### Why does the universe obey scientific laws?

• As far as anyone is aware, the universe consistently acts according to predictable laws (and scientific inquiry exists to determine those laws). Is there any metaphysical reason for this? Is such a question even answerable?

EDIT: I think my question was misunderstood, so I'll try to clarify. I know about the mathematics question, but this question is, why is the universe consistent? It's related to the problem of induction: just because all hitherto observed emeralds are green doesn't necessarily mean that all emeralds are green. Yet, those who have hypothesized that emeralds are green have (thus far) been found to be correct. In other words, as far as anyone can tell, the universe is consistent to the point where much of its behavior is predictable using known laws and statistics. Is there any philosophical discussion regarding why that appears to be the case?

FURTHER EDIT: The question is more fundamental than the simple, 'why are all emeralds green', to which the answer is obviously, 'because if it wasn't green, we wouldn't call it an emerald', and once I formulate the question better, I think that the answer becomes obvious. Let's use an actual law, F=ma. We've checked rocks, we've checked feathers; we've checked slow moving objects and fast moving objects, and yet, lo and behold, the law always seems to be true, and it's stayed true for at least a few hundred years (but we can reasonably assume that it was just as true a millennium ago). Now, I ask the metaphysical (in the most literal sense) question: why is this law always true? Why does the universe behave so consistently?

I suggest replacing 'scientific laws' with 'mathematical constructs'. That is, reality seems to be fundamentally _mathematical_. Lots of discussion has been had about this observation!

Because scientists rules B| ( Just a joke C: )

Uhm... We have defined the laws based on the universe's behavior, so of course they're consistent with it and it's consistent with them. In the places where we suspect the two diverge, research continues in an effort to refine the models to the point where they are consistent; in the places where two models agree with the universe but not each other, research continues to try to find ways to further test them and distinguish which model works better. That's inherent in rational thought, not just in science...

Physics has it that what we see as the 'universe' was once very small and expanded to what we now observe. Hence, whatever laws were present in that small region region of the multi-verse apply through the visible universe. I think this relates to the "consistency" part of the question. Some believe that other parts of the multi-verse obey different "laws". However, whilst those laws might differ vastly from the Standard Model, most would make a tacit assumption that the general principles would still stand. This is turn is because we don't know how to describe a universe without such laws.

What is the alternative?

It depends on what you think of as consistent and how far you're willing to go. The speed of light could be easily said not to be consistent, according to my intuition at least (special relativity). The shape of spacetime isn't consistent, in the same way (general relativity). The nature of an electron as a particle or a wave isn't consistent either, unless you take into consideration the rather weird variable of whether it's being observed (quantum mechanics). But we have managed to take this inconsistency and factor it into our formulas, which makes these things seem consistent again.

It's not that universe obeys, it's just that the "scientific laws" are constructed so that they suit the way the universe is.

It's related to a point that has already been made in some comments and answers but the terminology is loaded to the point of being very misleading. The universe does not *obey* scientific *laws* in the way humans obey laws.

You might find this text from Heidegger interesting: http://www.dhspriory.org/kenny/PhilTexts/Heidegger/ModernScienceMetaphysics.pdf

This is a awesome question! Unfortunately any answer does not provide a proper explanation. We need to ask this somewhwre else.

I don't 'rate' giving an answer so I'll comment. My physics teacher once said there is nothing to say gravity won't stop tomorrow. That has stuck with me for decades and I think illustrates what you are asking. My perspective for this philosophical question is, since we are still in the process of discovering what the laws currently are, we really don't have any idea if what we perceive as stable actually is. Currently things appear stable but we might discover something that changes our perspective. It is worth noting though that small changes to basic constants could obliterate the universe.

The universe doesn't obey anything; it just is. The question is, why does the universe behave in a way that can be described by relatively simple equations.

`It's related to the problem of induction: just because all hitherto observed emeralds emerald is green doesn't necessarily mean that all emeralds are green.` If the gem is not green, then it does not fit the definition of emerald. Thus all emeralds are green, no exception. I do not study philosophy, but from engineering POV it makes sense...

@jnovacho same sentiment here. Also, when there are "exceptions" to physical law, then the law is adapted - we don't see this as the universe misbehaving. For example, the recent proposal that the speed of light might not be what we though, based of neutrino observations from a supernova. Nobody would suggest that this constitutes to the universe not obeying laws.

It's because the universe police are a bunch of time-travelling mad monks with lightsabers. The universe has to obey the law, or it'll have to deal with those crazy fools and nobody wants that. That or the definition of the term "law" when used to _describe_ how something acts differs from the definition of the term "law" when used to _define_ how something _should_ act. http://www.oxforddictionaries.com/definition/english/law My money's on the mad monks.

I can't add this as answer so it's going here: It's not the universe that obeys laws of physics. It's the laws of physics that created the universe as we know it. The universe is mere outcome of these laws. Even if they are not consistent, we are the result of local bubble of conditions we call "consistency".

Scientific rules are invented by humans to quantize and classify events that occur in the universe, and if the universe disobeays science, the science is revised. Furthermore, many philosophical questions regarding universes, and our own, can be rephrased as... Why do durable timespans in which intelligent life evolve that can question the nature of the durable timespan, exist? in other words, only a universe with relative stability over time can provoke your question, and that you could only ask that question in a stable universe, where things bareley ever change from a routine of laws.

There are some serious looking investigations into the hypothesis that our universe is a numerical simulation, which would explain why it's logical, lol. In all seriousness, your question implies there could be a universe which *does not* follow rational laws -- but in what sense is such a conception "a universe"? IMO it sounds more like a **semantic chimera**, sort of like the idea that "there could be *nothing* instead of something" (an inappropriate **reification)** of the word "nothing").

It's really quite simple - scientific laws have nothing to do with legal laws. There's no question of obeying or disobeying, or finding loopholes. The universe seems to behave in a consistent manner? We can build our understanding of the facts around that. It doesn't? Well, we'll build it around that then. However, given that it's hard to imagine a universe that behaves significantly inconsistently, and yet hosts intelligent life, we can also invoke the anthropic principle - universes not consistent enough wouldn't be fit for life as we know it and you wouldn't be asking this question :)

If the universe did not conform to any laws, then we couldn't exist to observe these laws.

I'm really curious as to how in the world this question became the top question of the month. It's not really based on anything in philosophy, and it seems like nothing more than 'why is the world the way it is'. Any upvoters have any insight as to why this question became so popular? It would help me know what kinds of questions to ask here in the future

If our universe were "totally upside-down everywhere", then... there will be laws for that, just even more complicated then ours. But where is the threshold between "complicated but still predictible", and "no more"? All science is about this: if it exists, it *can* be figured out (even if not feasible). So there is no graduation at all: either it's predictible, or not. Finally, imagine a universe where *nothing* is predictible. Welcome to Hell.

@Matt, I believe this question is so popular because it is very much a worldview question since observational science does not tell us **why** the world is consistent, but merely tries to understand and explain its mechanisms in a consistent, categorized manner, thereby assuming it is consistent.

I think that the answer is that Newton's second law of motion (for example) is used to describe what we observe, but if we'd observe inconsistencies, we'd use different laws for different situations. In our example, if the object is moving so quickly that it approaches the speed of light, Newton isn't enough; we need special relativity. The question of the universe's consistency is therefore quantitative, a question of degree: why is the universe *as consistent as it is*? The right response, I think, is the anthropic principle: a less ordered universe wouldn't provide anyone to ask it anything

i feel that it's a pseudo question, but not obviously so

• Bobson Correct answer

7 years ago

I like immortal squish's answer, but I'm going to take it a step further.

Physics (and other science) as we know it is a way to describe how the universe behaves. If gravity worked in reverse, but it was consistent about it, that would be the physics. It's perfectly valid to say that the universe has a set of physics, for example. A different universe could have a different physics - at least in theory.*

However, that doesn't say anything as to why the universe has a consistent set of physics in the first place. The answer to that is that we don't know if it does. We only know what the physics in the area we're able to explore. Light could travel in spirals before it gets within the "bubble" of physics as we know it, where it begins traveling in a straight line. However, there is no evidence for this, nor can there be, by definition - everything in our area behaves consistently, according to the one set of physics.

If physics weren't consistent from moment to moment, at least in our local area, then it's highly unlikely anything even remotely resembling intelligent life as we understand it would have been able to emerge. If gravity started varying in how quickly it falls off, or the nuclear force equations changed, or suddenly there were one fewer type of quark, then everything would fly apart, or crush together, or annihilate itself, or so on. That is not to say that there can't be other physics - just that what we do have has to be consistent.

* Side note: This theory is a big part of how many science-fiction stories get around the apparent restriction on FTL travel - the traveler dips into other universes where the physics allows for it, or pulls some of it here, or otherwise goes "around" physics with other universes/dimensions/etc.

Just to edit in some of the things I've been saying in comments:

Is this just the anthropic principle? Sortof, in a much more general form than it's usually used. We can conceive of intelligence in a different universe with radically different physics. That isn't to say we can describe how consciousness could exist in a universe where gravity fell off twice as fast or one where atoms didn't hold together into molecules, but we can conceive that that awareness could exist. (See Boltzmann brains, for example).

What was that about life evolving? I've corrected it to "emerge". I didn't intend to invoke evolution. Spontaneously generated intelligence (such as the aforementioned brains) would count as "emerging", but definitely not "evolving".

Why couldn't we conceive of such an intelligence? Mostly, because of the lack of the ability to convey information. If fundamental particles (whether or not they're the same fundamental particles we have) don't behave in consistent manners, then there's no way to know anything about them or any larger structures based on them. We see color because of the wavelengths associated with a photon. If that photon suddenly became a proton, it would no longer convey that information. And without the ability to receive information from the environment, there's no way to observe (in the quantum sense) anything. And intelligent life that is unable to observe is incomprehensible to us.

+1 from me. It's the second paragraph that addresses what I was actually asking about; sorry if I was unclear. But as noted, even if we can't actually prove anything learned by induction (and so yes, it could in fact be that the universe isn't consistent) it has been so far (as far as we can tell). Just to clarify then, is the final answer an appeal to the anthropic principle? (In that in any universe, or any part of our own universe, only in systems that adhere to consistency support the beings that would question it)

@Matt - A **very** generalized form, yes. Basically, "Without consistency, it's impossible to have *anything* that we would recognize." We can conceive of a universe with different physics and what those physics may imply for how things work, but we can't conceive of how inconsistent physics would work, let alone an intelligent being that can survive said inconsistent physics.

One funny way a science fiction show called Futurama gets around the speed of light issue is that the ship doesn't physically move - the universe moves around it. Of course, this is the speed of light *after* it's been raised somehow hundreds of years in the future. Don't ask how those 2 sentences can describe the same universe.

I have a little bit of heartburn here. We recently validated the shape of the universe, so we *know* that light doesn't twist in spirals--we live in a flat universe.

@avgvstvs - No, we know that **based on what we can see** it doesn't twist. The whole point is that if *physics* were different beyond a certain area, then after crossing over the transition into our area, everything would behave exactly as expected, because it's now obeying known physics. ----- For the record, Occam's Razor is a valid argument against this being the case, but it's not proof of any sort.

I'm not sure I see why "Without consistency, it's impossible to have anything that we would recognize." It's pretty easy to conceive of an inconsistent universe where Boltzmann brains pop into existence, experience their surroundings as we experience ours for a period of time, and then morph into PBJ sandwiches. In such a case, "would have been able to evolve" is not a requirement. Without the 'given' of a consistent universe, how can we even say such a thing is unlikely?

@LarsH - Define "experience their surroundings" in a way in which there is no consistency. Photons are just as likely to travel slowly as they are to travel "at the speed of light". The same photon can randomly switch back and forth between any given speed and whether it's even a photon and not a free electron or some particle which doesn't even exist in our universe's physics. There is no way *I* can conceive of to gather any form of information from such an environment, and if you can't gather information, then observation is impossible.

*If physics weren't consistent from moment to moment, at least in our local area, then it's highly unlikely anything even remotely resembling intelligent life as we understand it would have been able to evolve.* This is circular reasoning. You invoke evolution as part of your explanation, but evolution is a scientific theory, and the question is why the universe obeys scientific laws. As a counterexample, it's easy to imagine a universe that contains intelligent life, that doesn't obey any scientific laws, and that is run according to the will of a god.

I think people may be misunderstanding... "it's highly unlikely anything even remotely resembling intelligent life **as we understand it** would have been able to evolve" (emphasis mine). I think that to say that intelligent life is impossible if the universal laws were inconsistent is presumptuous. We have no idea whether or not intelligence may arise. The only thing that we can be fairly sure of, is that it will be nothing like us. But that would also be true for any other life in *this* universe.

@BenCrowell - Yes, I keep meaning to edit it to remove that particular reference. I was using it in the sense of "emerge" without specifically meaning it in the "survival of the fittest" sense.

@Benjam - It's more a question of *information*. How can a being in a universe with inconsistent physics observe anything, when there can't be any information conveyed? After all, if photons spontaneously convert into electrons moving at right angles, you lose whatever information about color the photon had.

I've updated the answer to incorporate some of what I've been saying in these comments.

@Bobson, a universe does not have to be anywhere near as chaotic as you describe in order to be inconsistent. It could appear to be consistent most of the time, with occasional anomalies. In our universe, we have imperfectly predictable observational powers, yet this doesn't prevent us from experiencing. It just means that our experiences aren't always a perfect guide to reality. Nevertheless we get by pretty well, I think.

@LarsH - I would classify "consistent most of the time, with occasional anomalies" as a consistent set of physics, where the occasional anomalies are part of that set. Whether they're *explicable* doesn't really matter, but if they're consistently anomalous, then that's still consistent.

@Bobson: maybe you understood 'anomaly' in a different way than I meant. I meant, events that are not merely unusual, but don't obey the laws of physics. As such, it's not possible, by definition, for occasional anomalies to be part of a consistent set of physics.

@LarsH - You might need to define the scale of anomaly you're talking about. If a universe is 90% consistent, that still means that 10% of the information received at a later point will be corrupted. But it will *consistently* be 10% (or 10% per period of time). If a universe is *entirely* consistent, except for occasional anomalies, then the anomalies can be ignored. It's only when the "noise" of the anomalies start drowning out the information carried on the "signal" of physics that they are problematic. Effectively, either the universe can reliably transmit information or it can't.