# Dictionary of Mathematics 6e Companion Website

# Web links

Here is a list of recommended web links, arranged alphabetically by the relevant dictionary entries.

A B C D E F G H K L M N P R S T

abacus

http://totton.idirect.com/abacus/

A description of how one abacus works.

adders

http://computer.howstuffworks.com/boolean2.htm

An article demonstrating how a simple adder works.

analysis of variance

http://www.bmj.com/cgi/content/full/312/7044/1472

A description of the analysis and its interpretation in a medical context (subscription).

Archimedean solid

http://www.scienceu.com/geometry/facts/solids/

Links to the thirteen Archimedean solids, which can be manipulated to see the shapes fully.

Archimedean spiral

http://www.mathematische-basteleien.de/spiral.htm

An animation showing the Archimedean spiral.

Arrow’s Impossibility Theorem

http://www.sjsu.edu/faculty/watkins/arrow.htm

An illustration of the theorem.

bisection method

http://archives.math.utk.edu/visual.calculus/1/bisection.3/index.html

An interactive page which demonstrates the method for finding a root of a cubic equation.

blinding

http://www.bmj.com/cgi/content/full/321/7259/504

A full discussion of the ethics and principles of blinding in clinical trials (subscription).

bridges of Königsberg

http://nrich.maths.org/public/viewer.php?obj_id=2327

An interactive page in which you can construct your own problem like the bridges of Königsberg.

bubble sort algorithm

http://www.sorting-algorithms.com/bubble-sort

A demonstration of the bubble sort in action.

Buffon’s needle

http://www.mste.uiuc.edu/reese/buffon/bufjava.html

A simulation of Buffon's needle experiment.

catenary

http://www-history.mcs.st-andrews.ac.uk/Java/Catenary.html

An interactive exploration of the shape of a catenary.

Central Limit Theorem

http://onlinestatbook.com/stat_sim/sampling_dist/index.html

An applet that lets you define the population and then take multiple samples of different sizes to explore the behaviour of the Central Limit Theorem.

*Chalkdust*

http://chalkdustmagazine.com/

The Chalkdust website.

Classification Theorem for Surfaces

http://www.maths.ed.ac.uk/~aar/surgery/zeeman.pdf

A well-illustrated description of some types of surfaces.

compound interest

http://www.moneychimp.com/calculator/compound_interest_calculator.htm

A compound interest calculator.

conic

http://www.shodor.org/interactivate/activities/ConicFlyer/

An interactive demonstration of a conic section.

control chart

http://www.sqconline.com/control-chart-variables-enter.html

Construct a control chart for your own choice of parameters.

critical path analysis

http://www.mindtools.com/critpath.html

An article including an example of critical path analysis.

cuboctahedron

http://www.scienceu.com/geometry/facts/solids/java/cubeocta.html

A cuboctahedron which can be manipulated to see its shape fully.

discrete Fourier transform

http://www.jhu.edu/signals/fourier2/index.html

A discrete Fourier transform tool in which choosing different options from the signal menu illustrates a number of signals and the approximating function using a specified number of Fourier coefficients.

du Sautoy, Marcus

http://people.maths.ox.ac.uk/~dusautoy/

Marcus du Sautoy’s website at Oxford University.

eccentricity

http://www.math.odu.edu/cbii/calcanim/#defel

Two animations of ellipses with different eccentricities.

equiangular spiral

http://jwilson.coe.uga.edu/EMT668/EMAT6680.F99/Erbas/KURSATgeometrypro/related%20curves/related%20curves.html

Animations of related curves, and an interactive manipulation of the spiral in Geometer’s Sketchpad.

Euclid

https://mathshistory.st-andrews.ac.uk/Biographies/Euclid/

A fuller biography of Euclid.

forced oscillations

http://www.acoustics.salford.ac.uk/feschools/waves/shm3.htm

Animations and videos of forced oscillation and resonance.

Four Colour Theorem

https://serendipstudio.org/playground/fourcolor/

A Shockwave file allowing you to create your own map and colour it in, or see an automated solution with no more than four colours. fractal

http://sprott.physics.wisc.edu/fractals.htm

Examples of colourful fractal images.

Fry, Hannah

https://www.hannahfry.co.uk

Hannah Fry’s official website.

gambler’s ruin

http://probability.ca/jeff/java/gambler.html

A Java applet showing the gambler’s ruin problem.

golden ratio

http://www.maths.surrey.ac.uk/hosted-sites/R.Knott/Fibonacci/fibnat.html#plants

Shows the golden ratio in biology and the relationship to Fibonacci numbers.

helix

http://www.math.mcmaster.ca/gabardo/Pictures/animation01a.gif

An animation of a helix.

Hilbert, David

http://aleph0.clarku.edu/~djoyce/hilbert/

The 23 mathematical problems of Hilbert.

Hooke’s law

http://webphysics.davidson.edu/applets/animator4/demo_hook.html

An interactive illustration of Hooke’s law.

Kepler’s laws of planetary motion

http://astro.unl.edu/naap/pos/animations/kepler.swf

Animation which illustrates all three laws.

Klein bottle

http://www.kleinbottle.com/whats_a_klein_bottle.htm

A fuller description and images of Klein bottles.

Leonardo da Vinci

http://www.mos.org/leonardo/

An online exhibition about da Vinci.

life tables

http://www.ons.gov.uk/ons/taxonomy/index.html?nscl=Interim+Life+Tables

Gives access to the latest life tables.

magic square

http://www.vtaide.com/png/3x3‐E.htm

An interactive 3 × 3 magic square.

Mersenne prime

http://www.mersenne.org/

Home page of the Great Internet Mersenne Prime Search.

Millennium Prize problems

http://www.claymath.org/millennium-problems

The Millennium Prize problems home page.

Möbius band

http://www.popmath.org.uk/sculpmath/pagesm/mb.html

The Möbius band in art.

moving average

http://stockcharts.com/school/doku.php?id=chart_school:technical_indicators:moving_averages

Illustrations of the moving average from financial markets.

National Centre for Excellence in the Teaching of Mathematics

https://www.ncetm.org.uk/

The NCETM home page.

NRICH

https://nrich.maths.org

The official NRICH website.

Numberphile

https://www.youtube.com/user/Numberphile

The Numberphile YouTube channel.

parabola

http://www.calculus.org/Contributions/animations.html

Properties of the parabola with links to animated illustrations.

parabolic spiral

nationalcurvebank.org

An animation of a parabolic spiral.

Parker, Matt

http://standupmaths.com

Matt Parker’s official website.

pedal curve

http://mathworld.wolfram.com/PedalCurve.html

An animation of a pedal curve.

perfect number

https://mathshistory.st-andrews.ac.uk/HistTopics/Perfect_numbers

A brief history of perfect numbers.

*Plus* magazine

https://plus.maths.org/

The official website of *Plus* .

predator–prey equations

http://home.messiah.edu/~deroos/CSC171/PredPrey/PPIntro.htm

Simulations of fox and rabbit populations.

prisoner’s dilemma

https://serendipstudio.org/playground/pd.html

Play the prisoner’s dilemma against the computer.

relativity theory

https://www.allaboutscience.org/theory‐of‐relativity.htm

An article about relativity with a related video.

resonance

http://www.acoustics.salford.ac.uk/feschools/waves/shm3.htm

Animations and videos of forced oscillation and resonance.

sieve of Eratosthenes

http://www.faust.fr.bw.schule.de/mhb/eratosiv.htm

An interactive animation of the sieve of Eratosthenes used to obtain prime numbers.

slide rule

http://www.sliderule.ca/

Descriptions of various slide rules and how they work.

stereographic projection

http://www.math.union.edu/~dpvc/math/4D/stereo‐projection/welcome.html

A full description of stereographic projection with two videos to illustrate how it looks.

3blue1brown

https://www.youtube.com/channel/UCYO_jab_esuFRV4b17AJtAw

The 3blue1brown YouTube channel.

https://www.3blue1brown.com/

The official 3blue1brown website.

*twin primes*

http://primes.utm.edu/top20/page.php?id=1

More information on twin primes, including a list of the 20 largest pairs identified.

Please find below the web links from the previous edition of this Dictionary. Please note that archived links are no longer updated.