I think everyone would agree that before they were thought of in anyone's philosophy, the Universe existed. You'd agree that the Universe existed before humans existed, unless you're one of those fundamentalists who interpret the Book of Genesis literally, and even then there were a few days for the Universe to enjoy a pre-human existence. If you're not one of those extreme right wing all-things-literal Christians, then you'd go along with the Universe existing before life, any kind of life, arose on Terra Firma (or anywhere else in the cosmos for that matter ). You'd also have to go along with the notion that the Universe existed before the Earth (and therefore the Sun and solar system) existed, since the parent (the Universe) has to exist before the offspring (Earth, Sun and solar system) . In fact, to bring this string to its logical conclusion, the Universe existed even before our home parent galaxy, the Milky Way existed.
The origin of our Universe via that Big Bang event was roughly 13.7 billion years ago. Our own galaxy did not come into its own until three plus billion years post Big Bang. Planet Earth (plus Sun and solar system) came about some 4.5 billion years ago; the first stirrings of what we'd call life happened on Earth within a half a billion years of Earth's origin event. If you want to equate life in the Universe with life on Earth (terrestrial biology is the proverbial IT), then the Universe has been lifeless for the first 9.7 billion years of its existence.
Our Universe is bio-friendly otherwise we wouldn't be here to discuss the issue. That's often termed the Weak Anthropic Principle. A bio-friendly Universe is a Goldilocks Universe, albeit a dangerous Goldilocks Universe with lots of places that are too hot or too cold or otherwise not quite right and not quite bio-friendly. But, any port in a storm.
But before life was thought of in anyone's (not that there was anyone) philosophy, we're certain that:
* Chemistry still happened.
* Stars still shined and photons still did their photon thing.
* Gravity still grabbed; Black Holes still formed.
* Radioactivity decay still proceeded.
* Neutrinos still whizzed their merry way along the cosmic byways and pathways.
* Electrons still quantum hopped from orbit to orbit giving off and absorbing energy.
* Quarks still carried on their threesome relationships inside protons and neutrons.
Okay, there clearly was a time when the cosmos was lifeless and the above were cosmic truisms. There clearly might come such a time again if Planet Earth is the proverbial IT when it comes to the life part of "life, the Universe and everything". Humans aren't immortal; Planet Earth isn't immortal, and as I said earlier, the Universe can be a dangerous place. Perhaps humans don't even need assistance from the Universe at large to bring about their extinction and the extinction of all life on Earth. If life on Earth goes kaput, then:
* Hurricanes, tornadoes, thunderstorms, blizzards, floods and droughts will still happen on Terra Firma.
* Volcanic eruptions, earthquakes, avalanches, Ice Ages, tsunamis, meteor impacts, erosion, mountain building, and continental drift will still happen on Terra Firma.
* The tides will still ebb and flow; the Moon still waxes and wanes.
Now the $ 64,000 question is why is a lifeless Universe of any interest whatsoever? The answer is "determ", or in the case of a lifeless Universe, "no judge".
Many, especially the religious, think the Universe had a purpose, and that was to be fruitful and produce life, intelligence and consciousness, a way of the Universe being able to contemplate its own navel. That's often termed the Strong Anthropic Principle. Most scientists give that the thumbs down on the grounds that the Universe just is. The Universe doesn't have a consciousness, or a deity controlling it, and therefore the cosmos can't have a purpose to its existence, nor a ways and means that it can consciously direct itself toward such a goal.
However, many quantum physicists suggest that the Universe cannot have achieved a reality until such time as determ (life) appeared to give the Universe reality. That's often termed the Copenhagen Interpretation of quantum mechanics. The idea is that all possible realities exist in a state of superposition and only one becomes reality when someone actually observes and forces the numerous possibilities down to one certainty. All possible realities are grouped together and termed the probability wave-function or wave of probability. When crunch-comes-crunch and someone peeks, Mother Nature is forced to make a decision, the wave-function collapses and one and only one certainty results.
Until life appeared then, the Universe was in a superposition of all possible realities, a wave-function that was a composite of all possibilities. That first observer hence collapsed the wave-function of near infinite possibilities down to one reality. Or is that just so much bovine fertilizer?
Now between the time of the creation, that Big Bang event some 13.7 billion years ago, and the time of that first observer arising, the cosmos expanded and evolved. Stars formed, solar systems formed, galaxies formed, and so on. Now all that suggests that there was one reality, one chain of events, and a causality that was universal – the Universe was not in a composite of all possible states of reality even while no life existed. It's silly to think that that first first proto-cell billions of years ago determined the single structure or reality of the Universe we see around us today. For challenge to have come into being, the Universe had to have already been in a state of being. Therefore, the Copenhagen Interpretation of all things quantum is utter nonsense.
So, does the Universe exist even if nobody is looking? Yes! Did the Universe exist even when there was nobody to look? Yes! Are rig relevant? No!
Having settled the observer question, let's move on to the next phase.
In a universe without life, it's probably pretty meaningless to talk about concepts like free will. Then there's that whole sackful of concepts related to good-and-evil like morals, ethics, sin, badness, righteousness, etc. and as such there's no need for the concepts of heaven or hell. As such, scratch salvation, redemption, forgiveness, or damnation.
There are no emotions, suffering, pain, sorrow, pleasure, consciousness, or psychology. There's obviously no disease.
There's another bagful of concepts like the afterlife, reincarnation or resurrection that can go by the boards. Speaking of the latter, there's no such thing in a lifeless universe as miracles. There is no such concept required like survival of the fittest; There are no wars, no death, and certainly no taxes! There were no soft science concepts around like society, culture, education (no homework), politics and government (no politicians), no economics (no bills), no religion (no thou shalt nots), no philosophy (who needs angels and pins ), history (all those names, dates and places) and no environmental issues that needed addressing. There was no beauty (and no ugly either). In short, that pre-life era – that was what is known as the really good old days!
There's one other important contrast between a lifeless universe and the universe that, in this case specifically contains and singles out humans and human concepts, and that is probability.
Probability or uncertainty (two sides; same coin) dominates our existence. What odds my next child will be a female? What odds the next time I fly the plane will crash? What odds I win the lottery this week? What's the probability I will be promoted this year? What's the probability that I am normal, being of average height, weight, age, etc.? Even in science as performed by humans, probability or uncertainty dominates. Every measurement has error bars. Every forecast has some degree of uncertainty. Even the Sun rising tomorrow is not absolutely guaranteed (though I wouldn't lose any sleep over that unlikely event). Every theory can ultimately be found to be wrong or incomplete. And just where is that damn electron anyway?
The fundamental question is, is probability an intrinsic property of Mother Nature like mass and gravity, or is it a human invention; a human concept? IMHO, there are no error bars in Mother Nature's reality. Mother Nature knows the temperature is this, not around this but within this range. Mother Nature notes it will rain tomorrow, not just a chance of showers. Mother Nature knows that the Sun will rise tomorrow even though it will go nova the day after that. Mother Nature knew that Einstein's theory of gravity was more precise than Newton's theory of gravity millennia before Newton or Einstein was conceived of in anyone philosophy. And Mother Nature knows exactly where that damn electron is because the electron is.
Any observer, via instrumentation or via the five senses, usually has to interpret what that observation actually represents – it's not always obvious. If it was, science would have connected its work decades ago, or just be engaged in refining things from the tenth to the twelfth decimal place. Interpretation – the choice between two or more possibilities – well that's weighing probabilities.
* We've all observed a cat rubbing its head along an object. What's the probability the cat is putting its scent on the object or the probability does it have an itch to scratch?
* We might have observed a boat passing away from us and disappearing over the horizon. Is this because the Earth is probably round or did the boat probably sink?
* In quantum physics, observations suggest a wave-particle duality. But is it more likely a wave or is it more likely a particle?
* Is that unusual light in the sky probably an alien spaceship or is it probably a weather balloon?
* Does viewing a sunrise suggest t you that the Sun probably goes around the Earth or that the Earth probably is rotating around its axis?
* You spot that tornado on the horizon – maybe it will miss you or maybe it won. What are the odds? It certainly can't both hit you and miss you at the same time and place.
* Is Pluto probably a real planet or isn't it (and does it even cosmically matter)?
* My friend has a cold. I have a cold. Did I probably catch his or did he probably catch mine or was there probably something contagious in the meal we shared several nights ago?
* That Sasquatch I saw. Was it probably too much to drink or was it likely real and if it was real was it probably a bear or was it probably an unknown primate?
* Did the apple fall to earth because it's probably seeking its natural place or was it probably due to an external force called gravity?
* Is Schrodinger's cat probably dead or probably alive? It can't be both simultaneously despite what quantum physics suggest.
* Why is the night sky dark? Is it probably because the Sun's not shining in the sky at night or probably because the Universe is expanding or probably because there's only a finite number of stars and galaxies giving off light.
* Why did the chicken cross the road this morning? You may not know (though you can probably come up with a half-dozen possibilities) but the chicken probably does.
There is little doubt in my mind that to all of these probably observations there is but one answer (s). In many cases we've sussed out the answer (s). We don't have the answer (s) in all the cases. I say answer (s) because there can be more than one answer acting jointly, like there really was a Sasquatch and yes, you were also really, really drunk; yes the Earth is round, but yes, the boat sank as well. But its an either / or certainty of an explanation (s), not a bit of both ways by sometimes probably having your cake and sometimes probably eating it too, probability, as in sometimes the apple falls to earth because it is seeking its natural place and sometimes it falls to earth because of gravity; or that Pluto is a planet on odd days or in months containing an "R" and not a planet on even days or non- "R" months; or sometimes the night sky is dark because the Sun isn't in the sky, but at other times the night sky is dark because the Universe is expanding and at yet even on other occasions its only dark because there only a finite number of stars and galaxies.
The bottom line is that the Universe isn't governed by probability. Given identical sets of circumstances or conditions, the outcomes remain the same. Observers and observations are irrelevant. That's made crystal clear during all those millennia the universe was observer-free.