sayet shafik qusay and marvels at the beauty of it all. for alaska says it makes him realize how small we are. while a look at the sky helps silva raj chill out. what makes the modern city well the architecture among other things. many builders think the higher the better and have built towering concrete constructions. but concrete doesn t hold up forever so what s to be done when buildings and bridges start to crack and crumble researchers are working on how to stop the decay before it s too late.