[jfaucett]

Yes. For me the greatest remaining mysteries are more in this order.

1. Nature of Life (we are still nowhere near understanding how it arose or how living organisms work in all their intricate detail).

2. Nature of Consciousness - what is consciousness, how can living matter instantiate it, how can we quantify it, etc?

3. Origin of the Universe

4. Why do we seem so alone in the Universe?

5. Resolving Quantum Mechanics / Gravity

6. Understanding Time

[whatshisface]

I would bump the origin of the universe to the top, because no matter what universe-generating physics you come up with I can always ask, "but what set things up to work that way?" I'd also put consciousness up there, because it's fundamentally distinct from measurable things. Consciousness and the origin of the universe get place 0, and the others all get place 1 because they're solvable but we don't know in which order.

[andrepd]

I very much share that sentiment, in that I rate "the nature of consciousness" and "why does the universe, why does anything at all even exist" as fundamental questions of a completely different class, perhaps even unsolvable.

[pmoriarty]

"I would bump the origin of the universe to the top, because no matter what universe-generating physics you come up with I can always ask, "but what set things up to work that way?""

Except that it might not be possible to get outside of consciousness to have any testable way of explaining what set it up to be that way.

It seems that we are hard-limited by our consciousness, and have no way of going outside of it to peek at "the universe" beyond.

[redial]

> I'd also put consciousness up there, because it's fundamentally distinct from measurable things.

No one knows that it is not measurable. Is love measurable? is hunger? happiness? they seem to be as measurable as consciousness, that is to say we can at least measure them in binary as either present or not.

[andrepd]

How do you know everyone else is not a "p-zombie", indistinguishable in any external way from a human such as yourself, but devoid of internal "consciousness"/"subjective experience". Even the mere logical possibility of p-zombies indicates that consciousness is unmeasurable.

[redial]

Solipsism is basically the only defense against the conclusions from the evidence of the "real" world. But if you argue for solipsism then I say you have much bigger problems than consciousness because you basically rejected everything that has ever been "known" or experienced. If you reject our "shared reality" then anything is possible, including paradoxically, the "shared reality".

If you accept the shared reality on the other hand, consciousness is measurable to some degree. So the real question is do you or do you not accept we share experiences?

As an addendum, if it is all up to me as you suggested, I just made consciousness measurable so there is no need to keep arguing about it.

[pmoriarty]

"Solipsism is basically the only defense against the conclusions from the evidence of the "real" world."

Far from it. There could very well be an external world, and one populated by plenty of other and fully real human beings even, but your own personal view or understanding of it could be distorted or false.

This could be simply because you're hallucinating, or insane, or your brain could be injured, or could be living in a virtual reality (which itself exists in some other "real" reality), or you could be the proverbial brain in a vat, or aliens (or god or a demon/devil) could be deceiving you, etc.

[redial]

All those options are the same: they are either part of a shared experience or they are not. Nothing is preventing a demon from deceiving me right now, in fact one can come anytime I'd love to meet him, preferably her.

[pmoriarty]

"Nature of Life (we are still nowhere near understanding how it arose or how living organisms work in all their intricate detail)."

Not only that, but do you have an existence before you are born?

This might be a religious question to some, or perhaps involve a religious answer, but religion need not be involved. It's possible that in some not yet understood way an individual might exist before they're born and are somehow incarnated or embodied in to matter or the world as we know it when they're born.

Sure, it might sound kooky or something that science might never be able to answer (or maybe it could, who knows?). But the point is that that's all part of the mystery of life, and the answer could be a metaphysical or ontological one, not necessarily a religious one.

Another question regarding the nature of life is what exactly does it take to go from a non-living substance to a living one. In some way this is a question of definitions (which is difficult enough and controversial enough on its own), but even given an agreed-upon definition of life, it might not be clear how exactly the process from non-living to living take place, or at which point the non-living becomes living.

[md224]

It says a lot that you felt the need to hedge against the assumption that you were talking about religious beliefs. These days it seems like there’s a materialist mindset that assumes anyone who questions certain assumptions about consciousness (e.g. that it is a creation of the brain that begins and ends when the brain does) has ventured into the terrain of religion, the supernatural, or “magic” (whatever that’s supposed to mean). It doesn’t seem to occur to people that consciousness itself is completely inexplicable and therefore all bets are off regarding its true nature. These assumptions people have are based on faith (yes, faith) in a hypothetical explanation that has yet to materialize. Until scientists cross the Explanatory Gap (which is more like a chasm), nobody has the right to tell anyone that their speculation about consciousness is kooky or unscientific or whatever. The only thing that’s unscientific is letting one’s thought be constrained by rigid dogma regarding what is and isn’t possible.

I feel your pain (if I’m understanding you correctly, that is). It sucks to be trapped in a no-man’s-land between scientific dogma and religious dogma. We need a better way forward.

[redial]

The problem is one of humility. If you admit that something is at this point inexplicable then that is where you should stop explaining it. Sometimes I don't know is the only real answer. Because if you want to make this statement:

> It doesn’t seem to occur to people that consciousness itself is completely inexplicable and therefore all bets are off regarding its true nature.

You have to, ahem, explain it.

[md224]

Sure, but the problem is that many people don’t demonstrate this humility when they act like it’s ridiculous to wonder if consciousness exists prior to conception or after death. Ruling these out requires an unwarranted assumption about the relationship between consciousness and the brain.

I agree that people should show some humility and admit that we have no idea if or when consciousness begins and ends. Anyone who makes definitive claims about the temporal limits of consciousness should, as you said, provide an explanation of how they know this.

[redial]

It goes both ways. If you claim there is an unwarranted assumption about the relationship between consciousness and the brain you have to prove it. All I see is consciousness is highly correlated with having a brain.

> I agree that people should show some humility and admit that we have no idea if or when consciousness begins and ends.

I think our understanding of it is not as vague as you claim. We can see consciousness develop in all kind of animals; infants are less conscious than adults and elders show a higher degree of loss of consciousness. Furthermore, it is linked with brain activity somehow, as damaged brains show erratic consciousness related behavior. There is a lot more to learn, a lot, but to say that we know nothing is very dishonest in my opinion.

That is assuming we are talking about the same kind of consciousness you and I. But I've got a feeling we are not.

[redial]

> Not only that, but do you have an existence before you are born?

If you are inventing mysteries out of thin air why stop there? What if you will yourself into existence? What if it is you that is making "time" perceivable for the rest of us? Do your half-existing-yet-unborn-brother dies every time you are reborn into this plane but not if you will yourself to be born into another parallel universe?

[pmoriarty]

I didn't invent that question. It's a been a question that people have had for millenia.

Some people believe that one has a soul that exists before one is born in to a body. So in a way that's an answer to this question -- an answer that's been around for thousands of years. Clearly many people are concerned about it. I'm far from the only one, much less the first one.

[redial]

I was talking about the royal you: we. But more importantly, "when" the question was first asked doesn't change the nature of the question. Sure, you (we) can ask it, but it is no more insightful that the myriad of other metaphysical questions that have been asked through history that will never be answered because they lack a fundamental grounding in the shared experience we call "reality". Are there any blue reds? We can spend a millennia thinking about it.

[pmoriarty]

"Are there any blue reds? We can spend a millennia thinking about it."

It's pretty obvious that you can have blue reds: they're called purples or violets. Just squeeze some blue out of a tube of paint, and then some red, mix them together and you get a blue red. You can also have a black white: it's called gray.

Anyway, I'd agree that one could ask any number of metaphysical questions, but it could be argued that only some of them would be considered "great". One (arguable) measure to use for the greatness of questions is how many people do they occupy, and how critical do they consider those questions. Whether one exists before birth or after death would be considered "great" by this measure, whether there's a blue red would not.

[redial]

Violet is not blue and it is also not red. I'm not asking for a bluish red but for a 100% blue color that it is also red.

You are misusing the language, or rather I am in this case, to ask a paradoxical question. Where are all the cat dogs? This is a never ending game because we don't agree on the language. This is exactly the realm of metaphysics.

And greatness is in the eye of the beholder. To me greatness could be quantified by how much progress has been made in answering the question. After a thousand years and possibly millions of lives wasted trying to answer "is there existence before this life?" we are not one single iota closer to an answer. That implies a pretty bad question that is not grounded in reality, or at the very least not "grammatically" grounded in reality.

[modzu]

i would add morality to this -- at least problems in physics have a scientific framework within which they can be investigated. but why should we care? why should we be nice? of course there is plenty of rich philosophy on the subjcet

[mongol]

I would add Free will to it. Does it exist?

[jerf]

Also, what exactly is it that we mean by "free will"? Even just that question can get ugly, fast. I think I've only ever heard one definition of the concept sufficiently precise to even have a meaningful answer.

(In short, it was this: If we our model of the material universe is essentially correct, and if we assume that it is closed and that the material that we see is all there is, or at least all that can ever influence us, then suppose we define free will as the inability of any real external predictor to ever perfectly predict our actions in advance. I emphasize the word real to highlight that we are emphatically not talking about some abstract god, or something vaguely sitting outside of time, but the ability of a real device constructed out of real materials in real spacetime to predict your actions. We assumed away hypothetical infinite beings or math games at the beginning. In that case, it can be mathematically shown that you are simply too complicated to be fully correctly simulated by any system that attempts to build a model of your actions simply by external observation of you; you do not produce enough bits in your external actions to uniquely identify the state space of the inside of your head, not even if you turn the entire rest of the universe to the task (literally!). By this definition, it can be concretely answered: Yes, you have free will. Interestingly, this turns out to be true even if the universe is 100% deterministic, which definitely conflicts with most people's ideas about "free will"... but then, there's another demonstration of how rare it is for anyone to carefully define it before endlessly pontificating about it.

Also, while I consider this a valuable contribution to the field that any interested philosopher should ruminate on, I am not claiming that I 100% believe it, nor that it "solves" the problem. It is simply as I said at the beginning, the only sufficiently careful treatment of the problem that one can actually say it has an answer. Personally I find the presuppositions it is based on to be highly questionable. But it is at least worth pondering for a bit.)

[catamorphismic]

> In that case, it can be mathematically shown that you are simply too complicated to be fully correctly simulated by any system that attempts to build a model of your actions simply by external observation of you; you do not produce enough bits in your external actions to uniquely identify the state space of the inside of your head, not even if you turn the entire rest of the universe to the task (literally!).

Really? Which mathematical result is this?

Do scanning techniques such as fMRI and EEG count as external?