I am color blind

Left: Ishihara Plate displaying the number 45 (source: http://www.toledo-bend.com/colorblind/Color45.jpg)

I am color blind. I have deuteranomaly , which means that I perceive colors utilizing all three cones (red, green, and blue) in my eyes, but I have trouble with sensing colors with my green cones. Others forms of color blindness are classified under monochromacy and dichromacy. Those individuals perceive colors using only one or two cones. Because all three of my cones are functioning, my color blindness is not as severe as those with mono or dichromacy, but I still occasionally run across problems with my form of colorblindness. Because I have trouble with the green cones in my eyes, I am more sensitive to red light, and thus I have trouble distinguishing between some colors, especially red and green. I can easy identify most of the colors I see, but I cannot pass the Ishihara/PseudoIsochromatic Plate test (I missed it by one) that is used by the U.S. military. Individuals who cannot pass the Ishihara/PIP or FALANT (used as an alternate test by the U.S. Navy) are restricted from certain duties, one of which is aviation. In aviation, red and green lights are used to distinguish between the port (left) and starboard (right) sides of an aircraft to help pilots determine the orientation of other aircraft they see in the dark. Red and green lights are used because the longer wavelength and thus lower frequency of red and green light waves are less susceptible to scattering in the atmosphere, and can therefore be seen at the greatest distances. I can actually distinguish between the red and green used in aviation and can still get an unrestricted civilian pilot’s license from the FAA (there are actually a handful of colorblind airline captains!) if I pass the more practical color test in which I am tested with a light gun from the control tower and asked to identify if it is displaying red, green, or yellow, but military is most likely out of the question because of their stricter requirements. But other than that, being colorblind is awesome!

*sigh*

Water and Flames

Today I went to the open house for the University of Hawaii’s Institute for Astronomy. There were a lot of cool things there, including devices called Ruben’s Tube and Kelvin’s Water Dropper (the same Lord Kelvin who developed the Kelvin scale for temperature). The Ruben’s Tube is a long pipe with many holes along the top of the pipe. It is sealed with a speaker on one end, and tube connected to a propane gas tank on the other end. The speaker creates sound waves, which are longitudinal waves that have high and low pressure areas, within the pipe. The gas provides fuel for a flame, which responds to the low and high pressure areas created by the sound waves. Higher pressure areas have taller flames because more propane gas is escaping through the hole above it, while lower pressure areas have shorter flames because less gas is escaping through the hole above it. The attendant there told me that with a steady pitch and no wind, the flames will create a sinusoidal wave. Kelvin’s Water dropper features a large water reservoir suspended at the top of the device, which releases drops of water down two separate tubes. Before falling into a metal bucket below the reservoir, the water droplets travel through a tube with a conductive metal ring that is connected to the bucket opposite of it. Because of the ions from minerals that are contained in water, one bucket eventually becomes more electrically positive than the other, creating a voltage difference. This creates a visible spark between metal spheres attached to each bucket. As I walked around looking at other exhibits I noticed that many aspects of astronomy relies on physics as well as chemistry. And I here I thought astronomy was just looking at stars!