Not only is the universe constantly expanding, but that expansion is actually speeding up, seperating everything in the universe from everything else, faster and faster every second. The reason may surprise you, and may change the way you look at the night sky, so don't separate yourself from your seat, and join me for another dose of Super Cool Science S#!t.
everything in the universe was concentrated into one infinitesimally small point. It's thought that during this time, matter and energy were indistinguishable. Then suddenly, and for a yet unknown reason, when the universe was only about one hundred billionth of a trillionth of a trillionth of a second old, that point burst forth to create an event we now call The Big Bang. One misconception about the Big Bang is that energy and matter exploded from this point, and began their journey through space. What's actually happening is that space itself was/is expanding, carrying matter with it. The first few seconds of this expansion of space were incredibly fast, and during that time, energy cooled to form the first matter that ever existed. For the first 7.5 billion years or so, the rate of expansion within the universe was slowing down. It started to speed up after that, and the rate of expansion is increasing steadily to this day....
Before the late 1990s, scientists were almost certain that because of gravity, the rate of expansion was slowing, and would eventually reverse, leading to an event coined The Big Crunch, when matter would collapse back into an infinitely dense point. That theory was given up soon after the launch of the Hubble Space Telescope.
Little is known about what dark energy actually is, but we know something must be causing the increasing rate of expansion. Dark energy is thought to be some sort of invisible "energy-fluid" that fills the "empty" void of space. The Planck mission revealed that dark energy actually makes up about 68% of the universe... 27% of what's left is something called Dark Matter, a hypothetical type of matter that cannot be observed directly, but it's affects on the universe can.
So space is getting bigger all the time, and it's constantly speeding up. Everything we see is such a small amount of the universe that it really isn't "normal" matter at all, and what we can't see probably holds all the secrets to existence we've been searching for since the first humans looked up at the sky. Our understanding of the universe is getting better every day. What will we learn next?
If you enjoyed this post, consider upvoting and/or resteeming it. I try very hard to deliver quality, original content, and often my posts fly under the radar. I'm still a growing minnow (actually just a redfish), and I could use all the help I can get! Now that I've gotten that out of the way, you have yourself a wonderful day!
