The Oil Drum: Canada

No problem I like your responses also. And as you say you can't put the genie back in the bottle.
But I'd respond that if we are not careful we will smash the bottle and shoot the genie.
As far as crossections etc all I can say as showme :)
Like I said I actually worked on Penning Paul traps.
http://en.wikipedia.org/wiki/Penning_trap
A number of variants exist.

I worked on this. In fact this link is too my professor.
http://www.ncbi.nlm.nih.gov/pubmed/9920628

In any case consider mechanically spinning both the electrodes and magnets with the electrodes
and magnets designed to produce a non-linear field say a double well.
This sets up all kinds of secondary fields and compression of the magnetic field lines.
I've never seen anyone spin the piss out of there 10 million dollar traps but its something
I'd love to see done.

So in short yes you can beat thermal cross sections. And I really supect if I'm alive when we
finally develop fusion that at least part of the machine will have a mechanically spinning magnet
or electrode that generates a non-homogeneous rotating field causing plasma oscillations.
Right now these are considered the problem but I think they are the solution the ions are
allowed to "escape" but if you can spin fast enough you capture them with the time varying field.

This paper off the first page is going in that direction.

http://www.ncbi.nlm.nih.gov/pubmed/15446986?ordinalpos=1&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_DiscoveryPanel.Pubmed_Discovery_RA&linkpos=2&log$=relatedarticles&logdbfrom=pubmed

Lara M, Salas JP.

Real Observatorio de la Armada, 11110 San Fernando, Spain.

Imperfections in the design or implementation of Penning traps may give rise to electrostatic perturbations that introduce nonlinearities in the dynamics. In this paper we investigate, from the point of view of classical mechanics, the dynamics of a single ion trapped in a Penning trap perturbed by an octupolar perturbation. Because of the axial symmetry of the problem, the system has two degrees of freedom. Hence, this model is ideal to be managed by numerical techniques like continuation of families of periodic orbits and Poincaré surfaces of section. We find that, through the variation of the two parameters controlling the dynamics, several periodic orbits emanate from two fundamental periodic orbits. This process produces important changes (bifurcations) in the phase space structure leading to chaotic behavior. Copyright 2004 American Institute of Physics

Enough on that I'll get sucked in again :)

The only point I disagree on is carrying capacity of the earth. Here I think we are in overshoot.
Just flying over the US and China shows that we have developed all the best places and a good bit of the marginal lands. Flood plain ecosystems have been destroyed for so long people don't realize it.

Natural rivers in the south used to have huge natural dams called snags that built up along the rivers the riparian environment has been destroyed etc.

What I mean by living within our means is only using a small portion of the best lands say less then 10% so that all the natural ecosystems remain intact and this means leaving many rivers untouched by man all along there route. I don't know exactly the density that we need to be at to support keeping large parts of the worlds ecosystems untouched but its a lot lower than today.

Now since we must always have some high energy sources if we are going to have a technical civilization done correctly fusion could replace the use of hydroelectric altogether and we could rip out all or dams.

But it has to be done at the right time and place and for the right reasons and the right level. We are not ready for another endless power source we screwed up big time with our first one (oil).

So I hope that if we do achieve fusion it won't be for a long time and it will be in a society that wants it to rip out dams.

As far as space goes the more the merrier plenty of room to expand and a society that lives within its means would only lightly touch the planets it settles before moving on to others.

If we had star flight now we would basically be a scourge on the universe. We make locust swarms look benign.

Who knows if aliens exist but if they did I'm sure they would not want use "escaping" :)