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Showing content with the highest reputation on 01/06/18 in all areas

  1. I do blame victims, and I think it's right to blame victims, when they take silly risks. If you dash across a zebra crossing without looking, you take a silly risk, even though you have the right of way. It doesn't absolve the driver who hits you, they should be ready to stop. But when you take an obvious risk, even though you have a right to do so, I think you are partly to blame. Like I said, a lot of law hinges on what's reasonable. It's not always black and white. A person is innocent till proven guilty. But if I knew that someone had just been acquitted on charges of paedophilia, and I allowed him to babysit my kids, and they got abused, I would blame myself, as well as the paedophile. Because the risk should have been obvious, and I ignored it.
    2 points
  2. The picture below shows an image of a bed from a 3d printer, which I intend to equip with an array of 15 x 3 mm Neodym magnets to hold down a steel plate. The steel plate itself is not and can not be equipped with magnets. Theres a heated aluminium bed between magnets and steel plate and the magnets are specified to withstand 150°C.The left side shows all 12 magnet arranged with the same orientation, on the right side every second magnet is flipped. The distance between the magnet is wide enough so they don't noticeably attract/distract/disturb each other.Question: The goal is that the steel plate lays flat (Z direction) and does not accidentally move in XY direction. Is either magnet orientation better than the other in achieving this?
    1 point
  3. Are you familiar with TSPLIB: http://comopt.ifi.uni-heidelberg.de/software/TSPLIB95/
    1 point
  4. I suppose that depends how you define evolution. I see no maths in your proposition. Further you are talking about a more general usage of 'evolution' than the specific theory mentioned in your title. So which is it?
    1 point
  5. I assume the first convolution was a square wave convolved with itself. In the frequency domain, convolution is equivalent to the multiplication of Fourier transforms. That means the operation does not add or subtact any new frequencies to the mix, it merely alters the relative amplitudes of frequency components that already exist within the transforms. In your examples, it is suppressing the upper harmonics in the spectrum of the original square wave, and then the triangle wave. So the fundamental frequency, which is what you are mostly observing in the second convolution, is the same as the fundamental frequency in the original square wave - given by the reciprocal of that wave's period. These wiki entries may help: https://en.wikipedia.org/wiki/Convolution https://en.wikipedia.org/wiki/Triangle_wave
    1 point
  6. Acceleration of a clock has no additional time dilation effect. The only time dilation you would see in the vibrating object would be due to its velocity at any given moment. This is knwon as the "clock postulate" and has been tested by placing radioactive samples in high speed centrifuges and subjecting them to extreme g forces. The resulting measured decrease in the deacy rate of the samples was exactly equal to that expected for just the speed at which the sample was traveling with respect to the lab frame. If you are in an accelerating frame, then you will measure some time dilation effects in clocks depending on where they are located relative to you with respect to the acceleration. For instance, if you where in an accelerating rocket, and sitting at its midpoint with a clock, you would note that a clock in the tail would be running slow, while a clock in the nose would be running fast when compared to your own clock. This is despite the fact that all three clocks are experiencing the exact same acceleration.
    1 point
  7. Yeah, there are plans on the table but nothing AFAIK green lighted so far. http://www.space.com/37952-hunting-second-earth-next-generation-telescopes.html Hubble's primary mirror is 2.4 meters in diameter and JWST's is 6.5 meters. So not quite 10 times as big but still a big step up. I wonder will I still be around to see it. Well the Breakthrough Starshot team is looking for one fifth the speed of light using nanoprobes called Sprites. Funded by billionaire Yuri Milner and guided by Facebook guru Marc Zuckerberg and Stephen Hawking. The team have 5 or 6 sprites in orbit right now testing the telemetry and electronics. At 1/5 the speed of light they could reach Proxima Centauri in 20 years. We could start receiving data in 24 years. Not bad! The Sprites will utilize solar sails driven by a high power laser. This is the biggest problem. How do you power this laser for 20+ years? One of the other big problems is the Sprites have no brakes. How do you image planets as you fly by at 100 million MPH? https://breakthroughinitiatives.org/initiative/3
    1 point
  8. Never once do I mention Isaac Newton. His idea of the ether is far too outdated. Einstein's is based on matter telling spacetime how to reshape & spacetime telling matter how to move. My bad, yes I meant "On the Electrodynamics of Moving Bodies." They're neither, they're based on Bell's inequality (math). They may be used to test any theory in physics.
    -1 points
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