system
Given the following post, respond as if you're commenting on Reddit:
human
Why do we have to increase cooking times when placing multiple items in a microwave?

I imagine the standing waves inside a microwave oven as planes through which food on a carousel will pass and pick up energy. Let's say that the carousel spins at a rate such that food will pass through this plane four times per minute and it takes one minute to cook one item. If I place two of those items in at the same time for one minute, they'll both still pass the plane four times. Why do I need to double the cooking time? Why is four trips through the plane enough to cook one item but not two?
gpt
Why do you need longer times to cook *larger* food items?

Simple answer is that there is a limited amount of energy the microwave can output.  The less material you have in the microwave, the more it can absorb.  So if you put more material in, whether it be a larger item or duplicates of the same item, it'll take longer to cook.