Re:Einstein, Symmetry and the Future of Physics
by ChrisLomont on Thursday June 27, 2019 @04:09PM
(#20298154)
>The author of the article doesn't understand elementary physics as well as you do
Don't be so quick to make such judgments:
There is ample scientific interest in the differences between inertial and gravitational mass [1]. That they seem the same is a profound question known to Einstein. He explicitly assumed they were the same in his equivalence principle [2].
So their equivalence is a postulate, not derived from deeper theories. But one day we may find it is not consistent over time. It most certainly is a deep question in physics.
There are other theories of gravity, taken seriously, as possible future modifications to relativity, such as Brans-Dicke theory [3], that remove this equivalence principle, yet still agree with all observational evidence to date.
Current experimental evidence puts them equivalent to under 1 part in 10^-15 [2], with more experiments still being done.
Don't be so quick to make such judgments:
There is ample scientific interest in the differences between inertial and gravitational mass [1]. That they seem the same is a profound question known to Einstein. He explicitly assumed they were the same in his equivalence principle [2].
So their equivalence is a postulate, not derived from deeper theories. But one day we may find it is not consistent over time. It most certainly is a deep question in physics.
There are other theories of gravity, taken seriously, as possible future modifications to relativity, such as Brans-Dicke theory [3], that remove this equivalence principle, yet still agree with all observational evidence to date.
Current experimental evidence puts them equivalent to under 1 part in 10^-15 [2], with more experiments still being done.
[1] https://en.wikipedia.org/wiki/Mass#Inertial_vs._gravitationa...
[2] https://en.wikipedia.org/wiki/Equivalence_principle
[3] https://en.wikipedia.org/wiki/Brans%E2%80%93Dicke_theory