A asked in Science & MathematicsPhysics · 4 weeks ago

How is a scientific consensus defined?

Whether it be the theory of evolution or the theory of gravity, what level of acceptance and endorsement does there need to be in order to say that there exists a scientific consensus about something?

9 Answers

  • oyubir
    Lv 6
    3 weeks ago

    We don't gather in a high castle for a secret meeting, to define consensus, if that is your question.

    There is no scientific definition of consensus. Keep in mind that we are talking about science (I exclude math, although I am a mathematician myself. In math, there is no need for a consensus. A theorem is true or is not. Is proven or is not. Well, there might be some debates about the validity of a "theory". But the word "validity" and the word "theory" have not at all the same meaning in math than in science).

    In science nothing is "true". We have found the universe as is. There was no user manual attached to it (even if you believe that the Bible is the closest thing we have to a user manual, it gives nothing useful to make predictions — prediction on tomorrow weather, or on the efficiency of a drug, or on the evolution of climate).

    So, we are forced to surmise things and doomed to never know the truth. I mean, I surmise that if you drop your keys, they will fall on the ground. Because all observations have shown that all dropped keys fall on the ground, hence a scientific consensus that things tend to fall on the ground (and, with further details, that things tend to follow gravity theory).

    But that is "just a theory". I put quotes around the expression, because "just a theory" doesn't bear the same amount of doubt than in everyday meaning.  A scientific theory is, sure, "just a theory", but it is (else it is not a scintific theory) proven. Not proven to be true (that is impossible. Again, nothing can be proven to be true in science). But proven to be the most parsimonious testable theory that match the observations.

    So, that doesn't answer your question. But redefines about what there are "consensus": not about the veracity of a theory (again, no theory even claims to be true). But about the fact that this theory is the most parsimonious way to describe observations.

    "Parsimonious" here meaning, not "easiest", but "the one that need the less asumptions".

    For example, you can have beautiful theories describing courses of stars in the sky. Ancient people had some working one. Which were very valid (not "true", obviously. But ours certainly aren't neither. But good description of what they see in the sky. Testable theories. That could be used to predict eclipses and tides).

    You can have theories to describes the fall of objects on the ground.

    But, when Newton coins his theory that a single phenomenon, gravity, explains both movement of things in the sky, and falls of objects on the ground, very quickly it becomes a consensus. Because, clearly, it allows the same amount of predictive accuracy. Even more. And, it is parsimonious: a single theory does the job of 2 previous one.

    So, it is about that that we have a need for consensus: which is the best theory to describe phenomenons. "Best", in the sense "more predictive and parsimonious".

    That being said, there is still no definition of "consensus".

    I would say that there is a consensus, when scientist who are in favor of a theory don't even bother to prove it (prove that it is testable, predictive, parsimonious, ...), and, on another hand, scientist who disagree, have to prove their point.

    The burden of the proof weight on the one who is against the consensus (it is not exactly what the saying is. But it is what it means in practical)

    And most of the time, both sides of a debate, implicitly agree on who must carry the burden of the proof.

    For climate change, for example, in a scientific paper, you can skip the "climate change is real" part and go to the point (I published, decades ago, papers on the effect of climate change on snowpack evolution. I didn't have to start with convincing the reader that climate change is real). Climate change denier, on the other hand, need to start their paper with arguments against climate change (and generally, that is in fact the sole content of their article). Because they have the consensus against them.

    Likewise, when Newton published his paper on gravity, he, and his followers were focused on proving that this new theory was the good one. While others could publish new method to predict eclipse, without bothering to reexplain and reprove the "seven heavens" theory. Because they have the consensus with them (not really "scientific consensus", since science invention date from Newton, Bacon, etc.).

    Very quickly, people were convinced, and now (and since only decade after Newton) it is the one who want to claim that other reason than gravity explains light in the sky who need to prove their point. The rest of us can just write F=mMG/R² without argument and explanation. Because that is the consensus.

  • 3 weeks ago

    Consensus : General agreement.

    I guess it means that if a general agrees with it it is accepted as a theory. if the general does not agree is is accepted as BS.

    I may be wrong.

  • 3 weeks ago

    True scientific consensus takes decades to achieve at a minimum. When a theory does achieve this, it can also be said to have "universal acceptance". To have scientific consensus, a theory can have NO reputable scientific source that disputes it's authenticity. Gravity and Evolution reached consensus a long time ago. Global Warming, while close, still has not.

    In the history of human science, no theory that reached scientific consensus has ever been shown to be wrong later. Even upon unearthing dramatic new evidence, the theory still stands on the weight of the old and is tweaked to include the new, it never falls completely.

  • Jim
    Lv 7
    3 weeks ago

    Pre-publish for peer review.

    Other scientists will set up multiple experiments to duplicate results.

    If results are achieved, then the paper is "Peer Reviewed" and "published".

    Anytime afterward, if any experiment shows theory not supported, the process starts over again!

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  • 4 weeks ago

    It's a term coined by the 'global warming' activists, and has no scientific relevance.  A scientific theory is useful until and unless contradicting evidence is found. 

  • Dixon
    Lv 7
    4 weeks ago

    It doesn't have a special definition, it is just a consensus within the scientific community. That opinion will be apparent from conference talks, published articles and papers etc. I would say that in general scientific consensus is prudently skeptical but ultimately moved by the weight of evidence, regardless of previous ideas.

  • Zirp
    Lv 7
    4 weeks ago

    Science comes up with hypotheses to explain the observations.

    Until new observations or any other plausible reason suggesting that the hypothesis is wrong appear, you have consensus.

  • 4 weeks ago

    There is no consensus about the numerical definition of "consensus". I might suggest 75%, others might pick 80% or even 90%.

  • 4 weeks ago

    The consensus about a topic is difficult to achieve initially because of lack of knowledge about that topic or lack of strong evidence. But as the research progresses and more and more scientists starts enquiring or validating about that topic, consensus can be achieved. This is true that debate and controversies begins when the new theory about a particular topic emerges but consensus can be achieved as the time progresses. The example of consensus are the newtons's gravitational laws, principal of superposition, uniformity law etc.

     The collective opinion, judgment of the community of scientists in a field of study is known as consensus.

    The consensus have been achieved in the IPCC reports by the scientists. As of result of this consensus problem of global warming and its impact was taken seriously. This led to development of United Nation conference on environmental development(UNCED)at Rio Di Janeiro in 1992. The problem of global warming was accepted and international framework convention(FCCC) on climate change was constructed in which about 160 countries including the signing of the convention by President George Bush of United States.

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