Category: Super-Tech

Clarke Tech, God Tech and just plain cool

To the Moon

Emily Lakdawalla’s Planetary Society blog reported on the long-awaited discovery of a Lunar cave ‘skylight’ thanks to high resolution imaging from Japan’s Kaguya orbiter… Lunar cave sky-light from Kaguya in the Marius Hills

…subterranean caverns are a near perfect site for a large, well-protected outpost on the Moon – stable thermal environment and radiation shielding are just two of its virtues. Of course this finding synergises well with the discovery that the Moon is wetter than expected from examination of “Apollo’s” samples…

Space Review: Water on the Moon …it seems the USSR’s Luna 24 drilled a 2 metre deep hole and found the regolith to be “wet” – containing water in the parts per thousand range rather than the average “Apollo” sample levels of parts per billion. Potentially there’s a lot of water in the regolith… a lot more than we first expected, at least.

Now we have a place to stay and something to drink when we get there just how do we get to the Moon in style? Ad Astra Rocket Company is developing the VASIMR high-power plasma thruster, as reported here…

VASIMR testing at 200 kW

here too…

from MoonToday…

New Scientist: To Mars in 39 Days via VASIMR

…the last headline being the least accurate. A 39-day trip to Mars requires a 200 MW power-source and a 600 ton space vehicle (476 tons propellant/tankage, 100 tons reactor/VASIMR, 24 tons payload), neither of which is forthcoming soon. But a flight to the Moon needs just 200 kilowatts of power – inflatable solar concentrators from L’Garde could do that for about 24 kg of mass. A Moon shuttle isn’t a huge challenge if we dare!

Black Holes, Starships and Antimatter

Some interesting papers by Prof. Louis Crane and his Ph.D student Shawn Westmoreland

Are Black Hole Starships Possible?

…the right answer being “Yes! But they’re really hard to actualise.”

A note on relativistic rocketry

…Shawn refines previous work on just how high an exhaust velocity can be achieved by an antimatter-matter pion-rocket. Previous estimates were surprisingly low – Ulrich Walter computed a mere 0.2084 c, while Robert Frisbee computed ~0.33 c. Westmoreland gets a more hopeful 0.5804 c for a pure pion exhaust, and somewhat higher for basic pion-rocket plus thermalised gamma-rays re-radiated as collimated heat.


Categorical Geometry and the Mathematical Foundations of Quantum General Relativity

…some of Louis’ work on merging Quantum and GR Theories. Hawking radiation is the most relevant result of our best efforts to merge the two and Louis is one hard worker amongst many trying to crack this particular physics puzzle. If he achieves the goal then we’ll have a better idea of how to actualise black-hole star-ships.

Photon-rockets, particularly gamma-ray photons, are inherently high-energy affairs. Raw light requires 300 MW for every measly newton of thrust and Hawking radiation from low-mass black-holes may be the only way we know of converting raw mass into energy on the scale needed. A gamma-ray reflecting material or metamaterial would make the task much easier, but at present such a substance is “unobtainium”.

So what if we did have such? In that case we would need to focus about a million TONS of pure energy into a space small enough to cause it to gravitationally implode into a black-hole. For comparison the Sun puts out about 4.3 million tons of energy per second, but fuses 610 million tons of hydrogen to do so. Not an easy task then if we tried to do so with a super-hydrogen bomb. Coherent gamma-rays are needed, focussed on an infinitesimal target at a gargantuan energy production scale.

Once we have such a black-hole its energies will be of the right frequency to make more black-holes, but of insufficient power. Some kind of “gamma-ray battery” or “capacitor” will be needed to accumulate energy. Enclosing the gammas in a gamma-ray reflecting sphere might do, but the pressure would be unimaginable.

Consider: a photon perfectly reflected off a mirror imparts twice its incident momentum to the mirror. A single kilogram of energy is 90,000 trillion joules, all of which bouncing around would impart ~600 MN of reaction force per bounce on the enclosing volume. Multiply by 1 billion to get our needed energy supply and that’s 6E+17 newtons of reaction for each bounce of the contained photons. Divide by 3 if there’s no directional bias and that gives the average total force experienced by the walls in any direction. The speed of light divided by the linear dimensions of the volume gives the number of bounces per second. Multiply that by 6E+17 N. A mirror ball 3 km across, would experience 100,000 bounces per second, thus the total force is 2E+22 N. A pressure of ~28.3 billion bars.

We’d need some pretty impressively strong stuff to manage that! Of course the outward pressure declines with the inverse cube of the enclosure’s diameter, thus making it a more manageable ~28.3 thousand bars when ~300 km across. Considering the scale of the energies involved that’s manageable!

Deuterium fusion Starships II

Enzmann Starship

earlier post… Deuterium fusion rockets

Attaching a starship to a great big mass of frozen deuterium seems a good idea, in light of Dr. Friedwardt Winterberg’s updated e-print from June…

Advanced Deuterium Fusion Rocket Propulsion For Manned Deep Space Missions

…of course the trick is igniting the reaction and getting a high fusion-burnup fraction out of the fuel-target. Not so easily done, but Winterberg’s work makes the prospects look good with sufficient effort. The estimated exhaust velocity is fairly high, a bit over ~4% of c, [according to Brian Wang it can go as high as 6.3%] which means a 120,000 ton starship attached to 12,000,000 tons of deuterium can do a delta-vee of ~0.2 c. With an efficient magnetic sail that means the journey speed approaches ~0.2 c, albeit with the mass-penalty of the sail. Perhaps a plasma-magnet can be formed at such speeds, with a quite different decceleration profile to the mag-sail, since the artificial magnetosphere balloons to match the plasma ram-pressure. Essentially the size goes up as the relative speed goes down, thus allowing a more-or-less constant braking force. A decceleration of 0.1 m/s2 will bring the vehicle to a halt in ~19 years over about 1.9 light-years from 0.2 c.

In case you didn’t realise it’s a LONG way between the stars. Fusion-ship trip-times are decadal at best.

PS Even a Vex of 6.3% c, the maximum burn-out velocity is just 0.28 c. While that’s an incredible 84,000 km/s it does still mean that the nearest star, Proxima Centauri, is at least a 15 year trip.

AfterLives

Mankind’s first Science-Fiction, tales of visionary quests, let humans tread the pathways of the Immortals, gods and heroes. More recent varieties of SF have often focussed on the not-too-far-off here-and-now, but Big Stories and big themes lure even the hardest of hard SF writers back towards the eschatological and metaphysical. All sorts of “after-lives” have been imagined by SF writers, great and small. Alan Boyle, at his Cosmic Log, has pointed readers to the curious little collection of AfterLife tales by neuroscientist David Eagleman, Sum: 40 Tales From the After Lives. Other After-Life possibilities have been described…

(i) Resurrection as a Cyborg – One of the earliest versions of this SF trope, aside from “Frankenstein”, is a curious set of short stories about a Professor Jameson, by Neil R. Jones, who orbits his coffin in space and is revived by intelligent robots some 40 million years in the future to join them in a series of adventures. “Brain in a Vat” stories have followed ever since.

(ii) Resurrection on another planet – Most famously the late Phillip Jose Farmer‘s Riverworld series, upon which 36 billion people are resurrected via high technology – though no one at first knows this – and struggle to survive-in-style by taking charge of the resurrection machinery. Humans have ‘souls’ called wathans, but these are non-conscious when detached from the body, which has to be reconstructed by mass-creation technology that converts energy into matter.

(iii) Resurrection via Time-Travel – The Light of Other Days, a mind-blowing collaboration by Stephen Baxter and Arthur C. Clarke, uses wormhole-based time-viewers to record the lives and DNA of every person who has ever lived, and every foetus ever miscarried or aborted, and then nanotechnology to ‘resurrect’ them. Fortunately the human race, enhanced by wormhole direct-neural links, has figured out how to move en masse to other planets, to accomodate the resurrectees.

(iv) Souls as particles – Bob Shaw, in his Orbitsville trilogy and several short stories, pondered the possibility that the ‘soul’ might actually be a new kind of particle, a ‘mindon’, created by complex living matter. In the Orbitsville trilogy this idea has cosmological implications that explain much of the mystery of the alien Dyson Spheres.

(v) ‘Soul wave’ – SF is about asking “what if…” and David Brin rather cleverly asks “what if the old Jewish myths of ‘golems’ could be for real?” in his book Kil’n People. Duplicates of living people in clay, animated by a high-tech copy of an individual’s “soul-wave”, have transformed society. One Person can now do the job of a multitude, though with the drawback that one’s ditto only lasts for a short time before turning back into inert clay slop. And what’s the status of a ditto whose flesh-and-blood original has died? Are they legally alive? And where do “soul waves” go after?

(vi) What if “Death” is some kind of predator that only you can see – and avoid? Or the Angel of Death is an alien? Ian Watson poses these conundra in his tale Deathhunter, which is now 28 years old, but still enjoyable, especially the twist at the end. Nothing is as it seems in Watson’s AfterLife.

(vii) End of the World as Gateway to the Other World – which has several variants. On the one hand is the Omega Point scenario, in which the collapsing Universe allows an infinite number of experiences to be experienced in a finite ‘time’. William Shatner (James T. Kirk to “Star Trek” fans) has written a series of novels (“Quest for Tomorrow”) in which the protagonist has a direct line to the Omega Point, who may (or may not) be God. Thus Heaven is in the final fractions of a second – yet infinite in experienced time – of a collapsing Cosmos. Alternatively, the Big Crunch might be hostile to life, and Life might need to escape this Universe to live forever, as in Charles Sheffield’s tale Tomorrow and Tomorrow.
Another variant is the idea of the End of the Earth as a Gateway, which features in Brian Stableford’s The Walking Shadow. A complicated tale, which sees Paul Heisenberg, a professional ideologue, “jump” unexpectedly through time by becoming a silver statue in a kind of time-stasis in front of a whole stadium of people. This causes others to follow suit, ultimately journeying to the end of all life on Earth as-we-know-it billions of years from now, then travelling beyond it after Earth has been taken over by “Third Phase Life”.

More to come…

A Moistened Moon

The Moon is ‘wet’.

That’s the latest conclusion of a trio of observations by various spacecraft over a decade (here, here, here, here.) The question is: just how wet? Not very, but a whole lot more than we once thought. A thin layer of water molecules coats the whole surface of the Moon, at least part of the day, and more may well be found towards the Lunar poles. The colder the surface, the longer it sticks, and it’s very, very cold in the permanently shadowed polar craters – down to just 35 K… colder than Pluto! There, it’s hoped, the water has ‘stuck around’ for billennia and slowly accumulated to substantial amounts.

So, the Moon has water. And there are signs of more within the Moon, evidenced by hydrated minerals around new craters. That really throws that cat in amongst the pigeons, as current Moon-formation models have the Moon condensing largely from vaporised rock after Theia smacked into the Earth. Robin Canup, Moon-maker extraordinaire, commented that the current modelling doesn’t have enough resolution to really tell if bits of the collision that became the Moon were cool enough or not for water to be retained.

Science-fiction, of course, has featured underground water on the Moon for over 100 years – H.G.Wells mentions seas within the Moon in his “First Men in the Moon” and Herge has Tintin discover ice in a cave, are two famous examples. “Moon Zero Two” – a daft movie from 1970 – also mentioned, in passing, that the Moon Colony got its water from hydrated minerals underground. A silly movie for a lot of reasons, but it had some redeeming features, including a portable computer (!) which was quite a leap for 1970.

Digressions aside, what does it mean for the development of the Moon? Water – especially its hydrogen component – features heavily in a lot of industrial chemistry as well as sustaining life-as-we-know-it. A slew of processes become easier when there’s available water. But it’ll need to be heavily recycled because of the difficulty of gathering together significant amounts of moon-water. Learning to do that might teach us some useful tricks down here on Earth too.

Classic Freeman Dyson papers online…

Freeman Dyson, for a Physicist without a PhD, has done some utterly cool and amazing things during his long career. One paper he wrote 41 years ago, based on his “Project Orion” experiences from 50 years ago, is this…

Interstellar Transport …watch out, as it’s an 18 Mb pdf. In the paper he introduces us to the fusion-bomb propelled starship, which is probably the best use of fusion bombs anyone has ever suggested. In the years since his design has served as a baseline for all further discussion, with newer versions merely tinkering with fusion ignition itself. Potentially a fusion-bomb starship can reach 0.1 c, thus making Alpha Centauri a 44 year one-way trip.

Another classic is his discussion of the very long term future of Life in the cosmos, albeit Life that has become very large “Black Cloud” style dispersed entities…

Time Without End

…he covers life into the mind-bogglingly remote period of 10^(10^76) years, which is an unimaginably large number, but not infinite. Yet even infinity might not be enough time to exhaust physical Life’s potential in his analysis. More recent cosmological speculation modifies his conclusions, but the certainty with which we can skein so far ahead is much less than often imagined.

More Dyson material is available online here and there throughout the Web, a select few at this webpage…

Dyson at Wisdom Portal

…which is a testimony to his appeal across ideologies. Infectious optimism.

Nukes to LEO

The old Delta Clipper concept was a very cool outcome from the old SDIO, but NASA and its cronies killed it, either through false promises of “something better” (remember “VentureStar”?) or neglect. However not everyone has forgotten DC-X’s potential and Eric Davies has even proposed an upgrade to nuclear…

Nuclear DC-X

… not a pure NTR but an LOX Augmented NTR (LANTR) to have sufficient thrust-to-mass to get into orbit. According to the sources behind the original study (a 2004 review by Eric Davis) NTRs have been operated without any radionuclides entering the exhaust stream, so it should be “safe” within the atmosphere. Aside from prompt X-ray and neutron radiation from an operating reactor, that is, neither of which is lasting. We surround launching chemical rockets with a necessary danger zone and an NTR would be no different. Probably not even significantly larger either since the thing wouldn’t explode as mightily as an Ares V or a Shuttle in the worst case scenario. Plus a reactor core designed to run at 3000 K and 100 ATM is going to be a tough mofo to start with.

The proposed NTR is a centrifuged particle bed reactor, based on the “Timberwind” system studied by the SDIO. That, of course, made the Greens and NoNukers shit kittens when originally proposed, but I suspect the political mood is more receptive now to nuke-power than it has ever been, especially if people see more civilian action and more noises about nuclear disarmament. Lobbing Solar Power Satellite components to orbit 100 tons at a time should make an LANTR attractive to any right thinking Green – like yours truly – because the overall fossil fuel cost is reduced significantly.

Once enough installed beamed-power is available to launch Leik Myrabo’s Lightships then the LANTR can be moved permanently off-world, where it really should be. But until then it’s one solution we should examine while trying to reduce the cost to LEO.

Hat-tip to Brian Wang for spotting this one… Nuclear DC-X

Signs in the Sky

I just saw a UFO. A bright point of light apparently flying Westwards in the morning Brisbane sky, after I’d watched a turbo-prop flyover from the airport c.9 AM. Now I’m too much of a sky-watcher to think it was an “alien space-vehicle”. It was probably a plane reflecting the sunlight, as I’ve seen planes do countless times, but the way it faded away from visibility meant it was obviously a long way off. If not for the reflection it probably would’ve been a speck in the sky and I wouldn’t have noticed it. For a moment I thought “What if…” and then the sceptic in my said “probably not extraterrestrial.”

Prior to that ‘encounter’ I was contemplating a “New Scientist” piece on whether miracles were in violation of natural law…

Opinion: Do you believe in miracles?

…in which Hugh Maclachlan discusses Hume’s supposed water-tight argument that miracles prove anything or whether we must always assume that people who claim miracles are mistaken. If you believe in God, then miracles make sense, but are they violations of natural law? Since the word ‘miracle’ originally referred to ‘signs from God’ there’s nothing in the concept itself that implies natural law violation. Anything can be claimed as a ‘sign’ since God is usually claimed to be behind all natural phenomena anyway. People have claimed ‘weeping’ statues, and simulacra of Jesus and Mary in fence-posts and burnt toast to be ‘signs’, which isn’t much different from old style omens being sought in entrails and sun-sets.

Even the ‘grand miracles’ of Jesus’ Virgin Birth could well have been a natural event since parthenogenesis is known in a number of vertebrates, like sharks, lizards, turkeys and so forth. The events of Moses leading the Children of Israel through the sea and beyond have plausibly all been argued to involve fundamentally ‘natural’ processes. I’m sure just about every claimed ‘miracle’ in the Bible can be given some kind of naturalistic explanation. The most difficult to explain are events that involve the creation of matter (feeding the 4000 & 5000) or its transformation (water into wine), or its translocation (Elisha & Elijah in the Hebrew Bible and the apostle Philip in the Christian), but even those could involve ‘natural forces’ we’re yet to fully understand.

What makes a miracle a ‘sign’ is a person’s faith. But what sort of ‘faith’? Not the mere assent to a concept or idea, but the kind that drives a person to act. Everyone rewarded with a sign in the Bible – and, dare I say, in Life – has acted on what they felt led by God to do. Their expectations that God would act led to Him doing so and their perception that He had.

But why don’t we get what we want even if we act on faith? That has tormented people for as long as they have believed in miracles. Yet God waited more than 80 years to liberate the Israelites while Moses grew and matured, waited a decade to end Nazi tyranny, and let Israel be oppressed by the Assyrians and then the Babylonians for years before bringing judgement against both. Why so?

As I thought on this I was reminded by statements in the Letter of Yaakov (James) that God shines his Sun on the good and the bad. In otherwords He is impartial and loves both the sinner and the saintly, only acting when the evil have been given all their chances at repentence. Look at the little story of “Jonah” – God sent Jonah, against his instincts as an Israelite, to the capital of the Assyrians to lead them to repentence. Jonah wanted them destroyed, but God saw the Assyrians much as he saw the Israelites – flawed beings in need of repentence. The repentence of Nineveh averted the impending Judgement, perhaps the 625 BC attack by the Medo-Babylonian alliance – but we know eventually it fell in 612 BC to the ascendant Medes. Thus ended some ~120 years of Assyrian domination. Yet God didn’t forget the Assyrians – the Assyrian Church is still alive today.

I guess a God has to look to the long-term when working with human beings. Perhaps he can only act when the time is right.

Memristors Make Minds

Memristor minds: The future of artificial intelligence – tech – 08 July 2009 – New Scientist.

Memristors are the forgotten electronic component, predicted in the 1970s, but not observed in practice until recently… and now they turn up in the brain as synapses! Or synapses are a bit like memristors.

So to make a robot brain… use memristors!

WB-8 Contract details

Classical Values :: The Boys At Talk-Polywell Have Struck Paydirt.

Classical Values blog has posted a summary of discussions at TalkPolywell about encouraging news emerging from the legacy of Dr. Robert Bussard i.e. the Polywell research efforts of Dr. Richard Nebel and colleagues which is aiming at a net-power Polywell Hybrid IEC Fusion Machine – a Bussard Fusor. Seems they’re sufficiently impressing the USN with their results – independently audited too – that they’re getting funding for a new WB (“Whiffle-Ball”) machine to explore the fusion capabilities of Bussard’s designs. Given positive results from the ordered upgraded WB-8 and the plucky experimenters will be building a WB-9 with even heftier ion-guns.

Net fusion will be a clearer goal once all the data are in…