Wolfram|Alpha time travel



  • Scenario: I'm encoding a 3½ hour video of an undisclosed but easily guessable subject matter. I want to know how much longer it will take, but my encoder only gives me:

    • the total number of frames encoded
    • the number of frames encoded in the last second
    • various quality settings of the video
    • the current size of the output file
    • the current timestamp of the output file
    • the current bitrate
    • the number of frames duplicated or dropped

    From this, I devise a simple formula:

    ((3 hours 22 minutes 7.49 seconds)*(50hz) - 97971)/(48hz)

    Answers Wolfram|Alpha gives:

    • 2 hours 56 minutes 31.74 seconds
    • -2038 hours
    • -7.335×106 seconds
    • -122253 minutes
    • -84 days 21 hours 33 minutes 12.2 seconds
    • -84.9 days
    • -12.13 weeks
    • -0.2324 average Gregorian years
    • ≈ -0.23 × orbital period of Earth (≈ 1 Julian year )
    • ≈ -0.38 × orbital period of Venus (≈ 0.62 Julian years )
    • ≈ -0.97 × orbital period of Mercury (≈ 0.24 Julian years )
    • ≈ -0.044 × half-life of cobalt-60 ( 1.6635×108 s )
    • ≈ -0.089 × half-life of sodium-22 ( 8.2108×107 s )

    That's not Discoursistency™, that's actually a single positive answer followed by several negative answers. I'm going to assume the different answer is an anomaly.

    This isn't a problem with mismatched units, as you can verify by removing hz from 50hz. Apparently my video has already finished encoding and I have to go back in time to find it.



  • @ben_lubar said:

    3½ hour video of an undisclosed but easily guessable subject matter

    Gay bestiality porn?

    @ben_lubar said:

    This isn't a problem with mismatched units, as you can verify by removing hz from 50hz.

    It chokes on the multiple time units separated by spaces part, if you remove the x minutes and x seconds you get a (I assume) correct answer, if you add minutes again it chokes. I don't really know Wolfram, maybe it just doesn't accept this?



  • You can put + after hours and minutes and it works, but adding a unitless number to time2 and then dividing by time-1 shouldn't give me a wildly incorrect answer in time1. It should either give me an error or a technically correct answer in time3.



  • @ben_lubar said:

    but adding a unitless number to time2 and then dividing by time-1 shouldn't give me a wildly incorrect answer in time1. It should either give me an error or a technically correct answer in time3.

    Not to get all pedantic on you but ... Oh who am I kidding? You really have your units all B*****med up. Here's you original equation, units only:

    (s)Hz - {no unit}
            Hz

    Since Hz is basically s-1, this can be simplified to:

    (s)s-1 - {no unit}
            s-1

    Which reduces to:

    {no unit} - {no unit}
                s-1

    So your finally result should be in terms of time1, as you put it. Where did you get all this crap about time2 and time3?

     
     
     

    Edit: I see how you can get an intermediate step which contains time2 by bringing the bottom Hz up top, but that doesn't fit with your previous post, so I chose to ignore that route. In case someone else chooses to call me on this, here it is:

    ((s)s-1 - {no unit})s

     

    (s2)s-1-s



  • There are two possible interpretations of X hours Y minutes Z seconds:

    • (xyz×3600×60) seconds3
    • (x×3600 + y×60 + z) seconds

    Wolfram|Alpha chose "neither".


  • Discourse touched me in a no-no place

    @ben_lubar said:

    There are two possible interpretations of X hours Y minutes Z seconds:

    (xyz×3600×60) seconds3

    (x×3600 + y×60 + z) seconds

    Wolfram|Alpha chose "neither".

    Well, clearly, there are more than two possible interpretations, neh?


  • :belt_onion:

    the problem is the unitless 97971. put it in frames and then put frames per second instead of Hz.

    http://www.wolframalpha.com/input/?i=(((3+hours+%2B+22+minutes+%2B+7.49+seconds)*(50+frames+per+second))+-+97971+frames)+%2F+(48+frames+per+second)

    both adding as
    (((3 hours + 22 minutes + 7.49 seconds)(50 frames per second)) - 97971 frames) / (48 frames per second)
    or
    (((3 hours 22 minutes 7.49 seconds)
    (50 frames per second)) - 97971 frames) / (48 frames per second)

    work fine if you do it right.

    (I am buttuming that you mean frames per second when you put Hz)



  • TRWTF may be using a tool like Wolfram Alpha for something that a simple calculator can handle. Alpha is clearly too complicated for its own good.


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