essay on expanding universe

Expanding universe, dynamic state of the extragalactic realm, the discovery of which transformed 20th-century cosmology. The development of general relativity and its application to cosmology, along with the detection of extragalactic redshift, led to the realization in the 1920s that all galaxies are receding.

Some 13.8 billion years ago, the universe began with a rapid expansion we call the big bang. After this initial expansion, which lasted a fraction of a second, gravity started to slow the universe down. But the cosmos wouldn't stay this way. Nine billion years after the universe began, its expansion started to speed up, […]

The universe was born with the Big Bang as an unimaginably hot, dense point. When the universe was just 10 -34 of a second or so old — that is, a hundredth of a billionth of a trillionth of a ...

Edwin Hubble's observations of the expanding universe in the 1920s marked the beginnings of what's now known as the big-bang theory. We've since made monumental strides in determining when and how the big bang would have taken place by looking at what's known as cosmic background radiation using instruments such as COBE and WMAP in 1989 and 2001, respectively.

The expanding universe, a new idea based on modern physics, laid to rest the paradoxes that troubled astronomers from ancient times until the early 20th Century. Properties of the Expanding Universe. The equations of the expanding universe have three possible solutions, each of which predicts a different eventual fate for the universe as a whole.

The Universe's History The origin, evolution, and nature of the universe have fascinated and confounded humankind for centuries. New ideas and major discoveries made during the 20th century transformed cosmology - the term for the way we conceptualize and study the universe - although much remains unknown. Here is the history of the universe according […]

Point out to students that during the last 100 years our ideas of the Universe have changed immensely. Albert Einstein, for example, theorized that the Universe was static—neither collapsing nor expanding, an idea held by many scientists of his time. But in 1929, Edwin Hubble discovered that the Universe is actually expanding.

And if the Universe is really expanding faster than we thought, it might be much younger than the currently accepted 13.8 billion years. NASA/ESA/Hubble Heritage Team

This essay is an excerpt from A Brief Welcome to the Universe: A Pocket-Sized Tour by Neil deGrasse Tyson, J. Richard Gott, and Michael A. Strauss.. About the Authors. Neil deGrasse Tyson is director of the Hayden Planetarium at the American Museum of Natural History and the author of many books, including Astrophysics for People in a Hurry.Twitter @neiltyson Michael A. Strauss is professor of ...

June 5, 2007. When Albert Einstein was starting out on his cosmological quest 100 years ago, the universe was apparently a pretty simple and static place. Common wisdom had it that all creation ...