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Showing content with the highest reputation on 05/30/21 in all areas

  1. 'Robotic skin' is a highly active area of current research, and your OP seems to require a relatively low resolution, planar version of the same thing. I'm puzzled why you pick impedance as the sensed property for this. Most work in this field has been focused on traditional resistance strain gauges, piezoresistance, and capacitance methods though Fibre Bragg Gratings (FBGs) seem to have received a lot of attention recently. The EU Roboskin Project is funded to the tune of about 5 million Euros: details at https://cordis.europa.eu/project/id/231500
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  2. Here is what Lagrange* has to say about your setup in zero g. Some quick mathematics: [math]L=T-V [/math] where T and V are the kinetic and potential energy of the system [math]V=0 \rightarrow L=T[/math] [math]T=\frac{m v^{2} }{2} [/math] where v=velocity Or, in generalized coordinates [math] \frac{m\dot q^{2}}{2} [/math] Euler–Lagrange equations: [math] \frac{\partial L}{\partial q_{j} }= \frac{d}{dt} \frac{\partial L}{\partial \dot q_{j} } [/math] In our specific case without gravity: [math]0= \frac{d}{dt} m \dot q =m \ddot q[/math] [math]\dot q=0 \rightarrow \ddot q=0[/math] In other words; in zero g the device will not accelerate. Please present the mathematics and a comparison to my attempt at analysing the zero g case for your device. It means that a curious person may want to know how an idea is incorrect and what misunderstandings that caused wrong conclusions. And then reject the idea or try to improve it with the help of the acquired knowledge. Side note: When joining this forum I did not know much about Lagrange and Hamilton. I was curious and listened to expert members here and as a result I feel confident enough to try to apply the methods. I'm also confident that any errors will be corrected by expert members and more knowledge will be gained in the process. *) Trying to use standard symbols, see https://en.wikipedia.org/wiki/Lagrangian_mechanics
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  3. The result of the integral doesn't depend on which approximation you use. The second one is called the lower Riemann sum. There is another one with starts with what you would call \(f\left(x_{0}+\triangle x\right)\) instead of \(f\left(x_{0}\right)\), and ends with \(f\left(x_{1}\right)\) instead of \(f\left(x_{1}-\triangle x\right)\) It's called the upper Riemann sum. Your expression differs only in a second-order term in \(\triangle x\). You only see a big difference because your \(\triangle x\) is enormous in the image. You can actually do an even better fit by taking a polygonal approach to the curve (for the same step \(\triangle x\).) https://www.geogebra.org/t/upper-and-lower-sum?lang=en Sorry. This is the applet that I meant to show you. You must play with the n=10. Take it up to n=24, for example, and you'll see what I mean. https://www.geogebra.org/m/SNS8SYSg
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  4. Not hydrogen atoms. You want a conducting solid material, such as a metal plate, because the idea - at least as I recall it - is that with light above a certain frequency a current flows in a circuit, due to the emitted electrons, whereas below that frequency it doesn't. The experimental setup to "catch" the emitted electrons is shown in this diagram from the Wiki page: https://en.wikipedia.org/wiki/Photoelectric_effect#/media/File:Photoelectric_effect_measurement_apparatus_-_microscopic_picture.svg You can certainly ionise hydrogen or other gases with light with energy above the ionisation energy for the gas, but this is not what people mean when they talk about the photoelectric effect. As for capturing and containing them, you will struggle because they will repel one another and a bulk -ve charge will accumulate.
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  5. Science and morality are different disciplines - one is what we observe in the universe, the other is what we bring to it. Morality is not so straight-forward that we can afford to discard the millennia of thinking that has shaped our cultures. Instead we should be building upon that base, taking what is useful from our mythologies, and creating new ones in the shape of our aspirations. If they are such idiots why give them credence by engaging with them? Such people have the same mentality that has people believing in a flat earth and lizard people ruling the world. No one believing it will be reasoned out of it and it just raises their profile by putting them on the same platform as respected voices in science. It would be better to give a platform to reasonable people of religious leanings (yes they exist), so we can more quickly transform our mythologies and incorporate our scientific understandings. This is why i believe Sagan was the greatest communicator of science - he didn't just tear down old ideas, he offered a tangible basis for new ideas. And that basis is the same one that can be found in all spiritual traditions: wonder.
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  6. The hubris of claiming that established physics is wrong, but you - and pretty much only you - understand the “truth” is quite something. ! Moderator Note This is not an eccentric mass scenario. You had a thread on eccentric mass and it was closed. We aren’t discussing it again. Despite your confidence, you don’t actually understand the basics of mechanics. Physics is not wrong. You are. As you are here to preach and not learn, this is closed. Don’t bring up this or related topics again.
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