1288475983

1288475983

Tiny man in multiverse. 3D rendering

Photo by: bestdesigns

bestdesigns

What is the Multiverse?

What if there was another you, somewhere out there, doing all the things you wished you could’ve done? What if there was a multiverse, where all the possibilities and choices of our lives became real? It seems like just another fantasy of science fiction, but it’s closer to reality than you might think.

May 19, 2022

Several versions of a generic “multiverse” concept appear in physics, but I’d like to talk about just one, which I personally believe is the one that has the closest connection to known physics and the best shot at actually being tested.

Let’s start off our discussion of the multiverse with…just the Universe. By definition, it’s everything. Literally everything. The Universe contains the entire expanse of all-there-is in both time and space. If it’s a thing, it’s in the Universe. That’s it.

By contrast, the multiverse theory says that our Universe is not alone. Instead, it’s just one bubble among many (perhaps infinitely many) other Universes. Each one living their own lives and doing their own things, completely and totally and permanently separated from each other.

Curiosity Daily Podcast: Dirty Disinfectant, Hot Iron Blobs, Infinite Versions of You

Today, you’ll learn about how some cleaning products in your kitchen may be terrible for the environment even though they’re labeled “green,” hot blobs of iron playing games with Earth’s magnetic field, and how some far-out theories in physics predict there are infinite versions of you.

But how can you make a multiverse if the Universe is already all the things?

The answer lies in the earliest moments of the Big Bang. Cosmologists don’t fully understand what happened when our Universe was incredibly young, because the physics is just way too complicated, but they do suspect something extraordinary happened just a fraction of a second after the Big Bang: the Universe got big. Really, really big, really, really quickly.

This event is called “inflation” and in an incredibly brief amount of time, our Universe expanded in size by roughly a factor of 1050. That already is quite fascinating, but one of the strangest parts of inflation is that it just…sorta stopped, and since then our Universe has expanded at a much more leisurely pace.

But what if it didn’t stop? What if that period of insanely fast expansion kept going? Well, then life as we know it would be impossible because the Universe would grow too large too quickly for stars and planets to form. But what if inflation just stopped here, in this patch? What if what we call “the Universe” is just a tiny bubble that broke off and slowed down, while the rest of space continued on in its frenzied rate of expansion?

1307402863

1307402863

Multiverse, conceptual illustration.

Photo by: VICTOR HABBICK VISIONS/SCIENCE PHOTO LIBRARY

VICTOR HABBICK VISIONS/SCIENCE PHOTO LIBRARY

This is the multiverse. Inflation never, ever stops, and all of space just keeps on expanding forever, but pieces of it pinch off, forming their own isolated bubbles. Each individual bubble would be an entire “Universe” (technically, we should redefine “the Universe” to mean “all the bubbles, including our own” but to prevent confusion the theorists behind this idea coined the term “multiverse”).

In this picture, inflation never stops and the individual Universes just keep popping out, very quickly reaching an infinite number of Universes, all separated by extremely vast expanses of space. Each individual Universe starts with the same basic ingredients but in a new arrangement, like the random starting positions of a video game: in one Universe an atom may be over here, while in another Universe it may be over there.

With an infinite number of Universes to play with, every single possible combination becomes realized. That means that in the multiverse picture (if it’s true), there is a version of you doing all the things you wished you did in your life.

If it helps, they may be regretting those choices, and wishing they were you.

Dive Deeper into the Cosmos

Journey Through the Cosmos in an All-New Season of How the Universe Works

The new season premieres on Science Channel and streams on discovery+.

Paul M. Sutter

Paul M. Sutter is an astrophysicist at Stony Brook University and the Flatiron Institute, host of Ask a Spaceman and Space Radio, and author of How to Die in Space.

Next Up

What are the Chances of Life Appearing On…Earth?

Just how lucky are we on Earth? What were the chances that life would arise, let alone lead to intelligence?

What is “Dark Flow”?

It sounds super-scary: something from outside the universe, a force so unimaginable, is pulling every single galaxy towards it. What monstrosity of cosmic physics could it be?

Stuck at Home? What to See in the Night Sky this Month

In times of darkness and incertainty, opt for exploration of wonder in the skies.

The First Exoplanet Found…Outside the Galaxy!

This new planet has had a pretty rough life.

May Sky Watch: What to Look Out For This Month

Whether you can see it from home or stream it online, here are some of May's wonderous celestial events.

Meet WASP-127b, the Fluffiest Planet in the Galaxy

Take a planet with the mass of, say, Saturn. You know, pretty big, but not ridiculously big. Just…normal big.

SpaceX vs. the Universe

Fans of space are having a tough time picking sides over a recent controversy between SpaceX and astronomers. But what's the big debate all about? Astrophysicist Paul M. Sutter digs into both perspectives.

All Aboard the Starliner!

Boeing’s Starliner capsule launched on Friday. Astrophysicist Paul M Sutter has everything you need to know about the Starliner and its mission.

Why Charting the Most Extreme Objects in the Solar System Matters

So the astronomers called it “FarFarOut”, which is mostly a joke because the last time they found such a distant object it they nicknamed it “FarOut”, and this new world is much, much, farther out.

The Best Planets are Rogue Planets

We can debate the status of objects in the solar system all day long, arguing if little Pluto is a planet or not. But to tell you the truth, any planet in any solar system got the short end of the stick. The real winners of the galactic game are the travelers, the roamers, the rogue planets.

Related To: