Day: September 26, 2009

The Mach-Lorentz Thruster

Prof. James Woodward has spent more than a decade working out a Machian theory of inertia which holds the promise of a propellantless space-drive able to turn power directly into motion. Brian Wang, at Next Big Future has covered Paul March’s exposition of Prof. Woodward’s work…

Mach Effect 4: More Mach Effect Answers

…the hoped for efficiency is 1 N thrust per watt of power. That may not happen, but what about more modest thrust/power levels? What if we can get 1 N/kW? Consider the high-powered VASIMR we’ve discussed here, running with 200 MW of power. At top-gear, when it’s exhaust velocity is ~300 km/s, it’s using about 150,000 W for every newton of thrust. An MLT getting 1 N/kW and massing 200 tons, with that power supply would accelerate at ~1 m/s2. Where does that get us? Mars, when it’s at opposition and ~0.5 AU, is just 6.3 days travel away, while Pluto, at it’s aphelion at 50 AU, is but 63 days away. Nine weeks.

What about further goals? The Sun’s gravity-focus is 587 AU away, minimum – just 31 weeks. A small fleet of MLT propelled ships could drop gravity focus telescopes to spy, at high resolution, on all the nearby stars, confirming whether they have planets worth launching probes to. And those probes? Results from Alpha Centauri would be just 18 years away – including the time required to signal back. Results from Tau Ceti would be just 36 years away. In just 100 years we’d be hearing back from stars 42 lightyears away.

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…

Anchiornis huxleyi

Dinosaurs and birds were kin, so said Thomas Huxley in the 19th Century. Now a new dino-bird, Anchiornis huxleyi honours his insight and gives us a closer peak at a form between dinosaur and bird…

(from The Guardian)

Dating from before that timeless DinoBird Archaeopteryx, this newcomer is closer to dino than bird. Not all dinosaurs were involved in the origin of birds, mind you, since it was a small twig of the Dinosaur Family-Tree which eventually became birds as we know them today. Most big dinosaur groups – the sauropods, the horned dinosaurs (ceratopsians) and various fleet-footed plant eaters (duckbills and iguanodonts) – had diverged from the meat-eating theropods way, way back in the Triassic, long before the dino-birds took to the air. Yet even the ceratopsians are known to have produced feather quills on their tails, so that particular “birdy” aspect had evolved very early indeed. Some lines of evidence hint the dino-birds came from a warm-blooded common ancestor with the crocodilians, who lost a fully divided four-chambered heart as an adaptation to holding their breath on river-bottoms. Only more fossils will tell us what kind of creature became the crocs, dinosaurs and birds – and maybe even the pterosaurs.

Bristol University’s coverage… Origin of birds confirmed by exceptional new dinosaur fossils
Science News’ coverage… Feather-covered Dinosaur Fossils Found

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.