# data[].attributes.body
#1
In 1927 an astronomer named Georges Lemaitre had a big idea. He said that a very long time ago, the universe started as just a single point. He said the universe stretched.
#2
The universe began by having tiny hot partials mixed with light and energy.
#3
the video down below Ted Ed.

# data[].attributes.attachment_link.title
The beginning of the universe, for beginners - Tom Whyntie

# data[].attributes.body
#1
The conception of the Big Bang model assumes the existence of energy, time, and space, and does not comment about their origin or the cause of the dense and high temperature initial state of the universe. The Big Bang was "small".
#2
The Big Bang is comparing to its size to everyday objects.
#3
video down below.

# data[].attributes.body
#1
The ‘Big Bang’ is the model for the formation of our University in which space time, and the matter within it, were created from a cosmic singularity . The model suggests that in the 13.7 billion years since the Universe began, it has expanded from an extremely small but incredibly dense and hot primordial fireball , to the enormous but cold and diffuse Universe we see around us today.
#2
According to Big Bang theory, the journey from primordial fireball to the present-day Universe involves several stages linked to the temperature of the Universe at the time. From the moment of the Big Bang up until about 3,000 years after (the radiation-dominated era), the density of radiation in the Universe was greater than the density of matter.
#3
The video down below.

# data[].attributes.attachment_link.title
Why the Big Bang Definitely Happened | Space Time | PBS Digital Studios

# data[].attributes.body
#1
After the Big Bang, primordial protons and neutrons formed from the quark–gluon plasma of the early Universe.
#2
An English astronomer Fred Hoyle is credited with coining the term "Big Bang" during a 1949 BBC radio broadcast, saying: "These theories below were based on the hypothesis that all the matter in the universe was created in the big bang.
#3
The picture
below are the theories.

# data[].attributes.body
#1
pres the image.
#2
you tube
#3
NASASpacePlace

# data[].attributes.attachment_link.readable_text
What's This Big Bang All About?

In 1927, an astronomer named Georges Lemaître had a big idea. He said that a very long time ago, the universe started as just a single point. He said the universe stretched and expanded to get as big as it is now, and that it could keep on stretching.

What an Idea!

The universe is a very big place, and it's been around for a very long time. Thinking about how it all started is hard to imagine.

Some More Information

Just two years later, an astronomer named Edwin Hubble noticed that other galaxies were moving away from us. And that's not all. The farthest galaxies were moving faster than the ones close to us.

This meant that the universe was still expanding, just like Lemaître thought. If things were moving apart, it meant that long ago, everything had been close together.

Everything we can see in our universe today-stars, planets, comets, asteroids-they weren't there at the beginning. Where did they come from?

A Tiny, Hot Beginning

When the universe began, it was just hot, tiny particles mixed with light and energy. It was nothing like what we see now. As everything expanded and took up more space, it cooled down.

The tiny particles grouped together. They formed atoms. Then those atoms grouped together. Over lots of time, atoms came together to form stars and galaxies.

The first stars created bigger atoms and groups of atoms. That led to more stars being born. At the same time, galaxies were crashing and grouping together. As new stars were being born and dying, then things like asteroids, comets, planets, and black holes formed!

A Super Long Time

How long did all of this take? Well, we now know that the universe is 13,800,000,000 years old-that's 13.8 billion. That is a very long time.

What's in a Name?

That's pretty much how the universe began. Because it got so big and led to such great things, some people call it the " Big Bang." But maybe a better name would be the " Everywhere Stretch." What do you think?

# data[].attributes.body
#1
A Few Astronomers combined mathematical models with observations to develop workable theories of how the Universe began. The mathematical underpinnings of the Big Bang theory include Albert Einstein's general theory of relativity along with standard theories of fundamental particles. Today NASA spacecraft like the Hubble Space Telescope and the Spitzer Space Telescope continue measuring the expansion of the Universe.
#2
According to the theories of the big bang if we were to look at the Universe one second after the Big Bang, what we would see is a 10-billion degree sea of neutrons, protons, electrons, anti-electrons (positrons), photons, and neutrinos. Then, as time went on, we would see the Universe cool, the neutrons either decaying into protons and electrons or combining with protons to make deuterium (an isotope of hydrogen).
#3
The video down below.

# data[].attributes.attachment_link.title
The Beginning of Everything -- The Big Bang