You Are What You Eat
I was talking to my son the other day about how the body uses food for fuel to grow. Now, it’s pretty obvious when you think about it, but my brain had never made the connection that we are literally, what we eat. Our bodies use the mass of food to build itself.
I think the reason this struck me was how popular sci-fi, or fiction in general, often portrays things. Creatures grow incredibly fast for pseudo-science plot reasons. How many times in a story do we see things grow incredibly big really fast? It’s great for the plot and things can grow pretty fast so the idea isn’t completely unreasonable. But one thing that’s never talked about is where all that mass comes from?
Take Captain America. He takes the super-soldier serum and spontaneously grows in height and muscle. Where did all that extra mass come from? The serum? It hardly had the necessary mass. Maybe you could handwave some explanation of nutrients being injected into the chamber but the movie certainly doesn’t do anything to explain it.
Even when a movie does attempt to explain it, especially for younger minds, it doesn’t always mean anything. Take Star Trek II: The Wrath of Khan. The Genesis device works by reorganizing matter. The explanation specifically says “of equal mass”. I loved this movie as a kid (still do) but when the Genesis planet is created at the end, I didn’t get that it was made out of the nebula. I just thought a planet had been created because that’s what the thing did.
Later, while I learned and understood the conservation of mass law, I never thought about it in conjunction with growth. It was a concept that matter and energy don’t just disappear into thin air.
In stories, though, matter does tend to just appear quite a lot. Which is fine as far as it goes. Stories don’t have to match hard science. Mine certainly don’t. Stories are about what happens in them so as long as the “science rules” are consistent within the story, it doesn’t really matter what those rules are.
Except maybe when it messes up your understanding of how the real world works. Did this mess up my understanding of the world? Did it matter that I had never thought about where the mass comes from when things grow? In this case, I don’t think so. I literally had never thought about it before because it wasn’t relevant until I had to explain how all this worked to my son. I had been taught real science even if it hadn’t ever connected like this before.
So now I can recognize the fact that I am equal parts wheat, cow, chicken and sugar cane. Does it make a difference? On one level, not really, all we’re doing is rearranging carbon atoms. But on the other, how many bags of Oreos do I want to be hauling around every day?
