>The problem is when you work out the math on rocket that can sustain 1G for multiple days with any Earthly isp you realize the math just doesn't work.
>our best chemical rockets are more like 450 seconds
If we're talking about leaving the Solar system, and 1G rockets, why on Earth would you ever even think about primitive chemical rockets? Obviously, nuclear rockets are a mandatory first-step before getting close to that level of technology.
And given that we already have nuclear power plants, as well as designs (untested) for nuclear rockets, why even bring up chemical rockets?