How the Universe started

[Captain_Paulentineous]

Is it possible to ever know how the universe truely started? Like how long ago was the first spec of dust in the huge place that is space formed. How could somthing just come out of nothing? There had to be a time where there was just infinant blackness before the big bang or anything before that.
Any thoughts?

[Atheist Peace]

We should assume that the big bang started the universe, there is evidence for it and no alternative theory has ever been presented as far as I know. (Creationism isn't an alternative theory, as it has no evidence and never will)

[Richard the Lionheart]

We should assume that the big bang started the universe, there is evidence for it and no alternative theory has ever been presented as far as I know. (Creationism isn't an alternative theory, as it has no evidence and never will)

But then how did the Bing Bang originate? What Caused it? What was before it? There is also no evidence that would rule out Creationism.


@Alameda: That's one big and informative post!

[Kino]

Deleted by user.

[Francisco Montana]

Here's the most widely excepted take on how the universe began.

A Hot Big Bang

You have probably heard the term "Big Bang" before when people start to talk about the origins of the universe, but when people tell you that the universe started really small (tinier than a grain of sand) and incredibly dense, and then suddenly expanded to what it is today, things become a little more difficult to grasp. The theory of a Hot Big Bang is the most widely accepted hypothesis for the origin of the universe, but it still leaves many questions unanswered. How and why did the universe expand? What caused the galaxies to form? But, perhaps the most daunting question is: "What existed before the Big Bang?" These are questions that are very difficult to answer. Astronomers are like archeologists who study the fossils of the universe. They form their theories based on what they observe, and luckily Big Bang theory seems to fit rather nicely to these observations. So what happened during the Big Bang?


Looking at the Horizon

First things first, let's explain why this timeline has such an odd shape. We mentioned before that based on its expansion, scientists approximate the universe to be about 15 billion years old. However, we can't see the whole universe, and we don't know how big it is. We can only see as far as light can travel, and right now we cannot "see" galaxies that are more than 15 billion light-years away because they have not yet entered our horizon.

Have you ever watched the sunset at the beach, and noticed how the sun appears to just fall below the surface of the water? You know, however, that the reason the sun appears to drop is because as the Earth rotates, the sun drops lower in the sky as it becomes further and further from our line of sight. Finally, the sun sets on the "horizon" which is the farthest distance we can see due to the curvature of the Earth. We use this same term to refer to the universe because as far as 15 billion light years is all we can see--our horizon.

From the beginning...

So how did it all start? A very good question, and one that is highly debated. Most people agree that the universe started very small and very dense and underwent an initial inflation that lasted a infinitismle fraction of a second (thus the universe expanded much faster than the speed of light (and you thought nothing could move faster than the speed of light...). But the universe was still really hot, so hot that ordinary atoms couldn't even exist. Electrons caused very small packets of light called photons to scatter continuously, and if you can believe it, light was actually linked, or coupled, to the particles, causing the whole universe to glow. This is the stage that scientists like to call the primordial soup because the universe looked like a plasma "soup" of protons, electrons, neutrons, neutrinos, photons, etc.

(Just look at the picture below of Compton Scattering of photons off ionized particles.)


Anyhow, as you all probably know, things start to cool off as they expand, so as the universe continued to expand, it cooled off. Eventually, after about 300,000 years, it cooled off enough so that atoms could form. Photons are far more likely to scatter off ionized particles like protons and electrons (particles that have an electric charge) than neutrally-charged atoms, so finally the photons travelling through space could move in straight paths instead of constantly being scattered by electrons. As a result, the formation of atoms lead to the creation of the elements hydrogen and helium, and the now free-streaming photons made up a nearly uniform light radiation that filled the whole universe. The study of this radiation, which we call the Cosmic Microwave Background, may hold the key to some of the most pressing questions about the universe and its ultimate fate.

(This picture shows photons travelling in straight paths when ordinary matter forms.)


The Formation of Galaxies and Galaxy Clusters
Some regions in this universe were very dense, and they had enough gravity to overcome the expansion and form galaxies and galaxy clusters. That is why we are careful to say that distant galaxies and galaxy clusters are expanding away from each other. For example, our own galaxy (known as the Milky Way) is really part of a cluster of galaxies. And unlike distant galaxies, the galaxies in what we call our local group are actually moving toward us due to gravity!


Below is a picture taken by the Hubble Space Telescope of the spiral galaxy NGC 4414.



(Credit to Wisconsin Dept of Education for this very comprehensive breakdown)

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This one is a more modern take on it:

Universe started with hiss, not bang
10:30 12 June 2004
Exclusive from New Scientist Print Edition
David L Chandler

Mark Whittle, University of Virginia
WMAP, NASA
American Astronomical Society

The Universe began not with a bang but with a low moan, building into a roar that gave way to a deafening hiss. And those sounds gave birth to the first stars.

Cosmologists do not usually think in terms of sound, but this aural picture is a good way to think about the Universe's beginnings, says astronomer Mark Whittle of the University of Virginia in Charlottesville.



Whittle has reconstructed the cosmic cacophony from data teased out over the past couple of years from the high-resolution mapping by NASA's WMAP spacecraft of the cosmic microwave background radiation, the afterglow of the hot early Universe.

The variations in the cosmic background radiation expose the relative clumpiness of the early cosmos at a variety of different scales. These density variations began as quantum fluctuations in the moments after the big bang, and then propagated out as sonic waves. The denser regions became the seeds of galaxies and stars, which is why astronomers are so interested in them.

Translating the observed frequency spectrum directly to sound yields tones far too low for ears to hear - some 50 octaves below middle A - but transpose the score up all those octaves and you can listen to it.

As for volume, the intensity of the variations corresponds to about 110 decibels, as loud as a rock concert. Whittle has also used the best available cosmological models to map the way the vibrations evolved over time, showing how the chords of the big bang changed over the Universe's first million years or so.

Majestic cords
You can listen to the sound from the first million years after the big bang here: (0.5 Mb .wav file). The sound has been compressed to five seconds, with the volume held constant.

Whittle played the soundtrack at the American Astronomical Society meeting in Denver last week. Contrary to its name, the big bang began in absolute silence. But the sound soon built up into a roar whose broad-peaked notes corresponded, in musical terms, to a "majestic" major third chord, evolving slowly into a "sadder" minor third, Whittle explained.

For those worried that you cannot have sounds in space, that is true today, but it was not so in the Universe's infancy. For perhaps its first million years, the Universe was small and dense enough that sound waves could indeed travel through it - so efficiently, in fact, that they moved at about half the speed of light.

The new sonic reconstructions do not involve any new science, Whittle says, but like a good diagram or 3D visualisation, they may help astronomers teach complex ideas, and maybe understand the observations a bit more clearly themselves.

"Everyone was fascinated," said Steve Maran, the society's press officer, who added that even he had "learned from this, that the big bang actually was silent, then things got louder and louder".

Cool stuff, huh?

[Justinian]

I know you're all sick of hearing this, but nothing doesn't blow up. :wink:

[Darkragnar]

there wasnt nothing back then ,
there was 1 thing,
and that thing blew up

[Justinian]

How'd that one thing get there?

[Francisco Montana]

I know you're all sick of hearing this, but nothing doesn't blow up. :wink:

Uh, oh. Do I sense a touch of biblical synicisim?

Evolution and Creationism, IMHO, are not, or don't have to be, mutually exclusive.

There is alot science can't, and won't be able to tell us for a very long time. Who's to say, then, that anything is really out of the realm of possibility. If we are going to be intellectually honest, that is.

[UnkemptGoose]

There are alternatives, one is it has always been here never ending and ever expanding.

Another some scientists considering is it expands and contracts over and over. That comes with the discovery of dark matter and energy, I think.

With BigBang though, some theorized with stringtheory/M-theory, Universes are made in the 9th or 10th dimension where other "realities" bump into eachother and make a bang creating a Universe. Scientist think if this is true they can make a Universe in a Lab.

It's all guessing though, no one knows for sure yet.

I'm not sure but perhaps this theory goes along with the mulitverse theory, that there are an infinite amount of universes out there that mirror our own to some degree.

[Lee1026]

It takes generally some thousands of years to a light ray to cross a galaxy.

light can get to anywhere, instantanously. remember that if you travel at the speed of light. everything becomes infinitely small.

[Francisco Montana]

light can get to anywhere, instantanously. remember that if you travel at the speed of light. everything becomes infinitely small.

Execpt the infinitely large universe. :wink:

[Fenris]

light can get to anywhere, instantanously. remember that if you travel at the speed of light. everything becomes infinitely small.

The thing is, the light travels almost instantly in it's own perspective, but if we look at it, it will take a lot of time since WE are not travelling at the speed of light. So, basically, it always depends on the perspective.

Lee, I've got a question for you, and anyone else who can answer...

Ok, first, de wo agree that movement is only relative to other objects, particles, etc? So if I move at 3 km/h, I base it on immovable stuff on the Earth, but at the same time, since Earth moves, I could say I go much faster relatively to the moon, for example. So basically, if you are in emptiness, there is space but nothing else than space, no matter, you couldn't move, right?

And then, if a photon moves away from me, we could also consider that it's me, moving away from it, no? And since everything moves: Earth, Solar system, galaxy, cluster, etc. Well WE move really fast compared to X planet, for example, that is situated in another cluster, then what happens with time between both?

Basically, what defines what is moving?

There's a part I already have answered, that adding two speeds is not just 1/2*speed of light+1/2*speed of light, but is more complex and the result of adding 1/2*speed of light to 1/2*speed of light would result in 1/2*speed of light (or very close to it), thus both objects move as fast from each other than the speed they are each moving from their initial starting point.

That's pretty :wub: up... anyone can answer this?

[Lee1026]

you never moves; everything else moves relative to you. (you can define any old frame of reference you want, as long as it is not accelerating.)

[Darkragnar]

thats true thats what quantum computing is,the knowledge on how to use the computing power from another universe i hear its all the rage in M.I.T nowdays or atleast was 2 years back.

[HorseArcher]

of course for the following, you need to have an open mind, and need to understand/comprehand many things before your brain accepts certain ideas.

a parallel universe has been debated around. It's called the M-Theory

M-theory looks at events before the Big Bang, proposing that the Universe has 11 dimensions, six of them rolled up into microscopic filaments that can, for all intents, be ignored.

Professor Sir Martin Rees of Cambridge University told BBC News Online: "Steinhardt and his colleagues offer a fascinating idea, invoking the idea of more than one universe embedded in higher-dimensional space."The action of the Universe takes place in five-dimensional space. Before the Big Bang occurred the Universe consisted of two perfectly flat four-dimensional surfaces.

One of these sheets is our Universe; the other, a "hidden" parallel universe.

According to the Princeton researchers, random fluctuations in this unseen companion universe caused it to distort and reach towards our Universe.

The floater "splatted" into our Universe and the energy of the collision was transformed into the matter and energy of our Universe in a Big Bang.

According to Professor Sir Martin Rees: "All these ideas about the ultra-early universe highlight the link between cosmos and micro-world - the ideas won't be firmed up until we have a proper understanding of space and time, the 'bedrock' of the physical world."

[Fabolous]

Lord Alameda, those are some very big, very good posts. I learned alot from those.

As justinian said, nothing doesn't blow up, and if you say there was one thing, how did it get there. Hmm... i have an answer, God. :wink:

[Ulyaoth]

And how'd god get there?

[Francisco Montana]

And how'd god get there?

Some things, my friend, we'll just never know.

[HorseArcher]

Some things, my friend, we'll just never know.

for humans it's hard to comprehend that not everything as a beginning and an end. We see it every day in our world, things born and things die, but we just cannot understand that something doesn't cycle through any time and process based period. There is far much more out there, than we know. Humans throughout the ages, alwayst thought that they know everything and at the set of that time, they said many things are impossible. if you'd say 200 yrs ago that you can make a conversation with people around the world, by hitting buttons on a flat keypad, you'd be burned for witchcraft. Today someone saying that there are parallel universes or more dimensions exists, you get ridiculed. it's all the same. Trust me your great great grandchild will laugh on you and me on our world built on false ideas and our selfish beliefs. Just like you'd laugh on that 300 years ago, they thought, that if you'd travel faster than 50miles per hour, you'd die from it.