What is Cosmological Evolution?

[Magdalena]

Could someone explain to me what Cosmological Evolution is in a way that my 5-year-old son would also (sort of) understand it? --Please--Thank you. 

[xSilverPhinx]

Basically it's the the evolution of the universe, from the Big Bang to the present day, or of structures within the universe, such as the evolution of  black holes, galaxies or planetary systems.



Just after the Big Bang, when the fabric of space-time started to expand, temperatures were extremely hot. There were no atoms at the time, only quantum fluctuations. Most atoms are tiny building blocks of matter which have a positive centre (nucleus) and negative electronsphere (antimatter is the other way round). Because of the intense heat, plasma (one of the states of matter) started to form. The sun is plasma, fire is plasma. Plasma particles are charged particles where it's just too hot for electrons to bind to a nucleus and form an atom. During this plasma period light the universe was opaque to light because photons couldn't get through the dense "stew" of particles without hitting a stray electron.

After the expanding universe cools a bit we get the first hydrogen atoms, which are the simplest atoms and have one proton and one electron bound to it. Hydrogen is the most abundant atom in the universe till this day. Photons ("packets" of light) are no longer in thermal equilibrium with the universe which so they decouple from atoms and cosmic microwave background radiation is released, which is this beauty here:



Neil DeGrasse Tyson mentioned in one of his science videos that when you turn on your TV and get static noise, a small percentage of it comes from this ancient radiation. 

In comes this mysterious form of matter known as Dark Matter, called that way because it lets off no light whatsoever. It can't be seen with any instrument we have, only its gravitational effects measured. Dark matter is everywhere but only interacts with normal matter gravitationally. I call our everyday matter "normal" but our type of matter is only a tiny portion of all the matter present in the universe.

This is a computer rendering of the ginormous structure:



Fascinating stuff. Last time I checked, the scientific community didn't know for sure what it is.

Now that we have plenty of hydrogen atoms in the universe, and the universe has cooled sufficiently, star formation is possible. These atoms come together and under the weight of the immense gravitational pull, gas comes together, heats up and ignites, becoming stars in nurseries or nebulas. This is my personal favourite nebula, known as the "Pillars of Creation".



Our whole solar system can fit into a tiny portion of one of the pillars.

Here's another one, called "The Eye of God".

     

Stars are born, and they die when their fuel runs out. Big ones go out with a bang (supernovas) while smaller ones (such as our sun) go with a whimper. Stars convert hydrogen into helium, and then helium into carbon. When it runs out of those to burn, it creates iron, which isn't used as fuel. The death process has begun.  Black holes and dense neutron stars are created when massive stars die while smaller stars become mostly white or red dwarfs.

Dark matter plays a huge role in galaxy formation. Computer simulations show that a galaxy wouldn't form without the extra dark matter mass pulling stuff together. Some say that all supermassive black holes in the centre of every galaxy might also play a part.

Hmm...what else.

Future predictions:

Until a few years ago, people thought that the universe was slowing down, but it was discovered (by Hubble, I think) that it is in fact accelerating. In comes 'dark energy', which is pushing galaxies apart faster and faster, leading to the conclusion that the universe will die a dark and cold death. Eventually dark energy will push stars apart faster than light travels, so from our perspective, if our descendants are still around by then, there will be no such thing as starlight.

Another hypothesis is the the big bang will reverse and will end with a Big Crunch, but since the discovery of dark energy this hypothesis has become less popular.   

[Icarus]

That was a marvelous explanation xSP. I raise my glass to you.

[Magdalena]

Yes, thank you, xSilverPhinx. 

The reason I included a 5-year-old in my question is because someone asked me if I wanted to put my son in a religious club, their aim is to "help kids know God and to learn from the Bible." I, of course, said, "No, thank you." 

I'm assuming...in this bible club they teach that a god created the universe: The Book of Genesis.

The way Cosmological Evolution explains "the beginning" and "the end" is much better: 
"Basically it's the evolution of the universe, from the Big Bang to the present day, or of structures within the universe, such as the evolution of  black holes, galaxies or planetary systems." ― xSilverPhinx

...and us...yes? We are made of star-stuff. 

"The nitrogen in our DNA, the calcium in our teeth, the iron in our blood, the carbon in our apple pies were made in the interiors of collapsing stars. We are made of starstuff." ― Carl Sagan, Cosmos

[xSilverPhinx]

That was a marvelous explanation xSP. I raise my glass to you.

Thank you, Icarus.

I could ramble on and on about astronomy, an interest that started in childhood, in fact.

[Tank]

Cracking description xSPx!

[xSilverPhinx]

Yes, thank you, xSilverPhinx. 

The reason I included a 5-year-old in my question is because someone asked me if I wanted to put my son in a religious club, their aim is to "help kids know God and to learn from the Bible." I, of course, said, "No, thank you." 

I'm assuming...in this bible club they teach that a god created the universe: The Book of Genesis.

The way Cosmological Evolution explains "the beginning" and "the end" is much better: 
"Basically it's the evolution of the universe, from the Big Bang to the present day, or of structures within the universe, such as the evolution of  black holes, galaxies or planetary systems." ― xSilverPhinx

...and us...yes? We are made of star-stuff. 

"The nitrogen in our DNA, the calcium in our teeth, the iron in our blood, the carbon in our apple pies were made in the interiors of collapsing stars. We are made of starstuff." ― Carl Sagan, Cosmos

Yes, we are made of starstuff, which is one of the most beautiful ideas in science, I think.

Myths are interesting but religion are just boring in comparison to science. Maybe thousands of years from now Christian myths will join ancient Greek, Nordic, Celtic and other old myths for what they are, just a collection of stories that explain the universe from an ancient human perspective. They have anthropological but no scientific value whatsoever.

When I was around your son's age I would read The Magic School Bus series, my favourite being Lost in the Solar System (Amazon.com).

   

[xSilverPhinx]

Cracking description xSPx!

Thanks, Tank Is it odd that I find these kind of things fun?

[Tank]

Cracking description xSPx!

Thanks, Tank Is it odd that I find these kind of things fun?

Not at all. I love this sort of thing!

[Dave]

Excellent description, xSP!

On the star stuff thing - ask young kids if they was to touch star stuff. Then ask them to hold hands with their neighbour. Then tell them why.

[xSilverPhinx]

Excellent description, xSP!

On the star stuff thing - ask young kids if they was to touch star stuff. Then ask them to hold hands with their neighbour. Then tell them why.

That's bound to leave an impression!

[Magdalena]

Excellent description, xSP!

On the star stuff thing - ask young kids if they was to touch star stuff. Then ask them to hold hands with their neighbour. Then tell them why.

That's bound to leave an impression!

That's beautiful. 

[Magdalena]

Reminds me of the Olympic Ad from Dick's Sporting Goods:

Well...to some, the heart is just a pump--nothing more. 

[xSilverPhinx]

Reminds me of the Olympic Ad from Dick's Sporting Goods:

Well...to some, the heart is just a pump--nothing more. 

To me it's more than just a pump, it's a modified blood vessel.

[Magdalena]

Reminds me of the Olympic Ad from Dick's Sporting Goods:

Well...to some, the heart is just a pump--nothing more. 

To me it's more than just a pump, it's a modified blood vessel.