Standard Definitions for Science Threads

Vanity ^ | 31 January 2006 | PatrickHenry and Coyoteman

[PatrickHenry]

This thread is intended to be a workshop, where we can thrash out the definitions on which all the science-literate freepers can agree. When we are agreed on one final list, we can then link to it in future threads, in the hope of bringing some order to the linguistic chaos that too often prevails in the science threads.

In discussions about science and philosophy, we must be careful about our terminology, so that we're all using words in the same way. Dictionaries provide multiple definitions, but not all are appropriate in a specific context. It only generates confusion to substitute one meaning where another is clearly called for.

Every specialized discipline has its own terminology. That's what you must learn and use when dealing with that discipline. For example, the word "law" means one thing to a lawyer, another thing to a physicist, and yet something else to a grammarian. If you want to discuss "the law" with a professor of law, you'd best not confuse the conversation with other usages of that word. If you use the wrong terms, you'll fail to communicate. And no, you won't "win" the debate when others fail to reply on your terms. If they don't reply, it's because everyone who knows the topic finds your discourse meaningless.

If you insist on having your own personal language, which no one but you can comprehend, you are abandoning the best tool humanity has ever developed for becoming civilized. If your thoughts -- such as they are -- are intelligible only to you, then you'll have to be content to have your own personal debate -- with yourself.

These are Coyoteman's definitions:

Theory: a well-substantiated explanation of some aspect of the natural world; an organized system of accepted knowledge that applies in a variety of circumstances to explain a specific set of phenomena; "theories can incorporate facts and laws and tested hypotheses." Addendum: "Theories do not grow up to be laws. Theories explain laws." (Courtesy of VadeRetro.)

Hypothesis: a tentative theory about the natural world; a concept that is not yet verified but that if true would explain certain facts or phenomena; "a scientific hypothesis that survives experimental testing becomes a scientific theory"; "he proposed a fresh theory of alkalis that later was accepted in chemical practices"

Guess: an opinion or estimate based on incomplete evidence, or on little or no information

Law: a generalization that describes recurring facts or events in nature; "the laws of thermodynamics"

Assumption: premise: a statement that is assumed to be true and from which a conclusion can be drawn; "on the assumption that he has been injured we can infer that he will not to play"

Model: a simplified framework designed to illuminate complex processes; a hypothetical description of a complex entity or process; a physical or mathematical representation of a process that can be used to predict some aspect of the process

Speculation: a hypothesis that has been formed by speculating or conjecturing (usually with little hard evidence)

Observation: any information collected with the senses

Data: factual information, especially information organized for analysis or used to reason or make decisions

Fact: when an observation is confirmed repeatedly and by many independent and competent observers, it can become a fact

Belief: any cognitive content (perception) held as true; religious faith

Faith: the belief in something for which there is no evidence or logical proof; acceptance of ideals, beliefs, etc., which are not necessarily demonstrable through experimentation or reason

Dogma: a religious doctrine that is proclaimed as true without proof

Religion: (theistic): "1 the belief in a superhuman controlling power, esp. in a personal God or gods entitled to obedience and worship. 2 the expression of this in worship. 3 a particular system of faith and worship." Non-Theistic: "The word religion has many definitions, all of which can embrace sacred lore and wisdom and knowledge of God or gods, souls and spirits. Religion deals with the spirit in relation to itself, the universe and other life. Essentially, religion is belief in spiritual beings. As it relates to the world, religion is a system of beliefs and practices by means of which a group of people struggles with the ultimate problems of human life."

Impression: a vague idea in which some confidence is placed; "his impression of her was favorable"; "what are your feelings about the crisis?"; "it strengthened my belief in his sincerity"; "I had a feeling that she was lying"

Opinion: a personal belief or judgment that is not founded on proof or certainty.

And this is my own humble offering, which I've posted from time to time in various threads, and which I haven't yet attempted to integrate into the foregoing:

FAITH, REASON, KNOWLEDGE, AND BELIEF

Strictly speaking, what one "believes" on faith and what one "knows" are different things.

Belief: One can "believe" in the existence of the tooth fairy, but one does not -- in the same sense of the word -- "believe" in the existence of his own mother.

Faith: Belief in the first proposition (tooth fairy) requires faith, which is belief in something for which there is no evidence or logical proof.

Knowledge: The second proposition (mother) is the kind of knowledge which follows from sensory evidence.

Logical Proof: There is also that kind of knowledge (like the Pythagorean theorem) which follows from logical proof. In either case -- that is, knowledge acquired from sensory evidence or demonstrated by logical proof -- there is no need for faith, and that term is inapplicable to such knowledge.

Scientific theory: In between mother (knowledge from sensory evidence) and the Pythagorean theorem (knowledge from logical proof) are those propositions we provisionally accept (or in common usage "believe"), like relativity and evolution, because they are currently successful scientific theories -- testable, and therefore falsifiable explanations of the available, verifiable data (which data is knowledge obtained via sensory evidence). Here too, there is no need for faith, and that term does not apply in the context of scientific theories.

Proof: Except for math and geometry, there is little that is actually proven. Even well-established scientific theories can't be conclusively proven, because -- at least in principle -- a counter-example might be discovered. Scientific theories are always accepted provisionally, and are regarded as reliable only because they are supported (not proven) by the verifiable facts they purport to explain and by the predictions which they successfully make. All scientific theories are subject to revision (or even rejection) if new data are discovered which necessitates this.

Confidence: When a scientific theory has a long history of being supported by verifiable evidence, it is appropriate to speak about "acceptance" of (not "belief" in) the theory; or we can say that we have "confidence" (not "faith") in the theory. The word "faith" is inapplicable in this context.

It is the dependence on verifiable data and the capability of testing that distinguish scientific theories from matters of faith. Purely theological matters that are believed on faith are not capable of being tested, and thus theological doctrines are not scientific.

Reason: "Reason -- the faculty which identifies and integrates the material provided by man's senses -- is man's only means of perceiving reality, his only source of knowledge, his only guide to action, and his basic means of survival." -- Ayn Rand

Many people come into these threads unaware of the vital distinctions between reason and faith. It is necessary to distinguish between an axiom (which is a logical necessity) and an article of dogma (an arbitrary assumption), between objective fact and subjective experience, and between hypothesis (a proposed, testable explanation of an observed phenomenon) and conjecture (a guess based on virtually no data). Understanding these fundamental concepts allows us to distinguish reason-based science from faith-based doctrine. Reason and faith are commonly confused, but they are very different intellectual enterprises, with different goals. When properly understood, they are not in conflict.

[grey_whiskers]

When WHAT happens to me? Are you saying that I must be addicted to something?

You mean you're NOT addicted to Free Republic? ;-)

Cheers!

[grey_whiskers]

You might also want to add the correspondance principle. The Correspondance Principle says, "Any new theory must contain the old theory as a limiting case." The reason for the incluison is that some folks think that theories can be replaced and the old one junked. That's never true. The old theory must always appear as a limiting case.

One other note, might want to have the addendum that the old theory should be (at least somewhat) empirically validated: e.g. the law of gravitation vs. Aristotle's de Caelo; phlogiston vs. oxygen. The existence of phlogiston was a widely held [belief? theory? -- people weren't using empiricism as much back then, which was part of the problem :-) ]. Call it a theory. Nonetheless, it was discarded in favor of valence chemistry. Or another example would be Geocentric cosmology (epicycles, etc.). To a certain extent they could correctly predict planetary movements, but at the cost of a lot of trouble. But the theory was completely supplanted by Copernicus etc.

Cheers!

[grey_whiskers]

PH to Alamo_GirlI only pinged my small, hard-core science list for this one. But if I had given it any thought at all, I certainly would have included you.

G_W jumping in with an unavailing pun:

I guess that makes me strictly "soft-core." Thanks. I think :-)

Cheers!

[Alamo-Girl]

LOLOL! Thanks for the chuckle!

[grey_whiskers]

Sorry, past my bedtime.

I've been up Freeping too late and got an ear infection.

Prayers for the ear, for my self-discipline (in regards to sleep) are welcome.

Flames and taunts regarding the inefficacy of prayer are forwarded to either

a) /dev/null

or

b) your future address by way of the fireplace(*)

(*)Free electronic prize to the first freeper to identify the literary source from which I shamelessly stole choice b).

Cheers!

[Alamo-Girl]

I pray for a complete healing of your ear, a wonderful night's sleep and a perfect day tomorrow!

[spunkets]

"in situations to which both theories are applicable"

It's implied that the theory is applicable. There are not 2 theories though. The old one is an approximation as some limit is approached. " Quantum mechanics reduces to classical mechanics in the limit of large number of particles;"

No, the classical limit applies when the energies of the particles are continuous and much greater than h. That way quantization can be ignored. Consider a metal, a semi-conductor, a plasma, a black body, or the specific heat of a real gas. Quantum mechanics applies, even though these are systems of a large number of particles. In general, field theory involves large numbers of particles. A bowling ball, or a train have E, much greater than h, so quantizing such mechanics doesn't make sense. If h/x*p <<1, where x is the scale of length for the process, and p is the momentum, the wave aspect won't be seen. So it's the scale that allows the approximation. The approximation is the old theory arising out of the new one.

"special relativity reduces to Newtonian physics as v << c. But the new theory usually addresses (at first) specifically those cases in which the old theory fails."

Yes, as v/c->0, special relativity -> Euclidian. In this case, that's the limit. In GR, it's when the local energy density is low and the space is flat.

[spunkets]

"The existence of phlogiston was a widely held [belief? theory? -- people weren't using empiricism as much back then, which was part of the problem :-) ].Call it a theory. Nonetheless, it was discarded in favor of valence chemistry."

It was an unproven hypothesis. The correspondance principle only applies to theories based on a solid fundation of real evidence. W/o empirical evidence, there is no theory.

[grey_whiskers]

No, the classical limit applies when the energies of the particles are continuous and much greater than h.

Hmm, the energies of the particles are always quantized. In the macroscopic limit, the large number of particles means that the energy "seems" continuous, due to the additive effect of many small quanta. E.g. the individual energy states are so close together for a macroscopic system (say an automobile) that in practical terms you can't tell them apart. There is a difficulty in measuring small differences in large numbers... As far as the energy being greater than h, pass. The Road Runner notwithstanding, tunneling is not known to occur for macroscopic objects :-)

[grey_whiskers]

W/o empirical evidence, there is no theory.

Grey area due to semantics, there were cases in which it "appeared" to work; and the principles of empiricism were not firmly enough established that people back realized it was an unproven hypothesis. The distinction between hypothesis and theory wasn't as firm back then. One of the drawbacks of scholasticism. (See also Galen...; or some analogy to Owen Barfield's "ancient unities"...)

Cheers!

[spunkets]

"In the macroscopic limit, the large number of particles means that the energy "seems" continuous, due to the additive effect of many small quanta. E.g. the individual energy states are so close together for a macroscopic system (say an automobile) that in practical terms you can't tell them apart."

Only, because h/x*p << 1. "There is a difficulty in measuring small differences in large numbers.."

No. Have some coffe and ponder an electron gas in a metal, or the carriers in a semi-conductor. Then try x-ray scattering. All of these have a huge number of particles in the system. H/x*p is not << 1 here.

[spunkets]

" Grey area due to semantics, there were cases in which it "appeared" to work;"

Appearances don't count. It doesn't predict anything, because it doesn't explain reality. In most of those old cases that amount to hypothesis, the logic wasn't even that good. In hypothesis like "caloric", testing which could have been done, but was not, until someone finally realized that(Joule, I think.). They failed to note that the heat generated was a function of friction, not cutting. What matters is having a precise definition, independent of state of knowledge, instrumentation and "philosophy".

[spunkets]

"Hmm, the energies of the particles are always quantized. In the macroscopic limit, the large number of particles means that the energy "seems" continuous, due to the additive effect of many small quanta. E.g. the individual energy states are so close together for a macroscopic system (say an automobile) that in practical terms you can't tell them apart."

Also, consider the very first quantum theory. It had to do with heat and light. It was Plank's quantum theory that straightened out the divergence in the Stephan-Boltzman law.

"The Road Runner notwithstanding, tunneling is not known to occur for macroscopic objects"

The probability can be calculated though. Tunneling also depends on the barrier height, the size of the bounding region and the wavelength. Even quantum systems can have an essentially zero probability that tunneling will occur. A bowling ball has already tunneled out of any region it could possibly be held in.

[RadioAstronomer]

Thanks! :-)

[<1/1,000,000th%]

the belief in something for which there is no material evidence sufficient material evidence for consensus or empirical proof; acceptance of ideals, beliefs, etc., which are not necessarily demonstrable through experimentation or observation.

I wouldn't tie faith to material evidence. I don't think that usage would make sense to the other side of the argument.

[grey_whiskers]

g_w:Only, because h/x*p << 1. "There is a difficulty in measuring small differences in large numbers.."

spunkets:No. Have some coffe and ponder an electron gas in a metal, or the carriers in a semi-conductor. Then try x-ray scattering. All of these have a huge number of particles in the system. H/x*p is not << 1 here.

I think we are talking past one another here, I was not merely referring to uncertainty principle (theoretical limitation on discerning energy precisely), but also to the difficulty of distinguishing continuous from very small discrete steps...(only a practical difficulty, but still exists).

Cheers!

[grey_whiskers]

Also, consider the very first quantum theory. It had to do with heat and light. It was Plank's quantum theory that straightened out the divergence in the Stephan-Boltzman law.

Sounds like a "catastrophe" to me :-)

The probability can be calculated though. Tunneling also depends on the barrier height, the size of the bounding region and the wavelength. Even quantum systems can have an essentially zero probability that tunneling will occur. A bowling ball has already tunneled out of any region it could possibly be held in.

Yes, but for bowling balls the probability is so small as to be much less than experimental error, so it can be ignored for day-to-day work. It's one of the reasons I can't pick up 7-10 splits even AFTER several beers. :-)

Cheers!

[grey_whiskers]

I wouldn't tie faith to material evidence. I don't think that usage would make sense to the other side of the argument.

Sorry, I was just trying to be complete. What do you do with things like the Mons Angels, Shroud of Turin, etc. where you have either credible eyewitnesses without other axes to grind, or disputed physical evidence (carbon dating of a non-representative sample to muddy the waters, suggestions of Maillard reactions which are consistent with the chemical structure but not "topography" of the image...)

Cheers!

[grey_whiskers]

What matters is having a precise definition, independent of state of knowledge, instrumentation and "philosophy".

Interesting take. If you say that phlogiston (to choose one example) is not a theory, OK, then the statement about one theory not REPLACING another holds for that case, since phlogiston was not a theory. What do you do about "paradigm shifts" when the original paradigm was not a theory to begin with (see also pre-Copernican cosmology)?

Stirring the pot, part II:

Or for that matter, psychology, which Feynman called "cargo-cult science". It is empircally based, or at least "semi-empirical" ... :-)

How do you classify behaviourism vs. Freudianism, or the dispute between them?

[SuzyQue]

Good point.