Almost 14 billion years ago, The Universe started as a big bang…from a point that was infinitesimally small.
A colossal explosion occurred from a point smaller than the point on this pen.
Like any explosion, scientists expected that over time the explosion would slow down until it stops.
In a real world explosion, it’s the friction of the air and gravity that slows an explosion down.
So similarly, it was expected that the big bang explosion would also be slowing down due to the effects of gravity counteracting the effect of this big-bang expansion.
In the late 1990’s, two teams of scientists set out to measure this slow-down. They used the Hubble space telescope to look at type 1A supernova explosions. These special supernovae emit the syouame luminosity no matter where in the universe they are located, so they serve as standard candles.
They used these supernovae to determine the slow-down of the big bang explosion.
But what they discovered shocked these scientists. The results were so shocking that the scientists studying this did not themselves believe it. They had to double check, triple check and quadruple check their results, to make absolutely sure.
But the results did not change. They found that not only is the expansion of the universe not slowing down, it is not even steady….the expansion of the universe is accelerating.
The expansion is getting faster!
This is a complete shock to astronomers and physicists…because this kind of acceleration implies that there must be an enormous amount of mysterious energy that is driving this expansion.
There has to be energy because it has to push against all the gravity that is contained in the universe.
And frankly, scientists have no idea what this energy is or where it is coming from. And when scientists have no idea about something…they call it “dark”
Thus, this mysterious energy that is making the universe accelerate is expansion is called “dark energy.”
And it is an enormous amount of energy, using Einstein’s famous equation E=MC squared. It turns out that this energy of expansion is equivalent to more than 10 times all the visible matter in the universe – more than 10 times all the stars, galaxies, and everything that you can see with a telescope.
In fact, 70% of the Universe as we know it is comprised of Dark Energy. So, this is not some obscure insignificant force of nature, it is the majority of what the natural world is made of.
What exactly it is, no one knows…but the leading theory is that Dark Energy is a property of space itself.
It is a kind of Anti-gravity that emanates from the fabric and large volumes of space. And as space expands, more and more of this anti-gravity force comes into existence and thus, causes a positive feedback loop resulting in a runaway acceleration of expanding the universe.
What does this mean for you and me?
Well, it really doesn’t mean much right now. We don’t really feel the direct effects of dark energy…right now.
But in several trillion years…if we are still around, the fabric of space will expand so rapidly that it will overwhelm all of the gravity in the universe. All galaxies will break up, our solar system will break up, our sun will break up, the earth will break up…
In fact, all matter will break up including all atoms, nuclei of atoms, all particles – and the universe be destroyed and will be made up of pure energy…which will dissipate into the cold darkness of an unimaginably vast universe that is Trillions and trillions of light years across.
And what will happen after that….maybe another Big Bang…let there be light!
