Recent content by bob012345

  1. bob012345

    Undergrad Do photons have mass? Why not?

    That’s like saying I’m a billionaire but I just happen to have zero billion dollars at the moment.
  2. bob012345

    Undergrad Do photons have mass? Why not?

    Perhaps, but we are dealing with a gamma ray and a radio wave in the same reference frame. Consider what happens if both interact with a microscopic primordial black hole of comparable energy to the gamma ray for example?
  3. bob012345

    Undergrad Do photons have mass? Why not?

    I wonder if that is just an approximation? I would think that in principle, the energy difference between a gamma Ray and a radio wave would change the spacetime curvature even if in the most minuscule amount to change to geodesic.
  4. bob012345

    Undergrad Do photons have mass? Why not?

    Well something needs to have mass in order to curve spacetime.
  5. bob012345

    Undergrad Do photons have mass? Why not?

    So what effective mass is used when starlight is bent by the sun? Isn’t it just ##m=\frac{E}{c^2}##?
  6. bob012345

    Undergrad Non-Linear Infinite Resistor Ladder

    I do not know what typo you are referring to? Perhaps it’s the way I specified the termination term. I meant if the ##n^{th}## stage has two resistors ##10^{-n}## and ##10^n##, one can change the latter to ##0.9⋅10^n## or one can leave that alone and add another resistor in parallel ##9⋅10^n##...
  7. bob012345

    Undergrad Non-Linear Infinite Resistor Ladder

    Take the limit of ##\frac{R_n R}{R_n+R}## as ##R_n→0## which gives zero. So if one shorts the first stage the minimum resistance is 1 unit.
  8. bob012345

    Undergrad Non-Linear Infinite Resistor Ladder

    If one takes the Golden Ladder equation ##R^2 -R -1=0## and instead of solving it exactly, write it as ##R = \sqrt{1+R}## then start with any terminating resistance under the radical and iterate you will get the Golden Ratio ##\phi##. Then the number of iterations you do for a specific desired...
  9. bob012345

    Undergrad Non-Linear Infinite Resistor Ladder

    I was wrong to say changing the tail doesn’t change the ladder but like I said, it literally changes the ladder to be a different problem if it has no relationship to the actual infinite tail. In the original analysis above our tail value of ##0.9 x10^n## for the ##n^{th}## stage does and was...
  10. bob012345

    Undergrad Non-Linear Infinite Resistor Ladder

    Ok, but then changing the tail to low values is changing the problem significantly. It no longer the ‘tail’ but a different ladder.
  11. bob012345

    Undergrad Non-Linear Infinite Resistor Ladder

    Which circuit are you simulating with 100 stages? Our original ladder in post #1 or your ladder? Not sure what you mean by “changing the resistance at infinity”? It seems to me simulating a 100 stage ladder, it will make no difference what resistors you add or how you add them at the final stage.
  12. bob012345

    Undergrad Non-Linear Infinite Resistor Ladder

    Welcome to PF! I believe you are solving a different ladder that goes like this: The ladder being studied in this thread has the same top resistances but the shunts increase by ten for each stage. In your case where each stage changes both resistors by the same factor, it can be solved...
  13. bob012345

    Undergrad Non-Linear Infinite Resistor Ladder

    Here are recursion relations that give the exact polynomials for the numerator and denominator for any ladder with ##N## stages and a scaling factor ##q##. In all cases the first stage resistors are both 1 unit. For the ##N^{th}## stage, the shunt resistor is ##q^n## where ##n=N-1##. For example...
  14. bob012345

    Undergrad Non-Linear Infinite Resistor Ladder

    Doing that derives the limiting term as ##0.9⋅10^n## discussed in post #8.
  15. bob012345

    Undergrad Non-Linear Infinite Resistor Ladder

    I believe if it’s transcendental it is also irrational.