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| 04 Sep 2014 08:19 PM |
tl;dr version: If you question the Big Bang, post your question. I will respond and we'll keep this civil.
People like saying that the "Big Bang is just a theory" or things like that. First of all, a "theory" in science does not mean a guess or a hunch. Gravitational theory, atomic theory, cell theory, these aren't hunches. A theory in science is a model built out of facts and laws and has both explanatory and predictive power. Such as, with atomic theory, we can predict how chemicals will behave under certain conditions. It also explains why they behave as they do.
This thread is dedicated to people who question the Big Bang. It is not meant to arguments or for contentious purposes. It's simply meant to answer these questions.
If you question the Big Bang, post your question. I will respond.
Also, to keep the conversation civil, I will not be responding to aggressive, or even pass-aggressive comments.
If you're reading this and don't know what the Big Bang Theory even is, I'll explain.
Sir Edwin Hubble published a paper in 1929 titled, "A Relation Between Distance and Radial Velocity of Inter-galactic Nabulae". In Layman's terms, this simply means that he found a linear correlation between the speed that galaxies are receding from our own and their distances. The farther away a galaxy was, the faster it receded.
Now, this makes it seem like we're in the center of the universe. If all galaxies are moving away from us, we must be the center, right? Well, no.
Imagine a balloon with dots on it. As you blow it up, the dots are carried further apart. If you pick any dot before the balloon is blown up, when it is blown up, all other dots will move away from it, as if it is the center of the expansion. But, this happens for all the dots. All the dots appear to be the center, when in reality, none of them are. This goes even further: the further away a dot is from the other, the faster they move apart. The closer they are, the slower they move apart. Just like our universe.
From Hubble's discovery we get Hubble's Law, the basis for the Big Bang Theory. Hubble's Law sums up this phenomenon he discovered. The law is simply "v=Hd". Essentially, the greater the distance, the greater the velocity. The "H" in this equation is Hubble's constant.
Now, look back at the balloon analogy. If the balloon is expanding at a constant rate, if you ran time backwards, the balloon would deflate. Therefore, if you ran time back far enough, you could get to a point where all the dots on the balloon are on top of each other, when the balloon is completely deflated. If you knew how fast the balloon was expanding--if you could calculate its rate of expansion--you could determine how long it has been since the balloon has begun to expand. Essentially, you can determine the age of this balloon-universe.
This can also be understood mathematically. We know "v=Hd", and that velocity is defined as distance over time. So that means "d/t=Hd" is also true. You can rearrange this equation to get "t=1/H". This is known as "Hubble time". The time that has passed since the universe has begun to expand is equal to the inverse of the Hubble constant. If we were to go this far in the past, if we were to go 1/H seconds into the past, the universe would be infinitely small and all galaxies would be superimposed onto each other.
This is the Big Bang. The Big Bang is not just some random explosion. The Big Bang is the time when the universe began to expand.
You may wonder how the expansion rate of the universe is calculated. We know that "v=Hd" by Hubble's law. So, if we knew the velocities of enough galaxies that are moving away from us, and their distances, we could average these out and find out what the value for H is.
It's actually incredibly difficult to measure the distances of galaxies. You can't just use trigonometry. They're too far for that. Measuring their velocities is also difficult because they're so massive that there's no perceptible difference in apparent size.
But, there's away around this. It's called light.
There's a type of star called a Cepheid. Cepheids vary in brightness, they sort of pulsate. But there's a relationship known as the period-luminosity relation. In Layman's terms, the duration of the pulsations of the Cepheids is directly correlated with their absolute magnitude (brightness). Therefore, if we look at a Cepheid in a galaxy, we can determine exactly how bright it is. And if we know the amount of light given off, we can use the inverse square law to calculate its distance.
Now, there's the issue with velocity. Velocity is measured through something known as redshift. Imagine if you were above some water, and every second, you tapped the surface. You would produce waves in all directions. Someone at a distance looking down would see small waves coming to them, every second, another wave. Now, let's save you started moving away from the person but still tapping the water every second. You'd produce a wave, but a second later, when you tap the water again, you would be farther away. Therefore, the person looking at the waves would no longer have a wave reach them every second. They would be spread out more because you are moving away as you are tapping the water.
This is known as the Doppler effect. It's the reason why cars coming towards you sound high pitched, but going away from you, sound low pitched. Because the waves in front of it are smooshed together, while the waves behind it are stretched out. Stretched out equals lower frequency. In light, this equals a shift towards the red end of the spectrum. Hence the word "redshift".
Thus, if we simply look at how much the light from a galaxy is redshifted, we can determine its velocity away from us.
Now, you simply take the measurements of a bunch of galaxies. You get their distance and velocity, plug it in and calculate the value of H. Plug H into "t=1/H" ad you get the age of the universe. I could actually calculate this from you from the H provided at NASA if you wish. It's not that hard.
The Big Bang Theory has also predicted things like the cosmic microwave background radiation, and some other things I will not get into.
That is the Big Bang in a nutshell. It can essentially be summed up with the equation "t=1/H". |
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| 04 Sep 2014 08:20 PM |
That was a very well thought out, well written post. Overruled. |
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Flexably
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| Joined: 04 May 2012 |
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| 04 Sep 2014 08:24 PM |
I first thought you were talking about the TV show the way you titled your thread,haha.
But yeah,I always wondered...If the universe is expanding or getting smaller,whatever the scientists are saying today,Then what would happen if I ever reached the 'edge' of the universe? Would it keep expanding the more I try to reach the end of it? Would I go through it? What's on the other side? Is the universe just a giant bubble? Where did atoms/electrons etc. come from? I usually ask these questions,and I tell people about it,and they ask me 'How do you not get a headache from this'? lol. |
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| 04 Sep 2014 08:48 PM |
>"But yeah,I always wondered...If the universe is expanding or getting smaller,whatever the scientists are saying today,Then what would happen if I ever reached the 'edge' of the universe? Would it keep expanding the more I try to reach the end of it? Would I go through it? What's on the other side? Is the universe just a giant bubble?"
Good question. The universe is expanding, yes, but it doesn't have an edge. Let me explain.
If the universe was infinite, meaning, it goes on forever in all directions, then if we looked far enough in any direction, we would see something. Now, if we look up at the night sky, it seems dark and there's much more black than stars. So, it may seem like there's an edge to the universe. A place where stars just stop.
However, this is simply an illusion.
If you look at a star, the farther it is, the farther it is in the past. If a star is 1000 light years away, we are seeing it as it was 1000 light years ago. Therefore, if we point our telescopes at an object 13 billion light years away, we'll be seeing galaxies and stars as they were at the very beginning of the universe.
But, even though the sky seems dark, we actually see light in every direction we point the telescope. The entire sky is light up with light. It's just that the light is infrared light. This is known as the cosmic background radiation. There is an amount of radiation nearly equal in all directions coming from the background of all the stars. This is the energy left over from the Big Bang.
Since we can see this in all directions, that means the universe has no edge. Because the amount of light years we can see is equal to the age of the universe itself.
Now, the Big Bang model did originally predict three different possibilities for universes. The first was the "closed" model. Essentially, this model is like a 4D sphere. Like a 3D sphere, if you were to walk in 1 direction for long enough, you'd end up back where you started. Two parallel lines would eventually cross.
The second model was the "flat" model. That's essentially the universe we live in. It goes infinitely in all directions.
The third was the "open" model. This one, parallel lines will diverge after a while.
However, using measurements from the cosmic background radiation, it has been confirmed with pretty good certainty that we live in a flat universe. So, it goes forever in all directions and parallel lines never cross or diverge.
>"Where did atoms/electrons etc. come from? I usually ask these questions,and I tell people about it,and they ask me 'How do you not get a headache from this'? lol."
This is a good question too. While, it's not entirely sure where atoms/electrons originated, we do have some pretty good ideas.
Essentially, the universe has a total energy of zero. All the energy of mass is cancelled out by gravity. I'm not really good at explaining this, so I'd recommend watching Lawrence Krauss's lecture or reading his book called "A Universe from Nothing". In essence, it describes how the evidence suggests that the total energy of the universe is zero. Therefore, the energy would have required no energy to have been created. No energy means no work. Nothing could literally produce something.
When you say "where did atoms come from", there's many ways I can answer that. We know quarks pop in and out of existence all the time. And the subatomic particles are formed from quarks.
The subatomic particles form the atom. Electrons naturally are bound to the proton due to the electromagnetic force, and so we have hydrogen atoms.
Hydrogen atoms conglomerate due to gravity, and once you have a large enough "hydrogen cloud", the overall gravity is so strong that the hydrogen atoms in the center get smashed together, and fuse into helium, releasing a ton of energy. This is essentially what stars are.
Once the star gets large enough, it may collapse down. When it collapses into a small point, the density of that point is so excessive that it causes a nuclear explosion called a supernova. These supernovae are so powerful that they can create atoms like carbon and oxygen.
That's where larger atoms come from. |
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doggy00
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| Joined: 11 Jan 2011 |
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| 04 Sep 2014 08:53 PM |
| So..Correct me if I'm wrong, If I was to fly faster than light to a planet orbiting a star a few lightyears away,and it's technically in the past,let's say the star is at it's very end of it's life and is about to die,would it be basically gone by the time I arrive? |
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| 04 Sep 2014 08:53 PM |
What engine is in a MiG-21MF an4d how much DRY Thrust does it put out? How much in A/B? Radar system cabable of useing radar guided K-13 Variants? |
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| 04 Sep 2014 09:09 PM |
>"So..Correct me if I'm wrong, If I was to fly faster than light"
Not possible. You would have to have infinite mass to go the speed of light.
>"to a planet orbiting a star a few lightyears away,and it's technically in the past,let's say the star is at it's very end of it's life and is about to die,would it be basically gone by the time I arrive?"
If a star is, let's say, 1000 light years away, and it blew up 300 years ago, it would still look normal for another 700 years. If you teleported to it, you would see it exploding.
Because what we're seeing on earth is the light that has traveled 1000 light years. It's like a slow internet connection. We are really lagged behind some stars. Some as much as 13+ billion years.
If we were close, we would see it pretty much in real time. But the further you are away, the more you "lag behind". Such as, 300 light years away would lag you behind 300 years. So if the star blew up, you wouldn't know for 300 years. |
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doggy00
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| Joined: 11 Jan 2011 |
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| 04 Sep 2014 09:16 PM |
What if you were to use a use a telescope and look at a star 1 lightyear away that just blew up. Would the delay be the same? Also, so you're saying if there was a star 2 lightyears away from Earth and a space ship is 1 lightyear away from it (Even though that is nearly even possible, knowing a man would have to live for a very long time to travel that far), then the people in the space ship would see it in one year, but Earth would see it a year after the people in the space ship saw it? |
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SMS1337
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| Joined: 19 Feb 2014 |
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| 04 Sep 2014 09:17 PM |
i have a question how long did it take to write this post
mlg post |
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| 04 Sep 2014 10:04 PM |
>"What if you were to use a use a telescope and look at a star 1 lightyear away that just blew up. Would the delay be the same?"
The delay would be 1 year. If it's 1 light year away it means it would take the light from the exploding star 1 year to reach us.
>"Also, so you're saying if there was a star 2 lightyears away from Earth and a space ship is 1 lightyear away from it (Even though that is nearly even possible, knowing a man would have to live for a very long time to travel that far), then the people in the space ship would see it in one year, but Earth would see it a year after the people in the space ship saw it?"
Yes, pretty much. The light from the exploding star would hit the spaceship after a year and continue on until it hits earth in two years. |
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| 04 Sep 2014 10:05 PM |
>"how long did it take to write this post"
Not that long. It was all off the top of my head.
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eprent
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| Joined: 17 Oct 2013 |
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| 04 Sep 2014 10:07 PM |
Wow, finally a quality thread. Good to you, OP. Assuming you didn't copy/paste it anyways. |
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Despairus
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| Joined: 03 Sep 2008 |
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| 04 Sep 2014 10:10 PM |
| If the big bang created the universe, and the universe only contains all existing things, then what was the big bang contained in? Oh yeah, it /didn't/ exist. |
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| 04 Sep 2014 10:14 PM |
Although I don't believe in the Big Bang, this was well thought out.
And for those who wanna know why I don't believe in it, I don't believe there is enough proof. I don't think being able to decipher the age of the universe from cosmic background radiation is convincing. |
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| 04 Sep 2014 10:54 PM |
>"If the big bang created the universe, and the universe only contains all existing things, then what was the big bang contained in? Oh yeah, it /didn't/ exist."
The Big Bang was the rapid expansion of spacetime. It wasn't "contained" in anything. The Big Bang was not the start of an expansion inside of spacetime, but expansion of spacetime itself.
>"And for those who wanna know why I don't believe in it, I don't believe there is enough proof. I don't think being able to decipher the age of the universe from cosmic background radiation is convincing."
It's not about the cosmic background radiation. The Big Bang is based on a mathematical proof that I described in the OP. We know the universe is expanding, and we have measured the rate of its expansion. The rate of expansion is represented by the Hubble constant. It's roughly 70 km/s/Mpc.
Hubble's law states that v=Hd
We know v=d/t simply by definition, so we can rearrange the equation like so: v=Hd d/t=Hd d=Hdt 1=Ht t=1/H
We get "t=1/H" or that time is equal to the inverse of the Hubble constant. Since the universe is expanding, this is just the time that it has been expanding. If we go back that time, the universe would be infinitely small.
Cosmic background radiation just confirms a prediction made by the Big Bang model, which does add validity to it, but it's not how the age of the universe is calculated.
The age of the universe is calculated by measuring the Hubble constant and then plugging it into the equation t=1/H.
For example, on NASA's sight, the Hubble constant is measured to be about 71.0 km/sec/Mpc. So just plug it into the equation...
t = 1/h H = 71.0 km/sec/Mpc 1 mpc = 3.09×10^19 km H = (71.0 km sec^-1)(3.09×1019 km)^-1 H = 2.29×10^-18 sec^-1 t = (2.29×10^-18 sec^-1)^-1 t = 4.37×10^17 sec t = (4.37×10^17 sec)(60^-1 min sec^-1)(60^-1 hr min^-1) t = (1.21×10^14 min)(24^-1 day hr^-1)(365.25 yr day^-1) t = 1.38×10^10 yr t = 13.8 billion years
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| 04 Sep 2014 10:59 PM |
| op just disproved all higher beings |
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lVlORIS
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| Joined: 06 May 2014 |
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| 04 Sep 2014 11:08 PM |
| why is it so hard for you to accept that people have different beliefs and supporting beliefs than you do, op? |
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| 04 Sep 2014 11:16 PM |
Guys, stop posting about religion.
1. It's against the rules. 2. Most religious people believe in the Big Bang, as studies have shown. |
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lVlORIS
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| Joined: 06 May 2014 |
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| 04 Sep 2014 11:22 PM |
lmao
if religion is against the rules, so is the big bang
equal opportunity in the scope of flame-wars |
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lVlORIS
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| Joined: 06 May 2014 |
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| 04 Sep 2014 11:23 PM |
and your second point is irrelevant
as irrelevant of your "popcorn chicken must be popcorn" point
evidently you can't understand your own fallacious loopholes |
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