Posted by Athena Scalzi
https://whatever.scalzi.com/2026/06/04/the-big-idea-james-l-cambias-6/
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Math can sometimes get in the way of a good story, but author James L. Cambias didn’t let pesky physics stop him from majorly transforming Venus. Blast off in his Big Idea to see how he managed to make Venus habitable, albeit not for humans, in his new novel, The Ishtar Deception.
JAMES L. CAMBIAS:
For this guest post, I thought I’d walk readers through the mental process of one of my own Big Ideas from my new book. The Ishtar Deception is the latest in my “Billion Worlds” series of books and stories set at the end of the Tenth Millennium. In that era, the Solar System is a vast “Dyson Swarm” of space habitats and solar collectors, soaking up most of the energy emitted by the Sun. On the scale devised by the Russian SETI researcher Nikolai Kardashev, the civilization of the Billion Worlds is a Type II. About a quadrillion biological beings live in the Solar System, and a larger number of intelligent machines.
It’s a big setting, and it means I can tell a wide variety of stories. The first Billion Worlds book, The Godel Operation, was a picaresque adventure bouncing around from the ring around Uranus to a space habitat near Jupiter and finally to Mars. The Scarab Mission was a kind of “haunted house in space” set aboard a space habitat depopulated by some mysterious disaster. The third, The Miranda Conspiracy, was a political thriller inside the Uranian moon Miranda.
For The Ishtar Deception I decided to take readers into the inner Solar System. I’ve made references in past works to the fact that Mercury doesn’t exist any more in the year 10,000, so I couldn’t send my characters there. Instead, I decided on Venus. My super-spy character Sabbath Okada would be assigned to a mission on Venus, and that in turn gave me my title, since Ishtar is a prominent surface feature on that world.
I had made vague references to Venus being terraformed in the distant future, but when I finally looked at the effort involved I realized there’d be no way to get the job done in a mere eight thousand years. Transforming Venus would take too long.
And that made me wonder why anybody would bother to do it at all. If you live in, say, the year 6000, and have some unimaginable amount of energy (by our primitive standards) to play with, what’s the most useful thing you can do? If you apply it to trying to make Venus into a habitable world like Earth you’ll use all of it up to make some tiny incremental change.
To reduce Venus’s atmosphere to something bearable you would have to physically remove something like fifty billion megatons of carbon dioxide from Venus. If you could somehow lift a hundred tons a second (never mind where you’re putting it) that would take fifteen thousand years of constant effort. Meanwhile you’re going to need to move a hundred times as much hydrogen to Venus if you want to support a biosphere. And let’s not even talk about the nine-month rotation. I have no idea how to fix that.
Or you can use the same amount of effort to build a few million more cozy space habitats to add to the Billion Worlds circling the Sun. Much more efficient. It’s a no-brainer, really.
But . . . that would leave my novel with Venus as it really is. An incredibly massive atmosphere of carbon dioxide, with a surface pressure equivalent to the ocean bottom a kilometer down on Earth, a temperature of 470 degrees Celsius (hot enough to melt lead and tin), winds blowing 300 kilometers per hour, and oh by the way there’s a significant amount of sulfuric acid in that dense atmosphere. Humans would only survive such conditions in massive submarine-like vehicles and structures, and even machines would have trouble with heat and corrosion.
Sure, you can maybe live in balloons floating in Venus’s upper atmosphere, where the temperature and pressure are not too different from what it’s like on Earth, so all you need to do is make some oxygen to breathe. But, again, it’s hard to see how a balloon city on Venus would be better than a space habitat. And all the while, there’s a whole planet’s worth of matter — metals, silicon, sulfur, carbon, oxygen, phosphorus, and other treasures — just out of reach down there under that hellish atmosphere.
You can’t “bio-terraform” it, as Carl Sagan once suggested, by introducing blue-green algae and letting the plants do for Venus what they did for Earth. There’s just too damned much atmosphere! If your plants were perfectly efficient and broke down all of Venus’s carbon dioxide to oxygen, well then you’ve got a planet with an atmosphere of nearly pure oxygen at about 60 times Earth’s surface pressure. As one of the characters in my book notes, it’s hard to think of anything that wouldn’t burn under those conditions.
So I decided that my future civilization would just take a simpler, cheaper, faster approach. Forget about turning Venus into a world with oceans and forests, let’s just make it something that isn’t instantly lethal to both biological and electronic intelligences.
The result: “cryoforming.” All you do is build a big sunshade and park it at the L1 point between Venus and the Sun, blocking all the sunlight from reaching the planet entirely. The sunshade will, naturally, harvest all that energy so whatever else you’re doing on or around Venus will have plenty of power. And then you wait a few centuries for Venus to radiate away all the heat contained in that massive atmosphere and the upper part of the crust.
First the sulfuric acid rains out, puddling on the ground and collecting in little lakes. As Venus gets cooler the acid becomes a waxy solid. Then the carbon dioxide starts to crystallize, falling as dry ice snow. At first it melts on hitting the warm ground, of course, but eventually it sticks, and then accumulates. Without an energy differential the winds calm down, from hundreds of kilometers per hour to something more like what we see on Earth.
And overhead, an observer on the surface can see something that hasn’t happened on Venus in billions of years: the stars come out.
I figure my future civilization would stabilize the temperature a few degrees below the freezing point of carbon dioxide. Say, 50 or 60 degrees Celsius below zero. That gives you a planet with an atmosphere of pretty much pure nitrogen (with a few trace noble gases), and a surface pressure of roughly four times Earth sea level pressure.
Nice? It depends on what you are. If you’re a human, or some other biological being, you still need breathing gear and heated clothing to go outside. You probably want to live at a lower pressure so all your cities will be built of diamond blocks and graphene like high-tech sea bases, and it’s still dark all the time.
But if you’re a machine intelligence the new Venus has gone from hellish to something close to paradise! The air is dry and has no corrosive oxygen in it, yet it’s still dense and can provide superb cooling for your various energy-using systems. You and tens of billions of other machines can get to work digging up that crust with no pesky biosphere to worry about.
So my far-future Venus becomes one of the resource treasure-houses of the Solar System. And as any cursory glance at history will reveal, that’s going to create plenty of opportunities for conflict. The Great Powers of the Tenth Millennium — the Lunar Republic, the Trojan Empire, and my main character’s bosses in Deimos — will fight each other for a piece of the Venusian pie.
I don’t really have space to go into some of the other details — like the giant wheels in orbit that serve as space elevators, or the culture and sports and politics of Ishtar. And I’m certainly not going to spill any secrets about the plot. To get clearance for that you have to buy the book.
Just a warning: in a novel called The Ishtar Deception, it’s a good idea not to trust anyone.
The Ishtar Deception: Amazon|Barnes & Noble|Bookshop|Powell’s
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https://whatever.scalzi.com/2026/06/04/the-big-idea-james-l-cambias-6/
https://whatever.scalzi.com/?p=60939