Recent content by Mark_W_Ingalls

  1. M

    Explaining Curved Space-Time to a Friend

    Ah, gentlefolk, thank you very, very much! As I read and re-read your very charitable posts, I remembered "The Official String Theory Website" (http://superstringtheory.com/). Of course, all of your kind responses dovetail perfectly with Dr. Schwarz's! (I am blessed with an insatiable...
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    Explaining Curved Space-Time to a Friend

    Gentlefolk-- Thank you all sincerely for your answers so far. Perhaps (OK, probably!) I am too much of an engineer to think about such things, but still... The universe is nearly flat, correct? The universe is finite, correct? Then how can it be analogous to a sphere, instead...
  3. M

    I need some serious adivice for my futureengineers, math people me

    Hi, folks. May I tell you my story? :zzz: I studied agriculture as an undergrad; in my sheltered life, I didn't really think of an engineering career. I eventually lost my farm, due to economic conditions. I finally got a job working in the electronics industry; it was kind of like being a...
  4. M

    Explaining Curved Space-Time to a Friend

    Anybody-- A friend of mine, whom I highly respect, made the following comment the other day: "If you travel in one direction fast enough, you'll eventually get back to where you started." This was so strange an 'idea' I didn't even know how to respond! After awhile I asked him how...
  5. M

    Learning String Theory in high school

    Dear Berislav-- I am old. It is not easy for me to understand these subjects either. (String theory was just being dreampt of when I was your age.) I want you to know two things. First, you have helped me. Second, your life is not a sprint. If you must work a long time to understand...
  6. M

    Transitions from Rest State to Rectilinear Motion: Infinite Jerk?

    I just wanted to shut all the gates on my way out... I recalled the force - voltage analogy and I immedeiately visualized the response of an inductor-terminated X-line to a voltage step. F = V m = L v = i dV/dt = L di/dt, ... #:8-D M
  7. M

    Transitions from Rest State to Rectilinear Motion: Infinite Jerk?

    Thanks for stopping by, integral and pmb_phy-- I am familiar with the delta function; I also know that we EE's blow off the natural response and (In my case) any forcing function that is not "harmonic," e.g. sinusoidal, but I was thinking about a car pulling away from a stop light, or a train...
  8. M

    Transitions from Rest State to Rectilinear Motion: Infinite Jerk?

    Anyone- From long ago IIRC a body that transitions from a rest state to a rectilinear moving state undergoes nearly infinite jerk (change in 'a'). On the one hand, my memory is reinforced by the idea that not all functions have infinitely many derivatives... But on the other hand, I may not...
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