Comments on: Q&A: The distance to Planet X is 1.21 light-year. How long does it take a spaceship to reach X, according to the pi http://www.ufo-watch.com/conspiracies-2/qa-the-distance-to-planet-x-is-1-21-light-year-how-long-does-it-take-a-spaceship-to-reach-x-according-to-the-pi.html UFO videos, images and reports from all over the world. Wed, 23 May 2012 20:04:39 +0000 hourly 1 http://wordpress.org/?v=3.3.2 By: Bekki B http://www.ufo-watch.com/conspiracies-2/qa-the-distance-to-planet-x-is-1-21-light-year-how-long-does-it-take-a-spaceship-to-reach-x-according-to-the-pi.html#comment-10916 Bekki B Thu, 03 Nov 2011 07:22:29 +0000 http://www.ufo-watch.com/conspiracies-2/qa-the-distance-to-planet-x-is-1-21-light-year-how-long-does-it-take-a-spaceship-to-reach-x-according-to-the-pi.html#comment-10916 To an external observer, the time is t = 1.21 c-years / 0.73c To the pilot, this is reduced by dividing by a time dilation factor gamma (the second answerer got a sign wrong in his calculation of gamma, which is never less than 1, and then tried to make up for it by multiplying instead of dividing the distance by it) gamma = 1 / sqrt (1 - (v/c)^2) = 1/sqrt (1 - 0.730^2) Pilot time = sqrt(1 - 0.730^2)* 1.21 / 0.73 years To an external observer, the time is
t = 1.21 c-years / 0.73c

To the pilot, this is reduced by dividing by a time dilation factor gamma (the second answerer got a sign wrong in his calculation of gamma, which is never less than 1, and then tried to make up for it by multiplying instead of dividing the distance by it)

gamma = 1 / sqrt (1 – (v/c)^2)
= 1/sqrt (1 – 0.730^2)

Pilot time = sqrt(1 – 0.730^2)* 1.21 / 0.73 years

]]> By: rhsaunders http://www.ufo-watch.com/conspiracies-2/qa-the-distance-to-planet-x-is-1-21-light-year-how-long-does-it-take-a-spaceship-to-reach-x-according-to-the-pi.html#comment-10915 rhsaunders Thu, 03 Nov 2011 07:18:26 +0000 http://www.ufo-watch.com/conspiracies-2/qa-the-distance-to-planet-x-is-1-21-light-year-how-long-does-it-take-a-spaceship-to-reach-x-according-to-the-pi.html#comment-10915 First response is not correct. The speed is high enough that Einsteinian mechanics must be used to get the correct answer. Second response is on the right track; the only obvious error is the use of the term "light years" in the final answer; it should be simply "years". First response is not correct. The speed is high enough that Einsteinian mechanics must be used to get the correct answer. Second response is on the right track; the only obvious error is the use of the term “light years” in the final answer; it should be simply “years”.

]]> By: Brats http://www.ufo-watch.com/conspiracies-2/qa-the-distance-to-planet-x-is-1-21-light-year-how-long-does-it-take-a-spaceship-to-reach-x-according-to-the-pi.html#comment-10914 Brats Thu, 03 Nov 2011 06:42:59 +0000 http://www.ufo-watch.com/conspiracies-2/qa-the-distance-to-planet-x-is-1-21-light-year-how-long-does-it-take-a-spaceship-to-reach-x-according-to-the-pi.html#comment-10914 First we have to find the distance in the pilot's frame. The distance will shrink with a factor of gamma where gamma is 1/sqrt(1 + v^2/c^2) = 1/sqrt(1 + 0.73^2) = 0.807 so the distance in the pilot's frame is 0.807*1.21 = 0.977 light years now divide this by his speed 0.977/0.73c = 1.34 years so according to pilot, it will take 1.34 light years First we have to find the distance in the pilot’s frame. The distance will shrink with a factor of gamma where gamma is
1/sqrt(1 + v^2/c^2)
= 1/sqrt(1 + 0.73^2)
= 0.807

so the distance in the pilot’s frame is 0.807*1.21
= 0.977 light years

now divide this by his speed
0.977/0.73c
= 1.34 years

so according to pilot, it will take 1.34 light years

]]>