Visual fire

  • #1
Vinay080
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I am reading the book "A History Of Optics" by Oliver Darrigol, and I came across this sentence (under the heading Visual Fire):
In the Greek popular understanding of the visual process, the eye emits a fire whose rays probe the surface of the observed object
Isn't this a low-quality argument? This can be directly disproved by the fact that humans inbabilty to see in dark, viz. if humans can see things from the "fire" emitted from their eyes, then they can see things in dark. Is this just a bogus argument given push because of its fancy look or was there any strong support for this view?

The question took significance for me, as every concieved principles will be trying to look for generality, and this principle is also concieved to look for generality in explaining things; and I was wondering whether the proper support for this argument has anything to donate for the future development of the nature's explanation.
 
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  • #2
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Maybe the "fire" has to reach surfaces that are lit? It also has to reach red surfaces to give the impression of red...
We know that model is wrong today (and with the knowledge of a finite speed of light it is obvious), but with the limited knowledge back then it was a possible model.
 
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  • #3
Vinay080
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And..breaking news! I continued reading, and came to Empedocles; he is said to belive that the cause of vision to be because of both from the fire of eye and the flame of sun, based on the principle (though not rigorous, but by "analogy" hypothesis) that (quoted from the book)
By earth in us we percieve earth; by water in us water; by air in us, the gods' air; and consuming fire by fire in us

This lifts up most of the problems on the argument, based on the situation of those days; but understanding still more on their like arguments (if there are any) towards the model will be of interest to the future models (if required).
 
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davenn
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And..breaking news! I continued reading, and came to Empedocles; he is said to belive that the cause of vision to be because of both from the fire of eye and the flame of sun, based on the principle (though not rigorous, but by "analogy" hypothesis) that (quoted from the book)
This lifts up most of the problems on the argument, based on the situation of those days; but understanding still more on their like arguments (if there are any) towards the model will be of interest to the future models (if required).

And this is all still totally wrong in the light of known physics today

I suggest you start reading some more modern physics text books, at least 2000 years ahead of what you have been reading

Dave
 
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  • #5
256bits
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And..breaking news! I continued reading, and came to Empedocles; he is said to belive that the cause of vision to be because of both from the fire of eye and the flame of sun, based on the principle (though not rigorous, but by "analogy" hypothesis) that (quoted from the book)

This lifts up most of the problems on the argument, based on the situation of those days; but understanding still more on their like arguments (if there are any) towards the model will be of interest to the future models (if required).

Kudos to you!
Reading about and being aware of the history of science and how humans placed themselves and regarded their relationship to the earth and the cosmos is interesting in itself. Different cultures might have seen themselves in different a different light then others, you may be well aware.

You may have a different perspective on inductive and deductive reasoning, their strengths and weaknesses, from pursuing such an endeavor, other than that gained by studying the popular basic Plato philosophy courses or that stressed in such as geometry and its axioms.

It might give you also a better understanding of the axioms upon which of modern science relies, and whether or not there are some inherent faults or areas that need further investigation.
 
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  • #6
Vinay080
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I suggest you start reading some more modern physics text books, at least 2000 years ahead of what you have been reading
:biggrin: I am reading "History" book, which contains all the physics, back from past to present; but I do agree to learn more modern concepts as you suggested, I just happend to read the past theories in that book, and went on analysing their reasoning.

That being said, @256bits has said correctly, on the importance of studying history.
 
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