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    Spacecraft Engineer
  1. From wikipedia: "Testing was performed on a low-thrust torsion pendulum that is capable of detecting force at a single-digit micronewton level, within a sealed stainless steel vacuum chamber, but at ambient atmospheric pressure, because the RF power amplifier used an electrolytic capacitor not capable of operating in hard vacuum."
  2. A quick sort of philosophy question for the smart guys on this forum. I was just reading this article about Elon Musk when I stumbled upon this paragraph: Musk spends two to three days a week in Palo Alto, flying in late on Tuesday mornings. He works pretty much nonstop until he flies back to Los Angeles, where he lives. When he must pause to eat, he does so with amazing efficiency. I twice saw him consume an entire meal -- chicken, a vegetable, bread, and a Diet Coke or two -- in under five minutes, all while holding forth on topics such as how best to fix a rocket vibration problem or the ridiculousness of sales as a business function. "In the early days, when Elon would have lunch meetings, I used to have to tell people that they shouldn't worry if he'd already finished before they even sat down," says Mary Beth Brown, his longtime assistant. "He just doesn't realize how fast he's moving." That notion of ridiculousness of sales intrigued me, coming from a businessman. What do you think he meant by that?
  3. I've learned most of my English with Anki - http://ankisrs.net/ It's a great idea to start by reading this short ebook - http://dl.irpdf.com/ebooks/Part16/www.irpdf.com%285783%29.pdf After reading that you will understand that to learn a language, you need to read maybe first 5 chapters of a grammar textbook, then throw it away and then build your vocabulary until your head spins. They say that when you know 10000 sentences in a language, you are fluent.
  4. Eh, not if it was attached to a frictionless shaft. Did the prof spin when he held the gyroscope? Anyways, I just wanted to post some fun videos...
  5. Yep, the prof is a crackpot, I can see it. Anyways, it was a fun afternoon and I wanted to share... It's interesting that by hurrying the precession he was able to lift the thing so easily, almost as if defying gravity. It obviously confused scientists as late as 1989 - www.nytimes.com/1989/12/28/us/two-men-and-a-gyroscope-may-rewrite-newton-s-law.html Just one more video, obviously I am not the only one who likes to test things
  6. Landing on phobos is not really a landing. It's more like a randezvous. There's almost no gravity, so just by jumping, you could put yourself into orbit.
  7. I service scientific instruments and most of them come from either Japan, Europe or the US.
  8. Today my father told me about a physical fact that I, quite surprisingly, never heard about. He told me that when he was a small kid he would remove a wheel from his bicycle, and while holding the hub with his hand he would spin the wheel to test for friction. And he found out that he could easily let the hub just rest on his hand and the wheel would remain upright. The idea seemed ludicrous to me and I refused to believe him. So I tried to search youtube for this effect and here it is: Quite ashamed that I was so uneducated I searched further and learned about a professor called Eric Laithwaite, who apparently did a lot of work on this. He also claimed that spinning objects could in fact be lifted more easily and this could be used in space propulsion. He was quite famous for his work on linear induction motors at that time (he is sometimes called "the father of maglev trains"), so at first his discovery created quite a sensation, but then his claims about defying newton's laws discredited him into obscurity. This is a video of him showing how spinning makes objects lighter (around the 2:38 mark): What really happens is that the prof is hurrying the precession and thus the flywheel is forced upward. P.S. Fun fact - at one time, NASA became interested in his work, but mostly in his linear induction motor. They funded him to develop what we now call the mass driver. P.P.S Fun fact number two - NASA also assessed his work on gyroscopic antigravity as part of their Breakthrough Propulsion Physics Project and you can see the comments here (page 8) and here. Disclaimer: I just wanted to share, for me it's fun to read about things that seem impossible. No law breaking is shown here.
  9. I am a service engineer in Europe. My service case is twice as big and heavy as it needs to be, because I need to carry two sets of every tool - normal and american. I just laugh it off, but my hands hurt
  10. Except he isn't using holographs, only hand gestures for 3D manipulation of essentially a 2D image. I am no expert obviously, but I can't see how this would be more precise (or faster) than regular mouse clicking. Care to elaborate?
  11. Or a webcam from Vandenberg or something? Or do I just have to read updates on NSF forums?
  12. Oh thanks, I actually wasn't aware of this! But it's stated clearly in here: http://wiki.kerbalspaceprogram.com/wiki/Atmosphere
  13. Mine is from late 1992, breakup of Czechoslovakia into Czech and Slovak Republic. I was 6 at the time. My mother sat me down and we watched the live broadcast from the voting that took place in the parliament. My mother is a native Slovak (although she speaks Czech now), so it was kinda sad for her to think that she would have to travel across the border to visit her parents. That only lasted a few years of course, then both republics entered the EU and borders got abolished altogether. Some people still think that Czechoslovakia exists to this day, it results in funny situations when I introduce myself, I guess they need their textbooks updated
  14. This right here. Actually I wonder if this whole thing has any use. The 3D printing could be useful only for rapid prototyping, not actual production and the 3d hand gestures could be useful only for playing after work, not real design. Being a fan of Elon (ehm ... look to the left), I really think this was just a cheap publicity stunt. But everybody makes mistakes sometimes.
  15. Are you sure about this? IIRC Venera took only like two pictures before getting fried and Huygens probe took only one picture from the surface of Titan (but there are a few more pictures from descent). Anyway, here's a rehashed version of the Venera pictures, it nicely shows the thick atmosphere:
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