[Spaceships] Magsail acceleration question

[acrosome]

Does the acceleration of a magsail vary by the distance from a star according to the inverse square law, as does a lightsail? Logically it seems that it should, but the RAW in Spaceships doesn't seem to imply that.

If it doesn't, why not?

[Anthony]

Because the sail effect becomes larger or smaller depending on the solar wind, actual scaling is slower than inverse square.

[acrosome]

How does it scale, then?

Why not have the sail at maximum size all the time?

[Langy]

Originally Posted by acrosome

How does it scale, then?

Why not have the sail at maximum size all the time?

The scale is close enough to 'doesn't scale at all' that it doesn't matter, given the granularity of Spaceships.

The sail's size depends upon various conditions, but the long and short of it is that the sail is always at maximum size - the maximum size simply changes as you get closer (it contracts) or further away (it expands) from the star.

[lexington]

That's... weird. I'm can't seem to find any mention of that.

[Sunrunners_Fire]

Originally Posted by lexington

That's... weird. I'm can't seem to find any mention of that.

Because it is a property of what a magsail is and gets way more detailed than spaceships is setup to handle. See here for a more in-depth explanation. Or the pdf here or here.

[lexington]

Originally Posted by Sunrunners_Fire

Because it is a property of what a magsail is and gets way more detailed than spaceships is setup to handle. See here for a more in-depth explanation. Or the pdf here or here.

Those references don't say it grows and shrinks without deliberate action.

[Sunrunners_Fire]

Originally Posted by lexington

Those references don't say it grows and shrinks without deliberate action.

Neither did Langy. Or are you assuming that a magsail doesn't have a dedicated automated system that makes adjustments as necessary and appropriate?

[Langy]

Originally Posted by lexington

Those references don't say it grows and shrinks without deliberate action.

A mini-magnetospheric plasma propulsion system (which is a specific type of magsail) does have the sail automatically grow or shrink without deliberate action, I believe. The previously-linked references are primarily about a classic magsail, which uses physical wires to create the sail. The plasma system uses a plasma to carry the current instead, and automatically expands as the pressure drops.

I can't find the references to the plasma magsail I saw previously at the moment, though, so I can't say for sure how it all works.

EDIT: Though wikipedia agrees that it is automatic.

[malloyd]

The "sail" isn't physical, not even in the classic design. It's a volume around the current carrier limited by how far the magnetic field can reach. As the density of the particle wind goes down, the field can reach further away from the physical loop. It is after all the point to induce motion in those charged particles, and moving them sets up counterfields. The denser they are, the closer to your spaceship those induced fields will screen the rest of the universe from the field of your magsail.