xi'an and shanghai

my mum and i will go traveling in China soon, in the first week of september. if it all works out, we will spend 3 days in Xi'an( http://en.wikipedia.org/wiki/Xi'an)
and 2 in Shanghai(http://en.wikipedia.org/wiki/Shanghai)
one seems like the city of the past, and another is like the place of the future.what would it be like to go from one to another, in less than 3 hours?
i remembered going back to USA from a two week vacation in Europe few years ago. it was like returning from a different era, a different time in space. it felt very odd. the architecture and atmosphere in Europe certainly provide a very strong and intimate sense of history. At that time, i wasn't quite sure which place I would like to belong to ( imagine if i have a choice). i felt torn.
i wonder if there will be a stark contrast between Xi'an and Shanghai since both exist in the same country? i suppose being in either place allows us to appreciate both the distant past and modernity a little better? or maybe traveling there will alter my assumptions & impressions about the two places completely.
i don't know. i will find out in september.

anyway, i don't feel too well today. i couldn't sleep last night. the latte i drank yesterday evening kept me awake.i am re-learning my lesson about caffeine intake in the evening! besides, i have a very bad sore throat. everytime i am out of the house, i have a lot of deep-fried, barbecued or spicy food. they taste so good that i can't stop eating!so my mum made orange juice and chrysanthemum tea to sooth my throat. just for today, i will rest content with home-cooked food.