Playing loop...

Discussion in 'Physics' started by cmartinez, Aug 22, 2015.

  1. cmartinez

    Thread Starter AAC Fanatic!

    Jan 17, 2007
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  2. MrAl

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    Jun 17, 2014
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    Hi,

    That's cute. The ellipse is my favorite elementary 2d shape. The ellipse has many properties many people are never taught. It's probably the most interesting simple 2d shape. You would never think it could have so many different ways of thinking about it. I learned one property a long time ago in a calculus class but have forgotten how it works now. I might have to ask in a forum somewhere if i cant remember soon as it has been bugging me for a while now :) If i remember right this property allows the simplification of a certain elliptic integral which simplifies the calculation of the magnetic field formed by an elliptical shaped ring.
     
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  3. cmartinez

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    I'n sure that @WBahn is the right man to ask that question to... and perhaps @Papabravo too...
     
    Last edited: Aug 23, 2015
  4. MrAl

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    Hello again,

    Yes, but first i'll have to think about how to actually ask this question because i hardly remember anything about it.
     
  5. atferrari

    AAC Fanatic!

    Jan 6, 2004
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    How to play, you mean?
     
  6. nsaspook

    AAC Fanatic!

    Aug 27, 2009
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    elliptic curve cryptography

    Used as a Trapdoor function:
    http://arstechnica.com/security/201...tand-primer-on-elliptic-curve-cryptography/1/

    but even if the algorithm is perfect it can still be cracked if implemented in electronics so poorly it leaks information about the internal logic current usage causing electromagnetic leakage and allows you to find the secret key with a simple loop antenna around the CPU or FPGA. The EM signature of the device operation on the wrong key can be slowly filtered away until you see operational signatures that indicate correct key operations with a few thousand measurements.
     
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  7. MrAl

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    Jun 17, 2014
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    Hi,

    Well no, i can see by the shape of the table and the description that you only need to hit the ball over the focus in a straight line to get it to land in the hole, as long as you dont put any 'English' on the ball with the cue stick.

    What i was talking about were some properties of the ellipse. We all know the story about the foci and how they can help shape the curve, and the area, and that the circumference can not be computed with a set of elementary functions, and how sound travels in an eliptic shaped enclosure, and stuff like that. But there are other interesting properties that come out too when we try to find certain things out about the ellipse. Unfortunately i am having a hard time remembering them all so i will ask in a thread. Look for a thread called something like, "The Ellipse and It's Properties".
    I will start the thread in a few minutes as soon as i refresh how to type out the equation in Latex.

    I did not read much of the link posted in the most recent post before mine, but that looks interesting too so i might read up on that a little also.
     
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