Updated: Feb 22
Once upon a time — actually before time even existed — there was nothing. Nothing-nothing. In fact, in this timeless non-Universe, even "nothing" didn't exist. Then bang! Everything came into being with incredible speed.
This is the short story of how the Universe was created. But we know you're eager to find out more. Are we right?! Then come along a few billion years into the past, to the very moment when the entire Universe broke loose.
The Big Bang Theory
13.8 billion years ago, our Universe appeared from a single, tiny, dense, ultra-charged point called "singularity". The burst, as you can imagine, was violent. Everything expanded at the same time, with incredible speed, and at an unbelievable high temperature. Faster and faster, making the Universe to double in size every few seconds.
Scientists refer to this rapid expansion as "inflation". To picture how our Universe was created, imagine a balloon getting bigger and bigger. As it inflated, the Universe created energy that changed into matter and antimatter particles. In billions of years, these fundamental building blocks would combine and give birth to everything we know today: stars, planets, life and galaxies (including our Solar System).
Of course, this is just a theory. But it's the best one we have so far. Curious to know who came up with the Big Bang theory? Then you're going to love our next section.
Who came up with the Big Bang Theory?
For thousands of years, people believed that the Universe always existed. However, in 1927, priest and scientist George Lemaitre proposed an outrageous idea: the Universe was created from a single atom. "Bang!".
"Nonsense", said everybody.
"The Universe always existed. And always will", the voices reiterated.
So people went on about their business, until two years later when Edward Hubble begged to differ. He was convinced that the Universe was expanding...which meant Lemaitre was probably right. The Universe was created from a single, dense point.
But not everybody agreed this time either. Some nay-sayers even jokingly referred to this idea as the "big bang" theory. Well, the name stuck!
Today, many renowned scientists believe that the Big Bang is how the Universe formed. And they are closely watching it expand. Which leads us to our next question.
Will the Universe expand forever?
The verdict is...not in yet. Scientists have voiced several different opinions, but they haven't reached a consensus.
Some say that "yes", the Universe will expand forever. And while this might sound like good news, there's a downside. As it expands, the Universe' temperature will lower, eventually leading to a complete cool down, popularly called "the Big Freeze". Needless to say, at this stage, the Universe won't be able to support life anymore.
Other astrophysicists believe that the Universe's expansion will stop and reverse itself. This theory is, yet again, not very optimistic. As a result of the reversion, the Universe would collapse into itself leading to a "Big Crunch".
Another theory states that the Universe will continue to expand at accelerated rates. Because of the unbelievable speed, gravity won't be able to keep things together anymore. Stars would fly away from one another, and the Universe would tear apart. This theory is known as "the Big Rip".
However, don't worry. Even if any of these theories were to happen, they are billions of years away. Who knows...until then, maybe we'll discover that the Universe is meant to exist forever.
Now, shall we explore the Universe?
Congrats! Now you know how the Universe was created. So what do you say about exploring it? We're talking about launching your very own satellite into space, stepping in astronauts' shoes, or flying weightless. For real!
If you're a true Junior Astronaut at heart, find out how you can do all the above by checking out our participative space programmes. Dare to discover the Universe and, who knows, maybe you'll one day become an astronaut.