Science, Now + Beyond

How will the universe end? Here are the top contending theories

While the ‘will it end’ is beyond certain, the ‘how’ of the matter is still up for debate.

The Simpsons withstanding, everything, eventually, will come to an end. This is true for school, for work, for life, for Earth, and for the universe as well.

Up until the beginning of the 20th century, the universe was believed to be infinite and ageless. Enter Albert Einstein’s Theory of Relativity and Edward Hubble’s research into galaxies which brought into evidence new light. This evidence led scientists to pinpoint the approximate beginning of everything.

The universe, then, is near 13.8 billion years old, give or take 59 million years. According to some, it came into being courtesy of The Big Bang but didn’t come about with an explosion, as the name suggests. Instead, it started small, at a subatomic level, before rapidly inflating, bringing about stars, stardust, planets, and moons. It’s a hard concept to visualize as the universe is all there is – it’s edgeless.

And while the Big Bang is the widely-accepted theory of the universe’s origins, the end of the universe is a point of contention. There are a number of theories floating around such as The Big Bounce or The Big Slurp – fun names for what points to the end of times – however, there are three specific ones which hold the most consensus.  

These three are all based on the ever-growing expansion of the universe due to the presence of the mysterious dark energy. The mystery lies in the fact that besides knowing that it encompasses 68 percent of the universe and is causing the universe to expand at an accelerated rate, not much else is known.

1. The Big Rip

An illustration shows the timeline progression from the Big Bang to the Big Rip.
[Image description: An illustration shows the timeline progression from the Big Bang to the Big Rip.] Via Jeremy Teaford, Vanderbilt University
It’s already been established that dark energy is causing our universe to expand exponentially, and this theory posits that if this continues on indefinitely, things will expand all the way down to the subatomic level and then all matter will split or, as can also be said, rip apart. 

This idea was first proposed in a 2003 paper by physicist Dr. Robert Caldwell of Dartmouth along with co-researchers Dr. Marc Kamionkowski and Dr. Nevin Weinberg from the California Institute of Technology.

In 2015, an updated study on The Big Rip theory was released by professor Marcelo Disconzi of Vanderbilt University in collaboration with physics professors Thomas Kephart and Robert Scherrer. Disconzi’s research provided an approximate timeline of the universe’s demise – 22 billion years from now. According to him, The Big Rip will occur once the dark energy overpowers the gravitational forces in the cosmos. 

2. The Big Crunch

 An animation shows five galaxies collapsing into each other in a ball of flame.
[Image description: An animation shows five galaxies collapsing into each other in a ball of flame.] Via Wikipedia
On the other hand, this theory posits that one day, the universe will stop expanding. And because of this, all matter will begin to collapse in on itself crunching into oblivion. 

“In The Big Crunch, the universe will squash together in a gigantic ball of flame and maybe Bang once again,” explained theoretical physicist Michio Kaku. 

This refers to the theories of some scientists who hypothesized that we’re in a cyclic event. Once the universe collapses, it will then begin to form again. Consequently, our universe is the result of this conformal cyclic cosmology. It’s like a cosmic wave building up for billions and billions of years before it comes crashing in, only to pick up in the distance once more.

3. The Big Freeze

The image shows an illustration of the expansion of the universe and the decay of all matter within, specifically, a supposedly insurmountable black hole.
[Image description: The image shows an illustration of the expansion of the universe and the decay of all matter within, specifically, a supposedly insurmountable black hole.] Via NASA on Wikipedia
Also known as Heat Death, this theory plays on the laws of thermodynamics and builds upon the thesis of the universe continuing to expand at an increasingly faster speed. Galaxies and everything within will pull further apart from one another.

Eventually, all light will die as the stars will have drifted so far apart that there won’t be any more explosive reactions to make new ones. In this isolated system, we will reach entropy – the lack of thermal energy equals zero mechanical energy – thus, heat death.

In spite of sounding like Doritos’ new line of packaging, these three theories currently hold the most merit. And while any one of these may be the right one, it’s equally possible that none of these come true. 

Our collective understanding of the universe is still abysmally small but can only continue to grow. As our forays into space grow, humanity will get a clearer image of the universe’s fate.

Fortunately for us, that’s still billions of years away. Though, who’s to say we won’t meet our end, like the dinosaurs, in a freak meteor collision tomorrow?