Dyson Sphere - The Ultimate in Navel Gazing?

[Meredith]

Why not just mine the hydrogen from the star and use it to power several hundred million or billion rotating habitats?

You would be able to spread out the lifetime of the usable hydrogen in one system from 4billion years and stretch it out over a few trillion years.

 

[hyzmarca]

The sun is hot enough to boil diamonds. How exactly are you going to mine it?

 

[Asbo Zaprudder]

The Sun loses nearly 2 million tons of matter (mostly protons and electrons) every second via the solar wind. As the solar wind is a plasma, it would be possible to use magnetic fields to capture and contain it. Alternatively, you could collect it out where its velocity drops when it collides with the interstellar medium. There's reckoned to be a hot hydrogen wall between the bow shock and the heliopause at about 230AU from the Sun -- probably in the direction of Lyra.