Piketty's central thesis (at second hand) appears to be that in an era of slow economic growth (like the 21st century to date) characterised by high rates of return on investment (ditto) the rate of capital formation outstrips the rate of wealth creation, leading to centralization of wealth and an increasing gap between the rich and the rest of us. Marketization and trickle-down economics have signally failed to close this widening divide, and so it follows that the deregulation of trade and investment and the reduction in taxation of assets that have typified the past forty years are damaging to the social fabric; if we want to reduce inequality we will have to go after the capital concentrations with a pointy expropriative stick. (Cue right-wing/libertarian meltdown in 3 ... 2 ... 1 ...)

The current buzz-topic of the month is Thomas Piketty's magisterial tome, Capital in the 21st Century —currently at #1 on the New York Times bestseller list, #5 in the UK, and in the sights of every right wing pundit, goldbug, and economic quack globally. I have not read Piketty (yet) so I am about as unqualified to comment on his central thesis as anyone. But I've read the reviews, so I'm going to bloviate anyway—about the implications for a topic I occasionally obsess over, like a diseased cur chewing on an ulcerated hernia.

I believe we can safely say that the custodians of those huge steaming piles of money that are sucking yet more money into their orbit like so many fiscal neutron stars will resist any attempt to take their shinies away, by any means—fair or foul. It doesn't matter whether the money can actually buy them anything useful—arguably in billion-up concentrations it can't: go ask Steve Jobs how much being CEO of AAPL extended his life expectancy—or even whether you own it (ask the board of the Welcome Foundation, for example); but you don't get to be in charge of a giant heap of green folding paper by giving it away at every opportunity.

But is it possible to persuade them to do something useful with their capital? (And by "persuade" I mean hold a gun to their head: compulsory nationalization and redistribution without compensation, or invest in something useful and at least nominally retain ownership of the investment ...) What if we offer them tax breaks for investing in some really long-term project that doesn't necessarily offer them a return on investment any faster than the overall GDP growth rate, but which protects the nominal long-term value of their assets while ultimately growing the size of the economy?

The characteristics of such favoured "safe harbour" investment vehicles should be: a really long-term goal, a high capital investment (nine to eleven digits) required to get the ball rolling, and some way of providing them with an assurance that expropriation at pitch-fork point is averted by the very nature of the investment. Oh, and it should eventually flip over into delivering economic GDP growth beneficial to the "little" people—us—without degrading the biosphere that we live in.

I've got two candidates for such investments: (a) commercial thermonuclear fusion reactors, and (b) colonizing Venus.

Fusion: we are not fifty years away any more. We're about thirty years and $100Bn away. Or we're about 8-10 years and $200Bn and a Manhattan Program level of urgency away—it depends on the political and legislative framework. However, building tokamak fusion reactors (like ITER) is never going to be cheap; to get 1Gw of electrical power out implies a 5Gw thermal reactor (and a third of its power is going to go into maintaining the fusion reaction). More realistically, tokamaks will come in 5Gw power output and larger sizes, making them an order of magnitude larger than today's big-ass 1Gw PWR, AGR, and AP1000 reactors. We're looking at startup costs of $25-50Bn per reactor, and a requirement for up to 1000 of the suckers if we want to roll it out globally as a major energy source.

So: it's a project that will plausibly soak up $25-50Tn and take 10-30 years to roll out while needing 30-60 years to break even and start to provide a return on the capital investment. A good way of making the Koch brothers atone for their sins while preserving the illusion of their wealth, right?

Naah, that's small beer.

Let's get really ambitious and propose a scheme that will cost trillions and take centuries. I am referring, of course, to the colonization of Venus. Venus is usually written off as a destination for human space colonization due, I am convinced, to a lack of vision. Everyone focusses on Mars, probably because Mars doesn't have a runaway greenhouse atmosphere with a surface pressure of around 93 bar and a temperature of 480 celsius. (Mars is cold, chilly, and sits in a near-vacuum—0.01 bar.)

However, there is one place on Venus that is actually rather more hospitable to our type of life than almost anywhere else in the solar system: 50-55km up in the troposphere, the pressure drops to between 1.0 and 0.5 that of the Earth's atmosphere at the surface, and the temperature declines to between 30 and 70 celsius. Furthermore, the gas composition is mostly carbon dioxide. CO2 is dense; with a molecular weight of 44 daltons, it's actually denser than breathable air (80/20 nitrogen/oxygen dimers, average molecular weight around 29-30 daltons). A balloon or Zeppelin full of human-breathable air would actually float as well in the troposphere of Venus as a hydrogen balloon does on Earth. "At cloud-top level, Venus is the paradise planet," as Geoffrey Landis puts it. More here, with links to papers in the footnotes: let's just say that my money would be on a million people living in the clouds of Venus being both cheaper and faster to achieve than getting a million people living on or below the surface of Mars. Although neither project is ever going to be cheap, and my money is on either one costing somewhere north of $10Tn just to get rolling.

Of course, there's no guarantee that colonizing Venus would work out. Or even that it might not prove profitable in the long term, resulting in the giant pile o'gold problem returning to haunt another generation. But some of the billionaire elite already seem inclined to boldly blow their fortune where no fortunes have been blown before. As Elon Musk says: "it would be pretty cool to die on Mars, just not on impact."

So. Should we encourage the custodians of the shitpiles of capital that are damaging our global social fabric to atone for their sins by offering them huge long-term investment opportunities in colonizing Venus and rolling out commercial thermonuclear fusion reactors? (Both worthy(ish) projects that demand a fuckton of money and time which, in our current circumstances, the shrunken machinery of government simply can't afford.) Or should we try and take their hoards away via some other means? And if so, what?