Sci-fi engine thrust calculations

• Deleted member 690984
In summary, a technical manual is being written for a starship in a science-fiction series. The ship's sub-light engines are capable of a maximum speed of 15,000 km/s (0.05c) and require 18,750 teraNewtons of thrust to achieve this speed at a fully loaded mass of 5 million metric tons. The ship also has 30 reaction control thrusters that can produce a combined thrust of 375,000 gees for manoeuvring. The ship's maximum speed is limited by practical considerations to prevent time dilation effects. The fully loaded ship mass includes all components.
jbriggs444 said:
If it works by grabbing hold of some sort of cosmic fabric and thrusting against it then that takes much less energy but it flies in the face of the principle of relativity. Something that physicists are unwilling to part with.

On that topic for a moment, I read that Dr. Harold White managed to reduce the amount of antimatter needed to 500kg to generate a warp engine that would take a ship to Alpha Centauri in just shy of 5 months. However, are there any figures for this? What I mean is, does this imply only 500kg are needed if the engine is in constant use for the full five months, so, a use of 100kg per month?

The ships in my world do have a warp drive, however, they are still limited by the light speed barrier - i.e., a ship's maximum speed is the speed of light, but the warp engine negates time dilation effects. How would this factor into energy usage?

paulthomas said:
Dr. Harold White managed to reduce the amount of antimatter needed...
As far as I know, he's merely postulated a way to reduce the energy demands for an Alcubierre Warp Metric. It's all theoretical and maybe not even physically possible, and is as handwavium as you're likely to get for a sci-fi story, but in terms of how much antimatter etc., nobody knows.

paulthomas said:
...but the warp engine negates time dilation effects. How would this factor into energy usage?
However you need it to, really. This is not physics as we understand it operates in the universe, so you get to set the scene, @paulthomas. My only advice is to think your plot(s) as far ahead as possible in broad terms so you don't lock some ship attribute now that trips you up later.

Deleted member 690984 and jbriggs444
Thanks @Melbourne Guy and @jbriggs444 for your help in this area! It's definitely been most helpful!

Melbourne Guy

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