7th November 2011 - 07:56 AM
One other site didn't seem to think it would take nearly as long:
View Full Version : How long would it take to accelerate a person to the speed of light without dying?http://boards.straightdope.com/sdmb/archiv...p/t-203257.html
"Going by classical physics
Velocity = g * time where g is the acceleration constant.
In "weightless" space, a person would be continuously subjected to a force of one 'g' if the person were accelerated at 32 ft/sec2. Since this is equaivalent to Earth's gravity, the person would be subjected to no undue stress.
The speed of light is about 300,000 kilometers per second which equals 984,000,000 feet per second.
Since v=g*t then
t = v/g
t= 30,700,000 which is roughly speaking one year ( 1 year is about 31.5 million seconds).
As someone else mentioned, it isn't as straightforward as this because as we approach light speed, relativistic changes occur.
Here is a website for calculating relativistic changes:http://www.1728.com/reltivty.htm
So, uniformly accelerating a spaceship cannot be done with the same amount of force. At 50% the speed of light, the mass of the ship increases by 15%. At 90 % the speed of light, the ship's mass has increased by 229%. So, you would need to expend 2.29 times the amount of fuel to continue the accelleration at 32 fett/sec2. Eventually this would be very impractical because at 99% light speed, the ship's mass has increased seven-fold.
So, let's suppose we have a ship that has enough fuel to account for the relativistic changes in mass, then the answer would be about a year IF you wanted to go at 99% light speed (your mileage may vary).
To tell you the truth that surprises me. I thought it might take a century or more so it is practical in terms of a person's lifetime. However, constructing a spaceship that could accelerate at 32 feet/sec2 would be impossible by today's technology. Among other things it would require enough fuel to burn continuously to maintain a one 'g' acceleration for one full year.
One more thing how far would you have travelled by the time you reach 99% light speed? IF you headed in a straight line, you would be 2.8 TRILLION MILES from where you started. This is roughly one half of a light year so this seems about right."