I've heard that Auguste Comte, the founder of positivism, used the issue of the chemical composition of the Sun to illustrate his idea of questions that could not be answered.
Since it is obvious (in Comte's view) that we can never get a sample from the inside of the sun to test, we can never know what it is made of, and such an inquiry should be written off as "metaphysical," not positive.
Silly philosophers, eh? It is very easy in hindsight to say that Comte shouldn't have been so dogmatic about the possible reach of human knowledge, or the specific means by which chemical composition can be determined.
What about the inside of a black hole? Can we say anything definitive about THAT? If so ... how? since we can't go there? Or, if anyone of us could get within the "event horizon" for a time, we couldn't get information back.
In a recent blog post, a physicist, Sabine Hossenfelder, considers whether the question of the contents of a black hole ought to concern physicists, or anyone who philosophizes about physics. She is of the view, in general, that physicists should not speculate about that which is in principle unobservable, such as the other universes in a "multiverse". But she does NOT see the inside of a black hole as in the same boat, because, she writes: "no one really thinks that the inside of a black hole will remain inaccessible forever."
We are in Comte's position, then, Unable to see how we COULD get such information. But if we are wise we won't jump to the conclusion that we can't.
But I'm not sure I grok her point: she wants to say that the black hole situation is very different from that of the other universes. But could we not treat them both the same, and regard ourselves as Comte both times?
This claim certainly lit up the comments section of her blog in an enlightening way.
I don't understand why Comte would view the question of the chemical composition of the sun as "metaphysical." Clearly, it is empirical and, in his day, could not be answered for purely practical reasons.
ReplyDeleteHenry,
DeleteAll I know is what he said on the subject, which was quite clear.
"On the subject of stars, all investigations which are not ultimately reducible to simple visual observations are ... necessarily denied to us. While we can conceive of the possibility of determining their shapes, their sizes, and their motions, we shall never be able by any means to study their chemical composition or their mineralogical structure ... Our knowledge concerning their gaseous envelopes is necessarily limited to their existence, size ... and refractive power, we shall not at all be able to determine their chemical composition or even their density... I regard any notion concerning the true mean temperature of the various stars as forever denied to us."
Only 14 years after he wrote those words, a physicist named Gustav Kirchhoff made the critical breakthrough in the analysis of light to determine the composition of its source.
http://www.faculty.virginia.edu/rwoclass/astr121/comte.html