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Fact vs theory

  1. Feb 10, 2010 #1
    I was just curious as to when science goes from fact to theory? What do we know to be absolute? Are balck holes for example still theory? Is GR and SR still only theory? Where is our line of absolute fact?
  2. jcsd
  3. Feb 10, 2010 #2
    Why did this get moved to Philosophy? Physics is the study of real things. So I am asking what do we know is real (physics) and what is theory (physics and Philosophy).
  4. Feb 10, 2010 #3
    Define "Fact."
  5. Feb 10, 2010 #4


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    Gold Member

    This is the wrong way to think about it. Instead of talking about facts and theories (which imply absolutes), look at it as being about models and measurements.

    We create a model (to do something, for a reason). The model predicts things. We measure to see in the predictions were correct. Then change the model to make better (for our purposes) predictions in needed.

    So GR is a model. And we make measurements in the terms it requires.

    GR does predict black holes as a general "fact". And more detailed predictions can be made about how a black hole might lens light, or anchor a galaxy. We can then go looking for those "facts" too.

    But we never know anything absolutely about external reality. We just exhibit better and better modelling capabilities. We achieve our purposes ever more effectively.

    The pursuit of absolute truth and certain knowledge is a pipe dream. But there is nothing standing in the way of improved modelling.
  6. Feb 10, 2010 #5


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    The general physics forums are for discussing physics theory and application, not discussing the philosophy of science. This question goes to the philosophy of science.

    This question is actually a relatively simple matter of definitions. The answer is that a fact and a theory are two completely different things and no, there is no "science goes from fact to theory". Or put another way, a theory never becomes a fact.

    A fact is a piece of information known to be true. It is data. Observations.
    A theory, from the wiki, is "an analytic structure designed to explain a set of empirical observations."


    Now this question often comes from a misinterpretation of specific theories and their standing. So to address that possibility, gravity. Is gravity a fact or theory? Well, it is both. Gravity is, first and foremost, an observed phenomena. When you release an object from your hand and it drops to the earth, "gravity" is the name given to the phenomena that causes it to drop. Our current theories of gravity are theories that seek to explain this observational fact.
    Last edited: Feb 10, 2010
  7. Feb 10, 2010 #6
    Fact: Things fall down.
    Theory: This is caused by the curvature of space/time
  8. Feb 11, 2010 #7
    I am not sure how to explain what I am asking. For example we know things like how cells work, and DNA etc. But how much do we know about atoms? Not theory about atoms. That is what I mean by where theory begins. Does this make any sense?
  9. Feb 11, 2010 #8
    No. Things about how cells work is as much theory as our knowledge of atoms. In science, theories never move from theory to fact, regardless of how many times/ways they have been verified. There is no such thing as absolute fact in science, except for explicit observations. Your question is ill posed.
  10. Feb 11, 2010 #9
    You are not using the word 'theory' the way scientists do.


    Facts are just essentially data, a theory is the structure, or context, of facts about the world. A scientific theory offers an explanation and predictive power.

    A theory, in a scientific sense, is not equivalent to 'mere opinion', like the way the word is used by people in the more everyday sense.
  11. Feb 11, 2010 #10
    From a scientific perspective, fact is a colloquialism, so it is really not appropriate to compare it to theory, which is part of the scientific nomenclature.

    The term theory itself is problematic in science, and I would give a general definition of something along the lines of, a falsifiable, predictive explanation of natural phenomena. One of the most problematic question is the demarcation between a hypothesis and a theory.

    So essentially, you can say that the theory of special relativity or the theory of evolution are currently treated in their respective branches of science as facts, but the word fact itself has no specific meaning in science, because the philosophical underpinnings of science hold that any theory, no matter how much it is treated like a "fact", is potentially falsifiable.

    One mistake many people make is to think that, in science, a theory is synonymous with "guess" whereas scientists often treat specific theories the way that non-scientists would treat "facts".

    If you want further background, you might start here (http://en.wikipedia.org/wiki/Philosophy_of_science) and consider reading a book or attending a lecture on the philosophy of science, which is a fascinating (and often maddening) subject.
  12. Feb 12, 2010 #11
    Thanks. I have been reading philosophy of science all day now. Funny how any question by science can be answered by another question by philosophy and vice versa. It reminds me are arguments I had when I was a kid. Like when I would keep asking why, why, why until the other person got frustrated and said I DONT KNOW.
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