each other. It explained why things fall down and why the planets orbit around the Sun.

Electricity

If electricity makes life easier for us, you can thank Michael Faraday. He made two big discoveries that changed our lives. In 1821, he discovered that when a wire carrying an electric current is placed next to a single magnetic pole, the wire will rotate. This led to the development of the electric motor. Ten years later, he became the first person to produce an electric current by moving a wire through a magnetic field. Faraday's experiment created the first generator, the forerunner of the huge generators that produce our electricity.

Evolution

When Charles Darwin, the British naturalist, came up with the theory of evolution in 1859, he changed our idea of how life on earth developed. Darwin argued that all organisms evolve, or change, very slowly over time. These changes are adaptations that allow a species to survive in its environment. These adaptations happen by chance. If a species doesn't adapt, it may become extinct. He called this process natural selection, but it is often called the survival of the fittest.

Theory of Relativity

Albert Einstein’s theory of special relativity, which he published in 1905, explains the relationships between speed, time and distance. The complicated theory states that the speed of light always remains the same—186,000 miles/second (300,000 km/second) regardless of how fast someone or something is moving toward or away from it. This theory became the foundation for much of modern science.

The Big Bang Theory

Nobody knows exactly how the universe came into existence, but many scientists believe that it happened about 13.7 billion years ago with a massive explosion, called the Big Bang. In 1927, Georges Lemaître proposed the Big Bang theory of the universe. The theory says that all the matter in the universe was originally compressed into a tiny dot. In a fraction of a second, the dot expanded, and all the matter instantly filled what is now our universe. The event marked the beginning of time. Scientific observations seem to confirm the theory.

Penicillin

Antibiotics are powerful drugs that kill dangerous bacteria in our bodies that make us sick. In 1928, Alexander Fleming discovered the first antibiotic, penicillin, which he grew in his lab using mold and fungi. Without antibiotics, infections like strep throat could be deadly.

DNA

On February 28, 1953, James Watson of the United States and Francis Crick of England made one of the greatest scientific discoveries in history. The two scientists found the double-helix structure of DNA. It’s made up of two strands that twist around each other and have an almost endless variety of chemical patterns that create instructions for the human body to follow. Our genes are made of DNA and determine how things like what color hair and eyes we’ll have. In 1962, they were awarded the Nobel Prize for this work. The discovery has helped doctors understand diseases and may someday prevent some illnesses like heart disease and cancer.

X-Rays

Wilhelm Roentgen, a German physicist, discovered X-rays in 1895. X-rays go right through some substances, like flesh and wood, but are stopped by others, such as bones and lead. This allows them to be used to see broken bones or explosives inside suitcases, which makes them useful for doctors and security officers. For this discovery, Roentgen was awarded the first-ever Nobel Prize in Physics in 1901.

HIV/AIDS

In 1983 and 1984, Luc Montagnier of France and Robert Gallo of the United States discovered the HIV virus and determined that it was the cause of AIDS. Scientists have since developed tests to determine if a person has HIV. People who test positive are urged to take precautions to prevent the spread of the disease. Drugs are available to keep HIV and AIDS under control. The hope is that further research will lead to the development of a cure.