i know triple point is the temp. that water's(here use water as example) solid、liquid、gas state can be existent . http://www.youtube.com/watch?v=BLRqpJN9zeA the video is amazing and so, how can he change water's state? (solid、liquid、gas state can be existent at the same time, but how can we change its state?) lastly, how can we produce triple point? i'm sorry about i just have F.3 standard now so please explain it in a simplier way. thank you so much!