Science Dictionary

The kilometer (km) is a standard unit of measurement used in the metric system. Derived from the French "kilomètre," the unit is used to measure length and distance along a straight path.

By Mitch Ryan

In any scientific research, there are typically two variables of interest: independent variables and dependent variables. In forming the backbone of scientific experiments, they help scientists understand relationships, predict outcomes and, in general, make sense of the factors that they're investigating.

By Marie Look

Physicist and cosmologist Stephen Hawking was a fierce spirit who symbolized the foibles and complexities inherent in human nature. Learn more about him by taking our quiz.

By Nathan Chandler

The world often seems chaotic and events appear to occur randomly, but what's the difference between chaos and randomness?

By Mitchell Newberry

Nobel prizes offer lots of prestige and big payouts. But how do you become eligible for one? And can you lobby for yourself?

By Dave Roos

Planck's constant, which made an appearance in the Netflix series "Stranger Things," is one of the most important differences between reality at the atomic and subatomic level and what we can see around us.

By Patrick J. Kiger & Austin Henderson

As much as we might like to think that our collective knowledge has unlocked most of the mysteries of the universe, we've really only got a hold on a tiny fraction of the knowledge required to fully understand it all-and it's a weak hold at best. But every once in a while a new theory [...] The post 12 Of The Most Mind-Blowing Scientific Theories Ever Conceived appeared first on Goliath.

By Wes Walcott

From astronauts to doctors to an archaeologist, we present eight scientists whose contributions to science, engineering and math were inseparable from their identities as Indigenous Americans.

By Dave Roos

Questions, theories and debates about quantum physics can get muddled because of a number of myths and misconceptions. Here are four of them.

By Alessandro Fedrizzi & Mehul Malik

Under the right conditions, hot water can somehow freeze faster than cold water. It's called the Mpemba effect. We'll explain how it happens.

By Dylan Ris

Einstein famously called the phenomenon "spooky action at a distance," and physicists just won the Nobel Prize for their work on it, but what is quantum entanglement?

By Andreas Muller

The number 137, which is significant in multiple applications, has long been an object of fascination for physicists, mathematicians and mystics.

By Patrick J. Kiger & Austin Henderson

The late marine biologist Rachel Carson's groundbreaking book, "Silent Spring," debuted 60 years ago as one of the finest works of nature writing ever.

By Oisin Curran

Scientists are still trying to figure out the essence of dark matter. If they do, will it lead only to greater understanding, or can we develop new technologies?

By Patrick J. Kiger

Having one Nobel Prize winner in the family is a huge accomplishment. But the extended Curie family had five winners - and one was even awarded twice. How did they get so smart?

By Jennifer Marquez

So much about galaxies remains a mystery. We know what they're made of and that we live in one (the Milky Way), but how many galaxies are in the universe?

By Craig Freudenrich, Ph.D.

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

Frequency has to do with wave speed and wavelength is a measurement of a wave's span. Learn how frequency and wavelength of light are related in this article.

By HowStuffWorks.com Contributors

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

We take much for granted about our universe, like it's getting bigger. What if the universe stopped expanding and started collapsing inward with a giant crunch?

By William Harris

Payne-Gaposchkin, Cecilia Helena (1900-1979) was a British-born astronomer who became an authority on variable stars (stars that change in brightness) and the structure of the Milky Way Galaxy.

Al-Tusi, Nasir al-Din (1201-1274) was one of the greatest scholars of his time and one of the most influential figures in Islamic intellectual history.

Aberration of Light is a phenomenon in which a star or other celestial body, as viewed from the earth, appears to be slightly displaced from its true position.

Chronometer, a timepiece that is exceptionally accurate. Traditionally, the term refers to the marine chronometer, a rugged mechanical instrument used at sea to keep time for navigational purposes.

Cosmogony, the study of the origin and development of the universe as a whole and of the individual bodies that compose it.