16 October 2007

Tuesday actually brought a half-way interesting optics lab, thanks almost entirely to the involvement of fluid mechanics. What the hell are you looking at? This is a shadowgraph of air escaping from the nozzle of a can of compressed air, like what one uses to clean a keyboard. The edge of the nozzle is the dark shadow on the left. The bright streak with dark diamonds over it is the air escaping the nozzle. In this case, the air can's button is pressed all the way down and the air escaping is a) traveling at the speed of sound and b) at a pressure lower than the ambient air. The diamond pattern is actually a series of shock and expansion waves that bring the air back to ambient pressure. The photo was taken by expanding a laser beam, releasing the air stream into the beam's path, reflecting the resulting image onto an index card (see the lines?), and snapping a high contrast, black and white photo of the image on the index card. It's also brought to be extreme geekery.

Add Comment

Name

Subject

 

R H
G S
B V

#

 

You can also use the color name for example: [color=red]Your Text[/color]

Comment (required)