The web page explains that the universe may have started with the Big Bang, but the physics of the earliest moments is unclear. It also discusses the possible alternatives to the Big Bang, such as loop quantum gravity and string theory.
Explore eight alternative explanations of how the universe came into existence, from quantum fluctuation to cyclic cosmology. Learn the pros and cons of each theory, the evidence and references, and the implications for cosmology.
Some 400,000 years later the first stars formed from the clumps of hydrogen and begin to light-up the Universe. Evidence for the Big Bang includes: All other galaxies are moving away from us.
Learn how the universe was formed from cosmic inflation to the big bang, nucleosynthesis, recombination, dark ages, and reionization. Explore the cosmic microwave background, the first stars, and the future of the universe.
The Big Bang Theory is the leading explanation for how the universe began. It describes a time when everything we know—the billions of galaxies, stars, planets, even the fabric of space and time itself—was condensed into a single, unimaginably dense point. ... As more stars formed, gravity pulled them into vast cosmic cities known as ...
Learn how scientists at Harvard & Smithsonian study the origin and evolution of the Universe, from the Big Bang to the first stars and black holes. Explore their observations, simulations, and theories of Inflation, Cosmic Microwave Background, and Cosmic Dark Ages.
How did the creation of the universe lead to our existence? With the current fleet of Astrophysics missions, researchers are able to study the first stars and galaxies forming out of the darkness of the early universe with state-of-the-art technologies that act as powerful time machines, peering back over 13.5 billion years.
The early universe was extremely hot and dense, much like the centre of the Sun. NASA/SDO. As the universe expanded and cooled still further, there were fewer high energy photons (particles of light) in the universe than there had previously been. This is a trigger for the process called Big Bang nucleosynthesis (BBN).
Explain the formation of the universe and how we observe it. Understand the origin of our Solar System. Describe how the objects in our Solar System are identified, explored, and characterized. Describe the types of bodies in our Solar System, their locations, and how they formed. Explain what influences the temperature of a planet’s surface.
The elements in our bodies, the elements that make up our bones, the trees we see outside, the other planets in the solar system, other stars in the galaxy. These were all part of stars that existed well before our Sun and Earth and solar system were even formed. The universe existed for billions of years before we did.
How old is the universe, and how did it begin? Throughout history, countless myths and scientific theories have tried to explain the universe's origins. The most widely accepted explanation is the big bang theory. Learn about the explosion that started it all and how the universe grew from the size of an atom to encompass everything in existence today.
Our universe began with an explosion of space itself - the Big Bang. Starting from extremely high density and temperature, space expanded, the universe cooled, and the simplest elements formed. Gravity gradually drew matter together to form the first stars and the first galaxies. Galaxies collected into groups, clusters, and superclusters.
Around 13.8 billion years ago, all the matter in the Universe emerged from a single, minute point, or singularity, in a violent burst. This expanded at an astonishingly high rate and temperature ...
Learn how the big bang theory explains the universe's beginning and its early evolution, from the first second to the first 380,000 years. Discover the evidence, mysteries, and challenges of this popular cosmological model.
Learn about the Big Bang theory, the moment 13.8 billion years ago when the universe began as a tiny, dense, fireball that exploded. Explore the timeline of the universe and play a game to order cosmic events.
In Egyptian cosmology, people believed that the universe emerged from the primordial waters of the creator god, Nun, and these waters formed an abyss with boundless potential and endless possibilities. The sun god, Atum, was credited with bringing structure and form to the cosmos through his creative prowess.
Most astronomers think that the Universe was formed during an event called the Big Bang - a giant explosion which occurred between 10 and 20 billion years ago (see our "How Old is the Universe" page for a longer discussion of the age of the Universe...)During the Big Bang, all of the space, time, matter, and energy in the Universe was created.
A younger Universe should be less enriched in the types of heavy elements formed in stars: carbon, oxygen, silicon, sulfur, iron, and more, eventually revealing, at the earliest times, only the ...
The Steady State Universe: Eternal Creation. First proposed by Sir James Jeans in the 1920s, the Steady State hypothesis presents a radically different view of the universe. According to this theory, the universe has neither a beginning nor an end. Instead, as it expands, new matter is continuously created to maintain a consistent density over ...
