Naked Science Forum
Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: yor_on on 02/10/2010 23:02:39
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How do we do it?
Touch?
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Yes and No ! Let me explain. None of us has any doubt what touching or feeling an object is like so touching and feeling is a perfectly valid concept. However when you get down to the atomic and molecular level all the forces involved are localised electromagnetic forces entirely associated with the arrangement of the electronic structure of the materials involved so they are postly repulsive forces due to the electrons getting close to each other (but not touching) and the attractive forces associated with the chemical bonds and residual weaker attractive forces (Van der Waals forces) that hold the molecules in their solid or liquid structures giving surfaces their physical properties. In general most of the electrons stay in their places but occasionally some may be moved about as in charging objects electrostatically by rubbing them. Occasionally there is a residual attractive force between surfaces and the surface becomes "sticky".
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Strictly speaking feeling and touching are not the same.
You feel (perceive touch) with your brain, not with the body part touching (in contact with) an object.
Illustrated by the phantom limb phenomenon (http://en.wikipedia.org/wiki/Phantom_limb) where someone can feel a limb which has been amputated.
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RD I appreciate that what you say is true but we are here talking about the normal operation of the senses which are by definition related to the model of our surroundings created by our brain. By feeling I presume that the questioner is referring to feeling the quality of a surface rough, smooth, hot, cold etc. and not the detection of the presence of a limb and or whether it is in pain.
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Thanks Soul Surfer, RD.
So, could we then reduce all senses we have to electromagnetic phenomena?
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Yes with the sole exception of the behaviour of mass under gravity absolutely everything that we are aware of is electromagnetic and all our functionality is electromagnetic.
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Yes with the sole exception of the behaviour of mass under gravity absolutely everything that we are aware of is electromagnetic and all our functionality is electromagnetic.
It's true Yoron. You really do have a magnetic personality.
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Repelling am I?
Now .. .. .
*More Hurt*
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ahem.
:)
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Ehh, how about balance, can we reduce that to a electromagnetic phenomena?
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how about balance, can we reduce that to a electromagnetic phenomena?
Physical or mental?
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Now that's an attractive angle me lad.
:)
I was mainly considering it from a physical level..
Ah.
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He* Why not ' , ' both?
"But for the absence of a comma"
Loosely paraphrased from
"For want of a nail the shoe was lost, for want of a shoe the horse was lost "
Am I going mental, enough :)?
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Actually, it probably makes no difference. I'm sure they are both, ultimately, electromagnetic.
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But it remains to prove it...
Didn't Maxwell write something about it too?
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"silver hammer", or the other guy?
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Yes with the sole exception of the behaviour of mass under gravity absolutely everything that we are aware of is electromagnetic and all our functionality is electromagnetic.
It's true Yoron. You really do have a magnetic personality.
Not only does he have a magnetic personality, he is a smart son-of-a-gun. I wish I knew as much as he does about science. Thanks for comments. Joe L. Ogan
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Thanks Joe, you're pretty smart too me thinks.
We both are, and Geezer, although as it seems? He's more into music, I think?
ahem :)
Anyway, we wouldn't be here, arguing, having a good time, if we weren't curious :)
Then we have them that actually know what they are talking about too of course.
Not that such ever stopped me from having a opinion :)
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Hi, yor-on. I did not know that about Geezer. Now, I understand why I always feel like someone is in the background is playing a violin while Geezer is promulgating his opinion. Thanks for clearing that up. Thanks for comments. Joe L. Ogan
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The Arch Angels of Doom playing you mean?
Considering he can.. You know, he's actually a ..
♫♪♫ Taaam ♫♪♫ Ta ♫♪ Ta Taaaam ♫♪♫
(Ouch, We better keep this between ourselves Joe, do as I.. Whistle :)
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This, perhaps intentionally vague, question is impossibly fun to try to answer, especially the "feel" part. Our perceptions of our environment, like Soul Surfer said involve "the normal operation of the senses which are by definition related to the model of our surroundings created by our brain." The sensory portion of this is pretty well worked out, while the experiential component (the model), which involves integration of all the sensory input, is not.
I have some expertise regarding the sensory portion. Touch involves inputs from multiple sensors that detect temperature, crude and fine touch based primarily on pressure, vibration, joint angle, and tendon stretch. For example, when handling a cube the combination of these sensors can measure its size, hardness (how compressible), and especially detect edges and corners by the areal ratio of pressure sensors that are affected when pressing the fingers against them. In comparison, trying to determine which of two very fine sandpapers is the finest grit, rubbing the fingers over the sandpaper sets up vibrations from the dermal ridges (e.g. finger prints) and vibration sensors can signal very fine differences in frequency, and thereby the grit.
None of the above answers the question, and it is much more boring than the banter, but I just couldn’t pass this up. Steve
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Who said it was boring?
Welcome to TNS :)
Reading you reminds me of the claim that blind people actually can feel colors?
Now, you wouldn't happen to know about that?
different heat maybe? But that wouldn't work in a dark room?
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Yor_on. Sensory areas of the brain develop, in part, on the basis of neural activity from the periphery. The visual cortex normally receives connections, preferentially, from primary visual input from the eye (via the thalamic lateral geniculate and the midbrain superior colliculus). If the activity from the visual input is denied at birth, neural activity of other sensory inputs allow their axons to invade the cortex and make connections. So, the visual cortex of congenitally blind individuals does receive input from other senses, especially from those thalamic areas that mediate touch and sound that lie near the lateral geniculate. These individual very likely see touch and sound, sort of. Steve
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That's really cool Steve. The way our brains works never stops to amaze me. I have a link, yeah I'm a collector of 'links' :) that I think illustrates your description splendidly. Take a look and see if you agree. Blind? Who ?? Me? (http://www.youtube.com/watch?v=c49dS76KhGc)
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In fact, reading you make me quite hopeful :)
We seem to have an amazing level of adaption.
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Yor_on, auditory localization is one of our unrecognized skills. Your brain can sort out and focus on the person you are talking to at a very noisy gathering on the basis of the direction their voice is coming from. Put on a blindfold and have a friend move around while you listen. You should be able to point right at them. With a little experimenting you will find that high frequency and sharp onset noises are easiest to localize. I have done this and it is fun.
It is known that this ability is enhanced in blind individuals, but the portion due to brain reorganization (as apposed to behavioral adaptation) is maximized if blindness occurs very early in postnatal development. The blind boy in the video has somehow learned to be able to detect echos. I don't think that his acuity is very good and much of what he does involves knowing what to expect in his environment. The experts of this skill, bats and whales, have very large portions of their brains devoted just to echolocation. Steve