Science Dictionary

Berg, Paul (1926-), an American biochemist and molecular biologist, has been at the forefront of genetic engineering, both as an inventor of a pioneering procedure and as an advocate concerned about the risks of genetic research.

Greengard, Paul (1925-) shared the 2000 Nobel Prize in physiology or medicine for his discovery of how dopamine and a number of other transmitters in the brain exert their action in the nervous system.

Medawar, Peter Brian (1815-1987), was a British zoologist who shared the 1960 Nobel Prize in physiology or medicine with Sir Macfarlane Burnet of Australia for their work on the body's rejection of tissue transplants.

Lewontin, Richard Charles (1929-), an American evolutionary geneticist, introduced the study of molecular population genetics in the 1960's.

Merrifield, Robert Bruce (1921-) is an American biochemist who won the 1984 Nobel Prize in chemistry for his method of producing peptides and proteins.

Hubbard, Ruth (1924-) is an Austrian-born American biologist and biochemist whose contributions to the study of the biochemistry and photochemistry of vision in vertebrates and invertebrates have greatly advanced the understanding of the field.

Wright, Sewall Green (1889-1988), was an American geneticist who greatly influenced the fields of genetics (the study of heredity) and evolutionary biology.

Benzer, Seymour (1921-), an American geneticist, is one of the founders of modern behavioral geneties.

Altman, Sidney (1939-), a Canadian-born American molecular biologist, transformed scientific thought about how living cells work and how life began millions of years ago.

Nebulae are collections of dust and gases scattered across the galaxy. They're the sites where stars are born and what's left behind after they die.

By William Harris

The big bang theory is well-known, but there are many misconceptions about it. Like what? Let's start with this one: There was no bang.

By Jonathan Strickland

Modern science allows us to break atoms down into tiny components. But can scientists use their mighty machines to recreate the foundation of the universe?

By Jonathan Strickland

Some scientists believe that space is infinite. But is it? If it isn't, what form does space take? Is it a dodecahedron or a triple torus?

By Jonathan Strickland

Space collisions are the universe's car wrecks. Only in outer space, it's stars, asteroids and even galaxies doing the smashing.

By John Fuller

So much about galaxies remains a mystery. We know what they're made of and that we live in one (the Milky Way), but we're not sure how they form and evolve.

By Craig Freudenrich, Ph.D.

When a star dies, it becomes a black hole. Once something passes through the it's gone for good, never to be seen or heard from again. If we lived next to a black hole, would it suck us in too?

By Marshall Brain

For decades, stargazing scientists have been facing their own darkness on the edge of town as they try to explain one of astronomy's greatest mysteries: dark matter. Have they been successful, or will the universe carry its secrets for a long time?

By William Harris & Craig Freudenrich, Ph.D.

While routinely scanning the stars, NASA scientists came across something they didn't expect to see: a vast area of space empty of stars, planets and matter.

By Jacob Silverman

Scientists announced the discovery of the largest known planet in the universe. TrES-4 has a density similar to balsa wood, and some say this gas giant could float on water. Learn why this planet is so puzzling and how planet hunters make amazing discoveries like these.

By Jacob Silverman

The Freemasons is a secret organization that began in the 1700s and is still in existence today. Who are the Freemasons? And what do they do in their secret meetings?

By Stephanie Watson

There's a 45-million-ton asteroid out there with Earth's name on it. In 2029, it'll be closer to us than our moon is. And that's not even the fly-by that scientists are worried about.

By Julia Layton

A black hole occurs when a massive star dies -- its enormous mass implodes and becomes so heavy that it bends space. So how do astronomers detect something that they can't see?

By Craig Freudenrich, Ph.D.

How do scientists find details about the early days of our solar system? One way is to investigate comets. Find out how the Deep Impact spacecraft fired an impactor into Comet Tempel 1 to get some answers.

By Carolyn Snare

Every November, the Leonid meteor shower fills the sky with "shooting stars." This year, the shower is expected to peak twice. Learn how Leonid and other meteor showers work.

By Marshall Brain

Polymer crystals are amazing in that they can absorb many times their size. In fact, one pound of these crystal flakes can hold up to 50 gallons of water. Find out what these polymer crystals are and why they are able to absorb so much water.