[michaelmrose]

Presumably the redness of red is VERY hard to communicate fully brain to brain because the experience of it is dependent upon every input and computation before that point however we manage to do it well enough.

Its like saying that some deficits in computability prevent us us from doing arithmetic and therefore from launching rockets successfully at distant targets.

I might never know the exact pattern in my brain of the "redness of red" as experienced by you but it seemed to work well enough for my brain to form a pattern similar enough to communicate thoughts just as the incompleteness or inherent lack of precision of measurement don't prevent the rocket from being launched successfully.

[happythomist]

The issue is not whether we can pragmatically communicate the concept of "red" by piggybacking on some (presumed) common experience, but whether that experience of redness itself is information. It is obviously not, and I do not understand why you insist otherwise.

[Born_Again]

This idea boils down to if you believe the human brain exists purely in physical space. Let's assume it does. There is no free will. Every thought, every neuron, every sense can be represented and is controlled solely by energy and matter. We could record the electrical signals between your optic nerve and your brain, and send those same signals to your brain again in the future. We could recreate what you perceive as red by shocking your brain in the right place at the right time. If we perfectly understood the human brain, the sensation of red would be defined as a sequence of neurons that need to be turned on and off at the right time.

As far as I know, the only thing limiting us from perfectly understanding the brain is our limitations with measuring it. I don't know of any scientific studies that claim the brain exists outside of physical space.

Let's assume the brain doesn't exist purely in physical space. Free will exists. There is something immeasurable and outside of matter and energy that experiences the color red. Sensations are impossible to define because they exist only in this immeasurable world.

I heard about a guy that claimed it was obvious that the origin of lightning and earthquakes were from the gods themselves. I try not to think like that guy.

[happythomist]

> If we perfectly understood the human brain, the sensation of red would be defined as a sequence of neurons that need to be turned on and off at the right time.

A sequence of neurons firing is not equivalent to the sensation of red. It doesn't even tell you anything about the nature of the sensation of colour more broadly, or why the sensation of red looks the way it does and not like, say, the sensation of blue or yellow instead.

All you have is a material correlate -- a merely descriptive physical "law".

[Born_Again]

> A sequence of neurons firing is not equivalent to the sensation of red.

Have you seen videos where people perform experiments on people's brains while they're awake? The subjects experience sensations that are inseparable from their neurons firing.

I would say the sensation of red and neurons firing are the exact same thing to the person experiencing it. It's like saying a flashlight that is on is different than photons traveling away from a light bulb with a battery and a current. They're the same thing to the observer. The sensation of red is caused by and is only possible by neurons firing. The neurons firing causes and only results in the sensation of red. The observer does not know the difference.

> It doesn't even tell you anything about the nature of the sensation of colour more broadly

I don't think seeing red tells us about the sensation of color more broadly either. I think that's a concept created through human discussion, not by our senses.

> or why the sensation of red looks the way it does and not like, say, the sensation of blue or yellow instead.

I was talking to your point of "but whether that experience of redness itself is information". I don't know why red looks the way it does, but I imagine the reason exists in the physical world and we could find out if we understood the brain.

I do think in the future we could activate someone's neurons and have them experience red, blue, and yellow in any combination we want. And we could give someone else the same experience (hypothetically we perfectly understand the brain) by activating neurons in their brain. I think that is perfectly communicating color.

[happythomist]

> The subjects experience sensations that are inseparable from their neurons firing.

What does "inseparable" mean? That the sensation occurs at the same time that the neurons fire? That may be true, but it doesn't make them equivalent.

> It's like saying a flashlight that is on is different than photons traveling away from a light bulb with a battery and a current.

They're not the same, for what it's worth. The term "flashlight" conveys a certain intent and structure that "photons traveling away from a light bulb with a battery and a current" does not.

> The sensation of red is caused by and is only possible by neurons firing. The neurons firing causes and only results in the sensation of red. The observer does not know the difference.

The fact that two different phenomena are closely coupled via a cause and effect relationship does not make them the same phenomena.

If you push two magnets together, the fact that the same force causes them to attract or repel does not mean that the motion of the first is literally equivalent to the motion of the second, or that the force itself is literally equivalent to either motion. They are closely correlated, but ultimately distinct.

You just can't avoid the fact that qualitative phenomena do exist in their own right. They can't be explained away using a physical model that assumes from the get go that they don't exist.

Erwin Schrodinger said:

> Scientific theories serve to facilitate the survey of our observations and experimental findings. Every scientist knows how difficult it is to remember a moderately extended group of facts, before at least some primitive theoretical picture about them has been shaped. It is therefore small wonder, and by no means to be blamed on the authors of original papers or of text-books, that after a reasonably coherent theory has been formed, they do not describe the bare facts they have found or wish to convey to the reader, but clothe them in the terminology of that theory or theories. This procedure, while very useful for our remembering the facts in a well-ordered pattern, tends to obliterate the distinction between the actual observations and the theory arisen from them. And since the former always are of some sensual quality, theories are easily thought to account for sensual qualities; which, of course, they never do.

[Born_Again]

> What does "inseparable" mean? That the sensation occurs at the same time that the neurons fire? That may be true, but it doesn't make them equivalent.

Can a sensation exist without neurons firing? The root of our conversation is the question if a sensation purely exists in the physical world. If it does, then it is possible to measure it. If it doesn't, then that breaks our scientific understanding of the world and would be exciting news.

> They're not the same, for what it's worth. The term "flashlight" conveys a certain intent and structure that "photons traveling away from a light bulb with a battery and a current" does not.

Yes there is no strict definition of a flashlight. Let's use your definition of a flashlight. Is it possible in your mind to separate the concept of a flashlight and your definition? Without "your definition here", the flashlight no longer exists. My point was without firing neurons, the sensation does not exist.

> The fact that two different phenomena are closely coupled via a cause and effect relationship does not make them the same phenomena.

My wording was not the best. My point was that the sensation of red is physically equivalent to neurons firing. How do we measure a sensation? If we cannot measure a sensation, does it exist in the physical world? If it doesn't exist in the physical world, then what does it existence mean to the scientific community?

> If you push two magnets together, the fact that the same force causes them to attract or repel does not mean that the motion of the first is literally equivalent to the motion of the second, or that the force itself is literally equivalent to either motion. They are closely correlated, but ultimately distinct.

I agree that these forces are distinct. We can measure the force of each magnet separately and we can define the motion of one magnet without referencing the motion of the other.

> You just can't avoid the fact that qualitative phenomena do exist in their own right. They can't be explained away using a physical model that assumes from the get go that they don't exist.

What is a qualitative phenomena? I couldn't find information on this term.

If we can't measure a qualitative phenomena in the physical space, what does it mean to exist?

[michaelmrose]

Making up something you can't define and then describing the thing you invented as uniquely human is a bad argument.