How Tall Can People Get?
Dear Dr. Stern, My name is Jason and I am currently in the 11th grade. My brother and I were wondering whether it was possible for people to grow infinitely tall. My brother believes there is a limit to height because muscle strength would be insufficient to support a person that tall. I contend that there should be no limit to height if they live on an extremely small planet with huge mass. Please let us know who is right! Reply Dear Jason Presumably, you meant “arbitrarily tall.” Even with that change, I do not know what the proper answer would be, because the rules of your disagreement with your brother were not spelled out. On Earth, the answer is no: even trees do not grow arbitrarily tall, because of the difficulty of pumping sap very, very high. Pumping blood to comparable height would be very difficult (giraffes seem to have attained the limit) and even before that, the weight of an individual would make it hard to move or even stand. On another planet… if gravitation is very
