How do we know that we know what we know?

[ricolo41]

How do we know that the color I call "blue" is perceived the same as your "blue."? With bottom-up processing, how can we be sure that stimuli are perceived in the same way by everybody? One final question: since an atom is mostly empty space (equating to nothing), how does matter emerge from groups of atoms? In other words, how can we have something from nothing?

[Queso]

as for the color thing, that's something i've wondered ever since i was a little kid. but i'm sure with the frequency spectrum and all that, it's the same. although i really don't know, and am looking forward to what this thread has to offer.

welcome ricolo, by the way!

[Turtle]

___Your blue is not my blue is not anybody's blue for sure, however if it becomes important to compare our blues, then we can cooperatively reach some agreement. We may agree blue or agree not blue or agree to not agree.

___We know what we know by the scientific method. :)

[Queso]

our skin may be called the same, peach, white, or whatever. but your peach may look like my red, and your red may look like my blue. is that what you're trying to say?

 

if so, hypography, is this the way it is, or no?

[Turtle]

___Well, I wouldn't think in general that my red is your blue, but peach & red or blue & green do meld into an area of disagreement. I'm trying to say none of us can ever 'know' what someone else's experience is whether it's color or anything else.

___We each 'know what we know' from a unique perspective & unless or until we encounter a conflicting 'knowing', that is all there is to go on. Still, you only trust the knowing of others, you don't know their knowing.

___Sound confusing? Of course it is, but I think that's why ricolo asked. I'm pretty confident about all this, but I can't know for sure. :)

[Fishteacher73]

One final question: since an atom is mostly empty space (equating to nothing), how does matter emerge from groups of atoms? In other words, how can we have something from nothing?

 

 

As you stated atoms are mostly empty space. Atoms also conatin very strong internal forces that attract/repell each other and various sub atomic particles. The reason that the atoms of our butts don't simply slide between the space of the atoms of the chair is that atoms really just do not like being that close. You actually VERY RARELY truly touch anything. The atoms of one thing only get so close before they start repelling each other.

[Biochemist]

The reason that the atoms of our butts don't simply slide between the space of the atoms of the chair is that atoms really just do not like being that close. You actually VERY RARELY truly touch anything. The atoms of one thing only get so close before they start repelling each other.

This is good, because I am pretty particular about what (or who) gets close to touching MY butt.

[Fishteacher73]

That's not to say that your butt's not penetrated by many other things such as gamma rays... :)

[ricolo41]

The reason that the atoms of our butts don't simply slide between the space of the atoms of the chair is that atoms really just do not like being that close. You actually VERY RARELY truly touch anything. The atoms of one thing only get so close before they start repelling each other.

 

What does this mean, then, for our sense of touch? When we "touch" something, what exactly is it that our nerve endings are actually registering (where consequently our brain perceives that we are touching something) ?

[Queso]

we're touching it, but if you want to look at it on an extremely small scale, the atoms on the finger and the atoms on the door knob are actually repelling each other.

[Fishteacher73]

One can "feel" the force of repulsion if you hold two magnets with the same pole towards each other. You essentially have the same effect on the atomic level. (Although the nature of the forces is slightly different).

[lindagarrette]

___Your blue is not my blue is not anybody's blue for sure, however if it becomes important to compare our blues, then we can cooperatively reach some agreement. We may agree blue or agree not blue or agree to not agree.

___We know what we know by the scientific method. :)

It is possible for biologists to determine what colors we see. Since we all have the same genetic makeup in that department it would be highly unlikely if your blue were not the same as mine, unless you had an eyesight defect.

[Fishteacher73]

There have been various neurological issues (either through physical or chemical reasons) that the senses become confused and interpreted in terms of each other, such as the color of sounds, the smell of a pictures, etc. This is called synesthesia.

[zadojla]

Since we all have the same genetic makeup in that department it would be highly unlikely if your blue were not the same as mine, unless you had an eyesight defect.

Oddly, my eyes see slightly different colors. To my left eye, blues are brighter and more obvious. To my right eye, reds are brighter and more obvious. The difference is slight, but noticable. I discovered this about 30 years ago, lying in bed and looking at my bookshelves with each eye alternately. Even the blue sky appears different.

[infamous]

After thinking about this question a while, another example of varation in sensual experience became evident to me. We could also ask this same question about taste and or smell. Do we all taste the same thing when we eat broccoli, its well understood that some people like it while others don't. And about smell, we could arrive at similiar results for examples of different odors. Do we react differently to taste because the item actually tastes different or because our past experience has taught us to dislike it for some unknown reason. And the same for different smells, there are those that like the smell of new mown hay and those that don't. Are these only preferences, or are we really tasting and smelling entirely different things......?

[ricolo41]

Infamous,

Very good point about the inclusion of the other senses. I would have to agree with you. I pose to you another question: if people perceive stimuli in different ways, who exactly is "right" - the person who tastes broccoli as one would taste chocolate cake, or the person who tastes broccoli as one tastes a bitter vegetable? Furthermore, who/what gives us the right to decide who is right and who is wrong in conceptualizing reality?

[UncleAl]

Same biochemistry, same anatomy, same perception. We know there are low frequency genetic variations in cone proteins that result in fractionally different color perception in non-color blind people. It's in the literature in disgusting detail. If you have developing cataracts you lose color saturation. If you are over 30 your eyes' lenses are increasingly yellow and you have increasing difficulty telling deep blue from black - especially under incandescent light (for the obvious reason).

 

Color perception is cultural. Newton had to find a god-given octave and by god he did - ROYGBIV. Most uncontaminated cultures saw about five colors in the rainbow rather than seven. Traditional Japanese blue is rather turquoise. The advent of deep blue LEDs and diode lasers for DvDs required a new color, "true blue."

 

Forces are mediated by virtual bosons, matter is built of fermions. Atoms are kept inflated by Fermi statistics and the Pauli Exclusion Principle. You can squeeze down electrons, crushing them beyond Pauli exclusion into nuclei to create neutrons out of protons. It requires a bigs star of stuff to generate the pressure with gravitation. Nuclear matter has a density of 2x10^14 g/cm^3 near enough whether it is an isolated neutron or a neutron star. Stiff stuff! Neutrons are fermions. Crush the Earth and get a (very hot) neutronium basketball in turn inflated by Fermi statistics and Pauli exclusion. Crush nuclear matter beyond its Pauli exclusion and the next stop is a black hole.

 

Gravitation always wins.