Table of Contents
Is the observable universe a perfect sphere?
The comoving distance from Earth to the edge of the observable universe is about 14.26 gigaparsecs (46.5 billion light-years or 4.40×1026 m) in any direction. The observable universe is thus a sphere with a diameter of about 28.5 gigaparsecs (93 billion light-years or 8.8×1026 m).
Why is the observable universe a sphere?
Cosmic expansion means that points in space are spreading apart over time. The shape of the universe deals with the shape of space. A spherical balloon can expand as it is inflated, just as a flat rubber sheet can be stretched and remain flat. So our expanding universe could be flat, open, or closed.
What was there just after the Big Bang?
As space expanded, the universe cooled and matter formed. One second after the Big Bang, the universe was filled with neutrons, protons, electrons, anti-electrons, photons and neutrinos. During the first three minutes of the universe, the light elements were born during a process known as Big Bang nucleosynthesis.
What percentage of universe is observable?
NEW YORK — All the stars, planets and galaxies that can be seen today make up just 4 percent of the universe. The other 96 percent is made of stuff astronomers can’t see, detect or even comprehend. These mysterious substances are called dark energy and dark matter.
When did the universe become visible?
The Universe became transparent to the light left over from the Big Bang when it was roughly 380,000 years old, and remained transparent to long-wavelength light thereafter.
Is there more than the observable universe?
They found that the universe is at least 250 times larger than the observable universe, or at least 7 trillion light-years across. “That’s big, but actually more tightly constrained that many other models,” according to MIT Technology Review, which first reported the 2011 story.
What percentage of space has been explored?
To date, scientists have explored about 4 percent of the visible universe. That’s made up of planets, stars and galaxies that astronomers can see. Yet, there’s a vast part – the other 96 percent – that scientists cannot see.
Why can’t the Big Bang be observed from outside the universe?
Therefore, unlike other expansions and explosions, it cannot be observed from “outside” of it; it is believed that there is no “outside” to observe from. Metric expansion is a key feature of Big Bang cosmology, is modeled mathematically with the Friedmann–Lemaître–Robertson–Walker metric and is a generic property of the universe we inhabit.
What is the definition of the universe expanding?
It is an intrinsic expansion whereby the scale of space itself changes. The universe does not expand “into” anything and does not require space to exist “outside” it. Technically, neither space nor objects in space move. Instead it is the metric governing the size and geometry of spacetime itself that changes in scale.
What can we see in the universe?
Everything you can see, and everything you could possibly see, right now, assuming your eyes could detect all types of radiations around you — is the observable universe. In visible light, the farthest we can see comes from the cosmic microwave background, a time 13.8 billion years ago when the universe was opaque like thick fog.
What would happen if the universe is closed?
A closed universe could end consequentially with a scenario known as the “ Big Crunch ” — the opposite of a Big Bang, in a sense, and a state in which the universe contracts until it is compressed again to a single energetic point.