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Nicolette Sinensky


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How does virtuality translate into reality?

This week in my bioelectricity class, we spoke about electrical stimulation of nerves. One method of stimulation is to place a electrode directly on the surface of a nerve. One of the considerations of this method, however, is that the anode (positively charged side) and cathode (negatively charged side) of the electrode each cause a redistribution of charge around the electrode. Consequently, the anode induces a complementary "virtual cathode" and the cathode creates a complementary "virtual anode." These components aren't actually there, but we can observe a similar redistribution of charge that implies that something unseen is going on. Despite the fact that these components are not physically present, they have real effects on the functionality of both the electrode and the nerve. The virtual cathode and anode can cause a very real, measurable voltage change in the nerve, and can effectively block a nerve signal, which is dependent on the voltage.

In what other ways can intangible entities have physical manifestations? In this case, the unintended effect has a negative consequence, but can we find useful applications of such a circumstance?

Also, if these imaginary aspects can effect reality, what does that say about our definition of what is real and what isn't?


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    Apr 9 2012: I think that things like "reality" are best discussed in terms of relationships between different entities, sort of like how loud a sound is. Sounds are discussed in decibels with respect to the threshold for human hearing. Similarly, I think the term "reality" is only meaningful when we use it in a context.

    To apply this perspective to the virtual electrode example, some might say that the virtual electrode is just as "real" as the "real" one, because of its physical effects. On the other hand, some might say that we have no definite way of judging if either electrodes are real in the first place. Each of these arguments has its place, but it has to be rooted in context.
    • Apr 10 2012: That's an interesting analysis, Andrew. I'm not sure that I agree with your claim that reality is only meaningful in context, however. The virtual anode and cathode both act as though they are real, but they if you were to try to verify that hypothesis by, say, putting an axon fiber on the other side of the electrode, you would see the anode and cathode switch, contradicting your original assumption. Mathematical analogies are only useful under the set of circumstances for which they were intended, and oftentimes even fall short there.

      I believe that the truth is a very well-formed entity and only requires well-formed definitions to be understood. Any definition that would allow you to call the "virtual anode/cathode" a "real anode/cathode" is of less philosophical value than one that allows you to discriminate between the two while still allowing you to retain a certain set of definitive characteristics that make them useful to work with. It's like Plato's Forms...

      ...but also like Plato's Forms, sometimes you just wanna get the job done and don't care to be pedantic with the definitions. In that case, I think your approach is the right one.
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      Apr 12 2012: I agree with Andrew. It's like the wave particle duality or the Copenhagen interpretation of Quantum Mechanics (Schrodinger's Cat). Without context, reality may be a waveform of infinite possibilities. Its only during observation do we give our subjects substance.

      In the end we can never know what is real and what is not. We receive information through our senses and we process it with our brain, but they're limiting as well. If the entire human race was unable to sense color, does that make color non-existent? The concept of color isn't non-existent. We can measure it's wavelength, but the qualia would be completely missing.

      Just another note. Our retina is always firing; the absorption of EM waves causes the cones and rods in our eye to stop firing, so our brain only detects the lack of visual action potentials. We also don't pick up colors as individual channels, luminance, red-green, blue-yellow are paired together. Our eyes actually only sense the contrasts of the pairs. Knowing this tid-bit, would you say that the concept of color channels is "virtual"? We never sense them as separate entities, they always have to be paired together. Why not call "red-green" a singular entity, and label red and green as representations of virtual components that make up "red-green"?

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