(spaceships) rocket (super)science

[Anthony]

Originally Posted by jacobmuller

In a space opera setting - a "drive" system that "alters inertia" such that your 3G drive effectively gives you 3,000G but you still only feel the 3G, what does this do for delta-v?

It does whatever you define it as doing. I would be inclined to say it multiplies delta-V by the same amount, but you can't really get realistic answers out of a system that starts with an impossible assumption.

[malloyd]

Originally Posted by Anthony

It does whatever you define it as doing. I would be inclined to say it multiplies delta-V by the same amount, but you can't really get realistic answers out of a system that starts with an impossible assumption.

The derivation of the rocket equation starts with conservation of momentum, so assuming you alter the "inertia" and hence momentum of the ship and not the exhaust, then multiplying delta-V by the same factor you reduce your inertia makes some sense. And no this doesn't do anything to the exhaust velocity of the rocket, it violates conservation of energy instead.

But sure, if you can mess with conservation laws, depending on where you do it in the process of burning and expelling your fuel you might be able to change the exhaust velocity too, doing pretty much whatever you wanted to delta-V. On didn't want - the point your ship gets accelerated is after all where the pressure of the expanding gas acts on the inside of your nozzle, so it's maybe technically inside the field of your inertia reduction, so maybe your delta-V actually gets *worse*.