Making sense of the Big Bang

[Hellbent]

It's recommended you read this article before attempting the contents of this post: http://www.foxnews.com/scitech/2010/10/20/scientists-discover-oldest-thing-universe/

Light from the farthest galaxy is calculated to be 13 billion years old by the time it reaches Earth. When calculating this distance, do they take into account the fact that the universe is supposedly expanding, and if they do, then does that mean the galaxy is in actuality more than 13 billion light years away because it's moving away from us?

Is the galaxy even in existence anymore?

The light left the galaxy 13 billion years ago, right? How far away was the galaxy from Earth's position today when the 13Ga galaxy formed? Was it closer? (It seems to me it would have been much closer: I'll explain my reasoning in a moment).

How far away was it from the point where the nebulous stuff that would later become our Milkyway galaxy was 13 billion years ago? (Seems to me at this time the two points would have been at their closest).

Maybe at the big bang, the universe was expanding so fast, that when the universe was 600 million years old (the supposed age when this galaxy formed) the galaxy was moving away from the point where Earth formed in its Galaxy so fast that the light never made it here until now (13 billion years later) once the expansion had slowed enough for light to reach us (I assume the universe's rate of expansion has been slowing since it was very fast in the beginning).

So I wonder if the point where Earth formed was moving away in the opposite direction from the 13 billion year old galaxy?

At the point of the big bang, was the universe expanding faster than the speed of light? If so, what does that mean for the space/time continuum during that time; and for relativity? If not, was it expanding at near the speed of light? If so, wouldn't that bias the overall age of the universe to appear to Earthlings younger than it "actually" is?

How can you really measure anything from the way beginning in a meaningful way, when our Earthly understandings of relativity, space and time all but go out the window?

You know, ultimately, the universe's existence doesn't make sense. It shouldn't exist: we shouldn't be here.

[AndrewB]

Spacetime is confusing. Have a beer.

As for your last statement, let me just say this. There are only two possible states: Existence and nonexistence. Since it's absolutely and irrefutably impossible to experience the latter, the only thing that can therefore be experienced is the former. This is completely incompatible with the idea of universal nonexistence. Existence (and therefore sentience) is unavoidable.

[Ralphis]

PARAGRAPHS

[Stupid Bunny]

Hellbent said:

(I assume the universe's rate of expansion has been slowing since it was very fast in the beginning).

Oh, but here's the strangest part of all: this isn't true. On the contrary, the rate of the Universe's expansion has been increasing, which can only be explained through "dark energy" which would be driving this acceleration. What this means for the future of the Universe is subject to much speculation, though one thing that is certain is that, at some point in the very distant future, all galaxies outside of our supercluster will have redshifted so much due to their acceleration away from us (and us away from them) that they will be invisible.

[phi108]

On a related note, Wikipedia has a news item about the discovery of the most distant galaxy to be observed from earth so far:

http://en.wikipedia.org/wiki/UDFy-38135539

UDFy-38135539 (also known as "HUDF.YD3") is the Hubble Ultra Deep Field (UDF) classification for a galaxy which (as of October 2010[update]) has been calculated to have a light travel time of 13 billion years[1] with a present distance of around 30 billion light-years, thus making the galaxy the most distant object in the universe known to have existed and which has been observed from Earth.

The Hubble took the pictures of it in August-September, and teams did spectroscopy on that speck of light to figure out the redshift and distance. Cool stuff.


EDIT: But this was a cool part of the article:

The light travel distance of the light that we observe from UDFy-38135539 is more than 4 billion parsecs[14] (over 13 billion light years), and it has a luminosity distance of 86.9 billion parsecs (about 283 billion light years).[15] There are a number of different distance measures in cosmology, and both "light travel distance" and "luminosity distance" are different from the comoving distance or "proper distance" generally used in defining the size of the observable universe[16][17] (comoving distance and proper distance are defined to be equal at the present cosmological time, so they can be used interchangeably when talking about the distance to an object at present, but proper distance increases with time due to the expansion of the universe, and is the distance used in Hubble's law; see http://en.wikipedia.org/wiki/Comoving_distance#Uses_of_the_proper_distance for more on the physical meaning of this notion of 'distance').

[GreyGhost]

"Back then, intense ultraviolet radiation from the first stars was clearing the opaque fog that filled the cosmos by splitting its hydrogen atoms into electrons and protons, a process known as reionization."

I like the way they present theory as indisputable fact - so typical of Fox.

[Seeker_of_Truth]

The known universe is approximately 13 to 14 billion light-years across, but in my opinion, the universe is probably much larger than that. It's taken light 13 billion years to get here, so who knows how much the universe may have expanded in that time. If I had to take a guess, then I would say that if the galaxy were still to exist today (which I honestly can't say), then it probably is much farther than 13 billion light years away.

[Hellbent]

StupidBunny said:

Oh, but here's the strangest part of all: this isn't true. On the contrary, the rate of the Universe's expansion has been increasing, which can only be explained through "dark energy" which would be driving this acceleration. What this means for the future of the Universe is subject to much speculation, though one thing that is certain is that, at some point in the very distant future, all galaxies outside of our supercluster will have redshifted so much due to their acceleration away from us (and us away from them) that they will be invisible.

Very interesting. I do remember hearing about the increase in rate of expansion, now that you mention it. Invisible because the speed the objects will be moving away from us/each other will be greater than the speed of light? So eventually everything will be racing away from each other so fast that... that everything will... will ... will disappear: The disappearance of the Universe

[dew]

http://en.wikipedia.org/wiki/Cosmic_microwave_background_radiation
this explains why we can estimate how old the universe is. we are getting messages from a time when stars (or even atoms) didn't exist yet, so we can be fairly certain we won't discover any older cosmological objects older than the relic radiation.

[AndrewB]

GreyGhost said:

I like the way they present theory as indisputable fact - so typical of Fox.

I always thought they were known for presenting indisputable fact as theory.

[geekmarine]

I'm confused - are we talking about theory in the colloquial sense, as in, "Oh, I just took a guess," or are we talking about theory in the scientific sense, as in, "This hypothesis has been thoroughly tested and is supported strongly by available evidence?" I just want some clarification here, because people seem to tend to assume that theory means guess, when in scientific terms, that's not the case.

[Captain Toenail]

I would imagine there's some sort of massive cycle where the universe expands to a certain point, then collapses again. Who knows? The reality is probably so bizarre and illogical we would never consider it.

[magicsofa]

Captain Toenail said:

I would imagine there's some sort of massive cycle where the universe expands to a certain point, then collapses again. Who knows? The reality is probably so bizarre and illogical we would never consider it.

I have often pondered this question, and came up with an interesting idea when a friend was arguing that entropy will continue forever. This means all matter will continuously spread out, until you have subatomic particles light-years away from each other and stuff.

Here's my pontification: What if the energy spreads out until the universe becomes totally homogenized? Maybe you wouldn't have distinct particles, and some kind of field of quarks or strings or whatever. Or, maybe it would be sufficient to call a bunch of electrons and protons with no possible way of interacting (i.e. they are not "causally connected"). In any case, it seems possible that at this point the universe would essentially be a singularity and thus explode once again. What I'm saying is that instead of collapsing, it would expand until it was a single, homogenous point - just like right before the big bang.

Maybe I should put down the bong...

[phi108]

That's similar to what I just thought. I wondered if the universe is currently just as small as pinhead would be to the occupants of the NEXT cycle after it bangs again. But if the universe really has an infinite size, then spreading out shouldn't be a worry. Perhaps only the local, observable universe is spreading, while the more distant infinite expase is a variety of expanding/contracting regions (or multiple universes), and weirder things.

[Phobus]

Until we get near to, or hit, a defined edge, I'd not worry about it. As this isn't about to happen in my life time, I'll not worry about it.

[Twinzen]

StupidBunny said:

Oh, but here's the strangest part of all: this isn't true. On the contrary, the rate of the Universe's expansion has been increasing, which can only be explained through "dark energy" which would be driving this acceleration. What this means for the future of the Universe is subject to much speculation, though one thing that is certain is that, at some point in the very distant future, all galaxies outside of our supercluster will have redshifted so much due to their acceleration away from us (and us away from them) that they will be invisible.

This is absolutely true, and has the interesting implication that were an "intelligent being" (by human standards) to emerge in a couple of billion years from now, which might be very likely given the size of the universe, they would probably have to conclude that the universe is static and that it consists of only their own galaxy.

[Quasar]

If you really want your mind blown then look up the holographic theory, and the relationship between it and the behavior of matter trapped inside the event horizon of a black hole. Similar a bit. Like, to the point of being governed by the same laws. Very interesting implications for the multiverse theory.

[j4rio]

who knows, mayhap there are even more universes... considering "our" was created out of nothing, why not possible existence of more of "these".

[AndrewB]

j4rio said:

who knows, mayhap there are even more universes... considering "our" was created out of nothing, why not possible existence of more of "these".

This has been a well accepted theory for many years now.

[kristus]

In that case though, it's not a theory in the scientific sense of the word.

[magicsofa]

j4rio said:

who knows, mayhap there are even more universes... considering "our" was created out of nothing, why not possible existence of more of "these".

hmm...were they all created at the same "time" ??

I put quotes because, if you think about non-existence, there cannot be any time as there is no matter. Only existence allows time to pass :P

However, if there is one universe, created out of nothing, can another universe be created out of nothing? While the first universe is existing? Or would they all have simultaneous beginnings?

I guess, in a sense, it wouldn't matter. In either case it seems that the components of the multiverse would have to be entirely separated, such that no interaction is possible. As if there were nothing in between them - no actual distance, no space. And thus, no time. It would in fact be meaningless to say "Universe A was created at the same time as universe B," or "Universe A was created before/after universe B."

AndrewB said:

There are only two possible states: Existence and nonexistence. Since it's absolutely and irrefutably impossible to experience the latter, the only thing that can therefore be experienced is the former. This is completely incompatible with the idea of universal nonexistence. Existence (and therefore sentience) is unavoidable.

The first time I read this I was like "yeah." Just now I read it and thought something's amiss here:

First you speak of two possible states:

Existence
Non-existence

So, these two things are possible, right? The list of possible states. Moving on, you say that it is not possible to experience one of them - namely, non-existence.

Here is the problem. By 'experience' you seem to mean that some sentient form is there to feel, see, or otherwise receive stimuli from the universe. In this case you would not be saying that non-existence is impossible (which is already conflicting with the first premise, that the two possible states are existence and non-existence). Just that it can't be experienced. It does not follow that existence is unavoidable, unless experience is unavoidable. But that was supposed to be a conclusion. It goes like this:

1. Existence and non-existence are both possible.
2. To experience non-existence is impossible.
3. Therefore, to experience existence is necessary.
4. If existence is experienced, existence is necessary.

Don't you think that (3) is an assumption? Why does the impossibility of the experience of non-existence necessitate experience itself?

[dew]

j4rio said:

who knows, mayhap there are even more universes... considering "our" was created out of nothing, why not possible existence of more of "these".

interestingly enough, i heard my astronomy lecturer talk about the multiverse subject on a national radio this saturday. he said there's an experiment planned to test other universes existence through detecting specific gravitational relic waves that can only occur when two universes "touch" through some quantum tunneling voodoo.

[AndrewB]

magicsofa said:

I guess, in a sense, it wouldn't matter. In either case it seems that the components of the multiverse would have to be entirely separated, such that no interaction is possible.

But the different universes in the multiverse DO interact. I recommend viewing this:

The first time I read this I was like "yeah." Just now I read it and thought something's amiss here:

First you speak of two possible states:

Existence
Non-existence

So, these two things are possible, right? The list of possible states. Moving on, you say that it is not possible to experience one of them - namely, non-existence.

Here is the problem. By 'experience' you seem to mean that some sentient form is there to feel, see, or otherwise receive stimuli from the universe. In this case you would not be saying that non-existence is impossible (which is already conflicting with the first premise,

I don't see any conflict here. Existence and non-existence are the two possible states for some unnamed entity. I didn't say non-existence is impossible. I said that experiencing non-existence is impossible. It's not possible to find yourself in a position to say "Hey, I don't exist! Boy, this is really boring!" This shouldn't require much explanation.

that the two possible states are existence and non-existence). Just that it can't be experienced. It does not follow that existence is unavoidable, unless experience is unavoidable.

That IS the assumption, that experience is unavoidable. And given everything we know about life, our memories before birth (none), our memories while under general anesthetic (none), etc, this assumption seems to hold water.

1. Existence and non-existence are both possible.
2. To experience non-existence is impossible.
2a. Therefore, experience is necessary because it is the only possible state that can be observed.
3. Therefore, to experience existence is necessary.
4. If existence is experienced, existence is necessary.

MISQUOTED THAT FOR YOU.

Don't you think that (3) is an assumption? Why does the impossibility of the experience of non-existence necessitate experience itself?

Simply because the alternative is paradoxical and nonsensical. Yes, it is circular logic in a sense. We're so used to all kinds of scientific problems being resolved through a linear, start-to-finish set of logic that we have a hard time comprehending any logic can be circular and true at the same time. This may be because only the most profound questions ever asked are ones that necessitate circular answers. So while we're used to circular logic being invalid, we have a hard time accepting that there may be a couple of questions where circular logic is not only valid, but completely and utterly mandatory. I propose that the truth to our existence is indeed circular. Taking a step back, let's say that there are two suppositions:

1) Universal existence is not necessary. If something exists instead of nothing then it's because of some unknown cause and it's entirely reasonable that, through some chance or reason, existence may never have happened in any sense whatsoever.

2) Universal existence is necessary. Something exists instead of nothing because existence is necessary for observation and observation is just plain necessary.

Let's follow supposition 1 and suppose that existence never happened. Given some unnamed observer (which, by the way, can't possibly exist) an eternity of "time" will pass in an infinitely small amount of observational time. Also, "time" in this context is invalid because time is a property of our universe and can't be used in this supposition. So, to rephrase, this nonexistence universe is "doing" its non-existing, not over an infinite amount of time, and not over an infinitely small amount of time, and not over time at all, but instead not at all. What does all of this "feel" like? Obviously the answer is "nothing" because "feel" is something done by an observer, which cannot exist because existence is impossible in this supposition. So what can we make of all this? Well, not much because the more we explore this concept, the more ridiculous it becomes because it's chock full of paradoxes and impossibilities.

Let's follow supposition 2 now. We exist as observers. Why? Because we evolved into an intelligent being by some chemical process. Why? Because our planet contains life. Why? Because the conditions necessary to support life are extremely unlikely to exist on any given "planet", but still nonzero, which is sufficient in an infinite universe/multiverse. So why do the universes/multiverses exist? Because universal existence is the only possible state. Why? Because the alternative (supposition 1) is paradoxical and possible. So fine, they exist. Therefore, universal existence is the only possible situation. So why is the universe/multiverse infinite and neverending instead of fizzling out after a second or so? Because the latter leads to the same paradoxes as supposition 1 which is impossible. Therefore, the universe/multiverse must be infinite, vast, and neverending in order to support an observer which can only exist under extremely unlikely and near-perfect conditions.

In other words, when you follow supposition 1, nothing makes sense and all logic collapses. When you follow supposition 2, the logic leads to a kind of dead end, but it's a dead end whereby every piece of logic makes sense and resolves into a nice tidy piece of logic.

Given two possible suppositions, one being nonsensical and the other being sensical, it's easy to accept the sensical one.

[magicsofa]

I understand that non-existence is impossible and that existence is necessary.

I do not understand that it follows from the necessity of existence that experience should also be necessary. What if the whole universe was just cheese? What if, after the big bang, the whole universe was just a big cloud? Is there any experience going on in the cloud that resulted from the big bang? There may be evidence suggesting a very high probability that clouds of cheese/energy would evolve into stars and planets and so on, but is there evidence suggesting it's impossible to sustain a universe without life?

AndrewB said:

every piece of logic makes sense and resolves into a nice tidy piece of logic

AAH I CANT STOP RUNNING IN CIRCLES AAH

EDIT: PS: That video kills me. I know he's a "real" scientist. He just sounds like a dweeb, and he says silly stuff like "we had to bring out a whole new set of facts." There's no "FACT" in "THEORETICAL"

[AndrewB]

magicsofa said:

I understand that non-existence is impossible and that existence is necessary.

I do not understand that it follows from the necessity of existence that experience should also be necessary. What if the whole universe was just cheese? What if, after the big bang, the whole universe was just a big cloud? Is there any experience going on in the cloud that resulted from the big bang? There may be evidence suggesting a very high probability that clouds of cheese/energy would evolve into stars and planets and so on, but is there evidence suggesting it's impossible to sustain a universe without life?

I addressed this in my post, most of which you apparently ignored or didn't understand:

So why is the universe/multiverse infinite and neverending instead of fizzling out after a second or so? Because the latter leads to the same paradoxes as supposition 1 which is impossible.

Your idea of a universe made of cheese or not supporting shares many of the paradoxes of my scenario. A universe with no life would have all of its time pass in an instant because time is experienced by an observer. A universe with no observer is an irrelevant universe and is not really distinguishable from no universe at all. Eventually life would have to exist. To suggest otherwise would be to come face to face with the paradoxes of supposition 1.

magicsofa said:

IEDIT: PS: That video kills me. I know he's a "real" scientist. He just sounds like a dweeb, and he says silly stuff like "we had to bring out a whole new set of facts." There's no "FACT" in "THEORETICAL"

He doesn't seem to be one of the brightest scientists I've ever seen, but he did have some points about the multiverse that I thought would be insightful to you. The various universes are in fact not completely isolated from each other.

[Aliotroph?]

AndrewB said:

I addressed this in my post, most of which you apparently ignored or didn't understand:

Your idea of a universe made of cheese or not supporting shares many of the paradoxes of my scenario. A universe with no life would have all of its time pass in an instant because time is experienced by an observer. A universe with no observer is an irrelevant universe and is not really distinguishable from no universe at all. Eventually life would have to exist. To suggest otherwise would be to come face to face with the paradoxes of supposition 1.

He doesn't seem to be one of the brightest scientists I've ever seen, but he did have some points about the multiverse that I thought would be insightful to you. The various universes are in fact not completely isolated from each other.

Nonsense! Why would life itself give any significance to time or a universe? Life is just one of the processes that occurs in a universe. Removing it doesn't remove time. All the processes in the universe would still happen in their time relative to any other things happening. The concept of whether something is long or short would be irrelevant, but time would still function as it always does (which is to say at different speeds in different situations).

The guy in the video is also trying too hard to dumb down his explanations. I suspect he's used to teaching science to his mother or something. :D

[AirRaid]

Hellbent said:

Maybe at the big bang, the universe was expanding so fast, that when the universe was 600 million years old (the supposed age when this galaxy formed) the galaxy was moving away from the point where Earth formed in its Galaxy so fast that the light never made it here until now (13 billion years later) once the expansion had slowed enough for light to reach us (I assume the universe's rate of expansion has been slowing since it was very fast in the beginning).

This is a terrible assumption. What is there to slow it down? An object in motion will remain in motion until acted upon by another force. There's no friction, no gravity, no retarding force of any kind affecting these galaxies.

[Aliotroph?]

Gravity. That was the assumption for a long time. The fact that it appears to be accelerating its expansion is where dark energy comes into play.

[Sharessa]

All I want to be is the Universe.

[magicsofa]

AndrewB said:

I addressed this in my post, most of which you apparently ignored or didn't understand

I read it quite thoroughly, I just wanted to respond concisely on the one premise I am attacking.

A universe with no life would have all of its time pass in an instant because time is experienced by an observer.

You need to let go of your clock. Time is not something separate from matter nor is it measurable. Time is our word for the movement of objects, matter, or energy in any form. Time is also relative, which I'm sure you know has been tested thoroughly. Saying the universe's time passes instantly is a simple contradiction. If time is passing, it can't pass instantly, via the definition of time (movement).

A universe with no observer is an irrelevant universe and is not really distinguishable from no universe at all. Eventually life would have to exist. To suggest otherwise would be to come face to face with the paradoxes of supposition 1.

Eventually life would have to exist? Are you saying that it's possible for the universe to exist and, after some time, life springs up? This is an obvious incompatibility with your own statements.

Furthermore, you are saying that something cannot exist without an observer. Doesn't this observer have to actually experience the something? What would you say about an object that is not causally connected to the only observer(s) in the universe? No energy transfer can happen between objects which are not causally connected, so does this object NOT exist since it can't be observed?

That IS the assumption, that experience is unavoidable.

Assuming experience is unavoidable makes your ideas hold up - but the purpose of assumptions is to explore what might be true or false IF that assumption were in fact true. You have not proven that this assumption must be true.

And given everything we know about life, our memories before birth (none), our memories while under general anesthetic (none), etc, this assumption seems to hold water.

I'm confused - what is it we know about life that supports this? What is significant about our lack of memories in certain states?

We don't remember stuff shortly after birth because we haven't learned to observe time yet. It's just another hole - a person that is under anesthetic does not observe the universe, and yet it persists. Some philosophers try to say that if everyone died suddenly, the universe would disappear. Now, I firmly believe that all philosophers are inherently wrong, but these philosophers are even more wrong than most :P