this gives us a limiting, from cary emanuel siri, we can work out the maximum potential and from statistics we can work ou out -- we have two different intensities. we can look at how strong they got. this is how fast they are rotating. then we can just plot them and you can see these black dots represent that. notice what happens to those black dots. they start to flatten out. at some level you can't get a stronger hurricane. that's right at 75 meters. second. that's what i mean by limiting intensity. that is a brilliant statistical theory. it tells us about what is the maximum you can get given the set of values you have. think about that. if i measured the height of every one of you and then ranked them from shortest to tallest, i would have a single tall person in this room but i would not say that the tallest person that could ever be in this room. but i want to know that. i want to know what would be the tallest. what i would do is i would have another lecture next week. i'd get another 25 people, i get a different group of people and i get another tall person and then i'd have two pu