View Full Version : [SOLVED] Theory, Model and Law
news user
Sep20-04, 03:38 AM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>\nDear all,\n\nwe are having a small discussion on the meaning of the\nwords "theory", "model" and "law" as used by physicists,\nin their everyday work.\n\nWould it be possible to have a small definition, or at\nleast a feeling of how these words are used ? With\nsome emphasis on what differentiates them.\n\nThanks much, that would be kind\n\n--- Raoul\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>Dear all,
we are having a small discussion on the meaning of the
words "theory", "model" and "law" as used by physicists,
in their everyday work.
Would it be possible to have a small definition, or at
least a feeling of how these words are used ? With
some emphasis on what differentiates them.
Thanks much, that would be kind
--- Raoul
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>\n\nnews user <news@sisyphus.news.be.easynet.net> wrote in message news:<MPG.1bb7dc2c463f5f6f9897fe@news.easynet.be>. ..\n\nTheories are a hypothesis of how something might work.\nModels are mappings between theories and the experimental evidence.\nLaws are generally theories that have been elevated to the realm of\ntruth. Somtimes laws are used as foundation principles for a theory\nmeaning that if the theory can be proven correct, that is, the\nmodels predict the observed physical evidence, then the foundation\nlaws must be correct as well.\n\nIt\'s important to remember that theories, models and laws are\nalmost always incomplete. For example, Newtons law of Universal\ngravitation is a very good approximation of gravity, but we know that\nGeneral Relativity is a more complete theory. General Relativity\nitself is incomplete because it doesn\'t appear to work at particle\nscales. Even Laws can be sometimes overturned. For example, at one\ntime, it was the undeniable truth that the Earth was flat.\n\nGeorge\n\n> Dear all,\n>\n> we are having a small discussion on the meaning of the\n> words "theory", "model" and "law" as used by physicists,\n> in their everyday work.\n>\n> Would it be possible to have a small definition, or at\n> least a feeling of how these words are used ? With\n> some emphasis on what differentiates them.\n>\n> Thanks much, that would be kind\n>\n> --- Raoul\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>news user <news@sisyphus.news.be.easynet.net> wrote in message news:<MPG.1bb7dc2c463f5f6f9897fe@news.easynet.be>...
Theories are a hypothesis of how something might work.
Models are mappings between theories and the experimental evidence.
Laws are generally theories that have been elevated to the realm of
truth. Somtimes laws are used as foundation principles for a theory
meaning that if the theory can be proven correct, that is, the
models predict the observed physical evidence, then the foundation
laws must be correct as well.
It's important to remember that theories, models and laws are
almost always incomplete. For example, Newtons law of Universal
gravitation is a very good approximation of gravity, but we know that
General Relativity is a more complete theory. General Relativity
itself is incomplete because it doesn't appear to work at particle
scales. Even Laws can be sometimes overturned. For example, at one
time, it was the undeniable truth that the Earth was flat.
George
> Dear all,
>
> we are having a small discussion on the meaning of the
> words "theory", "model" and "law" as used by physicists,
> in their everyday work.
>
> Would it be possible to have a small definition, or at
> least a feeling of how these words are used ? With
> some emphasis on what differentiates them.
>
> Thanks much, that would be kind
>
> --- Raoul
Arnold Neumaier
Sep24-04, 08:08 AM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>news user wrote:\n\n> we are having a small discussion on the meaning of the\n> words "theory", "model" and "law" as used by physicists,\n> in their everyday work.\n\nTheory = a collection of well-organized concepts used to describe and\nideally explain a class of phenomena, and interrrelated by more or less\nmathematical reasoning.\nModel = a mathematical, formal idealization of a process or structure\nin real life, used to explain or predict the particular process\nor structure.\nLaw = an important statement valid in the context defined by a particular\ntheory.\n\n\n> Would it be possible to have a small definition, or at\n> least a feeling of how these words are used ? With\n> some emphasis on what differentiates them.\n\nFor example:\n\n\'\'The theory of thermodynamics is used to model dissipative\nphenomena close to equilibrium. The defining property of\ndissipative phenomena is the second law of thermodynamics, which says\n(in the statistical mechanics interpretation) that in all macroscopic\nsystems, some energy dissipates into unobservable degrees of freedom.\nThese are not accounted for in thermodynamic models and hence show\nup there as a loss of energy. In equilibrium, energy can no longer be\ndissipated, and energy is conserved; this is the first law of\nthermodynamics (valid only in equilibrium). A large part of engineering,\nfrom the steam engine to air plane design, is based on thermodynamic\nmodels for analyzing and predicting the behavior of machines.\'\'\n\n\nArnold Neumaier\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>news user wrote:
> we are having a small discussion on the meaning of the
> words "theory", "model" and "law" as used by physicists,
> in their everyday work.
Theory = a collection of well-organized concepts used to describe and
ideally explain a class of phenomena, and interrrelated by more or less
mathematical reasoning.
Model = a mathematical, formal idealization of a process or structure
in real life, used to explain or predict the particular process
or structure.
Law = an important statement valid in the context defined by a particular
theory.
> Would it be possible to have a small definition, or at
> least a feeling of how these words are used ? With
> some emphasis on what differentiates them.
For example:
''The theory of thermodynamics is used to model dissipative
phenomena close to equilibrium. The defining property of
dissipative phenomena is the second law of thermodynamics, which says
(in the statistical mechanics interpretation) that in all macroscopic
systems, some energy dissipates into unobservable degrees of freedom.
These are not accounted for in thermodynamic models and hence show
up there as a loss of energy. In equilibrium, energy can no longer be
dissipated, and energy is conserved; this is the first law of
thermodynamics (valid only in equilibrium). A large part of engineering,
from the steam engine to air plane design, is based on thermodynamic
models for analyzing and predicting the behavior of machines.''
Arnold Neumaier
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>news user <news@sisyphus.news.be.easynet.net> writes\n>we are having a small discussion on the meaning of the\n>words "theory", "model" and "law" as used by physicists,\n>in their everyday work.\n>\n>Would it be possible to have a small definition, or at\n>least a feeling of how these words are used ? With\n>some emphasis on what differentiates them.\n\nAs a non-physicist how about:\n\nProposal: a not-unreasonable suggestion of how something works.\n\nHypothesis: A quite well worked out proposal of how something works that\nfits much experimental evidence but can\'t quite explain some others (but\nusually indications that it might/ought to).\n\nTheory: A well tried and tested proposal that is generally used for\n\'engineering\' (that is gives the right answers reliably and has done for\na long time) and that nobody has any reason to doubt.\nNote1 that theories tend to have a well understood \'area of application\'\nwhere they work (to some known level of accuracy).\nNote2 that \'engineering\' is what most scientists do in this context.\n\nLaw: Archaic term for theory. Most laws are rather antique and still so\ncalled because of historic reasons. The \'Gas Laws\' for example are now\nconsidered neither accurate nor in general used for *accurate*\nengineering.\n\n--\nOz\nThis post is worth absolutely nothing and is probably fallacious.\n\nBTOPENWORLD address about to cease. DEMON address no longer in use.\n>>Use oz@farmeroz.port995.com<<\nozacoohdb@despammed.com still functions.\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>news user <news@sisyphus.news.be.easynet.net> writes
>we are having a small discussion on the meaning of the
>words "theory", "model" and "law" as used by physicists,
>in their everyday work.
>
>Would it be possible to have a small definition, or at
>least a feeling of how these words are used ? With
>some emphasis on what differentiates them.
As a non-physicist how about:
Proposal: a not-unreasonable suggestion of how something works.
Hypothesis: A quite well worked out proposal of how something works that
fits much experimental evidence but can't quite explain some others (but
usually indications that it might/ought to).
Theory: A well tried and tested proposal that is generally used for
'engineering' (that is gives the right answers reliably and has done for
a long time) and that nobody has any reason to doubt.
Note1 that theories tend to have a well understood 'area of application'
where they work (to some known level of accuracy).
Note2 that 'engineering' is what most scientists do in this context.
Law: Archaic term for theory. Most laws are rather antique and still so
called because of historic reasons. The 'Gas Laws' for example are now
considered neither accurate nor in general used for *accurate*
engineering.
--
Oz
This post is worth absolutely nothing and is probably fallacious.
BTOPENWORLD address about to cease. DEMON address no longer in use.
>>Use oz@farmeroz.port995.com<<
ozacoohdb@despammed.com still functions.
news user
Sep24-04, 08:12 AM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>In article <691af44f.0409200936.7cd2fa19@posting.google.com>, \ncte@palisad.com says...\n>\n>\n> news user <news@sisyphus.news.be.easynet.net> wrote in message news:<MPG.1bb7dc2c463f5f6f9897fe@news.easynet.be>. ..\n>\n> Theories are a hypothesis of how something might work.\n> Models are mappings between theories and the experimental evidence.\n>\n\nBut a (physical, not mathematical) theory must be falsifiable, right ?\n\nTo be falsifiable, it must specify an interpretation\n(the specification of the mapping to some observable elements)\nin addition to the mathematical description.\n\nThen, in what does it differ from a model ?\n\nAnd why do we call general relativity a theory, and the\nStandard Model a model ? I dont see much differences in\ntheir status....\n\n> Laws are generally theories that have been elevated to the realm of\n> truth. Somtimes laws are used as foundation principles for a theory\n> meaning that if the theory can be proven correct, that is, the\n> models predict the observed physical evidence, then the foundation\n> laws must be correct as well.\n\nOK... A law is a (part of a) much tested theory...\n\nThanks, george\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>In article <691af44f.0409200936.7cd2fa19@posting.google.com>,
cte@palisad.com says...
>
>
> news user <news@sisyphus.news.be.easynet.net> wrote in message news:<MPG.1bb7dc2c463f5f6f9897fe@news.easynet.be>...
>
> Theories are a hypothesis of how something might work.
> Models are mappings between theories and the experimental evidence.
>
But a (physical, not mathematical) theory must be falsifiable, right ?
To be falsifiable, it must specify an interpretation
(the specification of the mapping to some observable elements)
in addition to the mathematical description.
Then, in what does it differ from a model ?
And why do we call general relativity a theory, and the
Standard Model a model ? I dont see much differences in
their status....
> Laws are generally theories that have been elevated to the realm of
> truth. Somtimes laws are used as foundation principles for a theory
> meaning that if the theory can be proven correct, that is, the
> models predict the observed physical evidence, then the foundation
> laws must be correct as well.
OK... A law is a (part of a) much tested theory...
Thanks, george
Arnold Neumaier
Sep27-04, 03:32 AM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>\n\nnews user wrote:\n> In article <691af44f.0409200936.7cd2fa19@posting.google.com>, \n> cte@palisad.com says...\n>\n>>news user <news@sisyphus.news.be.easynet.net> wrote in message news:<MPG.1bb7dc2c463f5f6f9897fe@news.easynet.be>. ..\n>>\n>>Theories are a hypothesis of how something might work.\n>>Models are mappings between theories and the experimental evidence.\n>>\n> But a (physical, not mathematical) theory must be falsifiable, right ?\n\nA correct theory cannot be falsifiable, in spite of Popper.\n\nWhat happens with good theories is, at worst, that their region of\nvalidity or accuracy gets restricted as new data about more remote\ninstances come in.\n\n\nArnold Neumaier\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>news user wrote:
> In article <691af44f.0409200936.7cd2fa19@posting.google.com>,
> cte@palisad.com says...
>
>>news user <news@sisyphus.news.be.easynet.net> wrote in message news:<MPG.1bb7dc2c463f5f6f9897fe@news.easynet.be>...
>>
>>Theories are a hypothesis of how something might work.
>>Models are mappings between theories and the experimental evidence.
>>
> But a (physical, not mathematical) theory must be falsifiable, right ?
A correct theory cannot be falsifiable, in spite of Popper.
What happens with good theories is, at worst, that their region of
validity or accuracy gets restricted as new data about more remote
instances come in.
Arnold Neumaier
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>Arnold Neumaier <Arnold.Neumaier@univie.ac.at> wrote in message news:<4154417C.2060504@univie.ac.at>...\n> ...\n> A correct theory cannot be falsifiable, in spite of Popper.\n>\n> What happens with good theories is, at worst, that their region of\n> validity or accuracy gets restricted as new data about more remote\n> instances come in.\n>\nThis seems to award the accolade "correct" to theories that only agree\nwith nature in places, good in the same sense as the curate\'s egg.\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>Arnold Neumaier <Arnold.Neumaier@univie.ac.at> wrote in message news:<4154417C.2060504@univie.ac.at>...
> ...
> A correct theory cannot be falsifiable, in spite of Popper.
>
> What happens with good theories is, at worst, that their region of
> validity or accuracy gets restricted as new data about more remote
> instances come in.
>
This seems to award the accolade "correct" to theories that only agree
with nature in places, good in the same sense as the curate's egg.
Arnold Neumaier
Sep28-04, 11:50 AM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>DickT wrote:\n> Arnold Neumaier <Arnold.Neumaier@univie.ac.at> wrote in message news:<4154417C.2060504@univie.ac.at>...\n>\n>>...\ n>>A correct theory cannot be falsifiable, in spite of Popper.\n>>\n>>What happens with good theories is, at worst, that their region of\n>>validity or accuracy gets restricted as new data about more remote\n>>instances come in.\n>>\n>\n> This seems to award the accolade "correct" to theories that only agree\n> with nature in places, good in the same sense as the curate\'s egg.\n\nIndeed. All civil engineers and mechanical engineers fare very well\nwith using Newton\'s theory.\nSince Newton\'s theory predicts that, within engineering accuracy,\na number has a certain value, and upon measuring, it has that value,\nit is a correct theory.\n\nIf newton\'s theory were not a correct theory with a very large domain of\napplicability, it would no longer be taught at universities. But in fact\nit is taught to many, many more students than Einstein\'s!\n\nEinstein\'s more comprehensive theory just lets us calculate the\naccuracy to which we can expect Newton\'s older theory to hold true.\nIn most cases, it is far beyond the accuracy to which things are\nmeasured. In some cases (GPS, or very high speed devices), there are\nmeasurable differences - this simply limits (but not severely)\nthe context within which Newton\'s theory is valid.\n\n\nArnold Neumaier\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>DickT wrote:
> Arnold Neumaier <Arnold.Neumaier@univie.ac.at> wrote in message news:<4154417C.2060504@univie.ac.at>...
>
>>...
>>A correct theory cannot be falsifiable, in spite of Popper.
>>
>>What happens with good theories is, at worst, that their region of
>>validity or accuracy gets restricted as new data about more remote
>>instances come in.
>>
>
> This seems to award the accolade "correct" to theories that only agree
> with nature in places, good in the same sense as the curate's egg.
Indeed. All civil engineers and mechanical engineers fare very well
with using Newton's theory.
Since Newton's theory predicts that, within engineering accuracy,
a number has a certain value, and upon measuring, it has that value,
it is a correct theory.
If newton's theory were not a correct theory with a very large domain of
applicability, it would no longer be taught at universities. But in fact
it is taught to many, many more students than Einstein's!
Einstein's more comprehensive theory just lets us calculate the
accuracy to which we can expect Newton's older theory to hold true.
In most cases, it is far beyond the accuracy to which things are
measured. In some cases (GPS, or very high speed devices), there are
measurable differences - this simply limits (but not severely)
the context within which Newton's theory is valid.
Arnold Neumaier
robert j. kolker
Sep28-04, 11:51 AM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>Arnold Neumaier wrote:\n\n>\n> A correct theory cannot be falsifiable, in spite of Popper.\n\nYes it can. If a vetted sound experiment refutes a prediction of the\ntheory, the theory is Wrong. At least one of its assumptions is\nfactually false. This is an application of Modus Tollens. Logic 101.\n\n\n>\n> What happens with good theories is, at worst, that their region of\n> validity or accuracy gets restricted as new data about more remote\n> instances come in.\n\nIf guardian clauses are added to the theory, it is not the same theory\nthat one started with. Two theories are identical if and only if the\ntheorems provable in one are provable in the other and vica versa.\nAdding new postulates independet of the ones already there change the\ntheory.\n\nBob Kolker\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>Arnold Neumaier wrote:
>
> A correct theory cannot be falsifiable, in spite of Popper.
Yes it can. If a vetted sound experiment refutes a prediction of the
theory, the theory is Wrong. At least one of its assumptions is
factually false. This is an application of Modus Tollens. Logic 101.
>
> What happens with good theories is, at worst, that their region of
> validity or accuracy gets restricted as new data about more remote
> instances come in.
If guardian clauses are added to the theory, it is not the same theory
that one started with. Two theories are identical if and only if the
theorems provable in one are provable in the other and vica versa.
Adding new postulates independet of the ones already there change the
theory.
Bob Kolker
news user
Sep29-04, 08:29 AM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>In article <4154417C.2060504@univie.ac.at>, Arnold.Neumaier@univie.ac.at\nsays...\n>\n>\n> news user wrote:\n> > In article <691af44f.0409200936.7cd2fa19@posting.google.com>, \n> > cte@palisad.com says...\n> >\n> >>news user <news@sisyphus.news.be.easynet.net> wrote in message news:<MPG.1bb7dc2c463f5f6f9897fe@news.easynet.be>. ..\n> >>\n> >>Theories are a hypothesis of how something might work.\n> >>Models are mappings between theories and the experimental evidence.\n> >>\n> > But a (physical, not mathematical) theory must be falsifiable, right ?\n>\n> A correct theory cannot be falsifiable, in spite of Popper.\n>\n> What happens with good theories is, at worst, that their region of\n> validity or accuracy gets restricted as new data about more remote\n> instances come in.\n>\n\nI\'m not sure I get you, Arnold...\n\nI guess it boils down on whether a physical theory\nincludes a claim of its domain of validity...\n\nI was under the impression that it does. For example,\nthe Standard Model claims to be valid whenever gravitation\nis negligeable, isn\'t-it ?\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>In article <4154417C.2060504@univie.ac.at>, Arnold.Neumaier@univie.ac.at
says...
>
>
> news user wrote:
> > In article <691af44f.0409200936.7cd2fa19@posting.google.com>,
> > cte@palisad.com says...
> >
> >>news user <news@sisyphus.news.be.easynet.net> wrote in message news:<MPG.1bb7dc2c463f5f6f9897fe@news.easynet.be>...
> >>
> >>Theories are a hypothesis of how something might work.
> >>Models are mappings between theories and the experimental evidence.
> >>
> > But a (physical, not mathematical) theory must be falsifiable, right ?
>
> A correct theory cannot be falsifiable, in spite of Popper.
>
> What happens with good theories is, at worst, that their region of
> validity or accuracy gets restricted as new data about more remote
> instances come in.
>
I'm not sure I get you, Arnold...
I guess it boils down on whether a physical theory
includes a claim of its domain of validity...
I was under the impression that it does. For example,
the Standard Model claims to be valid whenever gravitation
is negligeable, isn't-it ?
Arnold Neumaier
Oct26-04, 12:55 PM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>news user wrote:\n> In article <4154417C.2060504@univie.ac.at>, Arnold.Neumaier@univie.ac.at\n> says...\n>\n>>A correct theory cannot be falsifiable, in spite of Popper.\n>>\n>>What happens with good theories is, at worst, that their region of\n>>validity or accuracy gets restricted as new data about more remote\n>>instances come in.\n>\n> I guess it boils down on whether a physical theory\n> includes a claim of its domain of validity...\n>\n> I was under the impression that it does. For example,\n> the Standard Model claims to be valid whenever gravitation\n> is negligeable, isn\'t-it ?\n\nYes, and when, in addition, energies are well below a putative\nunification scale. Failures outside this domain are not\ncounted as falsifications.\n\nIn today\'s understanding, people are careful to indicate the\nlimits where a theory is claimed to be valid, and the accuracy\nto which its answers are to be trusted. While this is not part\nof the theory proper, it is part of the theory as actually taught\nand applied. Indeed, although people try to extrapolate, one can\nnever be sure whether a theory is correct outside the domain where\nthe data were collected.\n\nBut one can be reasonably sure within the domain where enough data\nare available. Once this is the case, these theories can never be\nfalsified. Rather, if people find disagreement in experiments, the\ntheory falsifies the experimental arrangement or analysis.\n\nAll science students who ever did experiments in the lab know\nvery well that this is common practice.\n\n\nThe degree of caution and care at the highest\nlevel of quality has been increasing through the centuries.\nIt is now too late to ask Newton whether he believed his theory was valid\nwithout restrictions. (Or are there any hints in the Principia\nMathematica?) Certainly Newton\'s theory as taught today is\ntaught with the restriction that it is valid at speeds small compared to\nc and at distances large compared to the radius of the largest atom.\nBut we nevertheless believe that it is the \'same\' theory, and if\nNewton would live today, I think he would agree with that.\n\n\nArnold Neumaier\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>news user wrote:
> In article <4154417C.2060504@univie.ac.at>, Arnold.Neumaier@univie.ac.at
> says...
>
>>A correct theory cannot be falsifiable, in spite of Popper.
>>
>>What happens with good theories is, at worst, that their region of
>>validity or accuracy gets restricted as new data about more remote
>>instances come in.
>
> I guess it boils down on whether a physical theory
> includes a claim of its domain of validity...
>
> I was under the impression that it does. For example,
> the Standard Model claims to be valid whenever gravitation
> is negligeable, isn't-it ?
Yes, and when, in addition, energies are well below a putative
unification scale. Failures outside this domain are not
counted as falsifications.
In today's understanding, people are careful to indicate the
limits where a theory is claimed to be valid, and the accuracy
to which its answers are to be trusted. While this is not part
of the theory proper, it is part of the theory as actually taught
and applied. Indeed, although people try to extrapolate, one can
never be sure whether a theory is correct outside the domain where
the data were collected.
But one can be reasonably sure within the domain where enough data
are available. Once this is the case, these theories can never be
falsified. Rather, if people find disagreement in experiments, the
theory falsifies the experimental arrangement or analysis.
All science students who ever did experiments in the lab know
very well that this is common practice.
The degree of caution and care at the highest
level of quality has been increasing through the centuries.
It is now too late to ask Newton whether he believed his theory was valid
without restrictions. (Or are there any hints in the Principia
Mathematica?) Certainly Newton's theory as taught today is
taught with the restriction that it is valid at speeds small compared to
c and at distances large compared to the radius of the largest atom.
But we nevertheless believe that it is the 'same' theory, and if
Newton would live today, I think he would agree with that.
Arnold Neumaier
Arnold Neumaier
Oct26-04, 12:55 PM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>robert j. kolker wrote:\n> Arnold Neumaier wrote:\n>\n>>A correct theory cannot be falsifiable, in spite of Popper.\n>\n> Yes it can. If a vetted sound experiment refutes a prediction of the\n> theory, the theory is Wrong. At least one of its assumptions is\n> factually false. This is an application of Modus Tollens. Logic 101.\n\nSince a correct theory cannot be wrong, your statement does not\ncontradict mine.\n\n\nArnold Neumaier\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>robert j. kolker wrote:
> Arnold Neumaier wrote:
>
>>A correct theory cannot be falsifiable, in spite of Popper.
>
> Yes it can. If a vetted sound experiment refutes a prediction of the
> theory, the theory is Wrong. At least one of its assumptions is
> factually false. This is an application of Modus Tollens. Logic 101.
Since a correct theory cannot be wrong, your statement does not
contradict mine.
Arnold Neumaier
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>\n\nArnold Neumaier <Arnold.Neumaier@univie.ac.at> wrote:\n>robert j. kolker wrote:\n>> Arnold Neumaier wrote:\n>>\n>>>A correct theory cannot be falsifiable, in spite of Popper.\n>>\n>> Yes it can. If a vetted sound experiment refutes a prediction of the\n>> theory, the theory is Wrong. At least one of its assumptions is\n>> factually false. This is an application of Modus Tollens. Logic 101.\n>\n>Since a correct theory cannot be wrong, your statement does not\n>contradict mine.\n>\n>\n>Arnold Neumaier\n\nA "falsifiable" theory should be "imaginable to be wrong". Do you think a\ncorrect theory cannot even be imagined to be wrong?\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>Arnold Neumaier <Arnold.Neumaier@univie.ac.at> wrote:
>robert j. kolker wrote:
>> Arnold Neumaier wrote:
>>
>>>A correct theory cannot be falsifiable, in spite of Popper.
>>
>> Yes it can. If a vetted sound experiment refutes a prediction of the
>> theory, the theory is Wrong. At least one of its assumptions is
>> factually false. This is an application of Modus Tollens. Logic 101.
>
>Since a correct theory cannot be wrong, your statement does not
>contradict mine.
>
>
>Arnold Neumaier
A "falsifiable" theory should be "imaginable to be wrong". Do you think a
correct theory cannot even be imagined to be wrong?
Uncle Al
Oct27-04, 10:55 AM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>\n\n\nArnold Neumaier wrote:\n>\n> robert j. kolker wrote:\n> > Arnold Neumaier wrote:\n> >\n> >>A correct theory cannot be falsifiable, in spite of Popper.\n> >\n> > Yes it can. If a vetted sound experiment refutes a prediction of the\n> > theory, the theory is Wrong. At least one of its assumptions is\n> > factually false. This is an application of Modus Tollens. Logic 101.\n>\n> Since a correct theory cannot be wrong, your statement does not\n> contradict mine.\n\nPlane geometry contains no mistakes. It is incomplete (falsifiable)\nvs. hyperbolic and elliptic geometries. try navigating the Pacific\nOcean with Euclid. The three together are in turn incomplete against\nThurston\'s eight simply-connected geometric 3-manifolds with compact\nquotients.\n\nNewton made no mistakes. Newton is incomplete (falsfiable) against\nrelativity and quantum mechanics. The latter two are contradictory\nwhere they overlap. NONE of physics is formally correct. There is no\naspect of physical theory that is predictive and simultaneously allows\nPlanck\'s constant, lightspeed, and the gravitation constant all to be\noperative.\n\nNone of this means that a "correct" theory can be detectably falsified\nwithin its limited domain. The Standard Model has no known empirical\nproblems, neither does relativity from TeV particle accelerators to\nGPS to strong field pulsar binaries. Neither theory can be formally\ncorrect. Who bells the cat?\n\n--\nUncle Al\nhttp://www.mazepath.com/uncleal/\n(Toxic URL! Unsafe for children and most mammals)\nhttp://www.mazepath.com/uncleal/qz.pdf\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>Arnold Neumaier wrote:
>
> robert j. kolker wrote:
> > Arnold Neumaier wrote:
> >
> >>A correct theory cannot be falsifiable, in spite of Popper.
> >
> > Yes it can. If a vetted sound experiment refutes a prediction of the
> > theory, the theory is Wrong. At least one of its assumptions is
> > factually false. This is an application of Modus Tollens. Logic 101.
>
> Since a correct theory cannot be wrong, your statement does not
> contradict mine.
Plane geometry contains no mistakes. It is incomplete (falsifiable)
vs. hyperbolic and elliptic geometries. try navigating the Pacific
Ocean with Euclid. The three together are in turn incomplete against
Thurston's eight simply-connected geometric 3-manifolds with compact
quotients.
Newton made no mistakes. Newton is incomplete (falsfiable) against
relativity and quantum mechanics. The latter two are contradictory
where they overlap. NONE of physics is formally correct. There is no
aspect of physical theory that is predictive and simultaneously allows
Planck's constant, lightspeed, and the gravitation constant all to be
operative.
None of this means that a "correct" theory can be detectably falsified
within its limited domain. The Standard Model has no known empirical
problems, neither does relativity from TeV particle accelerators to
GPS to strong field pulsar binaries. Neither theory can be formally
correct. Who bells the cat?
--
Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
http://www.mazepath.com/uncleal/qz.pdf
robert j. kolker
Oct27-04, 10:55 AM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>Arnold Neumaier wrote:\n\n>\n> Since a correct theory cannot be wrong, your statement does not\n> contradict mine.\n\nSince a theory is capable of making an infinite set of predictions, we\ncannot test them all empirically. So there is no way of knowing if a\ntheory is correct. We only know when it is false.\n\nBob Kolker\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>Arnold Neumaier wrote:
>
> Since a correct theory cannot be wrong, your statement does not
> contradict mine.
Since a theory is capable of making an infinite set of predictions, we
cannot test them all empirically. So there is no way of knowing if a
theory is correct. We only know when it is false.
Bob Kolker
Ilja Schmelzer
Oct27-04, 10:59 AM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>"Arnold Neumaier" <Arnold.Neumaier@univie.ac.at> schrieb\n> news user wrote:\n> > In article <4154417C.2060504@univie.ac.at>, Arnold.Neumaier@univie.ac.at\n> > says...\n> >>A correct theory cannot be falsifiable, in spite of Popper.\n\n??????? A correct theory is not false and therefore will not\nbe actually falsified. But, if the Sun falls down and appears to be\na large light bulb some of the standard theories appear to be falsified.\n\n> > I was under the impression that it does. For example,\n> > the Standard Model claims to be valid whenever gravitation\n> > is negligeable, isn\'t-it ?\n>\n> Yes, and when, in addition, energies are well below a putative\n> unification scale. Failures outside this domain are not\n> counted as falsifications.\n\nThat does not make the theory unfalsifiable.\n\n> In today\'s understanding, people are careful to indicate the\n> limits where a theory is claimed to be valid, and the accuracy\n> to which its answers are to be trusted. While this is not part\n> of the theory proper, it is part of the theory as actually taught\n> and applied. Indeed, although people try to extrapolate, one can\n> never be sure whether a theory is correct outside the domain where\n> the data were collected.\n\nExtrapolation for tomorrow is also extrapolation, so you can never\nbe completely sure.\n\n> But one can be reasonably sure within the domain where enough data\n> are available.\n\nOf course. But this is not the point of Popper\'s theory.\n\n> Once this is the case, these theories can never be\n> falsified. Rather, if people find disagreement in experiments, the\n> theory falsifies the experimental arrangement or analysis.\n> All science students who ever did experiments in the lab know\n> very well that this is common practice.\n\nOf course, if an experiment is in disagreement with theory in a\nwell-tested domain, it is usually the experimental arrangement or\nthe analysis which are wrong. But this does not mean that the\ntheory is unfalsifiable.\n\n> Certainly Newton\'s theory as taught today is\n> taught with the restriction that it is valid at speeds small compared to\n> c and at distances large compared to the radius of the largest atom.\n> But we nevertheless believe that it is the \'same\' theory, and if\n> Newton would live today, I think he would agree with that.\n\nThat\'s simply economy of words in common language. Instead of\n"Newtonian theory original version"\n"Newtonian theory as SR-limit version"\n"Newtonian theory as GR-limit version"\n"Newtonian theory as classical limit of Schroedinger theory version"\nwe use simply "Newtonian theory".\n\nIlja\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>"Arnold Neumaier" <Arnold.Neumaier@univie.ac.at> schrieb
> news user wrote:
> > In article <4154417C.2060504@univie.ac.at>, Arnold.Neumaier@univie.ac.at
> > says...
> >>A correct theory cannot be falsifiable, in spite of Popper.
??????? A correct theory is not false and therefore will not
be actually falsified. But, if the Sun falls down and appears to be
a large light bulb some of the standard theories appear to be falsified.
> > I was under the impression that it does. For example,
> > the Standard Model claims to be valid whenever gravitation
> > is negligeable, isn't-it ?
>
> Yes, and when, in addition, energies are well below a putative
> unification scale. Failures outside this domain are not
> counted as falsifications.
That does not make the theory unfalsifiable.
> In today's understanding, people are careful to indicate the
> limits where a theory is claimed to be valid, and the accuracy
> to which its answers are to be trusted. While this is not part
> of the theory proper, it is part of the theory as actually taught
> and applied. Indeed, although people try to extrapolate, one can
> never be sure whether a theory is correct outside the domain where
> the data were collected.
Extrapolation for tomorrow is also extrapolation, so you can never
be completely sure.
> But one can be reasonably sure within the domain where enough data
> are available.
Of course. But this is not the point of Popper's theory.
> Once this is the case, these theories can never be
> falsified. Rather, if people find disagreement in experiments, the
> theory falsifies the experimental arrangement or analysis.
> All science students who ever did experiments in the lab know
> very well that this is common practice.
Of course, if an experiment is in disagreement with theory in a
well-tested domain, it is usually the experimental arrangement or
the analysis which are wrong. But this does not mean that the
theory is unfalsifiable.
> Certainly Newton's theory as taught today is
> taught with the restriction that it is valid at speeds small compared to
> c and at distances large compared to the radius of the largest atom.
> But we nevertheless believe that it is the 'same' theory, and if
> Newton would live today, I think he would agree with that.
That's simply economy of words in common language. Instead of
"Newtonian theory original version"
"Newtonian theory as SR-limit version"
"Newtonian theory as GR-limit version"
"Newtonian theory as classical limit of Schroedinger theory version"
we use simply "Newtonian theory".
Ilja
Arnold Neumaier
Oct28-04, 01:28 PM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>\n\n\n\nrobert j. kolker wrote:\n> Arnold Neumaier wrote:\n>\n>>Since a correct theory cannot be wrong, your statement does not\n>>contradict mine.\n>\n> Since a theory is capable of making an infinite set of predictions, we\n> cannot test them all empirically. So there is no way of knowing if a\n> theory is correct. We only know when it is false.\n\nIn this sense there is no knowledge at all. We can always doubt anything.\nIf something contradicts a theory, it might be the \'something\' that is\nfaulty. Who can tell? Checking leads to an infinite regress, unless you\naccept some things as the basis of all. That\'s what we do in science with\nthe \'laws of nature\'.\n\nKnowledge is always subject to trust in some things that proved to be\nreliable in the past, such as the power of logic, the reliability\nof memory, induction from the past to the future, etc.\n\nBut we have very good reasons to trust logic, and mathematics, and\nthe laws of Newton, Maxwell, Einstein, and Weinberg.\n\n(Some people such as Lubos Motl trust even the laws of Witten,\nbut I find these reasons much less compelling.)\n\n\nArnold Neumaier\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>robert j. kolker wrote:
> Arnold Neumaier wrote:
>
>>Since a correct theory cannot be wrong, your statement does not
>>contradict mine.
>
> Since a theory is capable of making an infinite set of predictions, we
> cannot test them all empirically. So there is no way of knowing if a
> theory is correct. We only know when it is false.
In this sense there is no knowledge at all. We can always doubt anything.
If something contradicts a theory, it might be the 'something' that is
faulty. Who can tell? Checking leads to an infinite regress, unless you
accept some things as the basis of all. That's what we do in science with
the 'laws of nature'.
Knowledge is always subject to trust in some things that proved to be
reliable in the past, such as the power of logic, the reliability
of memory, induction from the past to the future, etc.
But we have very good reasons to trust logic, and mathematics, and
the laws of Newton, Maxwell, Einstein, and Weinberg.
(Some people such as Lubos Motl trust even the laws of Witten,
but I find these reasons much less compelling.)
Arnold Neumaier
Rahul Jain
Nov2-04, 12:38 PM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>\n\n\nArnold Neumaier <Arnold.Neumaier@univie.ac.at> writes:\n\n> robert j. kolker wrote:\n>> Arnold Neumaier wrote:\n>>\n>>>A correct theory cannot be falsifiable, in spite of Popper.\n>>\n>> Yes it can. If a vetted sound experiment refutes a prediction of the\n>> theory, the theory is Wrong. At least one of its assumptions is\n>> factually false. This is an application of Modus Tollens. Logic 101.\n>\n> Since a correct theory cannot be wrong, your statement does not\n> contradict mine.\n\nI, like others in this group, don\'t quite agree with your statement. If\na conjecture is not falsifiable, it does not make any predictions. If it\nmade predictions that we knew to be true... well, those wouldn\'t be\npredictions, would they? What is a conjecture that does not predict? It\nis simply a catalog of previous observations. I don\'t think that\'s even\na conjecture, let alone a theory. Therefore, I believe that your\nstatement above is neither right nor wrong, but simply a\nself-contradiction.\n\nNow, you also seem to consider theories to be "limitable" retroactively.\nThis is essential for the scientific method. Once we realize the limits\nof a previously "correct" theory and come up with a more general theory,\nwe can only treat the old theory as an approximation that is valid as\nlong as the error is tolerable in a specific situation. The reason they\nare still used is because of simpler mathematics when applied to certain\nsituations. E.g., QFT is intractable when modelling protein folding.\nHowever, that doesn\'t make the approximate theory correct; it just makes\nthat theory more useful to certain scientific and engineering domains.\n\n--\nRahul Jain\nrjain@nyct.net\nProfessional Software Developer, Amateur Quantum Mechanicist\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>Arnold Neumaier <Arnold.Neumaier@univie.ac.at> writes:
> robert j. kolker wrote:
>> Arnold Neumaier wrote:
>>
>>>A correct theory cannot be falsifiable, in spite of Popper.
>>
>> Yes it can. If a vetted sound experiment refutes a prediction of the
>> theory, the theory is Wrong. At least one of its assumptions is
>> factually false. This is an application of Modus Tollens. Logic 101.
>
> Since a correct theory cannot be wrong, your statement does not
> contradict mine.
I, like others in this group, don't quite agree with your statement. If
a conjecture is not falsifiable, it does not make any predictions. If it
made predictions that we knew to be true... well, those wouldn't be
predictions, would they? What is a conjecture that does not predict? It
is simply a catalog of previous observations. I don't think that's even
a conjecture, let alone a theory. Therefore, I believe that your
statement above is neither right nor wrong, but simply a
self-contradiction.
Now, you also seem to consider theories to be "limitable" retroactively.
This is essential for the scientific method. Once we realize the limits
of a previously "correct" theory and come up with a more general theory,
we can only treat the old theory as an approximation that is valid as
long as the error is tolerable in a specific situation. The reason they
are still used is because of simpler mathematics when applied to certain
situations. E.g., QFT is intractable when modelling protein folding.
However, that doesn't make the approximate theory correct; it just makes
that theory more useful to certain scientific and engineering domains.
--
Rahul Jain
rjain@nyct.net
Professional Software Developer, Amateur Quantum Mechanicist
Phillip Helbig---remove CLOTHES to reply
Nov3-04, 09:37 AM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>In article <clni93\\$g7a\\$1@beech.fernuni-hagen.de>, "Ilja Schmelzer"\n<Ilja.Schmelzer@FernUni-Hagen.de> writes:\n\n> "Arnold Neumaier" <Arnold.Neumaier@univie.ac.at> schrieb\n> > news user wrote:\n> > > In article <4154417C.2060504@univie.ac.at>, Arnold.Neumaier@univie.ac.at\n> > > says...\n> > >>A correct theory cannot be falsifiable, in spite of Popper.\n>\n> ??????? A correct theory is not false and therefore will not\n> be actually falsified. But, if the Sun falls down and appears to be\n> a large light bulb some of the standard theories appear to be falsified.\n\nOf course, the key point is not that a correct theory be\nfalsifiED---which as pointed out above is impossible (and doesn\'t\ncontradict anything Popper said), but rather that a GOOD theory must be\nfalsifiABLE, i.e. it must make predictions which at least in principle\ncan be falsified.\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>In article <clni93$g7a$1@beech.fernuni-hagen.de>, "Ilja Schmelzer"
<Ilja.Schmelzer@FernUni-Hagen.de> writes:
> "Arnold Neumaier" <Arnold.Neumaier@univie.ac.at> schrieb
> > news user wrote:
> > > In article <4154417C.2060504@univie.ac.at>, Arnold.Neumaier@univie.ac.at
> > > says...
> > >>A correct theory cannot be falsifiable, in spite of Popper.
>
> ??????? A correct theory is not false and therefore will not
> be actually falsified. But, if the Sun falls down and appears to be
> a large light bulb some of the standard theories appear to be falsified.
Of course, the key point is not that a correct theory be
falsifiED---which as pointed out above is impossible (and doesn't
contradict anything Popper said), but rather that a GOOD theory must be
falsifiABLE, i.e. it must make predictions which at least in principle
can be falsified.
Arnold Neumaier
Nov3-04, 09:38 AM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>andre wrote:\n> Arnold Neumaier <Arnold.Neumaier@univie.ac.at> wrote:\n>\n>>robert j. kolker wrote:\n>>\n>>>Arnold Neumaier wrote:\n>>>\n>>>>A correct theory cannot be falsifiable, in spite of Popper.\n>>>\n>>>Yes it can. If a vetted sound experiment refutes a prediction of the\n>>>theory, the theory is Wrong. At least one of its assumptions is\n>>>factually false. This is an application of Modus Tollens. Logic 101.\n>>\n>>Since a correct theory cannot be wrong, your statement does not\n>>contradict mine.\n>>\n>\n> A "falsifiable" theory should be "imaginable to be wrong". Do you think a\n> correct theory cannot even be imagined to be wrong?\n\nOne can imagine a lot. What counts in physics is only imagination that\nleads to something constructive.\n\nWhat makes a theory good is not its potential falsifiability, but that\nit drastically reduces the number of possibilities which are present\nwithout the theory, without eliminating something that can actually\nhappen.\n\nIf you have no theory and put two marbles into your empty pocket,\nand then another two, you don\'t know how many marbles you can take out.\n\nIf you know arithmetic and the law of conservation of marbles you can\npredict that exactly four can be taken out. This is testable, and will\nalways come out correct. So you have a correct theory. Of course, its\nvalidity is not unlimited, since it assumes that your pocket does not\nhave a hole; so if some experiment does not conform to your theory\nsince you can only take out three, you suspect that the domain of\nvalidity was violated; you check for the hole - and surely you\'ll\nfind it.\n\nThis is exactly the way Newton\'s theory works, within its domain of\nvalidity. If it fails, we suspect speed close to c, or tiny distances.\n\n\nArnold Neumaier.\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>andre wrote:
> Arnold Neumaier <Arnold.Neumaier@univie.ac.at> wrote:
>
>>robert j. kolker wrote:
>>
>>>Arnold Neumaier wrote:
>>>
>>>>A correct theory cannot be falsifiable, in spite of Popper.
>>>
>>>Yes it can. If a vetted sound experiment refutes a prediction of the
>>>theory, the theory is Wrong. At least one of its assumptions is
>>>factually false. This is an application of Modus Tollens. Logic 101.
>>
>>Since a correct theory cannot be wrong, your statement does not
>>contradict mine.
>>
>
> A "falsifiable" theory should be "imaginable to be wrong". Do you think a
> correct theory cannot even be imagined to be wrong?
One can imagine a lot. What counts in physics is only imagination that
leads to something constructive.
What makes a theory good is not its potential falsifiability, but that
it drastically reduces the number of possibilities which are present
without the theory, without eliminating something that can actually
happen.
If you have no theory and put two marbles into your empty pocket,
and then another two, you don't know how many marbles you can take out.
If you know arithmetic and the law of conservation of marbles you can
predict that exactly four can be taken out. This is testable, and will
always come out correct. So you have a correct theory. Of course, its
validity is not unlimited, since it assumes that your pocket does not
have a hole; so if some experiment does not conform to your theory
since you can only take out three, you suspect that the domain of
validity was violated; you check for the hole - and surely you'll
find it.
This is exactly the way Newton's theory works, within its domain of
validity. If it fails, we suspect speed close to c, or tiny distances.
Arnold Neumaier.
Arnold Neumaier
Nov3-04, 09:38 AM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>Uncle Al wrote:\n> Arnold Neumaier wrote:\n>\n>>robert j. kolker wrote:\n>>\n>>>Arnold Neumaier wrote:\n>>>\n>>>>A correct theory cannot be falsifiable, in spite of Popper.\n>>>\n>>>Yes it can. If a vetted sound experiment refutes a prediction of the\n>>>theory, the theory is Wrong. At least one of its assumptions is\n>>>factually false. This is an application of Modus Tollens. Logic 101.\n>>\n>>Since a correct theory cannot be wrong, your statement does not\n>>contradict mine.\n>\n> Plane geometry contains no mistakes.\n\n.... as a mathematical theory, yes.\nBut it has limited validity as a theory of Nature, and I was discussing\nthe latter.\n\n\nArnold Neumaier\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>Uncle Al wrote:
> Arnold Neumaier wrote:
>
>>robert j. kolker wrote:
>>
>>>Arnold Neumaier wrote:
>>>
>>>>A correct theory cannot be falsifiable, in spite of Popper.
>>>
>>>Yes it can. If a vetted sound experiment refutes a prediction of the
>>>theory, the theory is Wrong. At least one of its assumptions is
>>>factually false. This is an application of Modus Tollens. Logic 101.
>>
>>Since a correct theory cannot be wrong, your statement does not
>>contradict mine.
>
> Plane geometry contains no mistakes.
.... as a mathematical theory, yes.
But it has limited validity as a theory of Nature, and I was discussing
the latter.
Arnold Neumaier
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>Arnold Neumaier <Arnold.Neumaier@univie.ac.at> wrote in message news:<417FEB11.7010008@univie.ac.at>...\n> robert j. kolker wrote:\n> > Arnold Neumaier wrote:\n> >\n> >>Since a correct theory cannot be wrong, your statement does not\n> >>contradict mine.\n> >\n> > Since a theory is capable of making an infinite set of predictions, we\n> > cannot test them all empirically. So there is no way of knowing if a\n> > theory is correct. We only know when it is false.\n>\n> In this sense there is no knowledge at all. We can always doubt anything.\n> If something contradicts a theory, it might be the \'something\' that is\n> faulty. Who can tell? Checking leads to an infinite regress, unless you\n> accept some things as the basis of all. That\'s what we do in science with\n> the \'laws of nature\'.\n>\nThis is essentially the Quine-Duhem thesis, and the heart of Quine\'s\ncritique of Popper. Who says the falsifying experiment is not itself\nfalse? And isn\'t the accepting of the "Laws of Science" which are\nbeyond testing by this thesis, a leap of faith?\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>Arnold Neumaier <Arnold.Neumaier@univie.ac.at> wrote in message news:<417FEB11.7010008@univie.ac.at>...
> robert j. kolker wrote:
> > Arnold Neumaier wrote:
> >
> >>Since a correct theory cannot be wrong, your statement does not
> >>contradict mine.
> >
> > Since a theory is capable of making an infinite set of predictions, we
> > cannot test them all empirically. So there is no way of knowing if a
> > theory is correct. We only know when it is false.
>
> In this sense there is no knowledge at all. We can always doubt anything.
> If something contradicts a theory, it might be the 'something' that is
> faulty. Who can tell? Checking leads to an infinite regress, unless you
> accept some things as the basis of all. That's what we do in science with
> the 'laws of nature'.
>
This is essentially the Quine-Duhem thesis, and the heart of Quine's
critique of Popper. Who says the falsifying experiment is not itself
false? And isn't the accepting of the "Laws of Science" which are
beyond testing by this thesis, a leap of faith?
Arnold Neumaier
Nov4-04, 03:38 AM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>DickT wrote:\n\n> isn\'t the accepting of the "Laws of Science" which are\n> beyond testing by this thesis, a leap of faith?\n\nRelying on that anything in the future is like in the past is an\nact of faith. The question is not about faith or not, but about\nfaith in what is best supported by past experience.\n\nTheories that conform with the past are easy to trust.\nBut they come in different degrees of stringency.\n\nTheories which are not restrictive at all but accommodates everything\n(such as astrology or psychoanalysis) are in vogue (as society shows)\nbut useless (and probably harmful). These are the ones that Popper calls\nunfalsifiable.\n\nHighly restrictive theories (what Popper calls scientific) are preferred\nby those who want to control their destiny as far as possible.\n\nTheories like Newton\'s, general relativity, or QED are extremely\nrestrictive and in agreement with past experience, hence both trustworthy\nand very useful.\n\n\nArnold Neumaier\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>DickT wrote:
> isn't the accepting of the "Laws of Science" which are
> beyond testing by this thesis, a leap of faith?
Relying on that anything in the future is like in the past is an
act of faith. The question is not about faith or not, but about
faith in what is best supported by past experience.
Theories that conform with the past are easy to trust.
But they come in different degrees of stringency.
Theories which are not restrictive at all but accommodates everything
(such as astrology or psychoanalysis) are in vogue (as society shows)
but useless (and probably harmful). These are the ones that Popper calls
unfalsifiable.
Highly restrictive theories (what Popper calls scientific) are preferred
by those who want to control their destiny as far as possible.
Theories like Newton's, general relativity, or QED are extremely
restrictive and in agreement with past experience, hence both trustworthy
and very useful.
Arnold Neumaier
Arnold Neumaier
Nov5-04, 08:20 AM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>\n\n\n\n\nPhillip Helbig---remove CLOTHES to reply wrote:\n>>>\n>>>>In article <4154417C.2060504@univie.ac.at>, Arnold.Neumaier@univie.ac.at\n>>>>says...\n>>>>\n> >>>>A correct theory cannot be falsifiable, in spite of Popper.\n>\n> Of course, the key point is not that a correct theory be\n> falsifiED---which as pointed out above is impossible (and doesn\'t\n> contradict anything Popper said), but rather that a GOOD theory must be\n> falsifiABLE, i.e. it must make predictions which at least in principle\n> can be falsified.\n\n\nWell, since my statement caused so much opposition, let me formulate\nmore carefully:\n\n\nThe philosopher Karl Popper claimed that falsifiability is the\nhallmark of scientific theories. But scientific practice speaks\nagainst him.\n\nA correct theory cannot be falsified, and in this sense is not\nfalsifiable, in spite of Popper. (Falsifiability can be asserted\nonly in a contrafactual sense, that there are _conceivable_ situations\nthat, according to the theory, are excluded. And for a correct theory,\nthese situation will never happen, hence are completely ficticious.)\n\nWhat makes a theory good is not its potential falsifiability, but that\nit drastically reduces the number of possibilities which are present\nwithout the theory, without eliminating something that can actually\nhappen.\n\n\nWhat happens with good theories is, at worst, that their region of\nvalidity or accuracy gets restricted as new data about more remote\ninstances come in.\n\nIn today\'s understanding, people are careful to indicate the\nlimits where a theory is claimed to be valid, and the accuracy\nto which its answers are to be trusted.\n\nFor example, the Standard Model is claimed to be valid whenever\ngravitation is negligible and, in addition, energies are well below\na putative unification scale. Failures outside this domain are not\ncounted as falsifications.\n\nWhile limits and accuracy claims are not necessarily part\nof the theory proper, they are part of the theory as actually taught\nand applied. Indeed, although people try to extrapolate, one can\nnever be sure whether a theory is correct outside the domain where\nthe data were collected.\n\n\nArnold Neumaier\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>Phillip Helbig---remove CLOTHES to reply wrote:
>>>
>>>>In article <4154417C.2060504@univie.ac.at>, Arnold.Neumaier@univie.ac.at
>>>>says...
>>>>
>>>>>A correct theory cannot be falsifiable, in spite of Popper.
>
> Of course, the key point is not that a correct theory be
> falsifiED---which as pointed out above is impossible (and doesn't
> contradict anything Popper said), but rather that a GOOD theory must be
> falsifiABLE, i.e. it must make predictions which at least in principle
> can be falsified.
Well, since my statement caused so much opposition, let me formulate
more carefully:
The philosopher Karl Popper claimed that falsifiability is the
hallmark of scientific theories. But scientific practice speaks
against him.
A correct theory cannot be falsified, and in this sense is not
falsifiable, in spite of Popper. (Falsifiability can be asserted
only in a contrafactual sense, that there are _conceivable_ situations
that, according to the theory, are excluded. And for a correct theory,
these situation will never happen, hence are completely ficticious.)
What makes a theory good is not its potential falsifiability, but that
it drastically reduces the number of possibilities which are present
without the theory, without eliminating something that can actually
happen.
What happens with good theories is, at worst, that their region of
validity or accuracy gets restricted as new data about more remote
instances come in.
In today's understanding, people are careful to indicate the
limits where a theory is claimed to be valid, and the accuracy
to which its answers are to be trusted.
For example, the Standard Model is claimed to be valid whenever
gravitation is negligible and, in addition, energies are well below
a putative unification scale. Failures outside this domain are not
counted as falsifications.
While limits and accuracy claims are not necessarily part
of the theory proper, they are part of the theory as actually taught
and applied. Indeed, although people try to extrapolate, one can
never be sure whether a theory is correct outside the domain where
the data were collected.
Arnold Neumaier
robert j. kolker
Nov6-04, 11:07 AM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>Arnold Neumaier wrote:\n> A correct theory cannot be falsified, and in this sense is not\n> falsifiable, in spite of Popper.\n\nThere is no way of knowing if a theory is correct. The only thing one\ncan do is experiment and if experiment and theory diverge (assuming the\nexperiment is kosher, of course) there is a problem with the theory. We\nwill never know if a theory is correct. We can only know for sure if it\nisn\'t.\n\nBob Kolker\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>Arnold Neumaier wrote:
> A correct theory cannot be falsified, and in this sense is not
> falsifiable, in spite of Popper.
There is no way of knowing if a theory is correct. The only thing one
can do is experiment and if experiment and theory diverge (assuming the
experiment is kosher, of course) there is a problem with the theory. We
will never know if a theory is correct. We can only know for sure if it
isn't.
Bob Kolker
Arnold Neumaier
Nov7-04, 04:06 PM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>robert j. kolker wrote:\n> Arnold Neumaier wrote:\n>\n>>A correct theory cannot be falsified, and in this sense is not\n>>falsifiable, in spite of Popper.\n>\n> There is no way of knowing if a theory is correct. The only thing one\n> can do is experiment and if experiment and theory diverge (assuming the\n> experiment is kosher, of course) there is a problem with the theory. We\n> will never know if a theory is correct. We can only know for sure if it\n> isn\'t.\n\nWe can _know_ whether a theory has been correct in the past,\nand we can _trust_ that it will remain so in the future.\nThere is no other kind of knowledge than that of the past.\n\n\nArnold Neumaier\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>robert j. kolker wrote:
> Arnold Neumaier wrote:
>
>>A correct theory cannot be falsified, and in this sense is not
>>falsifiable, in spite of Popper.
>
> There is no way of knowing if a theory is correct. The only thing one
> can do is experiment and if experiment and theory diverge (assuming the
> experiment is kosher, of course) there is a problem with the theory. We
> will never know if a theory is correct. We can only know for sure if it
> isn't.
We can _know_ whether a theory has been correct in the past,
and we can _trust_ that it will remain so in the future.
There is no other kind of knowledge than that of the past.
Arnold Neumaier
Alain Cochard
Nov9-04, 03:44 AM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>\n\n\n\nArnold Neumaier <Arnold.Neumaier@univie.ac.at> writes:\n\n> If you have no theory and put two marbles into your empty pocket,\n> and then another two, you don\'t know how many marbles you can take out.\n>\n> If you know arithmetic and the law of conservation of marbles you can\n> predict that exactly four can be taken out. This is testable, and will\n> always come out correct. So you have a correct theory. Of course, its\n> validity is not unlimited, since it assumes that your pocket does not\n> have a hole; so if some experiment does not conform to your theory\n> since you can only take out three, you suspect that the domain of\n> validity was violated; you check for the hole - and surely you\'ll\n> find it.\n>\n> This is exactly the way Newton\'s theory works, within its domain of\n> validity. If it fails, we suspect speed close to c, or tiny distances.\n\nThere is no way to know in advance the domain of validity. In case of\na failure of Newton\'s theory, if you look for high speed or tiny\ndistances (I guess you could add strong gravity to the list, and maybe\nothers), but, in spite of your efforts, you don\'t find any of these,\nyou\'ll have no other choice to say that it has been falsified once\nagain.\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>Arnold Neumaier <Arnold.Neumaier@univie.ac.at> writes:
> If you have no theory and put two marbles into your empty pocket,
> and then another two, you don't know how many marbles you can take out.
>
> If you know arithmetic and the law of conservation of marbles you can
> predict that exactly four can be taken out. This is testable, and will
> always come out correct. So you have a correct theory. Of course, its
> validity is not unlimited, since it assumes that your pocket does not
> have a hole; so if some experiment does not conform to your theory
> since you can only take out three, you suspect that the domain of
> validity was violated; you check for the hole - and surely you'll
> find it.
>
> This is exactly the way Newton's theory works, within its domain of
> validity. If it fails, we suspect speed close to c, or tiny distances.
There is no way to know in advance the domain of validity. In case of
a failure of Newton's theory, if you look for high speed or tiny
distances (I guess you could add strong gravity to the list, and maybe
others), but, in spite of your efforts, you don't find any of these,
you'll have no other choice to say that it has been falsified once
again.
robert j. kolker
Nov9-04, 03:45 AM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>\n\n\nArnold Neumaier wrote:\n> We can _know_ whether a theory has been correct in the past,\n> and we can _trust_ that it will remain so in the future.\n> There is no other kind of knowledge than that of the past.\n\nBy "_trust_" you mean assume or believe. An you are right. We only\n-know- what has happened. We do not know for sure what will happen.\nBeing alive is full of surprises. That is why we should never be bored.\n\nBob Kolker\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>Arnold Neumaier wrote:
> We can _know_ whether a theory has been correct in the past,
> and we can _trust_ that it will remain so in the future.
> There is no other kind of knowledge than that of the past.
By "_trust_" you mean assume or believe. An you are right. We only
-know- what has happened. We do not know for sure what will happen.
Being alive is full of surprises. That is why we should never be bored.
Bob Kolker
Arnold Neumaier
Nov9-04, 02:53 PM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>robert j. kolker wrote:\n> Arnold Neumaier wrote:\n>\n>>We can _know_ whether a theory has been correct in the past,\n>>and we can _trust_ that it will remain so in the future.\n>>There is no other kind of knowledge than that of the past.\n>\n>\n> By "_trust_" you mean assume or believe.\n\n\'believe\' has too many meanings, hence is ambiguous.\n\'trust\' is the strongest form of belief, meaning\n\'proceed as if it were true\'.\n\nFor example when we enter an air plane we trust that the\nlaws of nature make it fly as it did in the past.\nThis is quite different from the belief that\nthe universe was created 15 billion years ago.\nWe wouldn\'t enter the plane if safety would depend on our precise\nknowledge of the age of the universe.\n\n\nArnold Neumaier\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>robert j. kolker wrote:
> Arnold Neumaier wrote:
>
>>We can _know_ whether a theory has been correct in the past,
>>and we can _trust_ that it will remain so in the future.
>>There is no other kind of knowledge than that of the past.
>
>
> By "_trust_" you mean assume or believe.
'believe' has too many meanings, hence is ambiguous.
'trust' is the strongest form of belief, meaning
'proceed as if it were true'.
For example when we enter an air plane we trust that the
laws of nature make it fly as it did in the past.
This is quite different from the belief that
the universe was created 15 billion years ago.
We wouldn't enter the plane if safety would depend on our precise
knowledge of the age of the universe.
Arnold Neumaier
Arnold Neumaier
Nov14-04, 07:08 AM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>news user wrote:\n>>>If you know arithmetic and the law of conservation of marbles you can\n>>>predict that exactly four can be taken out. This is testable, and will\n>>>always come out correct. So you have a correct theory. Of course, its\n>>>validity is not unlimited, since it assumes that your pocket does not\n>>>have a hole; so if some experiment does not conform to your theory\n>>>since you can only take out three, you suspect that the domain of\n>>>validity was violated; you check for the hole - and surely you\'ll\n>>>find it.\n>>>\n>>>This is exactly the way Newton\'s theory works, within its domain of\n>>>validity. If it fails, we suspect speed close to c, or tiny distances.\n>\n> But, Arnold, if I get you, you say that if a theory has been\n> tested in some experimental conditions X, then will work in any\n> condition close to X (with closeness undefined ?).\n\nYes, this is what science is based upon. Situations where slight changes\nhave unpredictable consequences are mostly outside the scope of\nscience. The best one can do in such cases is to delineate the\nconditions under which predictions are possible, and to describe\nthe features that remain predictable in spite of the observed\nunpredictability. Indeed, this is what we do for systems we classify\nas chaotic.\n\n\n> This means you believe that the true laws of physics are somehow\n> pretty continuous, isn\'t-it ?\n\nYes. All known science is continuous; even the description of\nquantum jumps - we don\'t predict the jumps themselves but their\ndistributions, which are stable under small changes of the system.\n\n\n> Of course this assumption has itself been tested again and again.\n> But it is nevertheless also some falsifiable hypothesis on how nature\n> works, isn\'t-it ?\n\nScientists generally believe there is order in nature - which means\nthat unseen instances behave like seen ones, although the state is\nslightly different. That\'s why we have _laws_ which describe the\nunalterable, and _states_ which describe diversity.\n\n\n> Therefore, I dont undestand how you can guarantee that a theory is 100%\n> correct in its claimed domain of validity, when that claim relies\n> itself on some falsifiable hypothesis.\n\nThere are no guarantees at all about the future. But the past taught\nus that we can trust that certain things are indeed reliable.\nAt least as long as the designer of the Universe does not upgrade\nthe software of the computer on which he runs our universe!\n(Or, perhaps, we run into a bug of his programs?)\n\n\n> I mean, we may one day discover that newton\'s law fails for some\n> unexpected r within the currently claimed domain of validity, say\n> 1,234,567 km +/- epsilon... Extremely unlikely, sure.\n> But can we really be 100% sure it wont happen ?\n\nWell, try to get a project funded that is designed to discover what\nyou propose. You can at least be 100% sure that no one will fund it!\n\nIf what you propose would really happen and be reproducible, it would\nbe reinterpreted as the presence of some extra matter or extra force.\nBot more likely it would share the fate of cold fusion...\n\n\nArnold Neumaier\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>news user wrote:
>>>If you know arithmetic and the law of conservation of marbles you can
>>>predict that exactly four can be taken out. This is testable, and will
>>>always come out correct. So you have a correct theory. Of course, its
>>>validity is not unlimited, since it assumes that your pocket does not
>>>have a hole; so if some experiment does not conform to your theory
>>>since you can only take out three, you suspect that the domain of
>>>validity was violated; you check for the hole - and surely you'll
>>>find it.
>>>
>>>This is exactly the way Newton's theory works, within its domain of
>>>validity. If it fails, we suspect speed close to c, or tiny distances.
>
> But, Arnold, if I get you, you say that if a theory has been
> tested in some experimental conditions X, then will work in any
> condition close to X (with closeness undefined ?).
Yes, this is what science is based upon. Situations where slight changes
have unpredictable consequences are mostly outside the scope of
science. The best one can do in such cases is to delineate the
conditions under which predictions are possible, and to describe
the features that remain predictable in spite of the observed
unpredictability. Indeed, this is what we do for systems we classify
as chaotic.
> This means you believe that the true laws of physics are somehow
> pretty continuous, isn't-it ?
Yes. All known science is continuous; even the description of
quantum jumps - we don't predict the jumps themselves but their
distributions, which are stable under small changes of the system.
> Of course this assumption has itself been tested again and again.
> But it is nevertheless also some falsifiable hypothesis on how nature
> works, isn't-it ?
Scientists generally believe there is order in nature - which means
that unseen instances behave like seen ones, although the state is
slightly different. That's why we have _laws_ which describe the
unalterable, and _states_ which describe diversity.
> Therefore, I dont undestand how you can guarantee that a theory is 100%
> correct in its claimed domain of validity, when that claim relies
> itself on some falsifiable hypothesis.
There are no guarantees at all about the future. But the past taught
us that we can trust that certain things are indeed reliable.
At least as long as the designer of the Universe does not upgrade
the software of the computer on which he runs our universe!
(Or, perhaps, we run into a bug of his programs?)
> I mean, we may one day discover that newton's law fails for some
> unexpected r within the currently claimed domain of validity, say
> 1,234,567 km +/- \epsilon... Extremely unlikely, sure.
> But can we really be 100% sure it wont happen ?
Well, try to get a project funded that is designed to discover what
you propose. You can at least be 100% sure that no one will fund it!
If what you propose would really happen and be reproducible, it would
be reinterpreted as the presence of some extra matter or extra force.
Bot more likely it would share the fate of cold fusion...
Arnold Neumaier
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