## Does the universe shrink

In absence of dark energy, a flat universe expands forever but at a continually decelerating rate, with expansion asymptotically approaching zero.

With dark energy, the expansion rate of the universe initially slows down, due to the effect of gravity, but eventually increases.

## Is the universe getting larger

Even if the overall spatial extent is infinite and thus the universe cannot get any “larger”, we still say that space is expanding because, locally, the characteristic distance between objects is increasing. As an infinite space grows, it remains infinite.

## How long will the universe exist

Stelliferous Era. The observable universe is currently 1.38×1010 (13.8 billion) years old. This time is in the Stelliferous Era. About 155 million years after the Big Bang, the first star formed.

## Is space a physical thing

Space is the boundless three-dimensional extent in which objects and events have relative position and direction. Physical space is often conceived in three linear dimensions, although modern physicists usually consider it, with time, to be part of a boundless four-dimensional continuum known as spacetime.

## Is the universe flat

The global shape of the universe can be described with three attributes: Finite or infinite. Flat (no curvature), open (negative curvature), or closed (positive curvature) Connectivity, how the universe is put together, i.e., simply connected space or multiply connected.

## What is the big yawn theory

In physical cosmology, the Big Rip is a hypothetical cosmological model concerning the ultimate fate of the universe, in which the matter of the universe, from stars and galaxies to atoms and subatomic particles, and even spacetime itself, is progressively torn apart by the expansion of the universe at a certain time

## Is there a center of the universe

The center of the Universe is a concept that lacks a coherent definition in modern astronomy; according to standard cosmological theories on the shape of the universe, it has no center. Historically, different people have suggested various locations as the center of the Universe.

## How big is the universe

The proper distance—the distance as would be measured at a specific time, including the present—between Earth and the edge of the observable universe is 46 billion light-years (14 billion parsecs), making the diameter of the observable universe about 93 billion light-years (28 billion parsecs).

## How many light years is the universe

The radius of the observable universe is therefore estimated to be about 46.5 billion light-years and its diameter about 28.5 gigaparsecs (93 billion light-years, 8.8×1026 metres or 2.89×1027 feet).

## How Is time travel possible

Time travel to the past is theoretically possible in certain general relativity spacetime geometries that permit traveling faster than the speed of light, such as cosmic strings, transversable wormholes, and Alcubierre drive.

## Does outer space end

Outer space is not completely empty—it is a hard vacuum containing a low density of particles, predominantly a plasma of hydrogen and helium, as well as electromagnetic radiation, magnetic fields, neutrinos, dust, and cosmic rays.

## Is the universe a black hole

In the version as originally proposed by Pathria and Good, and studied more recently by, among others, Nikodem Popławski, the observable universe is the interior of a black hole existing as one of possibly many inside a larger parent universe, or multiverse.

## What is called space

Space, also known as outer space, is the near-vacuum between celestial bodies. It is where everything (all of the planets, stars, galaxies and other objects) is found.

## What does space mean in math

In mathematics, a space is a set (sometimes called a universe) with some added structure. While modern mathematics uses many types of spaces, such as Euclidean spaces, linear spaces, topological spaces, Hilbert spaces, or probability spaces, it does not define the notion of “space” itself.

## Is space a vacuum

Outer space has very low density and pressure, and is the closest physical approximation of a perfect vacuum. But no vacuum is truly perfect, not even in interstellar space, where there are still a few hydrogen atoms per cubic meter.