What Is The Evidence For The Big Bang?

Almost all astronomers agree on the theory of the Big Bang, that the entire Universe is spreading apart, with distant galaxies speeding away from us in all directions.

Run the clock backwards to 13.8 billion years ago, and everything in the Cosmos started out as a single point in space.

In an instant, everything expanded outward from that location, forming the energy, atoms and eventually the stars and galaxies we see today.

But to call this concept merely a theory is to misjudge the overwhelming amount of evidence.

There are separate lines of evidence, each of which independently points towards this as the origin story for our Universe.

The first came with the amazing discovery that almost all galaxies are moving away from us.

In 1912, Vesto Slipher calculated the speed and direction of "spiral nebulae" by measuring the change in the wavelengths of light coming from them. He realized that most of them were moving away from us.

We now know these objects are galaxies, but a century ago astronomers thought these vast collections of stars might actually be within the Milky Way.

In 1924, Edwin Hubble figured out that these galaxies are actually outside the Milky Way.

He observed a special type of variable star that has a direct relationship between its energy output and the time it takes to pulse in brightness.

By finding these variable stars in other galaxies, he was able to calculate how far away they were.

Hubble discovered that all these galaxies are outside our own Milky Way, millions of light-years away.

So, if these galaxies are far, far away, and moving quickly away from us, this suggests that the entire Universe must have been located in a single point billions of years ago.

The second line of evidence came from the abundance of elements we see around us.

In the earliest moments after the Big Bang, there was nothing more than hydrogen compressed into a tiny volume, with crazy high heat and pressure.

The entire Universe was acting like the core of a star, fusing hydrogen into helium and other elements.

This is known as Big Bang Nucleosynthesis. As astronomers look out into the Universe and measure the ratios of hydrogen, helium and other trace elements, they exactly match what you would expect to find if the entire Universe was once a really big star.

Line of evidence number 3: cosmic microwave background radiation.

In the 1960s, Arno Penzias and Robert Wilson were experimenting with a 6-meter radio telescope, and discovered a background radio emission that was coming from every direction in the sky - day or night.

From what they could tell, the entire sky measured a few degrees above absolute zero.

Theories predicted that after a Big Bang, there would have been a tremendous release of radiation.

And now, billions of years later, this radiation would be moving so fast away from us that the wavelength of this radiation would have been shifted from visible light to the microwave background radiation we see today.

The final line of evidence is the formation of galaxies and the large scale structure of the cosmos.

About 10,000 years after the Big Bang, the Universe cooled to the point that the gravitational attraction of matter was the dominant form of energy density in the Universe.

This mass was able to collect together into the first stars, galaxies and eventually the large scale structures we see across the Universe today.

These are known as the 4 pillars of the Big Bang Theory.

Four independent lines of evidence that build up one of the most influential and well-supported theories in all of cosmology.

But there are more lines of evidence.

There are fluctuations in the cosmic microwave background radiation, we don't see any stars older than 13.8 billion years, the discoveries of dark matter and dark energy, along with how the light curves from distant supernovae.

So, even though it's a theory, we should regard it the same way that we regard gravity, evolution and general relativity.

We have a pretty good idea of what's going on, and we've come up with a good way to understand and explain it.

As time progresses we'll come up with more inventive experiments to throw at. We'll refine our understanding and the theory that goes along with it.

Most importantly, we can have confidence when talking about what we know about the early stages of our magnificent Universe and why we understand it to be true.

[jessicaanderson]

The amount of people who don’t have a basic understanding of science in the comment section who seem to think their opinion is right compared to that of some of the greatest scientists in the world is actually quite concerning

[ElctrLun]

I can't believe you didn't mention Georges Lemaître, as he was the one who formulated the initial Big Bang hypothesis and spent a lot of time and effort to make it a serious contender to the then steady state model of the universe.

[DaveyJonesLocka]

It sounds like a lot of the argument is of the form “If the Big Bang theory is true, then (statement). Since (statement), then BBT.

I’m not dismissing the BBT (far from it), but any argument using the fallacy of the converse is invalid.

Give me more “If (statement), then BBT” and less “If BBT, then (statement).”

[BigNewGames]

If galaxies are all moving away from one another then how is that evidence of a big bang happening everywhere? If we reversed time the matter contained inside of each galaxy would go back to the center's of every galaxy making it appear as if the matter in a galaxy originated from the core or the supermassive black hole in their centers. And because every galaxy is not the same age, per the size of the supermassive black holes in their cores and the stars in the galaxies then it would indicate again that there was no single big bang from which all matter originated from. Even the fact that new stars are being born near supermassive black holes indicates that the universe did not start from a big bang.

The fact that galaxies furthest away are accelerating away from our perspective indicates only one thing. The volume of space is increasing everywhere. In order for the volume of space to increase exponentially with distance is a clear indicator that energy and matter is constantly being made. And since the supermassive black holes in the cores of every galaxy is located at the centers of all the expansion taking place, IE galaxies moving away from each other then all the evidence indicates that galaxies grow and expand, increasing in energy and matter over time and the energy and matter originates or is coming from the supermassive black holes in each galaxy.. This too would indicate that a single big bang did not occur and would also indicates that the laws of thermodynamics are wrong to assume that energy and matter cannot be created. If energy and matter cannot be created then the universe would be void of all energy and matter. but the universe is full of energy and matter. So we must conclude that energy and matter is slowly being created by the supermassive black holes in every galaxy.

Is there any direct evidence to support this postulate that energy and matter is being created by the supermassive black holes in every galaxy? Yes there is.

In 2019 ALMA Radio Telescope released a Doppler image of Sgr A*, the supermassive black hole in the core of our galaxy showing the motion and velocity of the gas near it. The Doppler data showed that massive amounts of energy and gas was flowing directly away from the black hole in every direction. This observation was completely contrary to Einstein's predictions made by general relativity.

I thought that actual observations were empirical evidence which supersede every theory, even laws of physics? Yet the actual observation of gas and energy quickly moving away from the supermassive black hole has not even sparked controversy among astrophysicists and their theoretical beliefs. Astrophysicists are still clinging the incorrect notion that a big bang happened. Which now with all the evidence appears to be a massive delusion on their part.

Is there not just one person or qualified astrophysicists who can debunk the Doppler image made by ALMA Radio Telescope in 2019? That image is empirical evidence indicating a big bang did not happen, general relativity and the laws of thermodynamics are wrong! Denying this evidence would be like denying the facts based on one's beliefs, which in psychology there is actually a term used to describe when a person denies actual evidence because it does not conform to their beliefs. It's called cognitive dissonance.

[StephenMattison]

Great video, great audio, TYVM! PS It doesn't look cold there, but at 00:52 it looks like we could see your breath. Where are you? Was it cold that day?

[fxtima]

I had to watch this shit in class and I still don't know wtf

[fishfreeancestry]

Something I have always wondered about this idea is how can anyone who believes the big bang doubt that the universe is a black hole? If all matter and energy was only in the form of energy, and compressed to a plank length how could it help to be a black hole?

[rkreike]

Q: The larger the distance to a galaxy, the larger the redshift. And then there are several theories about what causes that redshift?
And: If there would be a redshift because of the distance, then galaxies that are moving away seem to move away with increasing speed?
Or not?

[moremusic]

no one created God because if someone created "God"
Then "God" is not "God".
God cannot be limited by
1.space
2.matter
3.time
For big bang to have happened, there had to be "space" for "matter" to exist in. For example my house is where i keep my bed in. Space being my house nd my bed being the matter in this case. And "time" being when this matter was put into this space. Ie when my bed was moved into my house.
For God to be the creator, he had to be outside of time space and matter.
He has be everywhere at once, see past present and future at once, and he has to be able to create anything he wishes. Because he is outside of time space and matter.
So God has always existed, and that is something our human minds could not even grasp before our bodies would fall to the ground as our minds drift into madness.
But yeah that's my explanation to the popular question
"who created God"
No one. God has always existed.
But this theory makes way more sense than the atheist version, wich suggests
Something blew up out of nothing into absolute perfection for no reason at all.
I thought there had to be space for matter to exist in.
But according to atheists that space either magically appeared or has always existed.

[noot]

I bet 80% of dislikes are from flat earthers

[GloomyMarshall]

Can someone type the four pieces of evidence, I dont fully understand :, )

[IvanPlaysMusicToHeal]

I think it is still sensible to think that perhaps this is only what happened to our section of the universe. Perhaps this patch of around 4000 galaxies originated in a single point. But perhaps this is but a very small fraction of the full universe. 

[OljeiKhan]

"Even tough it's a theory, we should regard it in the same way that we regard gravity, evolution and general relativity."
You should rather take evolution out of there. Because besides all the scientific evidence that proves evolution, I HAVE A BOOK THAT SAYS OTHERWISE!! 

[cjczki]

If everything is moving away from us does that mean that we are the center of the universe? Or is the expansion something else because some should be moving towards/with us if it started in a different location.

[dendroxden]

I personally don't think that the theory has enough solid evidence to be considered a theory. Most of the pieces of evidence that it has are actually just assumptions. Who's to say that the red shift is actually showing expansion? Even if the universe is expanding, it is completely assumed that everything started at a point. The CMB also isn't concrete enough for me because we assume what it is and what it means.

I personally believe that the universe just always was. It had no beginning. Or if it did, it came about in a completely different way. Just my thoughts.

[mikailnoumi]

I don't believe in Big Bang and I don't consider that the evidence is flawless.
1) About Redshift: I don't think we can assume for certainty that it is caused by Doppler effect and that it shows expansion. Plus there are hundreds of galaxies who have a blueshift which contradict the expansion of Universe.
2) About Cosmic Microwave Background: It may be produced by other causes than Big Bang, for example we can guess that galaxies heat up the Universe in a homogeneous way.
3) About abundance of light elements : Mathematics can prove a lot things that don't even exist. So maybe scientists can just vary the calculations of their computers until it matches with reality, but that doesn't mean their theory is true.
4) About Evolution of Universe: Obviously no human can observe the universe's evolution, we can only make guesses. So when we look a galaxy aged 10 billion years, it looks different, but how can we be sure that it is a galaxy in formation ? Maybe it's just that galaxies evolve and were different. And even if we assume that it is a galaxy in formation, and that all galaxies were created at this time, it only proves that Universe evolves, and not that it had a beginning.

[PatrickPoet]

I found you by searching for a way to understand what the dark era was. It gave a nice intuitive idea in this video when you talked about it being like the light inside a star where the photons keep bouncing and eventually escape, except everything was a star. There was more than that though, right? Was there something in particular about early ionized hyrogen/helium that resulted in the energy from early photons being absorbed? Do you have a video that covers this mechanism?

[ToxicFaithPHD]

Bah, this is all nonsense. Obviously a supernatural being made everything with his magic powers. -Bronze age cultist...
or a modern american. can't tell them apart most of the time.

[urbansydney]

I’VE GOT A THEORY! What if God saw a beautiful waterfall and accidentally released his seed all over the earth, causing trees and animals to burst out of the ground? Science got nothing on that.

[thetinfoilhatmanbandcarava]

How did all of that condensed stuff get there before the big bang