4 Brian/Bryan Litz - Important

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by royinidaho, May 29, 2012.

  1. royinidaho

    royinidaho Writers Guild

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  2. ICANHITHIMMAN

    ICANHITHIMMAN Well-Known Member

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    I dont think the artical provides me with enough back ground on the equation to understand the artical. I cant wait to here Brians responce.
     

  3. Joe King

    Joe King Well-Known Member

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    Well what the hell are they waiting on? lets get it on a ballistics calculator already......................gun)
     
  4. joe0121

    joe0121 Well-Known Member

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    HMMMMMMM


    I get a feeling there may be some hyperbole in that article.
     
  5. emn83

    emn83 Well-Known Member

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    yup...nobody has yet seen the actual work the kid did....lots of physicists and mathematicians have been voicing skepticism about it
     
  6. BryanLitz

    BryanLitz <b>Official LRH Sponsor</b>

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    Although it's a meaningful break-thru in the field of mathematics, this will not affect how ballistic calculations are done at all.

    Here's my take.

    Newton formulated his laws of motion which are basically formulas which describe how things move, collide, etc. Then he and others set about to solve the formulas so we can predict things. We've been very successful at solving the formulas in many ways. Especially with modern computational power, we can apply iterative (time stepping) solutions which solve the equations of motion in tiny (0.001 seconds or smaller) time steps which result in answers that are approximate by math standards, but that just means they're not guaranteed to be accurate to the 100th decimal place; NOTHING of practical concern. What this young German (or Indian?) boy has done is to solve the equations of motion for projectile flight in an analytical form, which is what mathematicians consider 'exact'. The solution is far more efficient since you don't have to take many small time steps, but considering modern computational resources found even in small phones, the efficiency is a non-issue in most applications.

    Some more detail about the 'break-thru' solution:
    * The exact analytic solution assumes constant drag coefficient, which is only close to reality in pure subsonic flight. So the equation cannot be applied accurately to supersonic flight at all.
    * The 'stroke of genius' that made the analytic formula possible was a transformation of variables from positional space to 'velocity space'. Transformation of variables is a known means of solving problems in math but it takes great insight to find a transformation that will actually work.


    My hat's off to the young man for his genius. Unfortunately I don't see this break-thru affecting our ability to calculate trajectories any more accurately than we do now.

    In my experience, the biggest limitation with our ability to predict accurate trajectories is accurate inputs: MV, BC, atmospherics, range, actual value of scope adjustments, etc.

    Sorry to be a buzz kill, but the news is well known for pumping things up.

    Here's a link to a site where you can read more discussion about the actual math, by actual mathematicians:
    klackity comments on Teen Solves Newton

    -Bryan
     
  7. joe0121

    joe0121 Well-Known Member

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    There you have it folks. Nothing to see here move along...


    BTW Bryan. Love your book.
     
  8. HARPERC

    HARPERC Well-Known Member

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    Well yeah ok, but can he shoot?:rolleyes::D
     
  9. Eaglet

    Eaglet Well-Known Member

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    Roy, that's a great post. Good reading!
     
  10. Bart B

    Bart B Well-Known Member

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    While mathematics is the only science that's closest to being "exact," it would be great if someone could actually measure the exact position vs time of a projectile in flight to its maximum range then compare that to what math would calculate it to be.

    Makes me think of the Aberdeed Proving Ground's tests measuring 16" battleship guns shooting projectiles through round hoops suspended high in the air a couple hundred yards down range timing those 1 ton projectiles' time of flight. That's what was used to calculate the two dimensional ballistic cams' shapes used in rangekeepers computing the elevation angles those barrels were elevated to to strike targets up to 20+ miles down range.
     
  11. Eaglet

    Eaglet Well-Known Member

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    How would that help us Bart? Would that increase the present precision of our already great ballistics softwares. I just hadn't thought of it.
     
  12. Bart B

    Bart B Well-Known Member

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    It may not help us, but it would prove to others how great it really is. I don't think it would increase the precision if that precision matches actual measurements. It's like getting a second opinion on ones medical condition as medicine is definitely not an exact science.

    I've had skeptics challenge my work with Sierra Bullets' older software giving comeups from absolute boresight for their 155's in iron sighted Palma rifles with non-standard sight radiuses for rear sights moving exactly .025 inch for 3 minutes on their knobs. It's been accurate within 1/4 MOA at 600 as well as 1/2 MOA at 800 through 1000 yards.