... But our senses are our only direct cognitive contact with reality and, therefore, only source of information. Without sensory evidence, there can be no concepts; without concepts, there can be no language; without language, there can be no knowledge and no science. Aristotle looked to the outside world for answers, St Augustin looked for truth in the Bible.
By undercutting the validity of the senses we cut ourselves off from the real world. Try to disprove the evidence of sensory perception without using data obtained from such perception.
...

That's why I say that our mental models comprise an interface to the real world. We've got a pretty good system for data acquisition, and as you point out, reasonably accurate as far as it goes. But we don't see ultraviolet as bees do. We don't see infrared as pit vipers do. We don't hear things much above 22,000 cycles per second, as dogs do, or below about 18 cps as elephants do. We don't even experience reality in real time: when the fielder snags the ball, it's about a tenth of a second for the fact to become reality in his mind, due to the propagation delay imposed by the nervous system and the time it takes in the brain to process the data so acquired. My "fielder" example is selected precisely because it demonstrates what a marvelously wonderful system of perception and modeling we've got. But it's still just a model, as a plastic model of a fighter plane lacks salient details of a real full-sized one.

By the way, the word, "comprehend" doesn't primarily mean, "to understand" - that's only an analogical usage - it means to fully grasp, literally to wrap one's hand fully around the object. In order for us to comprehend the Universe, we would have to have one-to-one correspondence between elements in our mental database and items of the greater reality, and at both ends of the span between the subatomic and the supra-galactic.

Nothing I've said in any way undercuts the value of sensory perception: the fact that it is acquiring data in an incomplete way doesn't mean that it has no value, simply that we're really only sampling the data in a narrow bandwidth determined by our ancestral heritage and shaping by the changing environment. But the understanding that your worldview is only that, and different from that of every other single person on the planet is the beginning of awareness.

...I submit it is all faith.

Which I take to mean, having confidence that your model of the Universe is sufficiently accurate to be able to get along in the real world, though you understand the uncertainty resulting from the lack of complete information and a somewhat distorted understanding. "Act as though you knew what you were doing, and everyone will assume that you do."

[arnold]

That's why I say that our mental models comprise an interface to the real world. We've got a pretty good system for data acquisition, and as you point out, reasonably accurate as far as it goes. But we don't see ultraviolet as bees do. We don't see infrared as pit vipers do. We don't hear things much above 22,000 cycles per second, as dogs do, or below about 18 cps as elephants do. We don't even experience reality in real time: when the fielder snags the ball, it's about a tenth of a second for the fact to become reality in his mind, due to the propagation delay imposed by the nervous system and the time it takes in the brain to process the data so acquired. My "fielder" example is selected precisely because it demonstrates what a marvelously wonderful system of perception and modeling we've got. But it's still just a model, as a plastic model of a fighter plane lacks salient details of a real full-sized one.

By the way, the word, "comprehend" doesn't primarily mean, "to understand" - that's only an analogical usage - it means to fully grasp, literally to wrap one's hand fully around the object. In order for us to comprehend the Universe, we would have to have one-to-one correspondence between elements in our mental database and items of the greater reality, and at both ends of the span between the subatomic and the supra-galactic.

Nothing I've said in any way undercuts the value of sensory perception: the fact that it is acquiring data in an incomplete way doesn't mean that it has no value, simply that we're really only sampling the data in a narrow bandwidth determined by our ancestral heritage and shaping by the changing environment. But the understanding that your worldview is only that, and different from that of every other single person on the planet is the beginning of awareness.

There is no argument that we all have perceptual limits, that is why we invented machines to overcome them. My point is that having limits doesn't mean we can never know reality because of all the missing data. (not sure if you meant that).
Infallibility is not a precondition of knowing what one does know.

[StiffLegged]

For biologists, the fascinating complexity of life is not only explicable, it's inevitable. Take a nice stew of carbon, nitrogen, oxygen, hydrogen and other trace elements, add various external energy sources, and autocatalytic cycles of chemicals lead to more complex self-reproducing critters. Cook at room temperature for some billions of years in a 500 trillion square meter oven and voila!

Um, really? I've been told this ever since I was old enough to hear about the Miller-Urey experiment. Unfortunately, nobody has a real clue how this would happen and et voila is the usual hand-waving explanation as to how it could. The chemistry is unbelievably complex, the extraordinary range of conditions needed to pull off the necessary reactions is many many miles from *cook at room temperature" and almost no-one tells you that Miller-Urey produced some amino acids in minute quantities detectable only by very sophisticated methods: the overwhelming majority of reaction products would come in handy for waterproofing your overcoat or surfacing a road. Next time anyone tells you that fairy story, tell them "must try harder, do it again."

There is no argument that we all have perceptual limits, that is why we invented machines to overcome them. My point is that having limits doesn't mean we can never know reality because of all the missing data. (not sure if you meant that).
Infallibility is not a precondition of knowing what one does know.

I didn't say anything about "knowing"; I said we can't comprehend it. An entirely different concept.

"To know that you know what you know and that you do not know what you do not know, that is true knowledge."

Of course, there are those whose sense of self-importance requires the denial of the separate existence of "reality".

[photoptimist]

Um, really? I've been told this ever since I was old enough to hear about the Miller-Urey experiment. Unfortunately, nobody has a real clue how this would happen and et voila is the usual hand-waving explanation as to how it could. The chemistry is unbelievably complex, the extraordinary range of conditions needed to pull off the necessary reactions is many many miles from *cook at room temperature" and almost no-one tells you that Miller-Urey produced some amino acids in minute quantities detectable only by very sophisticated methods: the overwhelming majority of reaction products would come in handy for waterproofing your overcoat or surfacing a road. Next time anyone tells you that fairy story, tell them "must try harder, do it again."

Miller-Urey experiment ran for only one week in a 5 liter flask with a tiny spark. The Earth version ran for literally billions of times longer in a volume about 10^20 times larger with much higher fluxes of electrical, UV, and thermal energies plus with an environment with many potential catalysts in volcanic rock, meteoric metals, early clays, etc. Sure, the concentration of the interesting stuff in the Miller-Urey may have been small, but it is proof a reaction rate that would have produced much more substantive amounts over geological scales of time and space.

[arnold]

Which I take to mean, having confidence that your model of the Universe is sufficiently accurate to be able to get along in the real world, though you understand the uncertainty resulting from the lack of complete information and a somewhat distorted understanding. "Act as though you knew what you were doing, and everyone will assume that you do."

Again the meaning of words. To which I may add.
The essence of faith, is belief without evidence. Trust, however is an acceptance of risk based on prior experience or evidence.

---------- Post added 16-02-20 at 16:06 ----------

Miller-Urey experiment ran for only one week in a 5 liter flask with a tiny spark. The Earth version ran for literally billions of times longer in a volume about 10^20 times larger with much higher fluxes of electrical, UV, and thermal energies plus with an environment with many potential catalysts in volcanic rock, meteoric metals, early clays, etc. Sure, the concentration of the interesting stuff in the Miller-Urey may have been small, but it is proof a reaction rate that would have produced much more substantive amounts over geological scales of time and space.

In any case, ignorance of a phenomenon is not a validation of proposed alternatives.

[StiffLegged]

Miller-Urey experiment ran for only one week in a 5 liter flask with a tiny spark. The Earth version ran for literally billions of times longer in a volume about 10^20 times larger with much higher fluxes of electrical, UV, and thermal energies plus with an environment with many potential catalysts in volcanic rock, meteoric metals, early clays, etc. Sure, the concentration of the interesting stuff in the Miller-Urey may have been small, but it is proof a reaction rate that would have produced much more substantive amounts over geological scales of time and space.

It is no such thing. The chemical compounds required are not persistent under large fluxes of electrical, UV or heat energies. No sooner have they been made than they are very likely to break down, since the necessary reactions are easily reversible. The desired reaction products are also intermediates in a sequence of reactions which don’t suddenly stop because the biologists would like them to - crudely put, once you’ve got a tasty stew in the pot the cooker doesn’t turn itself off, it just keeps on cooking. Anyone here like hotpot that’s been on a hot stove for a couple of years? Thought not. The end product in Miller-Urey is the same as would waterproof your overcoat or surface a road and that isn’t reversible.

Further appeals to mysterious volcanic, meteoritic or clay catalysts just won’t wash because no-one has done any work to show which might help or how. It’s no better than appealing to the Tooth Fairy for how that coin appeared under your kid’s pillow. Origin of life experimenters have a long way to go to make their case and it would be more honest if they would admit it.

... To which I may add.
The essence of faith, is belief without evidence. ...

Ah, the definition preferred by religious institutions; one of the redefinitions designed to reinforce their "traditions and teachings". I prefer the primary definition of that term, which has to do with the degree to which one thing is representative of another. For example, if you see a portrait and know the individual pictured, you might say that the portrait is a faithful representation of the living person. Similarly, if you put a properly tuned acoustical guitar on top of a piano and strike an "E" on the keyboard, you'll see the two outer strings of the guitar resonating sympathetically, since the string's tuning is faithful to that of the piano. The idea that belief of a factual proposition without any basis is "faith" strikes me as absurd. "Confidence", perhaps, if you believe the people who told you what to believe are reliable witnesses. The institutional view is designed to make it easy for people to think they're doing the right thing without any real effort; but it's only when one embodies the Logos himself that he is "faithful". But that path is narrow and few go that way.

In any case, ignorance of a phenomenon is not a validation of proposed alternatives.

What? ?? ???

[robgski]

You folks are really getting into "angels dancing on the head of a pin territory"

[photoptimist]

You folks are really getting into "angels dancing on the head of a pin territory"

Yes, but first we must decide if these are full-frame angels and whether the pin has a mirror or is mirrorless.

[photoptimist]

It is no such thing. The chemical compounds required are not persistent under large fluxes of electrical, UV or heat energies. No sooner have they been made than they are very likely to break down, since the necessary reactions are easily reversible. The desired reaction products are also intermediates in a sequence of reactions which don’t suddenly stop because the biologists would like them to - crudely put, once you’ve got a tasty stew in the pot the cooker doesn’t turn itself off, it just keeps on cooking. Anyone here like hotpot that’s been on a hot stove for a couple of years? Thought not. The end product in Miller-Urey is the same as would waterproof your overcoat or surface a road and that isn’t reversible.

Further appeals to mysterious volcanic, meteoritic or clay catalysts just won’t wash because no-one has done any work to show which might help or how. It’s no better than appealing to the Tooth Fairy for how that coin appeared under your kid’s pillow. Origin of life experimenters have a long way to go to make their case and it would be more honest if they would admit it.

If Miller-Urey or the Earth had been a homogenous container with uniform conditions in all parts and all times, then it would have been like your overcooked crockpot. But neither Miller-Urey or the Earth were like that.

In Miller-Urey, the high-energy sparks were in the "atmosphere" and the spark-formed amino acids condensed out on the sides of the vessel and ended up in the liquid at the bottom. Thus, the rate of formation in the spark zone is much higher than the reverse rate of destruction in the cooled, placid liquid and the amino acid concentration would increase substantially over time.

The thing about chemistry is that even if a reaction is easily reversible, it doesn't mean that every molecule of created amino acid gets instantly destroyed. There's an equilibrium concentration defined by the concentrations of all the chemical species and the local conditions where those chemicals are. Phenomena such as condensation, precipitation, and evaporation tend to remove some chemicals from one location and boost the concentration of other chemicals (e.g., salt is rare in fresh water but becomes concentrated in the oceans by millions of years of the evaporation cycle.)

To the extent that some parts of the ancient Earth were hot and others were cold, some parts were wet and other were dry, some parts had high UV exposure and other did not, etc. there's an inevitable tendency to make ever more complex molecules. Nor is tar an inert material either chemically or biologically. Tar balls break down into a wide range of hydrocarbons and are actually food for hundreds of kinds of bacteria.

As for the hypothesis about the role of clay, it's simply false that "no-one has done any work to show which might help or how." A quick check of Google finds many articles mentioning the many experiments on the topic such as:
Role of Clay Minerals in Chemical Evolution and the Origins of Life | IntechOpen
Clays Aided First Life? - Astrobiology Magazine
The Role of Clays in the Origin of Life | SpringerLink

[StiffLegged]

Thank you for the links, they provided much merriment. I’m familiar especially with the professor in the second one, a Nobel laureate geneticist, and have watched a number of his presentations on the subject before. If I may, they’re more of the same handwaving and wishful thinking, with contributors unable to agree even on whether the early earth had a reducing or oxidising atmosphere.

Sorry, must try harder, see me at end of class.

[swanlefitte]

I am surprised open vs closed systems hasn't been brought up. A closed system tends to entropy. A sub system in an open system can be quite the opossite. Take the solar system as a whole moving toward entropy while the earth gets more complex.

[photoptimist]

I am surprised open vs closed systems hasn't been brought up. A closed system tends to entropy. A sub system in an open system can be quite the opossite. Take the solar system as a whole moving toward entropy while the earth gets more complex.

Great point!

One of the mind blowers in studying self-organizing system is that sometimes the "best" way to maximize entropy production is with an ordered system such as https://en.wikipedia.org/wiki/Rayleigh–Bénard_convection .

Amusingly, the stability of words and their meanings probably shows the least increase in entropy in a closed system. It's the open systems with immigration, innovation, social change, etc., in which words morph, mean different things to different subgroups, and lose precision.