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healyje
Trad climber
Portland, Oregon
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Nov 23, 2018 - 03:22pm PT
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It would seem to me that folks pretty much have to make a decision about which side of the idealism/realism divide they're on before theorizing, or at least it would seem hard to come to that decision as a result of theorizing. And, aside from Ed's realism comments, the biggest problem with Hoffman's line if reason can be summed up by his own observation of:
...species-specific perception...
How individual organisms would converge into a species, let alone how members of a species would converge on a shared interpretation of a perception is never addressed.
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Jim Clipper
climber
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Nov 23, 2018 - 03:34pm PT
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The abandonment of realism
Is a model or a proof any less "real"? "Biological" representation, seems as arbitrary a category as the first?
Maybe an aside, did "god" exist before we "created" it.
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Largo
Sport climber
The Big Wide Open Face
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Topic Author's Reply - Nov 23, 2018 - 04:12pm PT
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It's interesting to look at Hoffman et al's thoughts on this stuff because I am not a Hoffman adherent, though some of his tenets seem unavoidable. However, contrasting Hoffman with what has traditionally passed as "idealism" is to misconstrue what he is saying in several fundamental ways.
Traditionally, idealism "asserts that reality, or reality as humans can know it, is fundamentally mental, mentally constructed, or otherwise immaterial. Epistemologically, Idealism manifests as a skepticism about the possibility of knowing any mind-independent thing."
Hoffman goes a step further and says nothing is mind independent because nothing whatsoever has an independent, stand alone, self contained ontology. So he tries to do to death the belief of all independent things, phenomenon, etc.
We're not likely to settle this one anytime soon, but the notion of an "objective space time," that exists independent of mind, seemed so far-fetched relative to my own experience, I asked a cosmologist friend to give me his take on it from the science perspective, as well as on Hoffman (who he reminded me that, like many in the past who have scientifically dealt with cosmic scale issues, is constantly revising his position). Here is some of what he referred me to:
When we use literal terms like "bending" or "warping" with respect to space-time and gravity, keep in mind that these words are NOT being used in a literal way. Since the majority of concepts in General Relativity are far beyond and/or contrary to what perception presents us, we have come up with a few ways of picturing these concepts in our minds, none of which are very accurate, but it helps us relate the basic ideas.
For starters, gravity DOESN'T literally bend space-time. What it actually does is modify the space-time interval. This modification can cause straight paths to APPEAR to bend and time durations to alter - to an outside observer. A convenient though not actual way to imagine space-time is as one interwoven fabric where the border between time and space is a bit fuzzy, so we say that gravity can "bend" or "warp" space-time and alter the shape of this fabric/surface/whatever.
But time does not literally "bend." A massive object modifies the proper time interval around it such that an outside OBSERVER would PERCEIVE objects near the mass to experience less time, and space-time intervals would have their spatial components modified accordingly. It's much easier for us to simply say that gravity is space-time being warped.
What an astrophysicist means by "space" is the mathematical concept of a space-time metric. Sometimes we use the shorthand “space-time,” but that introduces its own confusion.
The key word here is metric. In math, a metric is a way that distance is measured. A familiar example might be moving along the surface of the Earth. If you want to go from Boston to Beijing, the shortest distance would be a straight line through the Earth. But we can’t do that — we are constrained to stay on/near the surface of the Earth. This results in a longer distance.
So our “space” of the Earth’s surface has a metric, which defines the distance we must move while constrained to the surface of the Earth. In the Earth’s spherical metric, the shortest distance between two points is along the Great circle. But this is longer than the straight-line Euclidean distance. So our metric is curved, or “bent.”
This is analogous to what is being referred to in the space-time metric — it is the distance one has to travel in order to get from A to B. The crux of Einstein’s Theory of General Relativity is this: The METRIC of "empty" space is curved by the presence of gravitating mass.
Things get a bit more complicated in GR because we are constrained to move in 3-D space, not a 2-D surface like on the Earth. So then the “bending” of 3-D space has to be in some 4th dimension. This is where the “time” part comes in.
To understand why, you must remember that in Relativity, the speed of light is constant in any frame. Speed means the distance covered per unit time. So if the distance (“metric”) is changing owing to gravitating mass, then time also has to somehow change in a compensating way, such that the speed of light remains constant. Mathematically, this appears in the METRIC as a fourth dimension corresponding to the speed of light times time.
This is the idea of 4-D space-time. The space-time metric defines the distance between any two points in 4-D space-time. Without any mass around, the 3-D distance is just the usual Euclidean distance. But in the presence of mass, this METRIC changes, or bends. The shortest distance between two points is now no longer a straight line, just like from Boston to Beijing on Earth. This arises because we are confined to move in 3-D space, instead of being able to move in some higher dimension like being able to tunnel through the Earth. This is what we mean when we say that space is curved.
Again, colloquially speaking, the word space might mean “nothing” to you. But in astrophysics, the word space, or space-time, refers to the METRIC by which distances between two points are measured. This is what is referred to by the idea that space can be bent — it really means that the METRIC becomes curved and not Euclidean.
Remember that physical theories like General Relativity seek to MODEL reality, and should not be confused as objective and literal evaluations of reality itself, whatever that means (for some, it is misinterpreted in a way that the model IS the territory, that space-time is an objective THING or phenomenon, and this is entirely mistaken).
Also, GR is fundamentally incorrect as it is logically inconsistent with quantum field theory. Both theories must be wrong, or at any rate, incomplete in some way, but presently there is no way to integrate or resolve both theories. A better theory likely exists, and most progressive astrophysicists believe it will be completely different than current theories.
A few of these ideas are presented by this video.
https://www.youtube.com/watch?v=lpo56peuj_A
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Ed Hartouni
Trad climber
Livermore, CA
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Nov 23, 2018 - 05:58pm PT
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For starters, gravity DOESN'T literally bend space-time. What it actually does is modify the space-time interval.
you should stick with meditation...
...you actually know something about that.
Also, GR is fundamentally incorrect as it is logically inconsistent with quantum field theory.
this is also a stretch... but it is the orthodox way that the inconsistencies are "explained." The problem with GR is basically the tricks that work to calculate in some quantum field theories don't work when treating general relativity. They also don't work in the regime of strong magnetic fields, even though they provide rather accurate calculations elsewhere.
It is not a very profound stance to take that future physical theory will look very different from today's...
...what astrophysicists have to say about it might be interesting, they're not on the front lines however.
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MH2
Boulder climber
Andy Cairns
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Nov 23, 2018 - 06:12pm PT
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the notion of an "objective space time," that exists independent of mind, seemed so far-fetched relative to my own experience
Are you talking about anyone's mind, or just yours? Do animals have minds?
I find it disturbing to imagine that the existence of the universe depends upon my mind, although that could explain a lot about the way things are.
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BASE104
Social climber
An Oil Field
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Nov 23, 2018 - 06:23pm PT
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It's not that there's a universe, and qualia happened or evolved in it. Everything in the universe is qualia. This chair is qualia, my body is qualia, my mind is qualia. The person listening to this is qualia. Every electron. Every photon. So the hard problem disappears, because there isn't anything but qualia. And this is exactly what Jewish mystics, Hindu mystics, Buddhist contemplatives - all of these are reporting that when you get to the fundamental experience of the nature of the universe, by going inward, what you find is there's nothing but pure perception, pure knowing, pure awareness. And that's the nature of things. So, somehow going from stem cells and wondering how they're like ants, we get to: What's the nature of the universe
I could ask for your experimental evidence, but I have a reckon that your lab is pretty primitive.
I can't believe you guys are still talking about qualia. I can't believe you guys still spend hours each day trying to outsmart each other.
I got my P3 rating. Just got a new wing for cross country. I'll be down in Florida doing tows for two months after Christmas. Tons of fun. Went there last winter. Cheaper than Columbia.
I wonder if this thread will literally outlive some of the posters. Most of us are ready for our AARP cards.
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capseeboy
Social climber
portland, oregon
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Nov 24, 2018 - 09:14am PT
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IT is all appearances. IT is all beliefs. IT is all absurdities and non-absurdities. IT is all pictures. IT is my new philosophy---Blenderism!
P.S. is AARP a scam?
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Largo
Sport climber
The Big Wide Open Face
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Topic Author's Reply - Nov 24, 2018 - 11:02am PT
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you should stick with meditation...
...you actually know something about that.
-
LOL. You guys give me credit for citing other people's ideas and proposals. NONE of the quoted material is mine, and as stated, I'm not even endorsing that material. Just looking at another take.
I'll have to tell that astrophysicist (cosmologist) at CalTec that she's "not on the front lines." Like many others in cosmology, she traversed in from QM. But rather than attack someone's credibility, take a shot at the issues presented, get jiggy with the logic that led them to those conclusions, and go from there. The idea that a standard take on these issues is not thoroughly understood by these people is plain silly.
And this: For starters, gravity DOESN'T literally bend space-time. What it actually does is modify the space-time interval.
Ed replied: you should stick with meditation...
...you actually know something about that.
Now Edward, are you suggesting that the person who actually said this "didn't know what he was saying?" Are you saying that gravity actually bends an external object or thing that IS space time?
And this: The word space, or space-time, refers to the METRIC by which distances between two points are measured. This is what is referred to by the idea that space can be bent — it really means that the METRIC becomes curved and not Euclidean.
Is it your belief that the above is mistaken, that space-time does NOT refer to the metric as described. If it doesn't, in your view, WHAT does it relate to, and why?
And MH2, you are using "mind" in the sense that your rational mind can "imagine" the world, when what Hoffman was saying is something totally different.
In reference to the above, and especially to the fact that our theories don't mesh, at all, I was directed to these short quips:
Because QFT follows on from General Relativity the flaws in QFT to some extent derive from GR, but it has also created a framework itself which just does not make sense. Both of these conceptual framework are deeply flawed and trying to unify them is really the very last thing we should be attempting to do. The fundamental issue lies with Newtonian Gravity because it is premised on the assumption that Masses attract each other simply due to their mass and that is just not correct. Masses attract one another due to their relative motion. Essentially they attract due to their Angular Momentum but it is not that simple. Macro Gravity is emergent from Quantum Gravity. In many ways it is just a spill over. Even the Strong Force is a vanilla version of Quantum Gravity because it acts between paired particles whose bindings act to cancel each others gravitational flux contribution.
If you have understood a word of what I have been saying, then you will understand that we need to wipe the slate and start again.
To compute outcomes of interactions one must compute every possible path and every possible transformation and sum them (Feynman path integral).
One must take into account the transformations possible due to uncertainty, this particle could become that one, etc.
This produces absurd numbers but they can be calibrated or “renormalized” by comparing to known properties of the real world. The theory still gives new predictions.
But when space and time are no longer just the coordinates, but themselves uncertain, this process completely blows up.
-----
My sense of the gripes coming in are that people inherently balk at the idea that uncertainty lies at the bottom of it all, while at the same time wanting to make the coordinates and metrics (space-time) into objective phenomenon that exist independent of perception. Isn't this the main objection - that an objective reality MUST exist independent of perception? It just MUST! That data says so, right?
Perhaps what cuts to the quick in this regard is the idea that there is no such thing as a 3rd person perspective. That it's all first person.
As Ed mocked, I DO know something about meditation - and this is it. Trying to reckon perception by way of models is like trying to wrangle down radiation in certain frequencies by looking at something blue (or red, violet, etc). Amazingly, whether you focus on blue or radiation, there is nothing purely "objective" (independent existence) there.
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Don Paul
Social climber
Washington DC
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Nov 24, 2018 - 03:12pm PT
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All religions start with the premise that the world isn't real, but an illusion until we get to heaven, nirvana, etc. Religion is a denial of reality, generally speaking. Maybe at one time, the best humanity could do was to invent a Rain God to explain the rain, but now it is mostly a matter of being in denial. The counterargument against SOLIPSISM is the commonality of experience.
With the belief in the essential privacy of experience eliminated as false, the last presupposition underlying solipsism is removed and solipsism is shown as foundationless, in theory and in fact. One might even say, solipsism is necessarily foundationless, for to make an appeal to logical rules or empirical evidence the solipsist would implicitly have to affirm the very thing that he purportedly refuses to believe: the reality of intersubjectively valid criteria and a public, extra-mental world. There is a temptation to say that solipsism is a false philosophical theory, but this is not quite strong or accurate enough. As a theory, it is incoherent. What makes it incoherent, above all else, is that the solipsist requires a language (that is a sign-system) to think or to affirm his solipsistic thoughts at all.
It's not a coincidence that our observations of the world match up. Yet even the consequence of death doesn't convince people who don't believe the world is real.
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healyje
Trad climber
Portland, Oregon
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Nov 24, 2018 - 03:20pm PT
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Yes, commonality of experience is entirely unaccounted for in Hoffman's logic and its fatal flaw.
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MH2
Boulder climber
Andy Cairns
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Nov 24, 2018 - 03:54pm PT
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And MH2, you are using "mind" in the sense that your rational mind can "imagine" the world, when what Hoffman was saying is something totally different.
It's good to know that you know what I am doing. And that you know what Hoffman is saying.
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capseeboy
Social climber
portland, oregon
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Nov 24, 2018 - 04:21pm PT
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Aristotle: the often ridiculed consequences of these opinions is that they destroy themselves. For by asserting that all is true we assert the truth of the contrary assertion and consequently the falsity of our own thesis.
infinity (countable and uncountable, plural infinities)
(uncountable) Endlessness, unlimitedness, absence of a beginning, end or limits to size.
(countable, mathematics) A number that has an infinite numerical value that cannot be counted.
To argue that there is a god do I have to be able to argue that there is no god?
In a mathematical infinity is anything possible?
Does science have any use for a frame of infinity?
I'm confused.
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MH2
Boulder climber
Andy Cairns
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Nov 24, 2018 - 05:13pm PT
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I'm confused.
Try to define your terms better, capseeboy.
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yanqui
climber
Balcarce, Argentina
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Nov 24, 2018 - 07:06pm PT
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Does science have any use for a frame of infinity?
When your calculator spits out a value for cos(x), sin(x), log(x) or the exponential function, generally it's the approximation of a value that is considered to be "close" based on the concept of infinity. Do we use those functions in science?
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Ed Hartouni
Trad climber
Livermore, CA
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Nov 25, 2018 - 01:13am PT
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If you have understood a word of what I have been saying, then you will understand that we need to wipe the slate and start again.
I am aware that you are saying that, I am also aware that you have no idea whether or not it makes sense to "wipe the slate clean and start again."
Quantum mechanics, quantum field theory and general relatively work spectacularly well. If that we not so we wouldn't be hand wringing to figure out how they fit together.
But however that happens, we will still have those pieces, just as we have Newtonian mechanics that your JPL friends use to slingshot their probes around the solar system, to figure out the orbital dynamics of stars in the galaxies, and the galaxies in the clusters of galaxies.
We "didn't wipe the slate clean" because we didn't have to, we understood exactly the domain we could apply Newton's laws in.
Your friend at JPL has been working on this for some time, I could go back and find your first post referring to your car pool to find out roughly how long. But anyway, how's that work coming along?
Maybe she has time to explain this paper:
Loops Rescue the No-Boundary Proposal
Martin Bojowald and Suddhasattwa Brahma
Phys. Rev. Lett. 121, 201301 – Published 13 November 2018
ABSTRACT
New and nontrivial properties of off-shell instantons in loop quantum cosmology show that dynamical signature change naturally cures recently observed problems in the semiclassical path integral of quantum gravity. If left unsolved, these problems would doom any theory of smooth initial conditions of the Universe. The no-boundary proposal, as a specific example of such a theory, is rescued by loops, presenting a rare instance of a fruitful confluence of different approaches to quantum cosmology.
which intrigued me but my limited understanding probably prevents me from fully appreciating.
here's the arXiv link:
https://arxiv.org/pdf/1810.09871.pdf
as for what general relativity does, it makes space-time dynamical.
the equivalence of inertial and gravitational masses have something to say about this...
and the remaining loose end, the observation of gravity waves, is now history.
What would you replace it with?
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healyje
Trad climber
Portland, Oregon
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Nov 25, 2018 - 02:29am PT
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Quantum Meditation - you may or may not be doing it [right].
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capseeboy
Social climber
portland, oregon
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Nov 25, 2018 - 09:38am PT
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I find it hard to believe Einstein had trouble understanding how the drinking bird works; however, I infer that this may be your point---that even very intelligent birds get stumped.
Of course scientist work with irrational numbers, doh!
I'm confused about being aware that I am aware. LOL.
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Ed Hartouni
Trad climber
Livermore, CA
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Nov 25, 2018 - 10:27am PT
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Remember that physical theories like General Relativity seek to MODEL reality, and should not be confused as objective and literal evaluations of reality itself, whatever that means (for some, it is misinterpreted in a way that the model IS the territory, that space-time is an objective THING or phenomenon, and this is entirely mistaken).
how is this "entirely mistaken"?
you make this assertion constantly, with nothing whatsoever to back it up.
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Ed Hartouni
Trad climber
Livermore, CA
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Nov 25, 2018 - 10:52am PT
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where did you find that video, Largo?
it does sound like something you'd agree to, the fervor of the narrator, the appeal to philosophy, the skewering of "orthodoxy."
The current program of finding a description of reality independent of space-time goes back to the 1960s (at least) and has to do precisely because of the implications of general relativity, that space-time is "dynamical," it is affected by the distribution of gravitational sources and fields in the universe. "Gravitational sources" pretty much means everything.
Take a clock and a meter stick and go out and measure and time... it would seem that the discussion of what is "ontic" in your world is all important, and since there is no way to ask or answer these question of "ontology" you are safe in pursuing this line of questioning.
So putting that aside (and it is a non-issue for cosmologists) there is great interest in what physics looks like without using space-time. This harks back to various posts I've made upthread regarding "pre-geometry" and thinking about early cosmologies, at times when the gravity was so strong that it "bends" space-time at the atomic level, necessitating its inclusion in the description of subatomic phenomena. Right now we don't know how to do that. In addition, how space time emerges from the even earlier universe is the source of much speculation.
But then I'm just a "type A physicalist with an ossifide world view stuck in the past."
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healyje
Trad climber
Portland, Oregon
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Nov 27, 2018 - 04:11pm PT
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Your suggestion to Largo would, however, require common species-specific perceptions of language, clocks, sticks, time, and space - just how that would occur short of magic is not addressed by Hoffman.
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