Norman Wildberger

Norman Wildberger

Norman is a research mathematician with a strong interest in education. He is the discoverer of Rational Trigonometry, and his YouTube site (user njwildberger) has more than 30K subscribers.

Location UNSW Australia

Activity

  • Norman Wildberger replied to Malcolm Day
    Allometry and why big animals live longer and beyond summary

    Thanks Malcolm.

  • Norman Wildberger replied to Manuel Sandoval
    Allometry and why big animals live longer and beyond summary

    Thanks Manuel.

  • Norman Wildberger replied to EVANTHIA KONTOGOURI
    Allometry and why big animals live longer and beyond summary

    Hi Evanthia, Yes that is a good point, thanks for bringing it to our attention. Next time around we will try to let people know when we have made a correction on a test. But good to see you did very well anyway!

  • Norman Wildberger replied to Michi Schaub
    Allometry and why big animals live longer and beyond summary

    Thanks for joining us Michi.

  • Norman Wildberger replied to Jonathan England
    Allometry and why big animals live longer and beyond summary

    Thanks Jonathan.

  • Norman Wildberger replied to Christine Abdelmoutaleb
    Allometry and why big animals live longer and beyond summary

    Thanks Christine.

  • Norman Wildberger replied to Nick James
    Allometry and why big animals live longer and beyond summary

    Thanks Nick.

  • Norman Wildberger replied to Dave Hardcastle
    Credits and thanks

    Well done Dave for making it through all the hurdles. And remember that the course material is now available to you for review in the future.

  • Norman Wildberger replied to EVANTHIA KONTOGOURI
    Credits and thanks

    Thanks Evanthia, glad you enjoyed the course!

  • Norman Wildberger replied to John Vie
    Credits and thanks

    Thanks John.

  • Norman Wildberger replied to Graham Gardiner
    Credits and thanks

    Well done Graham! And thanks for the lovely comments.

  • Norman Wildberger replied to Keith Cook
    Credits and thanks

    Thanks Keith. Hopefully that log stuff will sink in after a few months of ingestion.

  • Norman Wildberger replied to Antonio Avellan
    Credits and thanks

    Thanks Antonio.

  • Norman Wildberger replied to Helen Kilgour
    Credits and thanks

    Nice to have you with us on the course Helen, and yes you can use the materials as long as you credit us.

  • Norman Wildberger replied to Luis Argomedo Díaz
    Credits and thanks

    Thanks Luis.

  • Norman Wildberger replied to tahir rasul
    Credits and thanks

    Thanks Tahir

  • Norman Wildberger replied to Jenny Young
    Credits and thanks

    Thanks Jenny.

  • Norman Wildberger replied to Barrie Kane
    Credits and thanks

    Nice to have you with us Barrie, glad to hear you enjoyed the course.

  • Norman Wildberger replied to Mary Harding
    Credits and thanks

    Thanks Mary!

  • Norman Wildberger replied to John Vie
    Gravitation and Newton's inverse square law

    It is a really beautiful episode in the history of thought--Newton's derivation of Kepler's laws through his laws of motion and gravitation plus a geometric understanding of the brand new calculus that he helped invent. It would make a good course. In fact at UNSW we plan on running a PD course next year called Celestial Motion and Space Flight--it will be...

  • Norman Wildberger replied to Cesar Neves
    Allometry and why big animals live longer and beyond summary

    Thanks Cesar.

  • Norman Wildberger replied to Jitka Chapman
    Allometry and why big animals live longer and beyond summary

    Thanks Jitka for the nice comment and the many contributions to the discussion.

  • Norman Wildberger replied to John Vie
    Allometry and why big animals live longer and beyond summary

    You're welcome John!

  • Norman Wildberger replied to Dai Middleton
    Credits and thanks

    Thanks Dai! You have made a huge contribution to the course, and I know a lot of participants really got a lot out of your many thoughtful contributions. It has been a pleasure having you on the course with us.

  • Norman Wildberger replied to Tony Samson
    Beyond power and polynomial relations

    Hi Tony -- I do have vague plans to put together a Calculus course in the next year or so: but it will be a very Algebraic Calculus, which in my view is the right way of approaching it. I have a wordpress blog: https://njwildberger.com/ where you can keep in touch with my plans on that.

  • Norman Wildberger replied to Tony Samson
    Beyond power and polynomial relations

    Thanks Ivana for joining us!

  • Norman Wildberger replied to Antonio Avellan
    Allometry and why big animals live longer and beyond summary

    Hi Antonio, Sorry to hear about your difficulties, and hope that you find your way through them. Having some interesting other things to work on and think about can be helpful I am sure. May I interest you in my YouTube channel, user njwildberger? You might find lots more there to engage you interest. Thanks for your participation!

  • Norman Wildberger replied to Tony Samson
    Kepler's Third Law: the law of harmonies

    It certainly appears to be something of a coincidence. The pair of heavenly objects: Father Sun, Sister Moon etc. roughly comparable at least in size.

  • Norman Wildberger replied to Simon C
    Credits and thanks

    Glad to hear you made it through both courses! Congrats!

  • Norman Wildberger replied to Gerallt Jones
    Credits and thanks

    Thanks Gerallt.

  • Norman Wildberger replied to Meryl Goulbourne
    Credits and thanks

    Well done Meryl.

  • Norman Wildberger replied to maya tohmaz
    Areas under a hyperbola and the logarithm

    The better approach is to define ln(x) first as we have done here, in terms of an area under the graph of y=1/x. And then to define exp(x) as the inverse function to ln(x): that means we reflect the graph of y=ln(x) about the line y=x to get the graph of y=exp(x). Algebraically, y=exp(x) precisely when x=ln(y). This is not the way it is usually done it...

  • Norman Wildberger replied to Nancey Alexa
    Areas under a hyperbola and the logarithm

    Thanks Nancey--but the course is still going!

  • Norman Wildberger replied to Clare Fletcher
    Steiner's regions of space problem

    Exponential functions include ones like y=2^x. That is to be distinguished from polynomial functions, such as y=x^2. The exponential functions grow with x much more rapidly!

  • Norman Wildberger replied to Chris Pyves
    How many gas stations has your city?

    The curve with equation (x-y)(x^2+y^2-1)=0 ought to be regarded as a cubic curve, since if we expand it out we get degree three terms in x and y. However geometrically it is the product of a line and a circle. So it does not exactly look like a typical cubic, but nevertheless is one. Hope that clarifies things.

  • Norman Wildberger replied to EVANTHIA KONTOGOURI
    Multiplication of points on conics and cubics (an advanced topic)

    The definition of CxC is a bit subtle. Suppose that C and C' are two points on the conic, very close together. In that case the line C C' is close to being the tangent to the curve at C. Conclusion: when we multipy a point C by itself, we draw the tangent to the curve at C, then draw the line through O parallel to that tangent, and then see where that line...

  • Norman Wildberger replied to Malcolm Day
    How many gas stations has your city?

    Think about a tangent to the curve?

  • Norman Wildberger replied to Tim Curry
    Credits and thanks

    Thanks Tim!

  • Norman Wildberger replied to Ivan Alim
    Credits and thanks

    Thanks Ivan, glad you enjoyed the course. You can check out lots more of my YouTube videos from my channel Insights into Mathematics, user njwildberger.

  • Norman Wildberger replied to Tim Curry
    Gravitation and Newton's inverse square law

    Thanks, now corrected.

  • Norman Wildberger replied to Simon C
    Cubics and power laws summary

    Thanks Tim!

  • Norman Wildberger replied to Blaz Zabukovec
    Cubic curves I: historical aspects

    The reason is that given a fixed amount of surface area, we want to maximize the volume, to ensure that the cell can be as productive as it can be subject to the limits imposed by the surface area on inputs and outputs. And it is a famous result in mathematics that for a given surface area, the greatest volume is achieved for a sphere. Thus very generally...

  • Norman Wildberger replied to William Devitt
    Gas stations and population

    Thanks for the data William.

  • Norman Wildberger replied to Lawrie Brown
    Gas stations and population

    Nice.

  • Norman Wildberger replied to Simon C
    Gas stations and population

    Thanks Simon!

  • Norman Wildberger replied to Reino Warren
    Multiplication of points on conics and cubics (an advanced topic)

    Good point Reino, I have noted that on the question now.

  • Norman Wildberger replied to Ian MacAndie
    Multiplication of points on conics and cubics (an advanced topic)

    That's quite correct Ian. In complicated situations some visualization and getting the computer to make the calculation is a great tool.