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  1. Bass In Your Face

    Bass In Your Face Active Member

    Is there maybe some sort of language translation problem going on with the whole "direct hit" method being questioned? Maybe he misunderstands what we think his "direct hit" is? Or maybe he's not explaining it because he assumes we know whatever method he used? I thought the question was pretty clear, and he was asked at least 10 times.. so I cannot actually tell if the question is being ignored on purpose, or if there is a problem with the phrasing interpretation?
     
  2. DougW

    DougW Member

    Maybe re-write with your explanation of what you consider a 'direct hit' means?
     
  3. mm1145

    mm1145 Member

    how do you know this did you msser it it at this point if so how? or is this baised of a calculation if so what calculation did you use and how did you validate it?
     
    Last edited: Sep 8, 2016
  4. I was wrong, the whiteboard is tilting towards the back of the boat. This is clearly seen at position 14:15 of the video. Also, from 14:00 they show their leveling technique. They keep the measuring tape flush with the board, thus not giving an accurate measurement. They measure 90 centimetres at this point. If the board had been perpendicular to the water for this measurement I contest that it would have given a slightly less measurement.

    Also, just how accurate was 90 centimetres anyway? Could it have been actually 89.5, or .7, or .3, and a rounding error then occurs because human eyes see 90 is the nearest whole number of significance?

    I think if you consider both of these points it is possible that the measurements could have been out by a centimetre, or more maybe, and thus the laser could actually have been pointing downwards to a slight degree thus giving the illusion of a beam that is rising over distance, when in fact it is starting off slightly down and only towards the later measurements is it then rising.

    I believe Skephu is on to something with his train of thought. Can anyone else confirm my theory on the whiteboard and the measurements? If I have explained myself properly. The unit circle kept popping into my head. If I have a chance later I'll try and put something together to show what I mean.

    Edit: this also doesn't discount the idea that refraction and/or laser divergence was also an issue. And also the accuracy of later measurements.
     
    Last edited: Sep 8, 2016
  5. mm1145

    mm1145 Member

    I watched that but I could not understand why you where doing that. they seam to be based of an assumption that you got a perfectly result at your leaving control but that seams to be a dubious assumption.

    to elaborate your auto-cad meserments amuse your laser is pointing acculturate (flat on GE up on FE) but what if you got the level wrong? even by as much as few degrese (a few parts of a cm at that distance) and you would not have the tilt you assumed so your 1.63 and 2.6 would not be actuate. maybe at this distance 1.7 is closer to what GE would be ?

    your proof is a grainy image taken of a boat in the distance do you have a photo taken form the target boat at that time? if you can see the laser off the pilots jacket why did not somebody in the target boat take a pic of the pilots back?

    this is only suggestive of FE if 1.62 and 2.6 are actuate and you are correct that the laser is close to 1.62 every one of those assumptions is questionable at best

    Edited to add more explination
     
    Last edited: Sep 8, 2016
  6. Clouds Givemethewillies

    Clouds Givemethewillies Active Member

    I think just about everybody has underestimated the difficulty of adjusting and maintaining the pointing of the laser to better than 0.1 mrad ~ the laser divergence. Next time he needs screw adjustments such as micrometers acting on something like a one metre lever AND a fixed target on land such as a cross of retroreflective tape. We need to see the laser on the land target, and the boat, for each measurement, or forget it!
     
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  7. munchie

    munchie Member

    Comparison of the "it's right in my face" scene (at 6km) to another Youtube video

    Source: http://imgur.com/a/PhRrf


    The same effect can be seen with a handheld laser pointer from 1,5km away.

    Source: https://www.youtube.com/watch?v=WdW9Tl1aR8g


    I'm guessing the guy with the handheld laser pointer was not even close to hitting the observer bang on, still we see the same circular effect. Makes you wonder how close they were in the Balaton experiment.
     
    Last edited by a moderator: Sep 8, 2016
  8. Hama Neggs

    Hama Neggs Senior Member

    He's been asked that a dozen times and shown examples of where divergence is seen. Let's not pretend. He's not stupid and we're not stupid. He's clearly dodging the issue.

    All their measurements, even the time (and maybe distance?) intervals, are sloppy and a hot mess. Due to that, the experiment is a full bust.
     
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  9. Mick West

    Mick West Administrator Staff Member

    That's not really the same effect. The Balaton image is just an out of focus dot. The 1.5km example is more full frame.
     
  10. DarkStar

    DarkStar Active Member

    The Geoid is a lumpy spheroid -- deviations from it would be deviations from that spheroid. See...



    This is attempting to shift the burden of proof. You need to be able to show that isn't the case or we are free to reject your experiment as invalid.

    But we went over this already. Here is the evidence that shows you ARE having issues. You aren't even very far away and already have a 35cm wide beam here. You assert it isn't always this bad, and ok, let's say it isn't - but you need to be able to SHOW that this is the case at the time of your measurements because all you would have shown is that it's fluctuating over time. This SHOWS US a half-angle divergence closer to ~0.175 mRad, which means that at 5000 meters the beam would be closer to ~180 cm.

    20160816_064208 LEVELING 1-spread-25cm.



    I'm sure you will convince plenty of gullible people and if that is all you want to do then go ahead - congratulations.

    If you actually care to know what is true then you will listen to valid criticisms of the experiment and maybe try to respond with rational arguments and less foot stomping.

    How can you show that this isn't possible? What evidence did you collect that would help eliminate this? it wasn't like we didn't raise the specter of refraction BEFORE you started and that you were unaware of the issue putting the laser down near the water. You did those anyway with the FULL knowledge that this would be an issue.

    THIS is why we asked to see the laser spot on a board -- this is the way you could show the laser is still focused in a tight beam at the time of measurement.

    LakeBalatonLaserDiagram.


    I don't need to repeat this experiment to know it's wrong - I used far better experiments, with much higher signal to noise ratios, which I have shown you in this very thread but you ignore them. We can look at multiple angles of the sun over very large distances and see that they do not comport with a flat ground, we can measure the heights of mountains over multiple distances and see they do not comport with a flat ground, and we can mark a theodolite level with within 30" arc and see that distance objects do not comport with a flat ground.

    I've also shown that evening refraction over a lake can allow us to see much further than we normally could -- which you dismissed as:

    Where are those 1/100th of a C accurate temperature measurements below, at, and above the height of the beam proving that, at the time of measurement, there was no thermal inversion?

    I guess if I didn't have the evidence I would say "NOT RELEVANT" also.
     
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  11. Mick West

    Mick West Administrator Staff Member

    I think a significant indicator of the divergence of the beam is simply the amount of time it is visible in the video in the 6.044K segment . It's basically visible from 22:59
    20160908-085341-tkjmk.
    Through 23:19 ("It's hitting me right now"), where he loses focus:
    20160908-085557-6dvsg.

    Through 23:37 ("It's right in our face", "Just record it hitting your body")
    20160908-085701-rr3jy.

    Up to 24:02
    20160908-085926-8r652.

    So over a minute, basically at the same flickering intensity.

    The boat is drifting at this point, hence it's not staying in the same spot horizontally. In fact over the course of a minute it almost certainly has drifted several feet.

    Some indication of the amount of drift can be seen in the video taken very soon after DSCN2065, when what looks like a stick from a submerged branch comes into frame at 1:55
    20160908-090910-4zb2w.
    Then at 1:59, four seconds later, it's in a very different position relative to the background.
    20160908-091215-nske6.
     
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  12. Mick West

    Mick West Administrator Staff Member

    In MVI_7124 at 6:22 (i.e. at 6:50:24 + 6:22 = 6:56:24 camera time) there is the following sequence:

    Source: https://www.youtube.com/watch?v=e1ghrLTXOuY

    MVI_7124-Sail-Far-Away---loop.

    The distance between the first and last flash is about 2/3 the width of the board, so about 4 feet.
    So the beam is at least 4 feet wide at this point.
     
  13. skephu

    skephu Senior Member

    Then why is it not spread out vertically? Why does it not hit the board?
     
  14. Mick West

    Mick West Administrator Staff Member

    The above is likely reflecting off a camera that is pointed back towards the laser. Earlier shots are different:
    20160909-145310-65zaq.
    The laser seems to reflect off the pilots back, but stays in the same spot while the boat traverses the beam.
    20160909-145423-c4br3.
    What this actually is is the much wider beam hitting the reflective patch on the pilot's back.
    20160909-145826-b7wli.


    If it is actually at the patch level, that means it's at least the size of the red circle on the left, and if it's a bit above it then it could be bigger, like the red circle on the right.
    20160909-151628-vk2l8.
     
    Last edited: Sep 9, 2016
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  15. Mick West

    Mick West Administrator Staff Member

    Because you can only see it when it is reflecting off the camera glass. Like with the pilot's patch, above.
     
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  16. Mick West

    Mick West Administrator Staff Member

    So I think based on the above, we can safely discard any height estimates that do not show a clear pattern on the whiteboard. If you can't tell where the center of the beam is, then you don't know how much it has moved.

    Which really means that C5 is the last meaningful measurement. Unfortunately the prior measurements were done with the boat in motion, and are over too short a distance. So really nothing can be concluded.
     
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  17. deirdre

    deirdre Moderator Staff Member

    i think if it was actually at the patch level ie. if the bright spot in the middle was the beam beam, then the "splay" (refraction?) would have splashed on the white board like it does in the other white board pics. no?
    pink2.
     
  18. Mick West

    Mick West Administrator Staff Member

    Compare the last time we see the laser on the board:
    _IMG_7122.CR2
    Date Time Digitized: Aug 16, 2016, 6:49:51 AM
    20160909-153928-in7f9.

    With the first time we see the patch reflection.
    Date Time Digitized: Aug 16, 2016, 6:51:03 AM
    20160909-154201-bvohr.

    So it's later, and the boat is moving, so the back is lowered. It's also far brighter than the whiteboard hit, which proves it hitting the retroreflective patch.
     
  19. Sandor Szekely

    Sandor Szekely Banned Banned


    Mick you make statements here without definite proof.

    The calculation on the 4 feet of beam divergence is not valid just based on your false assumptions.
    You do not take into consideration a lot of things, like optical distorsion or boat alignment and many other.



    boa aligned.
     
  20. deirdre

    deirdre Moderator Staff Member

    how wide was the white board? because the right side and the left side of the board both hit the same spot.

    MVI_7124-Sail-Far-Away---loop.
     
  21. Sandor Szekely

    Sandor Szekely Banned Banned

    the picture is correct : that is the beam diverge at the distance.

    the laser beam is the white spot in the middle, the green light is the reflexion of the coat. (it may be bent multiple times and have a special reflective surface)

    What would you estimate that beam divergence? Do you know the distance from the shore?

    divergence.
     
  22. Sandor Szekely

    Sandor Szekely Banned Banned

    the white board is 2 meters wide

    you can't measure this like you say. The boat is not moving aligned with the camera and the beam and the 1200mm optics has a strong distorsion on the Z axis persective (depth).

    how come that on the last picture that I marked : the beam divergence is correct and here you claim that it could be 2 meters wide?
    this is just not logical - should I say impossible. I do not know the distances without references to these pictures...
     
  23. Spectrar Ghost

    Spectrar Ghost Senior Member

    Wouldn't optical distortion be indicative of greater beam spread? It would be immensely unlikely that it would act to focus the beam.
     
  24. deirdre

    deirdre Moderator Staff Member

    you tell me, you sent me the picture without timestamps.

    again, you tell me.

    and if the white spot is the beam then why cant i see the bottom of the green cone of light on the whiteboard?
     
  25. deirdre

    deirdre Moderator Staff Member

    post #701? it's not.
     
  26. Sandor Szekely

    Sandor Szekely Banned Banned

    no. Z axis optical distorsion is making depth of the picture distorted. nothing to do with focusing
     
  27. Sandor Szekely

    Sandor Szekely Banned Banned


    hey I have about 2000 pictures, you want me to run through them? how about giving me a reference number at least?

    I see the beam divergence less than a foot (less than 20cms) - hard to determine exactly as the coat is not a straight surface. We can estimate the max divergence.

    coat.
     
  28. deirdre

    deirdre Moderator Staff Member

    you sent me that picture in our PM entitled "your experiment". you didnt give me a reference number.

    does it matter anyway? IF the white part is the beam itself, then why cant i see the green lower part of the cone circle of light on the whiteboard?


    edit add: ok when i click on what you sent me and "save picture" you called it "zoom beam". if that info helps you at all.

    upload_2016-9-9_21-25-20.
     
    Last edited: Sep 9, 2016
  29. Sandor Szekely

    Sandor Szekely Banned Banned

    yes picture name is the reference, but unfortunately this is a snaphot from a video named zoom beam. I have to search for this - and maybe very hard to find the same moment.
    So we don't know the distance for the moment. It would be good to know to get the beam diameter compared to the distance.

    I think you can see the reflexion of the beam mostly upwards because the material of the jacket was bent.

    The beam it self does not hit anything other than the middle of the jacket so I think it is very well collimated.

    In pictures of laser beam direct hits into the camera you see the cone circle of the light.
     
  30. Spectrar Ghost

    Spectrar Ghost Senior Member

    It hits the reflective patch mick pointed out. It makes sense that it would be more visible only there. I don't think the shine has any relation to the beams width at that point. Just two minutes before, the beam hit the board and was at least a couple of feet across, as you can see in post #698.
     
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  31. Sandor Szekely

    Sandor Szekely Banned Banned

    jacket is about 1 meters wide. Why I do not see any laser divergence sideways?

    check what I wrote in post #699
     
  32. Sandor Szekely

    Sandor Szekely Banned Banned


    this is not a proof.

    you are suggesting that the divergence of the beam can be measured by elapsed time. This has nothing to do with it unless you can define the angle the boat was moving according to the beam.
    If the boat is moving absolutely parallel to the beam the camera could record that all the way too.

    this is missleading. Can you define the angle of the movement with the boat as well as the speed?
    sorry I can't even imagine what that "stick" or what else? is measuring here.
     
  33. Mick West

    Mick West Administrator Staff Member

    Sandor, the beam is not reflecting off the coat.

    A portion of the very wide beam is reflecting off the retroreflective patch on the coat, and this is moving with the boat.

    [​IMG]

     
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  34. Sandor Szekely

    Sandor Szekely Banned Banned

    if it was so, we would see a STRIP OF LASER beam on the jacket not a spot.

    The laser is moving with the boat as it is floating perfectly parallel with the laser beam.

    The movement of the P900 camera makes the spot reflexions in the attached video sequence.
     
  35. Mick West

    Mick West Administrator Staff Member

    Then why does it move sideways?
     
  36. I mentioned this a day or so ago and wanted to show with images what I meant, regarding the leveling method and it's accuracy:

    This is obviously very rough now, so forgive me for that, just in the door from work at 4am here. It appears as the measurements for leveling aren't being taken perpendicular to the water, but rather at an angle. You can see from this close up that Dave Moor appears to have the measuring tape pretty flush with the board.
    flush_with_board.

    From this picture it seems more apparent.
    wide_angle.
    So what I hear you say. Well when you really see the huge angle the whiteboard is at I think it makes a huge difference to the accuracy of the leveling.

    board_angle.

    When the 90 centimeter measurement is taken just before the 14 minute mark of the video, shown roughly with the yellow line (I'm not saying this is 90 centimeters where I've marked, I picked arbitrary points that look roughly correct), that would really map incorrectly onto the red vertical line. What they should have been trying to do is take a measurement perpendicular to the water, more like the blue line. The green line shows just how massive the angle difference was, possibly 15 to 20 degrees out, which would lead to a huge error when trying to level it.

    If I've shown what I mean correctly, then what @skephu mentioned earlier about possibly pointing the laser ever so slightly downward, and this doesn't even take into account any refraction (upwards or downwards) or divergence (which would also skew the result even more).


    Unfortunately @Sandor Szekely, if this is the case, the experiment is inconclusive even before you get passed the leveling of the laser. Any thoughts?
     
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  37. Mick West

    Mick West Administrator Staff Member

    No, you would see a bright light source. You understand retroreflective?
     
  38. Mick West

    Mick West Administrator Staff Member

    Not really, as the initial measurements were vertical, with a tape measure.
     
    Last edited: Sep 10, 2016
  39. The initial as in before they get on the water? The leveling measurements they take out on the water when they are adjusting the laser don't appear to be vertical though.
     
  40. Mick West

    Mick West Administrator Staff Member

    Yes sorry, I agree with you now, and retract my previous objection. I'd missed this image as I was on my phone:
    [​IMG]

    Not exactly in line with the board, but certainly not vertical.

    Also:
    20160909-221522-sgdhy.
     
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