How to Tell the Direction the Air Is Moving In / Mr. Denjiro’s Happy Energy! скачать в хорошем качестве

How to Tell the Direction the Air Is Moving In / Mr. Denjiro’s Happy Energy!

DENJIRO: I have here an alcohol burner that’s been lit. Let’s the shine light from a smartphone at it and observe the shadow. We can now see the updraft from the flame, which we couldn’t see before, as a shadow. This is a method called “shadowgraph.” There’s also a natural phenomenon called a “heat haze,” in which we can see air that has been heated by sunlight. Now, let me talk about the Schlieren method, which is an improved version of the shadowgraph. The light from this small light source here is bouncing off that concave mirror over there and gathering here. By using a camera instead of a screen, we can observe the light even if it isn’t dark. Now let’s look at a candlelight. If you look closely, you can see a shadow of the updraft. We’ll be able to see it even clearer by making one simple adjustment. I’m going to place a metal plate where the light is being reflected to and block part of the light. Watch what happens. GIRL: We can see the shadow really clearly! DENJIRO: So why are we able to see it better? The light that was not affected by the updraft was reflected by the concave mirror and gathered at a specific spot. Most of the light comes here, but the updraft that’s been heated by the flame bends the direction of the light. Therefore, the light that’s been affected by the updraft gathers at a slightly different spot. By hiding the light that was not affected by the updraft, we’re able to see the affected light even better. This is how the Schlieren method works. Let’s use this opportunity to observe some other stuff with this method. As you can see, displaying the shadow allows us to see phenomena that we otherwise wouldn’t be able to see. I hope energy will bring you all happiness. Our magic word is "Happy Energy!”