Chilling Venus

An old SF dream, independently invented by Olaf Stapledon and Jack Williamson, is the idea of terraforming. Venus has long been viewed as a suitable target. When CO2 was first found in huge amounts in the 1920s, Stapledon imagined giant electrolysis stations converting the atmosphere. In the 1940s the “dry formaldehyde” Venus was a popular model and became the setting of Poul Anderson’s “The Big Rain” – the planet-obscuring clouds were believed to be formaldehyde polymer dust and the surface was a dry 100 degrees C. Clever chemistry would convert the clouds into water and eventually the Big Rain would fall.

By 1960 the clouds were believed to be water and the surface was roughly 270 degrees C with about 2 bars pressure – thus Carl Sagan’s famous suggestion: seed the clouds with algae to convert the CO2 into oxygen. But by 1963 Sagan had abandoned the water cloud model and the temperature was estimated to be a scorching 700 K with about 100 bars of nitrogen causing a super-greenhouse effect and “cloudiness” was due to scattering. Larry Niven famously described the surface conditions as “a searing black calm” and proposed Earth only avoided such a fate by the early Moon stripping excess air away.

By 1968 Russian Veneras had shown the surface to be even hotter and the atmosphere to be almost all CO2. The clouds had become a total mystery because the measured water vapour levels were so low. Venus’ surface was depicted as a stormy darkness with red-hot patches of glowing rock. Carl Sagan’s idea of seeding the clouds had become SF mythology and remained unchallenged.

After the probes of 1974/5 – Venera camera landers and Mariner X – the clouds were known to be sulphuric acid and the surface was surprisingly bright. More like an overcast day on Earth than an abyss of Hell, though even hotter at 735 K. By 1976 serious studies for terraforming Mars had also led to a re-examination of Venus and the realisation that it was too dry for algae. To make O2 from CO2 requires H2O – and 90 bars of CO2 needs an ocean of water to turn into algae and oxygen. But all that oxygen was far too much oxygen. James Oberg’s “New Earths” proposed combining the oxygen with hydrogen tanked in from the Outer Planets – Saturn being a favourite. A bit “cart before the horse” because there would be no oxygen made without water…

A number of approaches were proposed through the 1980s, but the scenarios all required millennia. David Brin mentions a 10,000 year terraforming project being undertaken by the Earth Clan, to impress the Galactics that we “wolflings” weren’t too hot-headed and impatient to join Galactic society. Nice fiction, but unlikely for a standard human society to undertake. Paul Birch proposed in 1991 a different approach – why not cool Venus enough to freeze out the atmosphere and then bury it for later export off-world?

That’s the new “orthodoxy” of terraforming – chilling Venus’ atmosphere with a gigantic soletta parked in the Sun-Venus L1 point. A major question, then, is just how long would it take to cool, condense and freeze? Currently Venus’ “photosphere” – the region heat escapes from – is at a temperature of about 231 K, but this is due to the high cloud deck giving the planet a high albedo in visible and IR light. Chilled just a bit and the cloud deck would probably collapse since its main component is sulphuric acid, which boils at over 338 degrees C at 1 atm. With a higher emissivity Venus would lose heat somewhat faster, but just how much heat is there?

Carbon Dioxide (96.5% of the atmosphere), unlike nitrogen (3.5%), has quite a variable specific heat capacity – it stores more heat, the hotter it gets in the temperature range in Venus’ atmosphere. Nitrogen remains pretty stable, being a diatomic molecule, but carbon dioxide is triatomic and thus its ways of storing energy are quite complex. I’ve created a model of this process in an Excel spread-sheet and it has some interesting results, which I’ll elaborate on in a future post. But for now basically the hotter Venus’ photosphere is the quicker it’ll lose heat.

Once the temperature of the lowest layers reaches about 31 C the carbon dioxide will start condensing at the 74 bar pressure level, with interesting results – the phase-change heat liberated will drive convection, perhaps keeping the upper layers at a roughly constant 31 C until all the condensible CO2 below the 74 bar pressure level has rained out. Then it will only continue condensing, as the lower levels cool, down to a partial pressure of about 5 bar. Liquid CO2 can’t exist below that pressure – it’s either ice or gas past that point, and as it cools it will increasingly freeze-out, perhaps coating the underlying seas of cold CO2 in a pressure cap – except, unlike water ice, it’s heavier than its liquid phase. A bit of water might be needed to ice over the cold CO2 seas, which will be percolating into Venus’ regolith, and probably making geysers all over as it cools the underlying rocks. A big fraction might then be trapped in the regolith, but Venus’ sub-surface will probably be too hot for it to remain there indefinitely.

Once the CO2 is frozen out and capped over what remains? The nitrogen won’t freeze or liquefy under such conditions and so will make an atmosphere of about 3 bars, which would be a bit much for a prolonged human presence. The regolith might soak up a bit and some will probably “dissolve” in the CO2. Big thinkers have proposed haulling it off-world for Mars and free-space habitats, providing a long term export product. All the CO2 would be even more valuable as carbon nanotubes might eventually be the macro-engineering material of choice, with a theoretical 2 teraPascal strength. Stephen Baxter has Venus supplying carbon across the Galaxy for the War against the Xeelee in his novel “Exultant.” I would hope for something more peaceful.

My daughter’s first-typing… apryll jane georgia crowl, 5

Human Nature isn’t PC

A cute and informative article from Psychology Today

Ten Politically Incorrect Truths About Human Nature

…which is quite a good popular update of current evolutionary psychology ideas. One thing it brushes over a bit lightly is why men find older women less attractive than younger, yet men seem to age without us noticing. Simple fertility ratios between ages – older women are less likely to have kids who will then survive and be parents. Thus a two-fold process occurs – men who find older women attractive lose out in reproductive competition and women who age visibly are favoured, by reproductive success, over women who don’t age so visibly, thus confusing potential mates.

Yet there are still men and women who “buck the trend” – I always think of Isabella Rossellini when I think of ageless feminine beauty. Natural selection isn’t always a perfect gene-editor and variation within a population always produces differences – some women remain fertile into their 50s, while others might become menopausal in their 30s.

Abiotic Production of Oxygen/Ozone

Planets with carbon dioxide rich atmospheres won’t produce oxygen or ozone is amounts large enough to look misleadingly like an Earth-like planet…

Abiotic formation of O2 and O3 in high-CO2 terrestrial atmospheres

…but only if they have oceans. If the planet is frozen or a desert then the geochemical sinks for O2/3 produced by photolysis of CO2 won’t be working and they can build up. Thus signs of water, mild temperatures and oxygen means an oxygenic biosphere, not funny chemistry.

Except… Venus during its runaway greenhouse phase probably lost an ocean of water and had a very thick oxygen atmosphere as a result – but did that show? Scalding oceans covered in cloud, to an astronomer looking at its very cold cloud-tops (250 K) it probably looked like an “icehouse” and not a nice “Pale Blue Dot”.

Jesus is Lord!

Not a sign of a sudden conversion, but more of a gentle steering back into faith. For the last 8 years I have been an avowed agnostic – with occasional lapses. But recently I have had to admit to myself that I believe more than I doubt, so agnosticism is untenable. But just what do I believe now? I have always had problems with the view that the Bible was inerrant (“100% without error” as one Church web-site claims), but I have also had problems with calling it all irrelevant to faith whether the Bible stories are historically true and accurate.

If the Bible has to be “demythologised” then what remains distinctively Christian? What remains the “message” (kergma in Greek) of the Gospel?

Rudolf Bultmann gave a name to the demythologisation craze of the 20th Century, but really people had been rationalising over the Bible stories way back to Isaac Newton and Baruch Spinoza in the 17th Century. Unlike Newton or Spinoza I personally want to remain Orthodox in my doctrines, but even then that is a pretty broad target.

The first step, I think, is deciding what to make of the Bible. Nowhere within the text itself does it claim the books we call “The Holy Bible” is totally without error. Instead it is said to be “God-breathed” – i.e. the Spirit moved prophets and preachers to write the books that make it up. But all of them came to the task within a particular historical context – the Bible is not just history, but has a history. And that history has to be understood.

Also if the Bible is inspired – as Orthodoxy preaches – then reading it and gaining an understanding relies on the Spirit’s action as well. In fact I would make the claim that all error – heresies and so on – stems from exalting human understanding over the meaning the Spirit wishes to convey to us. That doesn’t mean Dogmatic Theology – writing bulging books of “god-talk” – can’t be done systematically or without use of scholarly techniques, but it should always remain open the moves of the Spirit.

More importantly the Bible isn’t the living Word of God without the Spirit. You can’t read it as God’s Word without listening to the Spirit’s voice. Else it’s just “The Bible” – a fallible product of fallible humans. And, unlike Jesus, the Bible didn’t have a Virgin Birth.

As the Book says “Why do you say I am Good? Only One is Good.”

The New Omega Point Theory II

At the Friendly Atheist blog I made this comment as a summary of Frank Tipler’s new Christian Omega Point Theory…

The “Theory of Everything” he promotes is nothing new – just the Minimally Extended Standard Model, plus a quantum gravity equation developed years ago. And Tipler’s use of the Many Worlds approach to Quantum Mechanics is nothing new either.

Somewhat batty is his ideas about Jesus using macroscopic sphaleron fields to cause super-rapid proton-decay, turning a tiny bit of mass into a neutrino beam to carry him across water, or turning neutrinos into “loaves and fishes” to feed the 4000. Basically he’s saying “miracles” are really “God-tech”, literally, and so only use physical law, rather than violating it. If you believe that God is the Omega Point then I guess those sort of miracles might work.

Most of his claims have pretty solid physics behind them BUT he’s saying his take on the physics is the ONLY valid approach. That’s where his claim to some kind of divine truth really has problems. His strident advocacy of the Many Worlds version of QM, for example, might have problems because of recent experiments that potentially falsify it.

Tipler also thinks the quantum gravity equation of Richard Feynman and Steve Weinberg is correct – but it has been rejected by most physicists working on quantum gravity because it has an infinite number of terms when expanded and can’t be renormalised. Tipler argues, perhaps validly, that many proofs in mathematics potentially involve an infinite number of statements, but I think most physicists working on quantum gravity are hoping for a set of equations their finite minds can handle. Tipler might be right but his case is a LONG way from proven.

As for his Apocalyptic hyperbole… well I’d blame it on his faith tradition’s penchant for “Left Behind” style dramas in human history. Except more than a few Futurists expect radical changes as Super-Intelligence is developed. He’s certainly not a lone lunatic voice on this one – for example Vernor Vinge thinks the Singularity is only 50 years away.

…and I feel I need to expand. My promised critique is waiting on getting a hold of his book, “The Physics of Christianity”, which isn’t looking good – maybe not until August (i.e. overseas order for my Birthday.) Even “Borders” doesn’t have it here in BrisVegas, which is annoying. But I’ve read a lot of his online material and so I think I have some idea of what he’s saying.

“Somewhat batty” isn’t an intentional insult BTW. Atheists tend to see all claims of miracles as absurd, and claiming that Jesus’s miracles are thanks to Omega Point technology (macroscopic sphalerons) is only a bit less weird. As a rule theists haven’t claimed to know the mechanism of God’s interactions with the world in any detail – Tipler is a pioneer, and a brave one in that regard.

Do I believe him?

Firstly, I am unsure if the specific miracles Tipler focuses on need to be explained as real events. Biblical scholarship has cast serious doubt on the nature miracles as anything other than parabolic fictionalising of prophecies about Jesus-as-Messiah. But the problem with that approach is that Jesus, as a real person, fades out of view if we start hacking away at the Gospels in an over-zealous attempt to demythologise. We have to use “discernment” to disentangle history and historicised prophecy in the New Testament, and that’s pretty subjective. In epistemological terms (“how do we know”) Tipler has used as much imagination as the demythologisers who decide what’s history and what’s not.

So if we accept them as events to be explained, then what? Tipler’s ideas become one possibility amongst many – and that’s my main issue with the Whole of his thesis: that physics has already uncovered The Truth. Which physics?

AIAA News on Woodward drive

The AIAA publishes a free newsletter and the January 2007 Issue contains a fascinating article on the implications of a working Mach-Lorentz Thruster, a concept based on Prof. James Woodward’s work on the cause of inertia. Ernst Mach, over a century ago, proposed that inertia is caused by the influence of the rest of the Universe on an accelerating mass. Woodward managed to put this concept into equations consistent with General Relativity – basically inertia is the gravitational analogue of electromagnetic back-reaction, which is quite well known and related to John Cramer’s Transactional Interpretation of Quantum mechanics.

By cleverly exploiting the finite time of back-reaction a propellantless thruster effect can be generated – which Woodward has claimed to have observed experimentally. The article’s author, Paul March, describes a 25 ton MLT propelled vehicle powered by fuel cells able to fly to the Moon in just 2.5 hours at 2 gee. Without the need for aerobraking such a shuttle could have a turn-around as little as an hour. Four trips to the Moon a day, two tons of cargo each time, could deliver 2,920 tons a year – and that’s just one shuttle. Coupled to a more enduring power-source a vehicle could accelerate to near-lightspeed in less than a year at 1 gee… but there’s more than a few places to go in the Solar System before we brave that voyage.

More on the Rainbow Body

An article which seems to be the basis for the Discover piece’s discussion of the Rainbow Body…

The Rainbow Body

…with some extra anecdotes. Father Tiso mentions his own vision of Christ, which is fascinating, plus some bilocation stories of Christian Saints. Post-mortem visions of Saints is pretty big in Catholic and Orthodox Christianity. Both believe that Saints share in the Beatific Vision – basically God’s eye-view of Creation – thus they can hear our prayers and know what’s happening here on Earth.

Crass Physicist Question: Just how do they do so much in a timely way?

Answer: There’s another dimension of Time.

Seriously, there’s a very notable Physicist who has been in the news about his “Two Time” theory, which seeks to complete various physical symmetries by adding another time dimension – call it “Orthogonal Time”. To hear all our prayer requests at once – and how many are asking a Saint to talk to God at the same time? – all a Saint needs to do is “move” a bit into Orthogonal Time.

If you have Eternity to play with, what’s a bit more Time?

A lot of Christians, especially Sectarians, think all deceased persons are really dead until they’re physically Resurrected by JC – but what did JC say about Abraham, Isaac and Jacob? That to God they were Alive! There’s a lot of sophistry brought to bare on this verse by Sectarians, but really they’re twisting JC’s words to deny the “literal meaning”. Other Protestants aren’t too sure what the post-life is really like – usually vague descriptions of Heaven or the New Jerusalem fill the void.

And me? More later…

Discover Magazine articles

A quick posting, plus some commentary later (I promise)…

Mirror World …Titan – a frozen Earth?

Soul Search …DIY uploading into your Rainbow Body.

Science and Islam in Conflict …when everything is Allah’s Will how can science claim consistency?

Circles of Life …how eccentric can an Earth get?

Hot Times on Titan …come 6 billion AD Titan will defrost to a toasty -73 C.

A link from the Soul Search piece is just an archive card at Australia’s ABC radio…

Father Francis Tiso …reconciling Christ and Buddha.

…which really interests me. I read about the Rainbow Body in John Robinson’s 1970 book on Christology (The Human Face of God) as a possible example of how Christ’s body was transformed. I’m sure fundamentalists might not like the idea of Buddhists resurrecting, but as Robinson (and many others) have pointed out Jesus was too big an event to be limited to just Christians. He made it possible for all people to resurrect into the New Life by defeating Death for all of us.

Early Buddhism agreed with Christianity that we’re all in thrall to the Power of Death – what Christians call ‘Satan’ and Buddha called ‘Mara’ – and outlined the way of approaching a true understanding of the escape route. I think the ‘Clear Light’ that Tibetan Buddhism aims for, and looks to for answers, is the same Light that the Gospel of John talks about which shines on all of us – and we reject it because of the consciousness of our sin that it causes. As The Epistle of James tells us, God shines his light on all with no partiality, but we’re led astray by our own desires. In the Tibetan Bardo Thodol the Light can only be entered by those prepared for it, freed from earthbound desires.

But what is freedom from desire all about? The Greeks called it Apatheia – freedom from passions – and it was considered it an attribute of the gods. I think it’s kind of hard to put into words, but it doesn’t mean we “feel nothing”. Instead we rule our feelings and aren’t ruled by them – and we rule them by recognising their causes, their progression and their dissipation. Mindfulness. In Christian terms, the Fruit of the Spirit – Love. More on that later.

Affordable SPS… Paul Roseman

The International Space Development Conference 2007 was held over the weekend of May 25-28 and was chock-full of ideas. One especially caught my attention because its developer, Paul Roseman, is a Sci-Fi fan like me who dreamt of working in space, and actually has a plan to bring that future about. Paul has graciously allowed me to reproduce his paper here on Crowlspace, and I would like to discuss it in some detail.

Here’s the abstract, to tease you into reading the whole speech,…

It may be possible, now, to build a 5 gigawatt space solar power system for about 10 years revenues at $0.10 per kilowatt hour. This can be done by utilizing an as yet unused materials stream available in low earth orbit (LEO). This method is required to lower the costs of this project due to the massive amount of material to be launched into orbit. The materials stream is used to create both the structure/frame of the solar collecting and microwave transmitter beaming satellite in geosynchronous orbit (GEO), and the shell of the habit/remanufacturing facility in LEO.

That materials stream is spent boosters. For many launches with strap on boosters, like the Space Shuttle or the Ariane V, these main boosters can be launched into LEO at some or little payload weight penalty. For the Shuttle, next to none; for the Ariane V, about half of the payload. In LEO, these boosters can be melted down and remanufactured into structural parts for the solar cells and microwave transmitter elements, manufactured on earth.

These boosters can also be captured and used to create the shell of the variable gravity, closed ecology, remanufacturing facility in LEO. Earth standard manufacturing hardware will be launched to space in containers which will be stuffed inside the booster shells. These booster shells will be connected and rotated with ion engines to induce an artificial martian gravity at the ends, with variable gravity down the spine. The solar power panels will be manufactured inside the structure and assembled on its frame, then connected to unmanned transport and taken to GEO, where they will be joined with the satellite to increase the power sent to earth. The closed ecology of the remanufacturing facility will save significant money by lessening resupply at $5,000 per pound.

The revenues of the project are $40 billion, determined by 10 years of 5 gigawatts of power delivered at $0.10 per kilowatt hour for 8000 hours per year. The costs are primarily determined by the standard launch costs of $5,000 per pound to LEO. They are estimated at $35 billion. Of that, current solar cell costs for 5 gigawatts are $5 billion for the cells and $22.5 billion to launch them to LEO. Ion engines and fuel are used to get the finished modular pieces of the solar power satellite to GEO, so that the costs are also quite reduced.

Optimistic? Of course, but nothing is ever done without taking a risk.

First point of my discussion is the question: How much can launch costs be improved in the short term?

Paul cuts costs by haulling the finished components of the SPS to GEO with solar-powered ion-drives – plus he uses the upper stages of the boosters for structural materials. He bases his cost estimates on the current rates of placing payloads to LEO – between $10,000-$5,000/lb ($22,000-$11,000/kg) – but there is a cheaper option that may be available soon. Elon Musk’s SpaceX is offering haulage to LEO via its Falcon 9 Heavy for a $90 million launch fee. Maximum payload is estimated to be ~ 27,500 kg, thus the per kg cost is $3,300/kg. Musk promises a “modest” discount for long term contracts, so let’s call it $3,000/kg.

Roseman cuts mass-to-orbit cost by using the lower stages of the launchers. On the SpaceX site there’s a technical description of the launcher available and I’m working on just how much a Falcon 9 could push into orbit. So watch this space…

Habitable planet around Proxima

No this is not a discovery announcement, so don’t stress. Instead Greg Laughlin has posted over on Systemic a discussion of what a positive detection of a habitable planet around a red dwarf star would require of current telescopic facilities. Proxima Centauri would be a surprisingly easy target and a logical one, since it is so close to our Sun allowing first class data to be gathered. Best of all it’s only 4.22 ly away – just 267,000 AU. Depressingly our fastest probes currently only do about 3 – 4 AU a year, so Proxima is still a long, long way off. Happily it’s also gradually getting closer, so by the year 27,000 it will be about 3.2 ly away. A few millennia shaved off the trip time.

In reality no one advocates a mere ~ 5 AU a year. The fastest seriously proposed vehicle is the Thousand AU (TAU) probe which can do a cracking 20 AU/yr. That’s a 10,000 year trip to Proxima at its closest. Of course there have been less serious designs for probes, the most detailed being the British Interplanetary Society’s “Daedalus”, which can do a mind boggling 0.122 lightspeed – almost 37,000 km/s – which puts Proxima a mere 35 years away, neglecting braking at the other end. With a magnetic-sail as a propellant-less brake a “Daedalus” probe could slow-down into orbit around Proxima, adding maybe 10 years to the trip time. A magnetic-sail would also allow the probe to visit all the planets in the system (Laughlin estimates anywhere between 2 and 5 terrestrial planets, as Jovian planets have already been ruled out.) Thus results from an orbital survey of a habitable planet could be beamed back to Earth some 50 years after launch.