Is the evolution of the universe deterministic, i.e., is it condemned to follow a predetermined existance, inescapably attached to the initial conditions and laws under which it sprang into life?
The way I see it, the present, past and future orbits of every massive object residing within the confines of the universe are not determined by mere chance but instead by the initial conditions that govern the birth and posterior evolution of the cosmos.
Clarifying a bit, what defines the configuration of the universe are (as far as I can tell): the initial explosive force of the big bang, the four elementary forces which regulate the interaction between particles and the basic constants of the universe, i.e., the universal gravitation constant, Planck’s constant, etc.
If, after all those factors have been set, you let the universe be born into existence and come back around to check how it turned out, say 15 billion years into the future, you would obtain the same panorama as you see now. If the experiment is repeated n number of times while maintaining the same set of rules and initial conditions you would arrive at the same scenario.
Therefore, as long as you exclude the existence of conscious beings who could eventually used their technological prowess to reshape the universe in a minor scale, the evolution of the cosmos is deterministic and not stochastic; thus luck or chance couldn’t be responsible for the structure of the universe and the orbital interactions within it
Only the entity who, based on its arbitrary judgment, designed the rules for cosmology, orbital mechanics and the such, could claim to be responsible for what you see and interpret now as the cosmos.
As far as we pitiful humans have been able to determine? No, it is not. Our current understanding of quantum dynamics says that impossible things are constantly occurring. The only constraint is that the more impossible things happen less often, and for a shorter duration, than the less impossible things.
As I implied above, by our knowledge of the way the universe works, it would be very, very improbable for the exact same script to be followed a second time around, given the exact same starting conditions. World-altering events constantly happen, for no reason that we can measure. Some times the random events wind up cancelling each other out, other times they cascade into macroscopic events that would be impossible were there not some outside unmeasurable influence.
I agree with Pun, if the universe were to begin anew there’s no way it would be as we observe it today. This is a one way, one of a kind ride, into…who knows, it’s beyond my imagination. On a smaller scale, if life on Earth were to restart, would we be here to witness it a second time? No way! Life would exist, but humans would not set foot on the planet. Sorry for the “jack move”.
I agree with Punoqllads on the “as far as we know” point.
I doubt we could ever predict the behavior of the entire universe, but that doesn’t mean that things wouldn’t happen the same way given the same initial conditions either.
We just don’t know.
I really don’t think we’re any position to say whether it’s likely or not. It’s true that given the tiniest variation things would change radically, but if there was no deviation even to the slightest degree, how would we know if things would be different?
Yes… I think this could easily be nominated as a Great Debate. I tend to lean to the non-deterministic side, since as far as I can understand (not very far) quantum mechanics, the processes that are most fundemental to the universe are themselves non-deterministic.
I think it has to do with randomness. If there are things that are truly random in this Universe, then things would happen differently. But, if there is no randomness, things would turn out exactly the same way. Which would mean we have no “free will”, rather we would do the same thing in the EXACT same circumstances if given the chance.
Think of the things you consider random. The roll of a dice, the flip of a coin, both are determined by how your throw them, the air around them, etc. Do quanta or other minute matter act randomly, or is there something deeper inside, determining the so-called “random” events?
The problem is that randomism and determinism are not as easy to distinguish as you might think. If you have a balloon filled with air, you can assume that the pressure is the result of random motion of the air particles. Yet the balloon does not assume a random shape. The pressure, volume and temperature vary in a deterministic way. OTOH, if you assume determinism: Take a particle bouncing back and forth some distance s. There is always some uncertainty in the measurement of velocity no matter how accurate the measurement. If the uncertainty in velocity is dV, then after a time of s/dV, the particle’s location is random.
Even ignoring quantum randomness (claiming there is an underlying order behind it, or whatever). How on earth could any being, omnipotent or otherwise, successfully observe that the universe was running the same script without changing it, even a tiny bit? And any change could easily cascade through the system, multiplied a billion billion times over the lifespan of the universe.
So, trying to make a “hole” from another dimension outside space-time into this universe to observe it would require allowing energy/matter to escape, or gravitational energy? Expansion of the unvierse through the hole? Anyway I’m getting silly, but it just seems that even a wind-up clockwork universe would be a tad difficult to prove any deterministic theories on.
Hope you don’t mind a few possibly dumb questions.
Does it make a difference whether you are talking about a universe that is a closed system? Can a universe be a closed system and still be infinite?
As posted by quasar:
I can kind of see this, and it seems to me to sort of tie in with the theory (?) that the sun will eventually be cold, and life on this planet as we know it will no longer be sustainable.
As for a being that might have created this universe, why would it had to have left the system?
The question is actually unanswerable. We can say that, due to quantum uncertainties, that two indistinguishable systems will not necessarily evolve in the same way. Are those two systems truely identical? We don’t know, and we can’t know. If they are identical, then there must be such a thing as random chance, causing the differences. On the other hand, if there are undetectable differences between the two initial systems, then we can say that it is due to those differences that the subsequent evolution differed, and the Universe can be deterministic. This is best summed up in a quote by Einstein, often taken out of context: “God is subtle, but not malicious. He often deals the cards where they cannot be seen, but I cannot believe that He plays dice with the world.” (emphasis mine, on the portion that’s often neglected). In other words, QM can be explained by assuming “cards dealt where they cannot be seen”, without assuming random events (“dice”). I personally share Einstein’s view, although to retierate, this cannot be proven either way, and is thus really more philosophy than science.
By the way, quasar, including sentient beings capable of altering the evolution of the Universe doesn’t change anything. We’re governed by the same laws as the rest of the Universe; if the Universe is deterministic, then so are we.
Spider Woman, what do you mean by “closed system”? In physics, that term means that it cannot interact with anything outside the system, but there is nothing outside the Universe, so the term isn’t really meaningful.
Actually, in the next phase of its evolution, the sun will become a red giant, growing in size and engulfing our planet. Expect that in about 4 or 5 billion years or so. Way before that, the heat produced by its expansion will be so intense as to make life on earth unbearable. We poor humans, if still alive and kicking, will have to migrate to outer space to seek refuge from the destructive impulses of our parent star.
Regarding God’s existence within the universe, I started a thread called “Is God dark matter?” It deals with God being potentially part of the dark matter that produces measurable gravitational perturbations upon the universe but cannot be seen, hence inviting speculation about it’s nature (black hole, neutrino, brown dwarf, God?).
Does that mean that the laws of physics predict your actions? Can your destiny be unraveled by an equation?
I can use Newton’s equations to predict the next solar eclipse, but there doesn’t exist an equation which would allow me to predict your next post. Conscious thought, and the actions which it motivates, are subject but not determined by the basic laws of the universe.
The point I was trying to make in my initial post concerns the breakdown of predictability at the moment when consciousness was born. At that point, rational beings started exerting their influence on their surroundings by means of planned actions, actions which could not have been extrapolated from the initial conditions that characterized the universe’s birth or by the laws that guided its evolution.
Therefore, the proposed determinism of the universe would cease to manifest itself at the genesis of consciousness.
I disagree. I think it is meaningful. Do the laws that govern a closed system apply to the universe? Entropy increases in a closed system. Does this apply to the universe? Yes, it does.
At what point? When life begins? When life evolved to the intelligence of a dog? When man arrived on the scene? Everything in the universe is governed by its laws. Either the universe is determinist or it is not. It cannnot change somewhere along the way.
I agree, Dr. Matrix. If the universe is deterministic, so are we and our thoughts and actions. This is because our brains are made of the same matter as the rest of the universe.
It is a mistake to conclude from this that we don’t possess free will. “Compatibilism” is a very old philosophical idea that says that free will and determinism are not incompatible concepts. Not that much is written about compatibilism anymore because most philsophers accept it in one form or another and pretty much think it is obvious. According to compatibilism, our freedom consists in being free to choose one action or another. We are not constrained in our action from without. But this does not mean that our actions are uncaused. In fact, argues the compatibilist, we could hardly said to be acting freely if our actions were uncaused, since we would not be the cause of our own actions – they would be the product of random forces. Our freedom lies in determinism being true at least to some extent.
Back to what I said in the first paragraph above: that determinism applies to us because we are made up of the same matter that makes up the rest of the universe. I suppose one could argue that we may have souls that are immaterial substances that are not governed by the same rules as the matter in the universe. I cannot refute this. It is conceivable that ordinary matter might be deterministic and our souls indeterministic. We may have a “mixed universe.” But I think much of the motivation for positing the existence of the soul dissolves once we take compatibilism seriously, i.e. once we see that determinism, rather than indeterminism, is necessary for freedom. The soul would have deterministic as well for us to have freedom. The point of positing the soul as an entity in the first place was to explain how we could be free in a determinsitic (or near deterministic) world, but it is just a philosophical fallacy to think that we needed anything besides determinism to do so. Once we see this, the soul becomes superfluous.
Quasar: You state that “Conscious thought, and the actions that it motivates, are subject to but not determined by the basic law of the universe.” What does it mean to be “subject” to a natural law as opposed to being determined by it? Are you referring to indeterministic or probabilistic laws in contrast to other laws of nature?
From what I understand, Dr. Matrix did not say s/he believes that the universe is deterministic, which your post seems to imply. I understood him/her to say it is either one way or the other; it can’t be both.
I did not mean to imply that the universe is deterministic not that Dr. Matrix believes it to be deterministic. Rather, I stated that we humans are deterministic IF indeed the rest of the non-human universe is, in agreement with Dr. Matrix. I did not take any position of the matter as to whether the universe is or is not determinsitic.
I argued that since our brains are made of ordinary matter, it follows that our brains would be deterministic if the matter of which they are made is deterninistic.
It then occurred to me that some people might believe in the soul, a different substance from ordinary matter. My point would be lost on these people, since they would argue that it doesn’t make any difference what our brains are made of. It think Quasar was movng in this direction (without actually saying the word “Soul”) by saying that consciousness was not subject to the laws of the universe.
So to counter the motivation for making this point about the soul, I made mention of compatibilism. Compatibilism does not disporve existence of the soul or come down for or against determinism. It simply gives us less motivation for seeking indeterminism in the universe in one form or another – such as in the form of the soul.
I do not know whether the universe is deterministic. Compatibilism requires some level of determinism, meaning that it does not equire determinism to be true at all as long as we have a universe that is deterministic-like on the the macro level. If my behavior was as randon as a quantum particle, I could hardly said to be acting as a purposeful agent.