Paul Callahan

Paul Callahan
Born	Unknown
Residence	United States
Nationality	Unknown
Institutions	Unknown
Alma mater	Johns Hopkins University

Paul Callahan is a Life enthusiast.

He expanded David Buckingham's Herschel conduit mechanisms, building the first known stable reflectors for glider. He also carried out computer searches to find some of the smallest patterns exhibiting infinite growth, including the smallest possible one-cell-thick infinite growth pattern. He also wrote the gencols collision search program.

External links

• Paul Callahan at Mark D. Niemiec's Life Page (Life Credits)
• Life page of Paul Callahan (ConwayLife.com mirror)
• Paul Callahan at the Mathematics Genealogy Project
• Paul Callahan (TileDemo) on Scratch

Patterns found by Paul Callahan

4

• 49P88

B

• Bistable switch
• Bx125
• Bx222

C

• Callahan G-to-H

F

• F116
• F166
• Fx153
• Fx176

G

• Glider stopper
• Glider to block

H

• HF95P
• HFx58B
• Herschel receiver
• Herschel transmitter
• Hive five

L

• Lx200

M

• Medusa

P

• P61 Herschel loop 2
• PF35W
• Period-44 glider gun

T

• Three-block shifter