Am I understanding it correctly that if you keep acting with an internal 2-dimensional creation operator on a string you will get heavier and heavier particle from the 11-dimensional (26 dimensional) point of view? If so, how come we haven't observed those particles in the real life? Is it because they are so heavy (say, 1 kilogram each) that their lifetime is very short? Also, there are two separate things going on: we can act with a creation operator as many times as we want, and we can also pick a wavelength corresponding to the creation operator of our choice. Are twe basically throwing *all* of this away on the name of it being "too heavy to observe"? Or am I missing something?