Anonymous
Anonymous asked in Science & MathematicsAstronomy & Space · 4 weeks ago

# What is outside the Universe?

The Universe is always expanding, so there has to be something outside of it. If it is expanding, there has to be something to expand into.

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• Manuel
Lv 4
3 weeks ago

Why does there have to be anything?, be safe.

• 3 weeks ago

Just a lot more universe.

• 4 weeks ago

No body knows ; the VOID.

• 4 weeks ago

Bottom line -- you're right ,and no amount of dancing on pin heads around this ,can avoid it .

Whether that expansion is into a another dimension, or simply into an already infinite space ,as possibly part of a multiverse , we just don't know  -- I least like the idea that our space is effectively expanding by creating "existence" ,where previously there was none .

• 4 weeks ago

We do NOT know that the universe is expanding.

We do know that SPACE is expanding: Between any two points in space, there is more space being added continuously.

Locally, the amount being added every second is very small. Inside "small" objects - for example, the Solar system - we can ignore it for practical calculations, including sending automated probes to photograph Pluto.

However, since this expansion happens everywhere, it adds up over long distances.

Over a distance of one million parsecs (3.26 million light-years) the amount of new space being added adds up to 70 km in one second. Over a distance of 13,800 million light-years (13.8 billion), it adds up to the speed of light.  That is why, in our Observable Universe, we cannot see beyond that distance: any photon coming directly towards us would never make it here.

There are possible geometries (shapes) that could allow space to expand within a universe, without the need for the universe itself to expand... even if the universe is already "full" of space.  In 3-D, the simplest one is the infinite universe (goes on forever in all directions). This does not mean the universe MUST be infinite. It simply means that an infinite universe is mathematically possible, even if we cannot see more than 13.8 billion light-years in any direction.

In higher dimensions, you could have a finite universe (finite in 3-D, that is) that also does not need to expand, even though the space inside of it keeps expanding. Such geometries are usually more complicated to describe.

As for "what is outside", it is more complicated to explain (except using mathematics). Imagine you are talking to a 2-D being who can only exist on Earth's surface. It cannot sense anything other than length and width. Because we are 3-D beings, we know that "outside the surface" is a dimension called "height": you can move up into the sky, or down into the ground, but for the 2-D being, these directions do not exist.

If our universe is expanding in a higher dimension "multi-verse", then you have to imagine a direction that is perpendicular to the three dimensions that you are familiar with.  We cannot see in such a direction. We cannot move in such a direction. We cannot even imagine what could exist in such a direction.

• 4 weeks ago

Matter is just one of many forms of energy, so my guess is that we are expanding into some other form of energy, whether it be dark energy or perhaps antimatter or dark matter. I think it may be impossible for a "nothing" to exist, thus something is everywhere. The natural energy conversion known as the Big Bang, simply began a defining system known as our universe, that basically resembles a drop of dye expanding in a glass of water.

• 4 weeks ago

"The Universe is always expanding, so there has to be something outside of it."

Nope.

• 4 weeks ago

Why do you say there must be some outside space that the universe is expanding into? That is not true. The universe can exist on its own. It does not need to be embedded in anything. Its expansion is internal. You can not view it from outside. You can't even imagine it from outside because there is no outside.

• 4 weeks ago

There is no outside to the Universe, which is defined as everything that is physical.  The maximum possible distance between locations is constantly increasing but this is not the same as a four-dimensional balloon inflating.

• Elaine
Lv 7
4 weeks ago

Why would there be anything outside of the universe?  The universe encompasses  everything and that includes what is beyond what we can see.