Are both sides of a coin equally heavy?

Whether the front and back sides of a coin are equally heavy, I am afraid that basically no one can give an accurate answer. First, there is no way to weigh them separately. Second, only people with scientific level can carry out quality inspection to see whether the molecular structures of the front and back are the same. What is the possibility of such a job? Flipping a coin decides one thing, just like drawing lots. It won't be like a sports competition in which all teams fight for fairness, but the reality is not good, so how many days will the game end? So it should be fair to draw lots first (if you meet the top two, it is fair to eliminate one, because the loser will definitely not be able to play, and you have to compete with another loser for the third place), and it is basically fair to draw lots after one round. Who do you mean by serving first? What's a fairer way not to flip a coin?