Guess at slowing of Earth spin

Discussion in 'Physics & Math' started by Billy T, Mar 11, 2006.

?

How big is "SLIGHTLY" (in first post of Billy T if not here)

Poll closed Mar 25, 2006.
  1. Less than 1.0E-4Meters

    58.8%
  2. Less than 1.0E-2Meters

    5.9%
  3. Less than 1Meter

    17.6%
  4. Less than 100Meters

    5.9%
  5. Less than 1000Meters

    0 vote(s)
    0.0%
  6. More than 1000Meters

    11.8%
  1. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

    Messages:
    23,198
    Assume 1000Kg satellite "A" is placed into geostationary orbit, (Eastward lauch from equator and this slightly slows Earth's rotation as more of initial angular momentum is in the orbiting satellite.) Then its twin, geostationary satellite "B," is launched from adjoining pad with same eastward roll over etc. but a little longer rocket burn, because after launch of "B" the Earth is spinning still more slowly and B's altitude must be SLIGHTLY higher than A's to be exactly sychronous with the new longer day.(Satellite A is no longer exactly sychronous once B is in orbit. Sorry SL if I did not make that completely clear in first version of this post. MAKE LARGEST YOU THINK REASONABLE GUESS AS YOUR VOTE.)
     
    Last edited by a moderator: Mar 11, 2006
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  3. superluminal . Registered Senior Member

    Messages:
    10,717
    Wait a sec. Maybe I'm missing the point, but if the definition of geostationary is that the satellite orbits in perfect synchrony with the earth's rotation, then (assuming the earth is perfectly round) that altitude will be the same for any satellite, no matter what the distribution of angular momentum is in the system. Right?
     
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  5. superluminal . Registered Senior Member

    Messages:
    10,717
    Ok. So I see my error. You are assuming that A may no longer be in geostationary orbit due to B's launch and you want to know what the new altitude difference is for geostationary orbit. I'd guess... Option 3.
     
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  7. kevinalm Registered Senior Member

    Messages:
    993
    I'll go with 1.0E-4 m , as that is what I said in the other thread that this pole was prompted by. Might as well be consistant, hey Billy.

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  8. Ophiolite Valued Senior Member

    Messages:
    9,232
    BillyT, I am shocked and astounded by the options you have provided for your questions, especially as you claim to be a scientist. All of the answers are correct except the last one. For example, 0.000000001 metres is less than 1,000m and thus answer 4 would be correct.

    This is an excellent illustration of
    a) the problem with polls of any kind.
    b) the strong influence of the character of any 'question' upon the resultant 'answer'. It is exactly analogous to poorly structured experiments that produce misleading results.

    Shame on you.

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  9. DaleSpam TANSTAAFL Registered Senior Member

    Messages:
    1,723
    The length of the day has some "jitter" anyway. That is going to be a much greater number than the number due to previous satellite launch. But given the premise of an otherwise perfectly stable day my guess is that the difference is on the order of angstroms.

    -Dale
     
  10. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

    Messages:
    23,198
    Most people understood, correctly that you were to:
    MAKE LARGEST YOU THINK A REASONABLE GUESS AS YOUR VOTE.*
    but now I have explicitly added this to the first post which explains "SLGHTLY"
    --------------------
    *I had this explicitly in the options I wrote in first post,when I did not know next step in setting up a poll would provide boxes to type options in. (First time I have set up a poll.) I did not find place to but above caps in at that later stage. I have edited first post, for you and anyone else, not making the obvious assumption. I stuck in "circular" also for same reason. Some things should be obvious, but it does not hurt to make them explicit.)

    PS I just now voted 1M, mainly because now that some have voted, I will not be the worst vote, when someone "cheats" and calculates the answer.
     
  11. Ophiolite Valued Senior Member

    Messages:
    9,232
    I understood exactly what you meant, but this is a science forum and you are a scientist. I think it is appropriate to expect precision in such an environment, from such an individual. If if was from the likes of Gustave I wouldn't have blinked an eye.
     
  12. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

    Messages:
    23,198
    I thought anyone could.

    The posting instructions tell you to keep the option statement short. This means one can and should asssume a reasonable level of competence on the part of the voter. Yes I was not complete and precise. E.g. I did not define "satellite", "geostationary"* etc. tell what is to be assume about the launch rocket , many things. If you think what you state, start a poll and see how many agree with you that I was not as precise as a scientist should be.
    ------------------------
    * I did briefly think this might lead to some confusion, especially for Russian readers, as with the northern location of their major cities, "geostationary" may also refer to the highly eliptic orbits they use with polar apogees for communication relays. (Those "geostationary" satellites dwell most of their orbit more distant from Earth, but can be seen from all high Russian latitudes etc.) I decided it was not necessary to precisely define everything. I.e. I decided to follow the poll's instructions. Sorry if you find this "unscientific."
     
    Last edited by a moderator: Mar 11, 2006
  13. Ophiolite Valued Senior Member

    Messages:
    9,232
    I have no interest in how many people agree or disagree with me. It is an absolute that the manner in which you structured your poll was flawed and ambiguous. I really did not expect you to make a big deal of it and start defending the indefensible.

    I have found all of your posts till now, many of which I have read and enjoyed, to be very sensible and well structured. I have differed from you on a couple of minor points, but nothing significant.

    I regret that you have chosen to react to this particular issue in such an emotional, defensive manner. I guess I should have used an even larger smiley after my original post.
     
  14. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

    Messages:
    23,198
    I regret you insistence on complete precision, full details, etc. These polls are not science. (Voting never decides that.) I will not reply more, but let others decide who is unreasonable on this issue.
     
  15. DaleSpam TANSTAAFL Registered Senior Member

    Messages:
    1,723
    Sounds like a perfect opportunity for another poll!

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    -Dale
     
  16. Ophiolite Valued Senior Member

    Messages:
    9,232
    I am not insisting on precision or full details. I am insisting upon a meaningful poll.
    Less than 1000 metres includes
    Less than 100 metres, which includes
    Less than 1 metre, and so on.

    That is not a lack of precision BillyT. The way you have structured the poll is simply wrong. It is meaningless. I am sorry you are too stuborn to see this. Goodnight.
     
  17. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

    Messages:
    23,198
    Be my guest, now that we both know how to set one up. :bugeye:
     
  18. superluminal . Registered Senior Member

    Messages:
    10,717
    I for one saw the flaw and immediately understood the intent. Given Billy's history, why would we take him to task for this? I am wondering who here would not understand the intent? I can't wait for the answer! I have been tempted to go and calculate the answer... Maybe I'll do that tonight.
     
  19. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

    Messages:
    23,198
    Please keep answer to yourself until few days before poll closes.

    I wish I could add: "Choose largest answer you think possible." where instead above the poll you see only: "(In first post of Billy T, if not here)" This was my first poll, I did not know what to expect or what could be changed later as I proceeded thru the set up proceedure, so I followed the instruction to keep options statements short instead of writting something like:

    Greater than 1.0E-4Meters and less than, or equal to, 1.0E-2Meters

    Which is unambigious, but excessly long by my understanding of the instrucion to be short. As this was first time I set a poll up, I feared (and still do) the above option statement might end up appearing as:

    "Greater than 1.0E-4Meters and less than, or equ"

    and that would be confusing. I. e. I gave credit to the voters to use a little common sense as you and all but one have.
     
    Last edited by a moderator: Mar 11, 2006
  20. CANGAS Registered Senior Member

    Messages:
    1,612
    It is cheating to CALCULATE the answer? That does explain some things.

    But, I burned up my weejee board decades ago.

    In a trash fire, not from excess use.
     
    Last edited: Mar 12, 2006
  21. superluminal . Registered Senior Member

    Messages:
    10,717
    I like the idea of guessing at it. My first reaction was that it must be extremely tiny. The earth is HUGE after all, and a 1000kg satellite is NOTHING. But this mass is moved very far away. It gives an insight into how fallible our intuition is when it comes to things far outside of our experience. I suspect the answer will be larger than we think... Or not!

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  22. CANGAS Registered Senior Member

    Messages:
    1,612
    Maybe so!

    And maybe not, I guess.
     
  23. kevinalm Registered Senior Member

    Messages:
    993
    Actually, the answer I really wanted was on the order of the Plack length. But maybe I should be disqualified, as I once did a vaguely related calculation that I meantioned in the other thread.

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