January 16, 2019

Wall Segments


San Diego, California, 2018.

Photo by I. Peterson

January 15, 2019

Structure


San Diego, California, 2018.

Photo by I. Peterson

January 14, 2019

Red Odyssey


Odyssey III by Tony Rosenthal. San Diego Museum of Art, Balboa Park, San Diego, California, 2018.

See also "Intersecting Disks."

Photo by I. Peterson

January 13, 2019

Stone Octopus


Wall mosaic, Boardwalk near Pacific Beach Lifeguard Station, San Diego, California, 2018.

Photo by I. Peterson

January 12, 2019

Casa del Prado


Casa del Prado Theatre, Balboa Park, San Diego, California, 2018.

Photo by I. Peterson

January 11, 2019

Playground Wheel


Waterfront Park Playground, San Diego, California, 2018.

Photo by I. Peterson

January 10, 2019

Rail Gull


Pacific Beach, San Diego, California, 2018.

Photo by I. Peterson

January 9, 2019

Utility Box Geometry


Utility box decoration, San Diego, California, 2018.


Photos by I. Peterson

January 8, 2019

Three Jibs at Dawn


Star of India, San Diego, California, 2018.

Photo by I. Peterson

January 7, 2019

Fishing Wall


Wall sculpture. Little Italy, San Diego, California, 2018.


Photos by I. Peterson

January 6, 2019

January 5, 2019

Double Entendre


Double Entendre by Bruce Gray. Lobby, DoubleTree by Hilton San Francisco Airport, Burlingame, California, 2018.

Photo by I. Peterson

January 4, 2019

Nonsimple


Nonsimple by Goran Konjevod. Exhibition of Mathematical Art, Joint Mathematics Meetings, San Francisco, California, 2010.

Photo by I. Peterson 

January 3, 2019

Ceiling Squares


Foyer ceiling, Hotel Granvia, Barcelona, Spain, 2007.

Photo by I. Peterson

January 2, 2019

Logarithmorum


The title page of John Napier's tables of logarithms. Published in 1614, these tables were recognized immediately as a significant new computational tool of great value to astronomers.

Reproduced from the collections of the Library of Congress.

January 1, 2019

2019


2019 = 3 x 673

2019 is the product of two primes whose sum is a perfect square (A141755): 3 + 673 = 676 = 26 x 26.

2019 is the first 4-digit number to appear six times in the decimal expansion of pi (A276686).

2019 is a semiprime that is the sum of four successive semiprimes (A158339).

2019 is a Happy-go-Lucky number (A091431). It is both a Happy number (A007770) and a Lucky number (A000959).

2019 is the sum of the first 22 perfect powers (A076408).

2019 is a number n such that n, 2n, and 3n together contain every digit from 0 to 9 (A120564): 2019, 4038, 6057.