The Universe Itself Keeps On Expanding, And Expanding…

Question from Andreas:
I know, this may have already been answered, but this piece of information so far successfully hid from my search for knowledge. This is why I’d like to ask a physicist
— Lawrence Krauss — these two questions regarding space and time.

Question 1:
First, as I get it, since Einstein there is no universal time, but a space-time. (Newton was so much easier to grasp for a simple human mind.) Means, space and time are tied together, influence each other and got into existence at the same time which was the big bang. Am I right so far?
Thus space started to exist and to expand since then, as did time — start to exist, that is.

So here comes my first question, because I don’t understand a “what was before” question I sometimes read or am asked (mostly by religious people). I don’t claim to understand Einstein, and I assume only a dozen people on Earth fully do — so maybe I got it all wrong, which is why I have to get this answered.
Is it true that there was no time before the big bang? If so, why are people asking themselves, how and when and why the big bang took place? It cannot be answered (well, the how can be answered to an extent) when there was no time in existence before, so there was no “before the big bang”… or what did I get wrong here?
And the implications? Am I right about shaking my head if people ask the “but what was before” question?!?

Question 2:
Another issue I have with time is distance, the speed of light and our view into the universe. Due to the limitation of the speed of light, we look backwards in time when we look into the universe and see distant galaxies. So we see the past. The farther away a star/galaxy is, the older the image we see. So how do we know if it’s still there? How do we know if a galaxy very far out, in a distant past, isn’t long gone and its stars exploded in nova and supernova explosions? And how far can we look back? I once read that the farthest out we can see is the actual time of the plasma that was “shortly” after the big bang… and we cannot see past that. And that we can see residual “background noise.” If that is true, how can we have a current picture of the universe? Isn’t everything we think about it an extrapolation of a past situation—the only thing that we can see, but we have to calculate how it might have developed since then to now in order to have a full understanding of the universe in its present state?

Isn’t it therefore impossible to have a clear picture of the universe, its number of galaxies, its size etc.? It could be no more than a wild guess, like “yes, we see the images, but we cannot put it together in one map of the current (state of the) universe…”

Those were my two questions.
I am really looking forward to seeing them answered by someone who actually understands what he’s saying, and can even do the calculations (e.g. the time+distance thing), as this gives me headaches for a year or two now, and I just couldn’t find it anywhere else… yet.

The biggest thanks in advance!

Answer by SmartLX:
With the disclaimer that I am absolutely not Lawrence Krauss, I’m happy to help.

Question 1:
There are multiple cosmological models with some kind of Big Bang, and there is a form of time “before” it in some of them. When considering the multiverse hypothesis in particular, you have to consider the possibility that before our system of space-time began others might already have been running. (“Before” in this context relates to causality; if something in another system of space-time caused ours to emerge, you can think of the cause coming before the effect.) If indeed there was no time before the Big Bang, though, then the “before” question is indeed inapplicable, and our ideas of cause and effect have a hard time applying as well.

To summarise in the context of the religiously-charged “what was before” question, we don’t know whether there was a before, if there was a before there didn’t have to be a god in it, and if there wasn’t a before then the Cosmological Argument is nonsensical. The Argument from Contingency is a version that attempts to get around the time-based limitations, but it still has most of the same flaws.

Question 2:
Statistically speaking, we know many stars we can see are long “dead”. Our sun has a total lifespan of about ten billion years, and the larger a star is the sooner it burns out. The best telescopes can pick up images from several billion light years away, and some of the far-out stars are hundreds or thousands of times bigger than the Sun. Even one billion light years out, time will be up for a significant percentage of them since they’ve had to last another billion years since they radiated the light we’re seeing.

So of course our picture of the universe is incomplete. We live in a fortunate time, cosmologically speaking, because the expansion of the universe hasn’t progressed to the point where all galaxies are out of sight of each other, or else we might not know there are other galaxies at all. As it is, we are constantly revising our estimates (and estimates they certainly are) about the contents of the universe based on the information we can gather. Right now the estimate for the proportion of stars with planets around them is rocketing upward as we find evidence of more and more extra-solar planets. Just because we don’t know everything doesn’t mean we can’t learn anything.

I think you misunderstand one significant thing. Our model of the present universe is not an extrapolation from an assumption of the Big Bang; rather our concept of the Big Bang itself is largely an extrapolation from the current state and movement of the universe. Put simply, everything is rushing away from everything else (unless held together by local gravity) so in the past everything was closer, further in the past everything was even closer than that…and at some point beforehand everything was together, and the physicists worked from there. We try to model the current universe based as much as possible on real observations of its present state, rather than extrapolating from an extrapolation – though sometimes we do resort to that.

Feel free to pick up on any of these points in a comment if you think it could be clearer.

The World of Leftover Energy

Question from Andrew:
Why do atheists like Stenger say that the universe can be eternal, when this does not hold?

Stenger argues that the universe can be eternal, non-created, extrapolating the law of conservation of energy-mass before the planck time, he says that because we do not see a violation to this law, the universe can perfectly be eternal.

But this is a fallacy as William Lane Craig exposed once. If the energy were eternal there would be no useful energy right now, it would have become useless, complete entropy an infinite time ago, and because we do not see this, the only conclusion is that the universe and the energy began a finite time ago. Where we Christians think, the best explanation is the creation by God.

Answer by SmartLX:
Even according to you, Stenger only said the universe can be eternal, not that it definitely is. If it isn’t, then God is only one possibility among who knows how many: spontaneous emergence (more on that in a sec), a previous universe, a deistic rather than theistic (let alone Christian) god and so on.

Anyway, there are at least three straightforward ways in which there can still be useful energy now after an eternity of existence. There might be others, but even one possible way is enough to keep someone like Craig from ruling out the possibility entirely.

1. There is infinite or potentially infinite energy as well as infinite time.
Our universe as we see it has existed for a finite amount of time since the Big Bang with a certain amount of matter and energy, but what if that only contained one portion of the available material of an endless universe or multiverse? Or can matter emerge regularly and spontaneously from the quantum foam as much as it likes, as long as the same amount of antimatter accompanies it and the total amount of “positive” energy stays constant? As Lawrence Krauss says, something can come from nothing if “nothing” is unstable.

2. The energy is periodically reclaimed.
Entropy doesn’t destroy energy (hence Stenger’s point), it only ends up radiating it towards the edges of the universe where it’s no use to anyone. If Big Bangs are regular rather than one-off occurrences, then there’s a long-standing hypothesis that the universe is first drawn together in a Big Crunch. The new singularity contains not only all the matter and energy of the crushed universe, but all the space as well. Whatever was lost to entropy is dragged back to a mathematical point, just like at the point of our own Big Bang, and the cycle can begin again.

3. The amount of available energy decreases exponentially.
The less energy there is, the slower it dissipates, the way a gush becomes a trickle when you tip out a bucket of water. Say that every billion years, the amount of available energy decreases by half. If so then a billion years ago there was twice as much, and two billion years from now there’ll be a quarter as much, but there will never, ever be none. It will approach zero (or, importantly, a non-zero constant) asymptotically, which is to say it will get closer and closer without ever reaching it. Perhaps the amount of energy we’re used to seeing in the world is practically nothing compared to the intense heat, light and motion that was everywhere in times gone by, with the universe in a state of near-saturation (perhaps asymptotically again). Without past reference points from before the Big Bang, which are probably impossible to attain, you can’t make a judgement that there can’t be this much energy now.

One final point: be very careful about expressions like “the best explanation” when discussing cosmology. If quantum mechanics have taught us anything, it’s that reality can be counter-intuitive, and the truth might well strike one as ridiculous. If there’s evidence for a claim then it’s a supportable claim, but if all it does is sound right then it’s worthless.

Answer Me These Questions Three

Question from Stephen:
Dear who ever is reading this,

I am a Christian, now before you get all mad and make judgements please hear me out I just want to ask you a few questions so I get what you believe. Okay so…
1. If you don’t believe in “God” do you believe in a “higher power?” And if you do who is that “higher power?” Would you consider yourself to be “God” over your own life?
2. If you don’t believe in heaven then where do you go when you die?
3. How do you believe the world came to be? Though the Big Bang theory? Or did the earth always exist?

Please respond back with your answers I just want to know more about atheists.

Answer by SmartLX:
No problem Stephen. If I got mad when someone simply identified as Christian, I wouldn’t be able to think straight when answering their questions. I’ve numbered your questions for easy reference.

1. Plenty of entities are more powerful than me. The sun makes me look completely insignificant, when considered in all its enormity. The nation of the Commonwealth of Australia has power over me, since I’m a small part of it. Gravity, while not necessarily an entity, has achieved more than I ever will. The thing is that none of these entities are concerned with the intimate details of how I live my life, so they’re not the kind of “higher power” I can appeal to for practical help in all things. (My country does concern itself with some broad aspects of my life, of course, but fortunately not all.)

Therefore I don’t think there is the kind of “higher power” you’re thinking of. In the absence of this, I certainly don’t feel like the God of my own life because I don’t have anything like that kind of absolute control over it. I do have some control, obviously, but that just makes me a functioning person with my own will, not a god. It suffices.

2. I described my position on death in an earlier piece. Read it here, and comment (here or there) if you have any questions.

3. All the evidence points to a Big Bang, or a similar expansion of all existing matter and energy from a single point in space about 15 billion years ago. The Earth formed about 10 billion years later, coming together from materials orbiting the Sun (which had formed a few hundred million years earlier). You don’t have to be an atheist to think this, and in fact many Christians believe that God caused exactly this to happen. Where atheists differ is that they don’t believe a god was required for it to happen.

A “Survey”

Question from Leonard:
Don’t you find it to be most odd that there is something instead of nothing?
Wouldn’t it be more logical and simpler for there to be nothing?

Answer by SmartLX:
These are not survey questions, Leonard. This is an argument, nominally rephrased as a pair of questions. Any questionnaire containing the above is essentially a push poll, and certain ethical implications follow.

It might be logical to think that there should currently be nothing, but only if we knew of any point in the history of the universe when there was nothing, and we don’t. As far as we know there has always been something, and our current laws of conservation of matter and energy tend to back that up. We have no idea what preceded the Big Bang, if anything, and it is far beyond our current understanding to simply assume there was nothing at all.

Putting this aside, the usual follow-up to this idea by apologists is that the only way there can currently be something is if someone created it. Firstly, if there was someone there then there wasn’t nothing, and secondly, where did the someone come from? Yes, many theists object to that question because their chosen someone is supposedly eternal and uncaused, but then what actually stops the universe itself from being that way? Adding an uncaused, intelligent, inexplicable being such as a god never, ever simplifies the circumstances, and is quite unnecessary unless you impose arbitrary constraints on the universe – which the god immediately breaks to justify itself.

Eternity, and not by Calvin Klein

Question from Brenton:
Is the universe eternal?

Answer by SmartLX:
We don’t know, but whether it is or not, neither option makes a god very likely.

Cosmologists now almost universally accept the Big Bang as a factual event which occurred about fourteen billion years ago. A far greater point of contention is whether the matter and energy in the universe have always existed, and were simply in some other state before they coalesced into the singularity which “exploded”, or if the Big Bang was truly the beginning of time and causality.

If the universe is eternal, there is no need for a creator god. Most theistic gods are regarded by their believers as eternal and thus in no need of their own creators; this is a real possibility for the universe itself.

If the universe is not eternal, and nothing material preceded it, then either it was created or produced by something or it emerged directly from nothing. Neither of these can be judged as more or less likely than the other based on our experience so far because, while we have no direct evidence of anything emerging from nothing (though quantum mechanics may suggest this possibility), we have no evidence at all of anything being created from nothing as creator gods are meant to have done.

That leaves the idea that something material (or with direct material influence) and outside the universe pre-dated it, and somehow resulted in its emergence. Again a god is possible here, but it could also be another previous universe, or the “quantum foam”, or any number of hypothetical entities. A god as an explanation is the least useful entity in this scenario because a full-blown intelligent god is itself an inexplicable cause, and it’s no more likely than any of the others. It’s also the only one which requires that we posit anything supernatural.

I realise that I’ve read quite a lot into your very simple question, but delving into these issues is the usual purpose of asking questions like this on an atheist website.

Thermodynamics (it’s not what you think)

Question from Anon:
Hi,

I’m engaged in a discussion with a Christian friend of mine who has presented this syllogism to me:

“1. Simply put, if there is no external cause of the universe, then the universe is either eternal or self-created.

2. But, it is cosmologically ridiculous and anti-scientific (i.e. against laws of thermodynamics) to propose that the universe is either eternal or self-created.

3. Therefore, the premise that there is no external cause of the universe must be false (i.e. there must be an external cause for the universe’s existence, e.g. God)”

I believe he is applying the law where it can’t be applied, but I’ve never extensively studied science in college so I’m not really sure.

My rebuttal was that the universe was not necessarily a closed system and he responded with this:

“I have to remind you that my academic background has required me to not only understand, but apply, thermodynamics. [He has an engineering degree.] I know what the 2nd Law of Thermodynamics means and it clearly eliminates the concept of an eternal universe. If there is any misunderstanding on my part, it is in what you mean by ‘the law of the universe.’ Further, whether the universe is a closed system or not is irrelevant, since the concept of a closed system is theoretical, i.e. we have never actually observed a closed system.”

Thanks and I hope you can sort this out for me.

Answer by SmartLX:
Well, it’s not the usual creationist argument that evolution breaks the 2nd Law simply by producing order, so at least it’s a change.

He’s got one thing right, the universe is unlikely to be self-created. We don’t know of anything that is, or even what that would mean if it were true. For an entity to be the reason for its own existence would require an exception to the idea that an effect follows its cause. Rather than call this ridiculous, however, I’d just say that time would have had to behave non-linearly near the beginning. It’s strange to consider, but it hasn’t been ruled out as far as I know.

To set up the next option a bit, an eternal universe would need to be one where multiple Big Bangs happen in sequence. We have to work from the scientific fact of the Big Bang to achieve a plausible eternal model, especially after Borde, Guth and Vilenkin successfully ruled out the leading eternal models that didn’t involve singularities.

Your friend’s thermodynamic objection to an eternal universe is that any process that’s already been running forever should have run down by now, because no process is perfectly efficient. There are at least two scenarios in which this is averted (possibilities only, mind you):
– The singularity that immediately precedes each Big Bang reclaims all of the matter and energy in the universe by bringing space itself back to a central point. This includes all of the “lost” energy that radiates from decaying systems and is normally declared unusable, so in the end nothing is truly lost and the universe really is perfectly efficient.
– Extending upon your friend’s response, not even the universe itself is a closed system. It receives energy from an outside source, such as other universes. If there is an infinite number of these as some have hypothesised, they can keep a universe such as ours going indefinitely. (If one takes “universe” to mean everything that exists, in other words the whole multiverse, then the idea is available that it may contain infinite matter and energy, and never have to run down for this reason instead. It’s all a matter of perspective, and to some extent semantics.)

As an afterword on eternal universes, it’s worth asking your friend exactly how he exempts his eternal God from the 2nd Law of Thermodynamics. I hold it to be true that whatever constraints you place on the universe to necessitate a god, you immediately have to break them to allow for the god, usually by way of special pleading.

Moving on to the third option, it’s telling that your friend’s syllogism uses “e.g.” and not “i.e.” to invoke God. God is an example of an external cause, not the only possible one. The alternative suggested by the above is a concurrent or previous universe, which is part of a great many theories out there. I would love to hear your friend’s reasoning that starts from the external cause at the end of the syllogism and arrives at the Christian God, because at a glance it’s far from a logical step. (The following isn’t a scientific argument, but additional universes seem a more plausible thing to posit than a god because at least we know there’s such a thing as a universe. If your 5-acre cabbage patch has been devoured and you find one fat little rabbit in the corner, you don’t suppose that Bigfoot ate the rest; you wonder where all the other rabbits are hiding.)

Finally, there is a fourth option not covered by the syllogism: that the universe simply came into being without being created, that the common straw-man concept of “something from nothing” actually happened. Something like this is put forward in Lawrence Krauss’ new book A Universe from Nothing; specifically, that the precursor to the universe in certain models could be thought of as “nothing”. Even if you don’t accept this as quite the same thing, it at least advances another alternative external cause to compete with God.

Most of the options are essentially still on the table, despite your friend’s attempt at an argument by elimination. Even the option he wants to be left with doesn’t help the case for God very much, if at all.

The Big Spill?

Question from Jethin:
Space, Time and matter expanding from a tiny spot as formulated in the big bang theory still looks to be confined especially to the question of where and how all the stuff came for the bang. What if the universe that we see is a part of a recycler that create a multiverse and our universe is just one of numerous other universes. A universe like the one we live in could emerge from the tip of a crater of an ultimate system of all creations wherein matter in the form of pure energy is spurted out from a central cauldron holding finite quantum of energy at enormous pressure and temperature. Like a lava flow, energy from this casing could escape through vents in the space-time fabric at higher dimensions, thus creating may be three or multidimensional universes. Studies on CMB radiation and the results therein leading to inflation theory of sudden expansion still call for more observational validations. Could this sudden expansion of our universe be triggered by the super charged energy outflow at tremendous pressure and temperature from an extra dimensional boiler?

What happens to all the matter that fall into a black hole? Spaghettification, singularity, Hawking radiation, black hole evaporation and what more, all such possibilities have been studied but still there is something missing. Should there be a link between singularity and big bang elsewhere; may be a link that is routed through that ultimate crucible of all creations. Like a reservoir, matter in its pure energy form could be encased in such a place from where the distribution starts to create different universes. The feeding source into it could be black holes pulling in materials from their own universes, stripping to its primal form and gushing into the mother pot. Is our universe a part of that energy-matter recycler that has been going on indefinitely?

Answer by SmartLX:
No freaking idea.

There are a great many models for explaining the beginning of the modern universe. Some posit that the Big Bang really was the beginning and some do not make that assumption. Every so often evidence comes to light that rules out one or more models, leaving the rest as candidates for what really happened. What you describe is closer to some of the surviving models than others, and so far I see no obvious reason to rule it out.

The important thing about your hypothesis for the purposes of this site is that it does not require the initiative or the intervention of a deity. It’s been some time since cosmologists turned to God to explain the as yet unexplained, because they’ve had no need. They might resort to God to explain the impossible, but they haven’t come up against that yet.

Eternal inflation? No. Eternal universe? Maybe, nevertheless. And what’s it to ya?

“These three scientists in particular, by virtue of their joint paper, are name-checked more often than any others by apologists not just arguing for an absolute beginning to the universe but claiming that this has been established beyond doubt.”

Question:
Scientists Arvin Borde, Alan Guth and Alexander Vilenkin, in their 2003 paper “Inflationary Spacetimes Are Incomplete in Past Directions”, ruled out past-eternal inflationary models of the universe. Does this prove that
1. the universe had an absolute beginning,
2. that it must have had a cause and
3. that the cause was God?

Answer:
No, no and no.

These three scientists in particular, by virtue of their joint paper, are name-checked more often than any others by apologists not just arguing for an absolute beginning to the universe but claiming that this has been established beyond doubt. Apologists up to and including William Lane Craig do this to support the cosmological argument for God, which requires such a beginning to be indisputable.

So what does the paper actually say? Feel free to read it via the link above (it’s dense but short), but the thrust is in the title: spacetime can’t have been inflating infinitely into the past.

That seems obvious since you’d think you’d eventually reach a singularity if you worked backwards, but models have been proposed wherein the farther back you go the slower the expansion is. Some reasoned that perhaps the universe has spent eternity inflating extremely slowly from a size barely larger than a singularity, speeding up as it went along.

Borde, Guth and Vilenkin examined this idea and found, essentially, that it wouldn’t work in the real world. In doing so they pretty much dismissed every model of an expanding universe (or multiverse) that doesn’t involve a proper singularity and Big Bang. Therefore, according to apologists, the universe definitely had an absolute beginning, which must have had a cause, and that cause was God.

That’s going way too far because, for a start, the paper doesn’t take a position on whether the now-confirmed Big Bang was an absolute beginning. There are many more universe/multiverse models wherein the Big Bang was merely an event in an ongoing sequence – where the matter in the singularity came from somewhere, not nowhere. Borde et al only intended to rule out a family of models that clearly don’t work.

Get that? Borde, Guth and Vilenkin did NOT rule out an eternal universe, even if the result of their paper is correct. They merely ruled out one kind of eternal universe, the kind where the Big Bang never happened. The fact that there was a Big Bang does not mean there was nothing before the Big Bang.

The Big Bang as absolute zero, or an absolute beginning in general, is a poor platform for apologetics in any case. The idea that whatever begins to exist has a cause is not based on anything which physically began to exist in the same way the universe supposedly did, completely ex nihilo (literally “from nothing”). We’ve never seen anything like that happen, so:
1. it’s curious that so many people assume the universe came about in this way,
2. there’s no basis for assigning a cause if it did and
3. even if it had a cause, it’s a huge leap to declare it any kind of god, let alone someone’s specific personal deity.

SmartLX