Daryen said,
Uh, not to be completely annoying, but shouldn't 6G be 60 m/s/s instead of 120 m/s/s?
That would make the result for 6G 138.8 instead of 69.4. (Which fits the 1/6 of 833.3 you were looking for.)
Yes, it does. I must have been thinking of the acceleration at 2-Gs when I multiplied by 6.
Thanks for catching my error.
Hecateus said,
correct me if I am wrong, but I believe your calculations don't take into account the effects of relativity in terms of time and fuel needed. Though I realise you are just keeping things simple.
You're right that I'm ignoring relativistic effects. I'm doing that because at the low velocities of most Traveller ships, relativistic effects are minimal. You're got to really get up into large fractions of lightspeed to have relativistic effects become apparent.
Empress Nicholle said,
Why is acceleration more important than velocity when determining relative ship positions? It's been a long time since I've used the old vector starship movement system in CT, so forgive me if I seem a little ditzy (no, I'm a redhead, not blonde) .
And don't vessels reach a terminal velocity? How do you figure what that is?
Taking the second question first....
Yes, technically there is a maximum of just under lightspeed, but Traveller ships will never even get close to that. However, we can take a SWAG (Scientific Wild-Ass Guess) at a maximum safe speed for Traveller ships.
The maximum speed an unarmored Traveller spaceship can safely reach is about 0.5% of lightspeed, which is about 1500 kilometers/second (km/s). This figure is based on the Striker armor rating of an unarmored Traveller ship hull and the impact energy (in TNT-equivalent) of a 0.1 gram piece of spacedust at that speed. If you want the math I can show it to you.
A Traveller ship accelerating at 1-G will reach this maximum safe speed in about 41 hours of continuous acceleration. Since safe jump distance from a large gas giant is only 17.6 hours at 1-G (and that includes a turnover at the halfway point and deceleration the rest of the way) it's unlikely that a Traveller ship would ever need to reach this theoretical maximum safe speed. Armored Traveller ships could reach higher safe speeds.
Remember that objects in a vacuum do not experience friction and so they keep whatever speed they had when their drives are shut down, unless something else (like a planet's gravity) acts to change their speed.
To answer the question about why acceleration is often more important than velocity, it's necessary to understand that most Traveller ships will never be moving at all that high a speed. Usually Traveller ships are just going to or from a safe jump distance from an inhabited world. This doesn't take very long, even for a 1-G Free Trader (7 hours for a size-A world at 1-G) and the max velocity the Free Trader reaches is only 126 km/s. A 6-G pirate can match that velocity in about 40 minutes or less. So the acceleration is more important since the velocities are so low that a high-G ship can easily gain the speed needed to intercept.
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