| | Choosing a theory, or the parameters used in a theory, to match observation and thereby make the theory describe reality correctly, is a time-honored tradition in science. As an example of "tweaking" of parameters to comport with the conclusion sought, Kepler set all the orbital parameters of the planets to be what they had to be in order to match the observed behavior. The parameters of motion of the [[PSR B1913+16]] pulsar pair were of course set by Hulse and Taylor to match observation. Interestingly, nothing about [[General relativity]] had to be "tweaked" to predict the precession of the perihelion of Mercury. | | Choosing a theory, or the parameters used in a theory, to match observation and thereby make the theory describe reality correctly, is a time-honored tradition in science. As an example of "tweaking" of parameters to comport with the conclusion sought, Kepler set all the orbital parameters of the planets to be what they had to be in order to match the observed behavior. The parameters of motion of the [[PSR B1913+16]] pulsar pair were of course set by Hulse and Taylor to match observation. Interestingly, nothing about [[General relativity]] had to be "tweaked" to predict the precession of the perihelion of Mercury. |
| − | Scientists commonly claim that E=mc² is true for what are, in fact, ordinary chemical reactions that emit energy, even though the mass change implied by such reactions is far too small to measure. This is because the formula can be proven (see below) for ''all'' interactions. So no one claims that chemical reactions ''prove'' or ''verify'' E=mc², just that it logically must be true. Nuclear reactions are another matter. The formula is verified constantly, and, in fact, its consequences can be seen in the atomic weights in periodic table charts hanging in science classrooms all around the world. Nuclear-fusion reactions, such as the transformation of hydrogen to helium, also demonstrate the validity of the formula E=mc². The transformation of 4 atoms of <sup>1</sup>H into one atom of <sup>4</sup>He occurs constantly in the Sun, and has a mass defect of .02916 amu, which works out to 27.162 MeV. Several interactions are involved in the total transformation, and their energies have been observed in the laboratory. Alpha decay energies have been measured for many isotopes, and agree with the mass change. See [[Quantitative Analysis of Alpha Decay]].
| + | It is common for [[atheist]]s to claim that E=mc² is proven by what are, in fact, ordinary chemical reactions that emit energy. Nuclear-fusion reactions, such as the transformation of hydrogen to helium, do not demonstrate any connection between the rest energy of a mass and the speed of light, as E=mc² asserts. |
| − | :Broken clocks are correct twice a day. E=mc² is correct all the time.
| + | Broken clocks are correct twice a day, and some isolated experiments have asserted verification of E=mc² in certain carefully framed scenarios. But no experiment has demonstrated E=mc² with any reasonable degree of generality. |