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Below is a photo I took (you can see my reflection on the fuselage) of the, Enola Gay, now on exhibit at Air and Space Museum’s Steven F. Udvar-Hazy Center in Virginia. The Enola Gay was the airplane that dropped the first atomic bomb on August, 6 1945 on the Japanese city of Hiroshima killing 70,000 people in less than a second and tens of thousands more from radiation by the end of that year. The bombing of Hiroshima and that of another Japanese City, Nagasaki, 3 days later ended the Second World War and ushered the nuclear age setting in motion political, social, and cultural changes what would reshape the world forever affecting the lives of hundreds of millions of people.  In a segment of a CNN documentary below the last surviving member of the Enola Gay crew, Theodore Van Kirk (1921-2014), reminisced about the war and the bombing. The nuclear age also had dramatic effects on science in terms of new scientific discoveries and applications as well as the way science was conducted. The names of many of the physicist who worked on the Manhattan project, which produced the first atomic bomb for the United States, have become the stuff of legend being celebrated or vilified in movies, word, and song. Among them stands out the scientific director of the Manhattan project, Robert Oppenheimer, who upon the explosion of the first atomic bomb famously remembered a line from the Hindu text, the Bhagavad Gita, “Now I am become Death, the destroyer of worlds”. The photo of the Enola Gay belongs to the author and can only be used with permission.
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In the video below Mark Rober builds a liquid sand hot tub for his nephews and in the process explains in a fun and simple way the science behind fluidized beds. As a side note, the song chosen by Rober as a musical background while his nephews play around in the sand will probably be recognized by the older generations as the 1967 international hit of the South African singer, Miriam Makeba (Mama Africa), “Pata Pata” . Most people are amazed by the multicolored fishes that they see in aquariums. Many wonder how such fishes can survive in the wild. After all, aren’t those bright colors on their bodies like a bull’s eye for predators? What must be remembered is that different wavelengths of light are absorbed by water to different extents. The most extreme case is that of red light. In the video below Kendall Roberg shows how colors change the deeper you dive. The video is about selecting the right fishing lure, but it demonstrates that as depth increases, the the color red is perceived as red to a lesser degree (because there is less red light to reflect) until it comes a point when it appears black. Other colors are also affected, but not as much. Besides clapping your hands and snapping your fingers, there is another way to make sounds with your hands. The approach I show in the video below exploits the facts that the palms of your hands are concave, and that when you place your hands opposite to each other and introduce a slight twist, the area around your palms acts like a seal turning both of your hands into suctions cups. Once you have arranged your hands in this position, you can press them against each other forcing out the air between them which will make a sound. The expelling of the air will create a low pressure area (not a vacuum, see below) between your hands, and when you break the seal, the air will rush back in and produce another sound. By pressing and releasing your hands repeatedly against each other you can rapidly produce rhythmical sounds. It is important to understand that the reason air rushes in when you break the seal is not that the air is “sucked in” by the vacuum in between your hands. As I have explained in my blog, vacuums don’t suck; it is the atmosphere that pushes. A column of air hundreds of miles high above you excerpts a pressure of 14.7 pounds per square inch (at sea level) on your hands. When you move your hands or fingers and break the seal, it is all that pressure that pushes the air back in. While clapping hands and snapping fingers are well known descriptions of how to make sounds with your hands, I don’t know what word to use to describe the method that I used in the video to produce sounds with my hands. If you know or want to suggest (or invent) a verb for it, please leave a comment below! |
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