I personally completely agree with all the thoughts exposed in the post. Though mostly I was intrigued by the figure labeled "Some important details for coloniz

I personally completely agree with all the thoughts exposed in the post. Though mostly I was intrigued by the figure labeled "Some important details for colonizing the universe.": http://johnsalvatier.org/assets/colonizing-the-universe.png http://johnsalvatier.org/assets/colonizing-the-universe.png Unfortunately author used it just as an illustration without giving any details. The dust and heating related constraints are self explanatory, what surprised me most was the slowdown fission/fusion curves. Since everything else on the plot seems to make sense I presume they just depict that whatever amount of fuel you take with you the amount of extracted energy will decrease following such a path as you accelerate closer to c.