What will happen if Einstein would not discovered the EMC2?

Answer 1

we would all be farting until the unicorns eat the pine trees

Answer 2

If Einstein had not discovered the equation E=mc^2, it may have taken longer for us to understand the relationship between energy and mass. This equation led to advancements in nuclear physics and ultimately to the development of nuclear energy and atomic weaponry. Without this discovery, our understanding of the universe and technological progress would have been significantly delayed.