Theories are all very well and could be the way to do this, but until you actually bolt one bit of metal to another, they remain as theories. Please wake me up when they can actually build a warp drive. I really hope this works out, we need a way off this rock.
Bob Stuart
"If humanity is going to stand the test of time, we need to expand beyond Earth." - We need to do that within a billion or so years. To get that chance, we should fix our current climate problem and preserve what we have learned so far. It is silly to try to terraform other planets if we can't even maintain the terraform we have.
So the third spacecraft design is Starship Enterprise? Gene Roddenberry was truly a visionary being.
Steve White
I'm intrigued to know what would happen if you created such a bubble here on Earth... would the bubble speed through the Earth leaving it untouched or would it cause carnage?
If this is going to work it will be bigger than the all the rest of aerospace history until now. First "realistic" solution for FTL travel, no unobtanium requirements. But those 30 orders of magnitude energy savings are equivalent to reduce the energy consumption from around 2500 Suns (3.8 * 10 at power 26 Watts per Sun) to 1 W (less than an economy LED light bulb). Well, we should stop spending billions on toys like SLS and Starship and go for the real thing.
Brian M
Given that the theory is valid and the engineering possible, its still going to be some time in the future. So why argue for "modern nuclear fission reactors" as the power source, surely a practical fusion power plant would feasible by then - Or maybe that will still be 20 years away!
Venus works for us. Same gravity, same size, same devil rules.

All you have to do is put in geosynchronous orbit a lot of solar panels to block the sun and microwave the energy back to Earth and with enough panels blocking the sun the planet will cool off over hundreds of millions of years so if we destroy the Earth in the meantime we will have a truly sister planet to move to. By varying the amount of blockage we can terraform the planet to an Earth like temperature range.
And in fact you could make a robot to make the panels continuously for millions of years generating more and more panels blocking the sun so that we don't have to do much work--just design the robot and put it in orbit. It can pull the materials from meteors and comets that sling by from time to time.
Well this theory if true explains what has always perplexed me: How the occupants of UFO's withstood the G force of some of their maneuvers.
IMHO, trying to use any kind of spaceship to travel to other stars would be extremely impractical (as tiniest accident/collision/breakdown on the way would mean horrible ending)!

Only practical/safe way would really be (but assuming massive technological progress) turning the whole Earth into a mobile planet by adding a grid of giant tower fusion drives, like in the Chinese movie "Wandering Earth"!

(Then Earth can also be saved from sun turning a red giant, by taking Earth to farther orbit!)

(Also imagine using the same tech for changing paths of asteroids & comets to make them collide w/ Mars & Venus (in a controlled way to keep their orbits still stable) to slowly increase their mass, water, atmosphere (& later turning them to mobile planets too)!)