Announcement

Collapse
No announcement yet.

Circle Division

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Stargazer
    replied
    Originally posted by JoeCB View Post
    As a bit of aside info, all the discussion about "old school" dividing procedures using real dividers... I have a nice old pair of Vierner calipers by Brown and Sharpe that have a feature I had not seen before. There are a pair of tiny punch marks that are used to set dividers to a predetermined measurement. Note the one "pit" and the corresponding on the sliding jaw.

    Joe B Click image for larger version  Name:	caliper.JPG Views:	0 Size:	520.0 KB ID:	1929518
    Those are nice calipers! How old are they?

    Leave a comment:


  • Stargazer
    replied
    Originally posted by Paul Alciatore View Post
    Basically, the simple and quick answer is NO.
    Don't mean to be disagreeable but he answer is yes. The Peano axioms and Zermelo-Frankel set theory provide a solid foundation for basic arithmetic. Even if one objects to set theory as a basis for arithmetic foundations, the Peano axioms can also be understood and established by way of category theory.

    Leave a comment:


  • JoeCB
    replied
    As a bit of aside info, all the discussion about "old school" dividing procedures using real dividers... I have a nice old pair of Vierner calipers by Brown and Sharpe that have a feature I had not seen before. There are a pair of tiny punch marks that are used to set dividers to a predetermined measurement. Note the one "pit" and the corresponding on the sliding jaw.

    Joe B Click image for larger version

Name:	caliper.JPG
Views:	82
Size:	520.0 KB
ID:	1929518

    Leave a comment:


  • Paul Alciatore
    replied
    Basically, the simple and quick answer is NO.

    Why? Because 1 + 1 = 2 is the very definition of two. It is defined and therefore not something that is provable. There are fancy mathematical terms for that but this is what they amount to.



    Originally posted by dian View Post
    can somebody tell me if it can be proved that 1+1=2?

    Leave a comment:


  • Paul Alciatore
    replied
    Exactly!



    Originally posted by jim stewart View Post

    sure. But math isn't.

    -js

    Leave a comment:


  • Paul Alciatore
    replied
    Engineering IS a total act of continuous compromise.



    Originally posted by nickel-city-fab View Post
    Paul, you have a wonderful way with words. Very clarifying, thanks. I have always heard that one couldn't divide a circle by 7, but I would have to ask "Under what conditions?" The tools and techniques available to the HSM today, are so refined that error is either immeasurable, or negligible. I am a fan of George Thomas' writings about his "Versatile Dividing Head" and his system takes you down to one hundredth of a degree using extremely basic and simple techniques. Would I be able to measure a hundredth of a degree? probably not. But for my shop and what I do, it is an acceptable compromise. And isn't engineering just a collection of acceptable compromises?

    Leave a comment:


  • nickel-city-fab
    replied
    Perhaps another way to say it would be, "It depends" on what scale you are referring to, and which scale is appropriate for the immediate problem. Chaos theory goes into this a bit.

    Of course, I like "It depends" instead of boxers or briefs. Or commando.

    Leave a comment:


  • Stargazer
    replied
    Originally posted by dian View Post
    can somebody tell me if it can be proved that 1+1=2?
    Yes. The Peano axioms work just fine to establish a basis for arithmetic.

    Leave a comment:


  • Stargazer
    replied
    Originally posted by mklotz View Post

    One of the most intriguing questions mathematicians (and many physicists) proffer goes something like this...

    Is mathematics some sort of fundamental property of nature that we have been gradually discovering or is it the most incredible mental construct mankind has ever assembled?

    Think about it. Newton managed to bundle all of the phenomenon of gravity into a single, simple equation. Was this a discovery on his part or an incredible mental construct on his part? If the exponent on the 1/R^2 term is changed by even a slight amount from two, stable orbits are impossible. Did we just luck out with our creation of algebra so that the square of a number was the perfect fit for the description of gravity or are inverse square forces a natural feature that we happened to discover?

    I don't waste any time thinking about philosophical crap like this; it gets in the way of doing something useful.

    However, if you think you can inject theology into math, you should start by answering this question.
    This is a great question that has deeper implications for mathematics education than first meets the eye. The standard view in mathematics, both mathematical philosophy and mathematics as practiced is mathematical platonism. Put differently, it's the conjunction of the theses that

    (i) mathematical objects exist;
    (ii) mathematical objects are abstract; and
    (iii) mathematical objects exist independently of human minds.

    in the 1980s, a man by the name of Hartry Field attempted to ground math in fiction. The "fictionalist" approach said that mathematics was ultimately about nothing, but something tatken to be true because it was useful. His book "Science Without Numbers" attracted a lot of attention and scrutiny from philosophers of mathematics, and it was ultimately shown to be a failure. In science, particularly quantum mechanics, you can't dispense with mathematical objects or their relationships. Further attempts to salvage the fictionalist approach have all fallen up short.

    When you think about it, it's really hard to defend the idea that mathematics is something that just happens to be a useful construct. Everything in the world is made up of atoms which are made up of particles. The particles themselves are just excitations of a quantum field. Physicist Peter Woit refers to this level as the congruence between mathematical and physical objects.

    Just because we don't experience a perfect circle in our shops doesn't mean that such a circle or a relationship doesn't exist, it just doesn't exist when you factor in the time and space relations on the macro scale in our shops.

    Leave a comment:


  • Mcgyver
    replied
    Originally posted by dian View Post
    no, that cant be it.
    ?? did you get a different answer

    Leave a comment:


  • mklotz
    replied
    Originally posted by dian View Post
    can somebody tell me if it can be proved that 1+1=2?
    Here you go...a page from Whitehead and Russel's Principia...

    https://quod.lib.umich.edu/cgi/t/tex...aat3201.0001.0 01&frm=frameset&view=image&seq=401

    but be advised, if you're not a professional mathematician and use math more as a tool, your time would be more profitably spent learning some practical math rather than farking about with abstruse, quasi-philosophical stuff like this.

    Leave a comment:


  • dian
    replied
    no, that cant be it.

    Leave a comment:


  • lynnl
    replied
    Originally posted by dian View Post
    can somebody tell me if it can be proved that 1+1=2?
    Yes. Put 1 egg* into an empty basket. Then add (i.e. +) 1 more egg. Then carefully count the eggs in the basket. Repeat multiple times to confirm, in case you miscounted the first time.

    *Note: If eggs are not available, suitable substitutes would include apples or oranges, or even watermelons.

    Leave a comment:


  • dian
    replied
    can somebody tell me if it can be proved that 1+1=2?

    Leave a comment:


  • Astronowanabe
    replied
    JR> And I have always been horrible at math

    Folks that build stuff can't really be horrible at Math;
    Bad at arithmetic? maybe.
    They use to basically beat it in to us (well the nuns did anyway).

    Sure arithmetic as drilled in school helps expressing ideas to others
    and gives you a language/vehicle to learn what others have done.
    But after that math is patterns, and patterns of patterns that just keep going
    till they are completely divorced from our every day real world but
    can still be brought back in a way that matters here.
    The way arithmetic is pushed (fairly dry) has ruined math for lots of folks
    but it is more like saying you can't sing if you can't spell the lyrics in
    some weird language you don't use.

    I'm just semi-ranting because it bugs me to see "bad at math"
    getting airtime it does not deserve because you are obviously
    able to apply the ideas.

    Leave a comment:

Working...
X