What is the universe made of? How did it come into existence? Was there anything before it? Where did the laws of nature come from? As difficult as these questions are, scientists are grappling and attempting to address them with bold new ideas – and new experiments. By combining mathematical models with observations, they are able to develop workable theories of how the Universe came to be.
Over and over again, the universe has proven to be far stranger and more complex than we can even begin to imagine. Astronomers have put forth numerous hypotheses and explanations of the origin of the universe.
The Big Bang theory is the prevailing cosmological model explaining the existence of the observable universe. It postulates that the universe began in a tremendous explosion about 13.8 billion years ago. During those earliest moments, the universe was filled with energy, much of it in the form of intense heat. As the universe grew and cooled, some of this energy transformed into matter. We once thought that atoms were the most fundamental building blocks of matter. Today, we know that atoms are made of many smaller pieces, known as subatomic particles.
Professor Brian Cox is a British physicist and professor of particle physics at the University of Manchester. He investigates the universe’s biggest questions and explains what these particles are and their role in the creation of the universe.
Since the beginning of the 21st century, the way the universe is viewed has changed dramatically. As of September 2021, more than 4800 planets have been discovered orbiting distant stars. Black holes are now known to be present at the center of most galaxies, including the Milky Way galaxy. The age, size and shape of the universe have been mapped based on the primordial radiation left by the big bang. And it has been learned that most of the matter in the universe is dark and invisible, and the universe is not only expanding, but accelerating in an unexpected way.
Stephen Hawking’s approach to the universe considers space-time to be a hologram in which the geometry of the entire past would project off of the present. Brian Cox also agrees with that we might be holograms and suggests that it is possible the universe might not be at all as we perceive it to be. But more on that in another video.
