Today’s Wonder of the Day was inspired by Veronica. Veronica Wonders, “What is the Big Crunch Theory?” Thanks for WONDERing with us, Veronica!

Many of our Wonder Friends already know about the Big Bang Theory. It’s an explanation of how the universe began. Scientists spend a lot of time trying to learn where the world came from. But they also work to find out where it’s headed.

One possibility for the future of the universe is the Big Crunch Theory. If you’re familiar with the Big Bang, you know the universe was once a tiny dot of matter. Then, that tiny dot grew quickly. It became everything that exists today. And the universe is still expanding, carrying galaxies farther and farther away from each other. The Big Crunch Theory says that, one day, the universe will stop growing. Then, it will begin to shrink.

As the universe grows smaller, it will also get hotter. One way to think of this is as the opposite of the Big Bang. Instead of expanding and cooling, the universe will shrink and heat up. Finally, everything that exists in the universe will collapse into a tiny point, right where it began.

And then what? If you’re asking yourself this question, you’re not alone! People have long WONDERed what might happen after a Big Crunch. Some believe the universe may start over again with a Big Bang. Others think the universe will blow up like a bubble in a new place. Some even believe this process occurs over and over, resulting in many universes other than our own.

Is the Big Crunch inevitable? Definitely not. In fact, many experts today doubt it will happen. That’s because, in order for the Big Crunch to occur, the universe’s growth has to slow down. But the exact opposite is happening. Instead of slowing down, the expansion of the universe is speeding up.

How is that possible? Experts point to dark energy. They still don’t completely understand how dark energy works. But it makes up about 70 percent of the energy in the universe. And it’s pushing the universe to grow faster. As dark energy speeds up the universe’s expansion, galaxies move farther away from each other. That makes the Big Crunch less likely.

Without the Big Crunch, many other possibilities exist. One is the Big Freeze. This theory says the universe will continue to expand and cool. Eventually, it will lose all heat. Instead of winding up a tiny point of very hot matter, it ends as a large amount of cooled matter.

If you’re thinking none of these options sound so great for Earth, you’re right. But any of these events would be billions or trillions of years in the future. Scientists have plenty of time to find ways to avoid a total catastrophe

Some experts believe that life will continue to evolve as the universe changes. They think this could result in life forms that can live in the world of the Big Freeze. Others suggest finding a way to escape. They say one solution is to build a new universe in a laboratory. Then, Earth’s entire population can evacuate into the new world.

That may not sound realistic. But with advances in science and technology, who knows? How would you protect the world from the Big Crunch? How about the Big Freeze? No idea is outside the realm of possibilities.

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