Archive for the ‘Ask a Rocket Scientist’ Category

  • Ask a Rocket Scientist: Mailbag edition: The truth about jetpacks, space elevators, & more

    Aug 5, 16 • ndemarino • 5enses, Ask a Rocket ScientistNo CommentsRead More »

    By Prof. Werner Von Karmann Ah, it’s the dog days of summer. People holing up in a cool place and thinking of things around them. So I guess that’s why this month we got several interesting questions from our readers. I’ll try to answer some of them and also give you, dear reader, some additional things to think about. … W. Wright asks: “Where’s my jetpack? And shouldn’t I have a hoverboard, at least, by now?” The ability to fly has been a longtime dream, probably since the first hominid. There are different machines today that enable a human to fly — airplanes, gliders, helicopters, and rocket ships. Some believe that the ultimate machine would enable a person to hover (that is float around in mid air) with the smallest of inconvenience and machinery. So, in the 1950s and ’60s the Bell company, the same company that builds helicopters, engineered the first jet pack that was capable of flying up to 33 ft for a duration of 21 seconds. This prototype utilized hydrogen peroxide as a propellant, avoiding the nasty problem of combustion but rather spewing H2O2 around was seen as not a big deal. The short distances and duration seemed a poor promise and the project, funded by the Army, was discontinued. The main problem comes down to how to provide sufficient thrust to first push a person up

  • Ask a Rocket Scientist: Skybound: Looking (up) at nature, nurture, & mimicry

    Jun 3, 16 • ndemarino • 5enses, Ask a Rocket ScientistNo CommentsRead More »

    By Prof. Werner Von Karmann Dear Prof. Von Karmann, Does anything in nature fly the same way as airplanes, helicopters, or rockets? — Michael D., Chino Valley Mike, thanks for your question. Over the millennia, humanity has watched nature for inspiration. Today, we call it biomimicry, which is a fancy word for observing the nature around us and adopting what one observes into a machines we build or applying that observation to the mathematics or physics used to design a machine. In Western folklore, we have the story of Icarus. Long story short: Dude made wings to fly like a bird. Not a happy ending to that one. You gotta know the limits of the knowledge extracted from nature when you apply it to manmade devices. Like don’t fly too close to the sun or your wings will melt. When it comes to flying, you can go for endurance (long flight) or attack (fast and agile maneuvers). In nature, you can see how animals evolved to conserve energy for endurance, as visible in pelagic birds and fish, and for those fast attack maneuvers in raptors, such as Peregrine Falcons. For endurance, you have to minimize expended energy. When it comes to a vehicle, bird, or fish moving through air or water, the force that provides the vertical force for flight or horizontal force to push it along is called lift

  • Ask a Rocket Scientist: 2π in a pie

    Mar 4, 16 • ndemarino • 5enses, Ask a Rocket ScientistNo CommentsRead More »

    By Prof. Werner Von Karmann Apple Pie Recipe (Fannie Farmer Cookbook) basic pastry dough for 9” two-crust pie 3/4-1 cup sugar 1/2 teaspoon salt 1 teaspoon cinnamon 1/2 teaspoon nutmeg 1 & 1/2 tablespoons flour 6 large, firm, tart apples 2 tablespoons butter Preheat the oven to 425 F. Line a 9” pie pan with half the pastry dough. Mix the sugar, salt, cinnamon, nutmeg, and flour in a large bowl. Peel, core, and slice the apples and toss them in the sugar mixture, coating them well. Pile them into the lined pan and dot with the butter. Roll out the top crust and drape it over the pie. Crimp the edges and cut several vents in the top. Bake 10 minutes, then lower the heat to 350 F and bake 30-40 minutes or until the apples are tender when pierced with a skewer and the crust is browned. ***** There was this apple tree that my parents planted when they bought their first home. It was a large tree that dad nurtured over the years, carefully pruning and spraying it each season. Every fall, it yielded an abundance of fruit — bags and bags of fruit that he used to make apple pies and stock up the freezer, which provided us with luscious desserts for several months. When my father was dying, one of the last things he taught

  • Ask a Rocket Scientist: Super-powered, super-sized computational tools

    Jan 1, 16 • ndemarino • 5enses, Ask a Rocket ScientistNo CommentsRead More »

    By Prof. Werner Von Karmann The phone rang and my officemate Merrit answered the phone. Still focused on my computer screen, I watched as a stream of numbers scrolled past, numbers that represented my latest simulation of whether vortex structures off the tip of a helicopter rotor blade were converging to an answer or were diverging off into NaN (not a number) world. We were both Ph.D. students, part of a NASA research group of over 100 people who already had their Ph.D.s. There was a future astronaut in the group who would later die in the Shuttle Columbia accident. The algorithms and theories we were using were named after the person(s) in the next office(s). The building we were in was the Numerical Aerodynamic Simulation Facility. Upstairs, was a Cray 2 supercomputer and on our desks we each had Silicon Graphics Inc. workstations. I still had my Mac 512 from grad school. That same building now houses the Pleiades supercomputer; the same one that’s featured in that movie, “The Martian.” Merritt launched into a discussion with the other person on the phone. His voice rose in pitch and I heard him say, “Well it’s not like it’s …” But, indeed, it was rocket science. When the editor of 5enses asked me to host this column, I saw it as an opportunity to help answer some questions about the physical

Celebrating art and science in Greater Prescott.

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