A Brief History Of Existence (at Yume's request)
Ok Yume. You asked for it. So get your dictionary ready and try to keep an open mind. I’ll try to simplify as much of it as I can, but if you have any questions after reading it, ask away.
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As you probably know, the theory proposed by science to explain the early formation of the universe is called the Big Bang. The basic idea is that Einstein’s general theory of relativity can be combined with large scale observations (red shift of galaxies, correlation function of galaxies) of today’s universe to extrapolate the conditions of the universe at any time, past or present.
Since the temperature and density of the universe is dropping today, it is reasonable to assume that in the past, the temperature and density was much higher. This assumption was confirmed in the 60s when the cosmic background radiation (CMB) was first detected. The Big Bang model of the universe necessitates the existence of this phenomenon, and sure enough, the CMB is there.
According to the Big Bang theory, about 13.7 billion years ago, the universe was in a state of unimaginable density with enormous temperatures. As for the first 10^-33 seconds of the universe, Einstein’s physics cannot currently offer a compelling model (His theory of gravity predicts that there would have been a gravitational singularity, a point where density becomes infinite, but this conflicts with major ideas of quantum mechanics). To remedy this problem, I will soon discuss a theory to explain the first instant of existence, and the instants that preceded it.
So, from this tiny, tiny, incredibly dense state of existence (at 10^-33 seconds after ‘creation’, the universe was about the size of a marble), the universe began to expand at an unbelievable rate (exponentially, fuelled by a false vacuum). But it is important to remember that this wasn’t a typical ‘explosion’. It was not like an explosion in an empty room, it was like an explosion in which the room itself expands outward from that very small, infinitely dense space. This period of rapid expansion is commonly referred to as ‘inflation’.
Soon after the inflationary period, the universe began to cool, the four elementary forces of physics emerged (gravity, electromagnetic, strong nuclear, weak nuclear. Current theory suggests that at such high densities, temperatures and over such small spaces, these forces are actually the same, and the 4 separate forces that we observe today are actually one in the same), and the first elementary particles began to form (quarks, protons, etc.). These eventually gave rise to the first atomic particles, hydrogen and helium.
Over time, gravitation drew these atoms together and ‘clumps’ of hydrogen and helium began to form. These regions slowly became more and more dense. Hmm…can you think of something that is really just a super-dense clump of hydrogen and helium? If you said “the Sun”, pat yourself on the back. So, these dense regions eventually grew so dense that nuclear fusion began to take place spontaneously in the core, resulting in the first stars.
However, these weren’t your average stars. These were MASSIVE stars. As such, they consumed their nuclear fuel (hydrogen) relatively quickly and exploded in probably the largest supernovae that the universe has ever witnessed.
But the great thing about stars exploding is all the cool stuff that they produce. Moments before they burst, the pressure is so incredible that the star is able to fuse other atoms together to produce all new elements. This is how (most) of the elements we know of today (yes, even the stuff that you are made of, carbon, oxygen, etc) were formed, and they continue to be formed each time a star explodes.
So, jump ahead a few billion years, after this process has happened a few million times and you get a place like this. Massive amounts of stars and other matter has clustered together to form what we call ‘galaxies’.
Then one day, in the galaxy that we refer to as ‘The Milky Way’, a star exploded, maybe even exactly where you are sitting now. From this supernova, a nebula was formed full of all kinds of funky shit; carbon, hydrogen, iron, gold, chlorine, boron, etc. Then, through the same process that formed the massive stars, clumps of this stuff began to form right here where our solar system sits. Most of the material gathered in the center and came to be known as the ‘Sun’. It was the only body large enough to sustain a nuclear reaction in its core.
The rest of the material gathered into smaller clusters, known to us as planets, moons, asteroids and comets.
NOTE: Evidence for the Big Bang: Hubble law expansion, CMB, abundance of primordial elements (i.e. H, He), galactic evolution, quasar distribution.
So, there it was, the planet that we live on today. But it was just a rock back then, pretty barren, with no life to speak of. Lucky for us, the elements of life are floating around pretty much everywhere and amino acids (the basic building blocks of life) are found all over the place. After some chance happenstance (probably with a bolt of lightning or static electrical shock) some amino acids were joined to form the first ever RNA molecule. A molecule that, by natural chemical processes, could replicate itself.
(If you wish, I can go into much deeper detail regarding the formation of this molecule)
Depending on your definition of life, this molecule could actually be considered the first form of life on earth. But fortunately for us, this molecule could not replicate itself perfectly; the proteins which help to fix and control mutation had not yet developed, so each new RNA molecule would be significantly different from its ‘parent’.
So, after a few million years of random mutation, this molecule eventually evolved into a single celled organism with many complex chemical reactions taking place. It is important to remember that every living being is nothing more than a multitude of complex chemical reactions taking place simultaneously.
Next, fast forward through a hundreds of millions of years of physical and cultural evolution and BANG! Here we are. Sitting at our computer, discussing such ideas through a system of communication we call the “Internet”. If you want me to, I suppose I could walk you through some of this evolution, but I would rather refer you to this very interesting article titled, “Testing Darwin”. Please read it and direct any questions you may have to me.
http://www.dreamviews.com/forum/viewtopic.php?t=11711
Ok, now comes the really tricky part. The $1,000,000 question is, “What caused the Big Bang?”. An ill-informed theist may be tempted to use this opportunity to justify their belief in God. But not so fast, we wouldn’t want to jump to any conclusions would we?
To test if you are actually reading this 1,700 word post, Yume, I’ve devised this test. If you are reading this, please put the phrase “Wow, that took a long time to read”, at the beginning of your response.
There are a number of theories on this topic, some more convincing than others. One states that the universe is actually a, rather large, “virtual particle”. In quantum physics, it is a known fact that subatomic particle can and do pop into existence spontaneously (i.e. without cause) quite regularly. Also, it’s very possible (although highly improbable) that a hydrogen atom, a water molecule, or even a fish, could spontaneously pop into existence through the same process.
Likewise, it is possible that an entire universe could pop into existence without cause. And given enough time, the improbable becomes inevitable. So it’s only natural that one day it would happen. However, this raises pesky questions about where and when it “popped” from (Although, the argument that God created the universe raises the question, “then who created God?”). At some point in the future, I’ll type up a fascinating article that I have on the subject.
Here’s an excerpt: “All matter plus all gravity in the observable universe equals zero. So the universe could come from nothing because it is, fundamentally, nothing.”
Anyways, I’d rather present to you my personal favourite explanation for ‘creation’. Behold, the Ekpyrotic scenario. To get the gist of it, first you’ll need a basic understanding of string theory…
Imaging you’re looking at a clothesline from a distance of 30 feet. It would appear to you as a 1-dimensional object, simply a line in space. However, if you moved closer, say 5 feet away, you would notice that it actually has 2 dimensions, length and width (i.e. the line has perceivable thickness. Now, if you move even closer, you will notice that the clothesline is actually 3-dimensional. It has length, width and depth.
Unfortunately, this is as many dimensions that you or I can see (along with time, the 4th dimension). One implication of string theory, however, is that there are actually 11 dimensions. Seven of which are too small (or too large) to be observed by the human senses alone.
So, back to the ekpyrotic scenario, this model posits that the observable universe is actually a 4-dimensional “brane” (the term used for an n-dimensional plane) floating around in higher dimensional space along with many other such branes. (Picture a bunch of bedsheets blowing in the wind).
At some point in the past, the universe (our visible brane) was completely empty and void of matter and energy. Then, this brane collided with a parallel brane resulting in a massive explosion, creating all matter and energy that we observe today. From our brane, this process would look like a ‘big crunch’ followed by a ‘big bang’ (sound familiar? It’s not hard to see where the ekpyrotic model leaves off and the more conventional evolution of the universe, which I previously explained, picks up). Trillions of years later, the branes would have gradually returned to their previous state of emptiness and another collision would hit, restarting the entire process. This process has been happening for an infinite amount of time stretching into the past. So basically, there was no ‘beginning’ of the universe, it is infinite in both past and future.
I apologize for blowing your mind.
So, there you have it. A brief, slightly muddled history of existence according to Brady F. Baker (and a multitude of the world’s leading physicists, cosmologists and evolutionary biologists). Although they would probably cringe at how I described it.
Please post any questions that you have.
