Changes

Perhaps the most precise direct empirical verification of E=mc² was done in 2005 by Simon Rainville ''et. al.''<ref>[http://www.nature.com/nature/journal/v438/n7071/full/4381096a.html Nature 438, 1096-1097 (22 December 2005)] doi:10.1038/4381096a; Published online 21 December 2005</ref> The article states that &quot;Einstein's relationship is separately confirmed in two tests, which yield a combined result of 1−&Delta;mc²/E=(−1.4±4.4)×10⁻⁷, indicating that it holds to a level of at least 0.00004%. To our knowledge, this is the most precise direct test of the famous equation yet described.&quot;

Perhaps the most precise direct empirical verification of E=mc² was done in 2005 by Simon Rainville ''et. al.''<ref>[http://www.nature.com/nature/journal/v438/n7071/full/4381096a.html Nature 438, 1096-1097 (22 December 2005)] doi:10.1038/4381096a; Published online 21 December 2005</ref> The article states that &quot;Einstein's relationship is separately confirmed in two tests, which yield a combined result of 1−&Delta;mc²/E=(−1.4±4.4)×10⁻⁷, indicating that it holds to a level of at least 0.00004%. To our knowledge, this is the most precise direct test of the famous equation yet described.&quot;

==Alleged Experimental verification--the Cockcroft-Walton experiment==

==The Cockcroft-Walton experiment, not to be taken as a verification or "proof"==

In 1932 English physicist John Cockcroft and Irish physicist Ernest Walton performed the first artificial nuclear transmutation of nuclei, for which they were awarded the 1951 [[Nobel Prize]] in physics -- '''''but not for any verification of E=mc²'''''.<ref>[http://www.nobelprize.org/nobel_prizes/physics/laureates/1951/cockcroft-lecture.pdf John D. Cockroft ''Experiments on the interaction of high-speed nucleons with atomic nuclei''], Nobel Lecture, Dec 11, 1951</ref> The award was for ''&quot;their pioneer work on the transmutation of atomic nuclei by artificially accelerated atomic particles.&quot;''<ref>[http://www.nobelprize.org/nobel_prizes/physics/laureates/1951/# Nobel Prize Organization]</ref>

It is important to be aware that this experiment is not one of the ones usually cited as validating E=mc².  That was not its goal.

Verifying E=mc² was not the goal of the experiment, and the Nobel prize was awarded for the transmutation itself, not any verification of the equation.  This experiment could not possibly prove any general truth to the equation.  But data from this experiment showed a rough correlation with the equation for the particular transmutation involved, and on that basis supporters of the equation insist that this experiment verified the equation.

 

Verifying E=mc² was not the goal of the experiment, and the Nobel prize was awarded for the transmutation itself, not any verification of the equation.  This experiment could not possibly have proved any general truth to the equation.  But data from this experiment was consistent with the equation for the particular transmutation involved.

They bombarded [[Lithium]] atoms with [[protons]] having a [[kinetic energy]] less than 1 [[Electron-Volts|MeV]]. The result were two (slightly less heavy) [[alpha particle]]s, for which the [[kinetic energy]] was measured as 17.3 MeV

They bombarded [[Lithium]] atoms with [[protons]] having a [[kinetic energy]] less than 1 [[Electron-Volts|MeV]]. The result were two (slightly less heavy) [[alpha particle]]s, for which the [[kinetic energy]] was measured as 17.3 MeV