NATS 1880 Chapter Notes - Chapter 13: John Von Neumann, Self-Replicating Machine, Positron
11 Apr 2016
School
Department
Course
Professor
Document Summary
Alpha centauri (nearest star to sun) is 2700 au away. Would take voyager probes 100,000 yr to reach it. Pioneer 10 and 11 have plaques that provide info about humankind (drawings) Voyager 1 and 2 have more sophisicated messages incl. pics and music. Einstein"s special theory of relaivity sets speed of light (300,000 km/s) as the max speed in the universe. Even at the speed of light, would take over 4 years to reach alpha centauri. Energy requirement is also a challenge to space travel. Energy requirement depends on object"s mass and speed (mass x speed[squared]) Also need energy to slow down to land. At current energy costs, would take 2. 5 quinillion dollars to reach the nearest star. Newton"s 3rd law is the basis of rocket propulsion (for every acion there"s an opposite and equal reacion) A squid uses this propulsion technique (takes in water and squirts it out rapidly behind it)
