Comment on “Aerodynamic Center and Center of Pressure location. Computation and Misconceptions”

​At https://www.youtube.com/watch?v=67eTLeNwLgE

Alexander,

You are using what looks like to be a good computer tool for these calculations and visualizations. But you don’t explain your tools and give links to let others know what to use, or what you recommend. I watched your hysteresis video. It is really shaky and hard to watch. You could use computer tools. You hand writing is clear and your mathematics good, but you can get more out of the computer tools. You can share that ability and insights with others.

Your aerodynamics would be more powerful and helpful and help you grow, if you also do experiments to demonstrate. I recommend trying sound card oscilloscopes, usb oscilloscopes, cameras and microphones as basic tools that anyone might have. Find ways to use them and much that is done with traditional dumb instruments (the human does all the work) can be done with smarter computerized methods. You have the skills to build and use that sort of thing. Please decide what you want to create in your life. Your writing on paper and your work on the computer are clean and orderly. But your camera work, and your wiring messy. Put more effort into clean and organized layouts, it will help you get to where you want to go faster.

Keep up the great work! If you want an interesting problem try making a nice clean and quantitative version of the Franck-Hertz experiment. Then apply what you learn to ionizing air around vehicles. And look at what is called “electron affinity”. It is easier to add charge to things, than to ionize. Many electrostatic methods are too costly if you have to pay ionization energy costs, but tiny electron affinity bond energies can be enough to move things.

You “have” seen lidar systems that can scan the air far ahead of a vehicle, and you have seen tools for scanning boundary layers. You should also know how the lasers are used to ionize the air in particular patterns, and how multiple acoustic sources are used in phased arrays to move air in 3D haptic (“holodeck”) systems. And you should know how to 3D scan real object (including models and planes and things you and others make yourself) to then have the raw detailed data to test things and measure. Reality is far more complex than any computer model. I can tell you how much more. But it means that good engineering is a balance between making things, precise measurement, modeling for control and planning, and counting the cost of memory and computers to do enough to make it work, without getting so heavy and expensive it will not fly.

Richard Collins, Director, The Internet Foundation

@Alexander Beliaev

I try to review the entire Internet, and in the past year or so have been spending more time looking at the many helpful videos on YouTube. YouTube has no clue about education, or people like yourself mentoring and helping others. So they provide no tools for collaboration. Ideally, you could share your models, algorithms, and data just as you share MP4 videos. You would think that a group as large as Google (owns YouTube now I am pretty sure), would know how to share ANY format – lossless images, time series, models, simulations, 3D datasets, anything It is just data. You are talking to people here, but without links below the video, they all have to search for you and your materials. It is possible to put links in the videos, but that is really clumsy and hard to find anything in even a short video.

I studied aerodynamics more that 40 years ago, and try to keep up with new methods and approaches, sensors and controls. So a good easy-to-use compressible fluid flow modeling and simulation tool looks very attractive. You have introduced some ideas here and some images for people to try to hold. But if they had the tools and the data and could study and use those for long enough for their brains to absorb and internalize the motions and rule, they could start dreaming in these terms and begin to look for new things.

I found groups who are working on nonlinear compressible motions in the vacuum. Those relativistic corrections are identically the Mach relations for compressible flow. The vacuum is rather hard to compress. Maxwell said something along the lines of “harder than steel” to suit the speed involved. They are going to need people who have familiarity with fluid dynamic simulations. There are also many groups working on many times the speed of sound vehicles. So rather exciting times now. But with everyone writing it down on paper, or in words, the knowledge and intuition about these new things does not diffuse well at all on the Internet. It takes years or decades to get from one group to another – mostly because people write it on paper (PDF is the same as paper), then someone has to read it, find all the pieces, re-engineer the equations, rewrite the software from scratch. The “open” groups are trying to address this a bit, but they are mostly terrible at sharing. And those sites tend to be owned by other groups who only want to sell things, not help create new technologies and industries.

Richard Collins, Director, The Internet Foundation

I would rather see YouTube make a deliberate attempt to support STEMC (I add computers) and education world-wide. They are rich enough and it would be seen as something positive for their image.

A nonlinear vacuum or a vacuum with physical properties is a mature and honorable topic. I have been reading those for more than 50 years, and the people who write well about that are the top thinkers in science and mathematics and engineering and philosophy. But it is scattered all over the world, much on the Internet, and much blather and junk as well. The Lorentz equations for simple relation between velocity and energy can be thought of as a simple nonlinear property of the vacuum for motion of particles with stable energy. I have to find and document and try to find place for everything on the Internet. I do count the value to the human species of everything I see, but often I just write down what I find, who is doing, how many and what impact on society. Judging by one dimension is always likely to be wrong. I can just about handle a thousand things at once, but would rather teach the whole Internet to do that and make it part of how knowledge is stored – lossless, traceable, auditable, immediately usable, accessible to all.  Nothing left out, but all accessible and all contexts known.

Good luck with your paper.

Richard Collins, Director, The Internet Foundation