What is the Universe?
To answer this question in simple terms, we have to say that the universe is everything. That’s correct, the universe is everything human beings believes exists – all physical matter that we can touch and see, all the energy as we understand it, all of time and space.
People sometimes refer to the universe as all of the physical objects, planets, stars etc. This is essentially saying the same thing but with a slightly more “cosmic” feel. Some scientists believe that our universe may not be “everything” there is, but is just everything that we can imagine. These scientists propose that there may be other universes that are not connected to ours. This is sometimes explained this way: we live in one of many “worlds”
Old and Continuous
When compared to human existence the universe is very old. The best theories developed about the universe indicate that it has been subject to the same scientific laws throughout history. Some scientists theorize, however, that other “universes” may be governed by completely different laws of science.
Human beings have developed theories about the universe since the earliest recorded times. In Greece, the wisest of men proposed that our universe has outer limits (in terms of space and time). They also believed that there were a finite number of celestial bodies – stars, planets etc.
As technology allowed human beings to closely observe objects in space the theories were fine tuned and more scientific evidence was put in place. We have found that our solar system is part of a galaxy made up of millions upon millions of stars. We call this galaxy the Milky Way. Yet the universe, as we understand in the 21st century, is probably composed of thousands of galaxies that each contain millions of stars.
Universe of Separate Parts
Scientists have been able to discover that the many galaxies that make up our universe vary quite a bit in size and shape. Telescopes show that some of these galaxies may actually contain billions of stars, making some much larger than our Milky Way galaxy.
Scientists have also developed some theories about how the universe came to exist. The well-known Big Bang theory proposes that our universe expanded from a dense central point so concentrated that it exploded and spread the planets, stars and other matter across space. Some theories state that our universe is still expanding from this original center, while others believe the universe has stopped growing or may even be contracting. Astronomers have come up with numbers to estimate the age of the universe. The best guess seems to be 13.7 billion years of age.
One of the most interesting parts of this study lies in the words and phrases used to describe something so vast and ancient that we can only understand it with our imaginations. We use the term “universe,” a word from the Latin language that seems to imply that this is all one thing, connected in some way and perhaps rotating in some manner as well. The first theories of this kind were developed centuries ago.