• “It is not the job of mathematicians to do correct arithmetical operations. It is the job of bank accountants.” – Samuil Shatunovsky


    Besides researching mathematics and reading about mathematics, I also enjoy collecting objects related to mathematics and physics. Below are links to pictures of my collection. (Thanks to my wonderful wife for taking and editing the photos for me.)

    Niels Henrik Abel: (biography)

    … from Norway. Released on June 5, 2002, celebrating his 200th birthday.

    Niels Bohr (physicist): (biography)


    … from Greenland. Released in 1963. Note the formula for calculating the change in energy as an electron moves from one orbit to another in the Bohr Model of the Atom.

    Augustin Cauchy: (biography)

    … from France. Released on Nov. 10, 1989, celebrating his 200th birthday. Note the Cauchy Integral Formula at the top of the stamp as well as diagrams of two other important discoveries of Cauchy.

    Rene Descartes: (biography)

    … from France. Released on June 9, 1937, commemorating the 300th anniversary of the publication of Discours de la Méthode

    Albert Einstein (physicist): (biography)

    Einstein Medallion – Note the diagram on the right. Einstein’s General Theory of Relativity predicts that massive objects like the sun can bend light rays. This is the visual representation of the sun’s gravity bending light rays from a distant star, observed during a solar eclipse. This was one of the experiments used to verify his theory.

    Einstein Silver Medal from Germany. Released in 2005 to honor Einstein, commemorating the 50th anniversary of his death. Note the famous formula on the bottom.

    Einstein Coin from Switzerland. Released in 1979, celebrating his 100th birthday.

    Einstein Stamp from Germany. Released in 1979, celebrating his 100th birthday.

    Leonhard Euler: (biography)

    Euler Coin from Russia. Released in 2007, celebrating his 300th birthday. Note the Euler Zeta Function on right side of the coin. Euler was the first to prove this special case of the Riemann Zeta Function. Great stuff!

    Euler Stamps from the USSR. Released on April 17, 1957, celebrating his 250th birthday. Note the green Gauss stamp next to it!

    Euler Currency from Switzerland, appearing on the Swiss 10 franc note.

    Euler Print circa 1833, from an original portrait.

    Carl Friedrich Gauss: (biography)

    Gauss Coin from Germany. Released in 1977, celebrating his 200th birthday.

    Gauss Stamp with the Complex Plane from Germany. Released on April 14, 1977, celebrating his 200th birthday.

    Gauss Stamp from Germany. Released on February 23, 1955, commemorating the 100th anniversary of his death. Note the purple Euler stamps all around.

    Gottfried Wilhelm Leibniz: (biography)

    Leibniz Coin from Germany. Released in 1966, commemorating the 250th anniversary of his death.

    Nikolai Lobachevsky: (biography)

    Lobachevsky Coin from Russia. Released in 1992, celebrating his 200th birthday.