Why does microwave Mac & Cheese stand straight up?

Question

I bought that Microwave Mac & Cheese and after the 3 minutes of microwaving, I pull it out and all the macaroni has aligned themselves to be straight up and down. It's very creepy and x-files to me. Why is this happening? Is it a bad sign that I shouldn't be microwaving? What is the science of this odd macaroni behavior?

Answer 1

The water boils inside the macaroni tubes and one end or the other flips up to let the steam bubble out.  It doesn't happen when you heat M&C in a pan because the heat comes from the bottom so convective motions randomize the noodle positions.  A microwave heats in the fluid so there aren't any bulk motions to move the noodles around.  

Answer 2

omg i know exactly what you mean. it freaks me out too!

i always have to knock them down with my fork right away.