What was the size of the universe at recombination?

Erik Anson: ≈ 42 Mly (“the region of space that is currently part of our observable Universe had a radius of approximately 46 Gly/1100 = 42 million light-years at the time of recombination.”)

How big was the universe at the big bang?

In the first period, the universe grew from an almost infinitely small point to nearly an octillion (that’s a 1 followed by 27 zeros) times that in size in less than a trillionth of a second. This inflation period was followed by a more gradual, but violent, period of expansion we know as the Big Bang.

How big was the universe at the end of inflation?

According to this paper at the end of inflation the universe’s scale factor was about 10−30 smaller than it is today, so that would give a diameter for the currently observable universe at the end of inflation of 0.88 millimeters which is approximately the size of a grain of sand (See calculation at WolframAlpha).

Was there a Big Bang before the Big Bang?

The initial singularity is a singularity predicted by some models of the Big Bang theory to have existed before the Big Bang and thought to have contained all the energy and spacetime of the Universe.

What happened 380 000 years after the Big Bang?

One second after the Big Bang, the universe was filled with neutrons, protons, electrons, anti-electrons, photons and neutrinos. Roughly 380,000 years after the Big Bang, matter cooled enough for atoms to form during the era of recombination, resulting in a transparent, electrically neutral gas, according to NASA.

How big was the universe at the moment of its creation?

If the best models of inflation are right, somewhere between the size of a human head and a skyscraper-filled city block. Just give it time — 13.8 billion years in our case — and you wind up with the entire Universe we see today. Follow me on Twitter. Check out my website or some of my other work here.

How big was the universe now?

The observable Universe is 93 billion light-years in diameter. Some scientists believe its true size is even scarier than that. By using the Bayesian model averaging, scientists estimated that the Universe is at least 250 times larger than the observable Universe, or at least 7 trillion light-years in diameter.

What happened to recombination after the Big Bang?

About 370,000 years after the Big Bang, two connected events occurred: the ending of recombination and photon decoupling. Recombination describes the ionized particles combining to form the first neutral atoms, and decoupling refers to the photons released (“decoupled”) as the newly formed atoms settle into more stable energy states.

How fast did the universe expand after the Big Bang?

Scientists think they can pick the story up at about 10 to the minus 36 seconds — one trillionth of a trillionth of a trillionth of a second — after the Big Bang. At that point, they believe, the universe underwent an extremely brief and dramatic period of inflation, expanding faster than the speed of light.

How long does recombination of the universe last?

Recombination lasts for about 100 ka, during which universe is becoming more and more transparent to photons. The photons of the cosmic microwave background radiation originate at this time. The spherical volume of space which will become the observable universe is 42 million light-years in radius at this time.

What is recombination in cosmology?

This is what is called recombination in cosmology, the period when the temperature dropped enough to allow electrons to bind to nuclei and form the first neutral atoms. Recombination also marks the time when the universe became transparent as photons can travel long distances before being absorbed or diffused by matter.