On Sun, Dec 10, 2017 at 10:06 PM, <[email protected]> wrote: > > Excellent summary. TY. But why would Einstein think there could be a > covariant theory for accelerating frames >
The speed of light doesn't change even for an accelerating observer nor does the spacetime distance between 2 events. Einstein figured there must be a reason why. Also, before Einstein there were 2 different kinds of mass, inertial mass and gravitational mass, Einstein had a hunch there was really only one sort of mass and tried to find a relation between the two. And he found it. > > > when an observer inside such a frame can do measurements to confirm > acceleration and differences with other such frames > The observer can't tell if he is accelerating or in a gravitational field. > > > unlike the case for inertial frames which are clearly equivalent? > Not everything is equivalent. You and I may not be accelerating and both be in inertial frames but if we are moving at different velocities then 2 events that are simultaneous for me may not be simultaneous for you. The fact that simultaneity is not the same for everyone turns what would otherwise be a logical paradox into something that is just very strange ; if we're both in inertial frames and in motion with respect to each other then I see your clock running slow and you see my clock running slow. John K Clark -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
