Einstein had a few important but easy to state ideas about the speed of light and gravity, that he analyzed at length with non-controverial comprehensible (to e

Einstein had a few important but easy to state ideas about the speed of light and gravity, that he analyzed at length with non-controverial comprehensible (to experts) math, and made a bunch of predictions that many scientists verified. The quantum menchics theory was much more controversial, and Einstein opposed it.