# Noam Elkies

Noam Elkies | ||

Born | August 25, 1966 | |
---|---|---|

Residence | United States | |

Nationality | American | |

Institutions | Harvard University | |

Alma mater | Harvard University |

**Noam D. Elkies** (born 1966 in New York City) is an American mathematician who has made several contributions to Conway's Game of Life. Most notably he proved the still life conjecture that no infinite still life can have a density larger than 1/2.

He has found several important oscillators, including the first known oscillators of period 20, 22, 24, 25, 27, 39, and 49. He constructed the first period 33 oscillator with the help of Achim Flammenkamp and the first period 39 oscillator with the help of David Buckingham. He has constructed some pipsquirter oscillators that are often used in the construction of larger oscillators thanks to their easily-accessible domino spark, and also some infinitely-expandable traffic jam oscillators.

He has found several unique guns as well, including the first true period 24 and 48 guns in June 1997. He also contributed to the construction of the first true period 50, 54, 55, and 56 guns. He and Dave Greene found the first 2c/5 gun in March 2003.

His most notable spaceship discoveries are the first orthogonal c/5 period 30 spaceship with David Bell in May 1998 and the the first orthogonal c/5 period 15 spaceship with Tim Coe in December 1997.

## Patterns found by Noam Elkies

### 6

### 9

### C

### P

- P15 pre-pulsar spaceship
- P156 Hans Leo hassler
- P18 bi-block hassler
- P32 blinker hassler
- P32 blinker hassler 2
- P42 glider shuttle
- P49 glider shuttle
- P5 bouncer
- P50 traffic jam
- P6 bouncer
- P60 B-heptomino hassler
- P60 traffic light hassler
- P7 bouncer
- P8 bouncer
- P9 bouncer
- Period-20 glider gun
- Period-24 glider gun
- Period-690 glider gun
- Pi orbital
- Pipsquirter 1
- Pipsquirter 2

## References

- Elkies, Noam D. (1998),
*Voronoi's Impact on Modern Science, Book I*, Proc. Inst. Math. Nat. Acad. Sci. Ukraine, vol. 21, pp. 228–253. arXiv:math/9905194v1 (math.CO) - "Game of Life Status page". Retrieved on April 20, 2009.
- "Life Credits". Mark D. Niemiec. Retrieved on April 20, 2009.

## External links

- Homepage of Noam Elkies at Harvard University
- Noam Elkies at the Mathematics Genealogy Project
- Noam Elkies at Wikipedia