Changes

: On point (7), I think there is circularity in your argument, assuming what it is at issue by insisting that E remain constant.--[[User:Aschlafly|Andy Schlafly]] 20:05, 15 August 2011 (EDT)

: On point (7), I think there is circularity in your argument, assuming what it is at issue by insisting that E remain constant.--[[User:Aschlafly|Andy Schlafly]] 20:05, 15 August 2011 (EDT)

::It's not so easy as you think. To invalidate a theory with an experiment you have to carefully consider every other aspect that could influence the measure. If a theory works good, but a new experiment finds that in some conditions the theory doesn't work anymore, the experiments has not falsified the theory, but only proven that this theory has a finite range of applications. Examples are Newtonian mechanics, classical electromagnetism, even nonrelativistic quantum mechanics. Today general relativity has not been proved correct on big scales, while it works correctly within the solar system. Special relativity is thought not to have similar (distance) limits, but may have corrections due to quantum gravity, which today are only conjectured and not seen experimentally. I'll tell you a secret: "true" theories do not exist, and all the theories have limits of applicability. Today

::It's not so easy as you think. To invalidate a theory with an experiment you have to carefully consider every other aspect that could influence the measure. If a theory works good, but a new experiment finds that in some conditions the theory doesn't work anymore, the experiments has not falsified the theory, but only proven that this theory has a finite range of applications. Examples are Newtonian mechanics, classical electromagnetism, even nonrelativistic quantum mechanics. Today general relativity has not been proved correct on big scales, while it works correctly within the solar system. Special relativity is thought not to have similar (distance) limits, but may have corrections due to quantum gravity, which today are only conjectured and not seen experimentally. I'll tell you a secret: "true" theories do not exist, and all the theories have limits of applicability. Today we don't know the limits of both relativity theories, because they agree with ''all'' current experiments.

we don't know the limits of both relativity theories, because they agree with ''all'' current experiments.

::(16) The truth is that who doesn't know relativity is ignoring 100 years of history of physics.

::(16) The truth is that who doesn't know relativity is ignoring 100 years of history of physics.

::Andy, let me explain to you some math stuff. Suppose you have a function of two variables, e.g. ''f(x,y)''. Suppose you want to change the value of the first variabile: what does the second? Well, you have to decide it: you can keep ''y'' to a fixed value, or you can change ''y'' as ''x'' varies: in this case ''y'' become a function of ''x'': ''y=g(x)''. The original expression becomes ''f(x,g(x))'' and is a 1-variable function, that you can call ''h(x)''. In other words, you have to specify a trajectory in the ''(x,y)'' plane. This is also the way limits work: you have to specify the trajectory.

::Andy, let me explain to you some math stuff. Suppose you have a function of two variables, e.g. ''f(x,y)''. Suppose you want to change the value of the first variabile: what does the second? Well, you have to decide it: you can keep ''y'' to a fixed value, or you can change ''y'' as ''x'' varies: in this case ''y'' become a function of ''x'': ''y=g(x)''. The original expression becomes ''f(x,g(x))'' and is a 1-variable function, that you can call ''h(x)''. In other words, you have to specify a trajectory in the ''(x,y)'' plane. This is also the way limits work: you have to specify the trajectory.