Astronomers can use telescopes to look deep into space, where essentially we are looking back in time, and try to understand how the universe began. We know from observations that the universe is about 14.5 billion years old, and that it's currently expanding due to some Big Bang or moment of Inflation sometime in the past. Based on the current structure of our universe, and the theories behind how it began, astronomers are trying to predict the fate of our universe. What will eventually happen to the universe billions of years from now? Below are four current theories.
- Infinite Expansion: The universe will expand forever. We will survive, but eventually loose contact with places that are too far away and ultimately be isolated in darkness.
- The Big Rip: The expansion of the universe will continue to increase until it expands so fast that spacetime itself is ripped to shreds. The fate of humanity is unknown.
- The Big Chill: The universe will expand and continue to cool until it reaches absolute zero. At this temperature, all movement will cease and black holes will evaporate into the vacuum of space. Essentially we will freeze to death.
- The Big Crunch: gravitational pull from black holes will cause the expansion of the universe to stop, and the universe will collapse back onto itself. We will not survive, but a new universe may be created in a second big bang after the crunch.
As time goes by we hope to learn more about the structure of our universe and be able to accurately predict which one of the above (or a completely different scenario) will be true. Sadly, none of these scenarios are "happy endings". I guess our best hope lies in the bubble universe theory. This says that other universes have budded off of ours and are completely separate and now unbound to ours. If we are in trouble in the future, maybe we will have the technology to travel to a more stable bubble universe and continue to live there!
Image credit: LSST
