tag:blogger.com,1999:blog-1500584444083499721.post3938145401801413067..comments2024-03-24T09:28:42.755+01:00Comments on CJ on Mathematics and Science: Gravitational Mass = Inertial Mass by Definition: Hard ThinkingClaes Johnsonhttp://www.blogger.com/profile/07411413338950388898noreply@blogger.comBlogger14125tag:blogger.com,1999:blog-1500584444083499721.post-71466496955844525122016-05-22T14:57:15.938+02:002016-05-22T14:57:15.938+02:00ok, you don't have to answer if you can't....ok, you don't have to answer if you can't. What the kitchen experiment shows is that mass does not change with the choice of Euclidean coordinate system, which is not surprising and as such not worth making a big fuss about.Claes Johnsonhttps://www.blogger.com/profile/07411413338950388898noreply@blogger.comtag:blogger.com,1999:blog-1500584444083499721.post-75082062084107410282016-05-22T14:22:40.878+02:002016-05-22T14:22:40.878+02:00So now when it is clear that the equivalence princ...So now when it is clear that the equivalence principle can be tested (it would show quite spectacular differences in a vacuum free fall experiment) it is time to move the goalpost to the speed of light... nice.Anonym2noreply@blogger.comtag:blogger.com,1999:blog-1500584444083499721.post-33947429717416498322016-05-22T14:14:55.652+02:002016-05-22T14:14:55.652+02:00The discussion illustrates the sad fact that since...The discussion illustrates the sad fact that since Einstein there is no clear distinction between (i) definitions/conventions/agreements, which all are valid/true by construction /language and (ii) statements about physical facts which may be valid/true or not. You can test your standpoint by asking yourself if constancy of speed of light is (i) or (ii)? What is your answer?Claes Johnsonhttps://www.blogger.com/profile/07411413338950388898noreply@blogger.comtag:blogger.com,1999:blog-1500584444083499721.post-26775704178716499302016-05-22T13:43:00.955+02:002016-05-22T13:43:00.955+02:00But it is not really true by definition, only with...But it is not <i>really</i> true by definition, only within the theory, because you can check it against the physical reality.<br /><br />If you make a prediction based on the theory that is contradicted by empirical observation, then it is not generally true (Newtonian mechanics is one such example). You kind of illustrates the procedure with your latest post about a falling mass connected with a mass on the table through a string...<br /><br />The name for this procedure is <i>the scientific method</i> and is the central part of all natural science. If you argue against this procedure you are in quite the trouble and not scientific.<br /><br />Anonym2noreply@blogger.comtag:blogger.com,1999:blog-1500584444083499721.post-32406077904097436442016-05-22T13:30:13.789+02:002016-05-22T13:30:13.789+02:00You are contradicting yourself. First you say that...You are contradicting yourself. First you say that since it is an empirical fact we may take it as a definition. Then you say this definition has no physical content. But, yes, the equivalence of heavy and inertial mass says that all bodies subject only to gravitation have the same acceleration. That is as you say an empirical fact and thus has physical content. A lot of content in fact, as Einstein showed.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-1500584444083499721.post-58567514001450357452016-05-22T13:16:08.652+02:002016-05-22T13:16:08.652+02:00Ok, so you agree that the equivalence principle is...Ok, so you agree that the equivalence principle is a definition, but you still believe that a definition true by construction can have physical content, and doing so you follow in the foot steps of Einstein who has confused generations of physicists. But I repeat: A definition does not say anything about the physics of the world, just something about conventions of language. Claes Johnsonhttps://www.blogger.com/profile/07411413338950388898noreply@blogger.comtag:blogger.com,1999:blog-1500584444083499721.post-76523086649053003912016-05-22T12:38:04.127+02:002016-05-22T12:38:04.127+02:00Whether something is a definition or not is not a ...Whether something is a definition or not is not a matter of evidence. Anybody that formulates a theory is free to choose whichever definitions he wants, and the value of the theory then depends on its predictions. I guess it can be said that Einstein took the equivalence of inertial and heavy mass as a definition. It seems you criticized precisely that in a post a few days ago. You called it then an 'empty definition', which made me believe that you thought it was empty because it necessarily has to be that way. But that is not so.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-1500584444083499721.post-85101973497894708692016-05-22T10:29:41.679+02:002016-05-22T10:29:41.679+02:00In any case, since equality seems to hold experime...In any case, since equality seems to hold experimentally to any degree of precision, one should seriously consider the possibilty that it is a matter of definition, a matter of how force is defined and measured, which is not so clear and therefore may very well boil down to definition. What is your evidence that it is not definition?Claes Johnsonhttps://www.blogger.com/profile/07411413338950388898noreply@blogger.comtag:blogger.com,1999:blog-1500584444083499721.post-63403831342336515772016-05-22T09:23:35.248+02:002016-05-22T09:23:35.248+02:00That gravity does not tear things apart is kind of...That gravity does not tear things apart is kind of a strange argument, right?<br /><br />What is the relative strength between electronic and gravitational coupling now again...?Anonym2noreply@blogger.comtag:blogger.com,1999:blog-1500584444083499721.post-72553307898264719562016-05-22T09:22:50.204+02:002016-05-22T09:22:50.204+02:00forces acting per volume ??forces acting per volume ??Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-1500584444083499721.post-21782408160478312132016-05-22T08:57:49.534+02:002016-05-22T08:57:49.534+02:00It is true for forces acting per volume, and gravi...It is true for forces acting per volume, and gravitation is such a force because it does not tear things apart, nor does inertial forces. Another way of thinking is to relate inertial force ultimatelty to gravitational force with the same result of equality of inertial and gravitational mass.Claes Johnsonhttps://www.blogger.com/profile/07411413338950388898noreply@blogger.comtag:blogger.com,1999:blog-1500584444083499721.post-87987343478797363502016-05-21T19:08:11.769+02:002016-05-21T19:08:11.769+02:00So when you write inertial mass, you really mean t...So when you write inertial mass, you really mean the density of inertial mass, right? More seriously,you seem to mean that inertial mass and heavy mass, *must* be equal. Why? This means that all object accelerate at the same rate when only subject to gravitation and no other forces. Why does it have to be that way? It is certainly not true for other forces.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-1500584444083499721.post-79481515436993404372016-05-21T17:50:19.903+02:002016-05-21T17:50:19.903+02:00This is because mass density is per volume.This is because mass density is per volume.Claes Johnsonhttps://www.blogger.com/profile/07411413338950388898noreply@blogger.comtag:blogger.com,1999:blog-1500584444083499721.post-63492933211034962462016-05-21T11:15:57.090+02:002016-05-21T11:15:57.090+02:00'per unit of volume'? Where does the volum...'per unit of volume'? Where does the volume come in?Anonymousnoreply@blogger.com