I am not a cook. I do have a physics degree. One time I pondered, "What's with the boiling water? And even caring about corrections for altitude?" Water boi

I am not a cook. I do have a physics degree. One time I pondered, "What's with the boiling water? And even caring about corrections for altitude?" Water boils at a particular temperature. While boiling, at STP, it is at that temperature and stays there. Thus, when you immerse something in boiling water for a specific amount of time, you know this food item is experiencing a particular temperature for a given time. Boiling water allows for standardization on the temperature end, so you can assure yourself that, if you get the time right, well, you've standardized both of those things and your macaroni will be like someone else's macaroni, assuming they came from similar boxes. The stability of the boiling water temperature takes away a lot of the guesswork.