The last 25 years I thought that time dilation, mass increase and length contraction is "scaled" that way that on the first glance the crew of an accelerating starship could think everything is newtionain. I thought that when a starship accelerates constantly with 1g for 10 years (from the crews pov) it reaches roughly the speed that gives them a time dilation, mass increase and length contraction of factor 10, so they expierience a 10 light years journey (from stationary pov) in just one year of their personal time. From stationary pov they need 10 years and time ist slowed down to 0.1, from ships pov they need one year because the distance is contracted by 0.1. So I thought that you have to accelerate for 100 years with 1g (ships pov) to get a time dilation of factor 100.
Yesterday I read that article.
https://en.wikipedia.org/wiki/Space_travel_using_constant_acceleration
which states:
At a constant acceleration of 1g, a rocket could travel the diameter of our galaxy in about 12 years; if the last half of the trip involves deceleration at 1g, the trip would take about 24 years.
1g constant acceleration for 12 years could only be meant from the ships pov.
But on the other hand it says:
A half-myth: It gets harder to push a ship faster as it gets closer to the speed of light This is a half-myth because it depends on the frame of reference. It is true for those watching from the planetary reference frame. For those experiencing the journey (in the ship's reference frame) it is not true. For both the planetary frame and the ship's reference frame, the ship will change speed in a Newtonian way—push it a little and it speeds up a little, push it a lot and it speeds up a lot. However, in the planetary frame the ship will appear to be gaining mass due to its high kinetic energy, and the mass-energy equivalence principle. Should the engines be giving a constant thrust, this will result in progressively smaller acceleration due to the higher mass it is required to accelerate. From the ship's frame, the acceleration would continue at the same rate.
which seems to backup my thoughts. But apparently I was wrong that the scaling of the effect acts the way I thought.
Am I wrong, or the article?