combustion specialist several mcalister has found a way to simulate the process. first she simulates an ordinary wall far. so narrow i let it burn a little bit here when you can see it there's a lot of unburned fuel in there so it's not burning very well. the plume of the fire is narrow so the flames can pull in fresh replacement air from all sides. but then a question in here. no using a chimney service simulates the air flow of a mega fire. burns much faster much more clearly or get sparked up and people all over. they can hear the flow but it creates. this flow which is the result of an astonishing mechanism as the fuels accumulate and you get more and more fuel down on the ground they burn longer so instead of having simple line of fire you end up with an area of fuel that's on fire so as that area gets bigger and bigger the plume above it gets wider and wider the. hot air rushes upwards and forms a natural chimney which blocks the air coming in from above and the sides instead the fire sucks in fresh air from down below generating strong winds on the ground.

stephen: although if they really wanted to scare us they'd use footage from the sequel where kevin mcalister friend of child sex traffickers in new york city. we've got a great show for you tonight, i will be talking with the author of "too much and never enough" mary trump. are you going to stick around to watch that, joe? >> yes, absolutely. >> stephen: oh, great. we'll be right back.♪ never run dry of... killer attitude. good moves. or hydration. neutrogena® hydro boost. the number 1 hyaluronic acid moisturizer instantly delivers 2 times the hydration. and keeps hydrating all day long. running dry of supple, bouncy skin? never! hydro boost. pair with hydro boost wipes to cleanse and hydrate. neutrogena® itchy? scratchy? family not get charmin ultra strong.rate. it just cleans better, so your family can use less. hello clean bottom! enjoy the go with charmin. an extra 15 percent credit on car and motorcycle policies? ok? that's 15 percent on top of what geico could already save you. so what are you waiting for? dj khaled to be your motivational coach? yo devin! remember to brush in a circl