In Ages Long Ago II…

Nick Lane is a prolific writer and has some very interesting pieces available at “New Scientist” as well as his own web-pages. Very readable work from a biochemist. Here’s a sampler from “New Scientist”…

The Big O …not orgasm, but Oxygen and its variations through geological time. During the Carboniferous it was 35% of the atmosphere (just 21% today), yet a few million years later it was just 12% at the end of the Permian. How did Life respond?

Has the mystery of sex been explained at last? …why do we have sex when some animals get along without it just fine? Or do they? The old explanation is that sex helps defend against external parasites… BUT that doesn’t quite work. What about genomic ‘parasites’?

What’s the point of being warm-blooded? …maintaining a high, constant body temperature is what burns most of our calories in a day, and that’s true for almost all mammals and birds. Why the waste heat? Why not burn slower like our reptilian ancestors?

Was our oldest ancestor a proton-powered rock? …Think ‘Chemiosmosis’ and you’ll get the idea. The LUCA (Last Universal Common Ancestor) was a cell in a ‘rock’… read more for details and an engrossingly told story. A summary in 10 Steps is available too.

Finally, not from Nick Lane, is this ABC News item…

Cell’s Power Packs Came from Within

…which studies how mitochondria – the common energy factory of all eukaryotes – came to be converted from a free-living bacterium to energy centre. Apparently the transfer molecular machinery that shuttles materials from mitochondrion to host cell came together from diverse bacterial parts organised in those first eukaryotes, and the researchers recreated just how.

In Ages Long Ago…

Not the opener to “Voltron”, but the latest synthetic palaeo-news.

First, appropriately enough, the first tracks of the First Crawling Things…

Found: The first ever animal trails …reported by “New Scientist”, some rock-hounds have discovered 565 million year old anemone trails. Well… they look like anemone trails at least. Older ‘trackways’ are known, but they’re not obviously animal tracks since things like gas-bubbles under algal mats can leave similar markings. These are the real deal.

But why then? The Ediacaran/Vendian came just after the last Big Glaciation (Snowball Earth) and a multitude of squishy, shelly Things appeared and left fossils. Why not earlier?

The next news item answers that…

First breath: Earth’s billion-year struggle for oxygen …seems cyanobacteria, the oxygen-making variety, didn’t appear until c.2.7 billion years ago, took 300 myr to oxygenate the air, then collapsed during the subsequent Ice Age, caused by oxidation of the methane greenhouse of the time. The first series case of climate change due to Life’s by-products, perhaps. An earlier one might’ve been caused by the methanogens themselves, who warmed the Archean Earth.

After the end Archean Ice Age, the Earth languished in an epoch of smelly oceans – hydrogen sulphide and sulfate dominated – but finally something shifted, probably the Greening of Rodinia about 800 mya. This mass erosion event caused by lichens and terrestrial algaes, set the Earth for the Snowball Earth events and the subsequent explosion of animal Life. Or so the story goes as told by Nick Lane. Like all such Proterozoic Tales, there’s a lot we just don’t know.

The implications are interesting. Where did the oxygen making bacteria come from? Could they have drifted in from Venus as its oceans were wafted into the stratosphere and photolysed? That’s my pet theory – we’re all Venusians. Of course Panspermia implies all the suitable solar planets and moons are really one common biosphere.

Pluto and Beyond…

Marc Buie, Pluto guru, has spent several years of computer time – or scrapings of time over several years – to process observations of Pluto done with the HST…

Unusually Rapid Changes on Pluto

…reported with panache, by Paul Gilster at Centauri Dreams and all over the web. Pluto has rather dramatic seasons it seems. And, c.14 July 2015 we’ll know a lot more as “New Horizons” flings past at very high speed, snapping at a resolution of ~100 metres (i.e. really HIGH.) While chasing this news item I ran into a very handy web-page…

New Horizons Real-Time Simulation

…which gives a live countdown to arrival and a count-up from Launch, plus positional data. A companion page is here…

Spacecraft Leaving Our Solar System

…with similar data for “Voyager” 1 & 2 and “Pioneer” 10 & 11 on display. Our first Interstellar probes, “Voyager” 1 & 2 are expected to be signalling until 2025 or so. Maybe 2027… the first 50 year Mission?

Antimatter Rockets & “Avatar”

Brian Wang, at “Next Big Future”, reports on the conceptual ancestor of the ISV “Venturestar” from Giga-Movie “Avatar”. As he notes, the designer is Charles Pellegrino, long-time friend and colleague of James Cameron, and inventor, with Jim Powell, of the antimatter-propelled “Valkyrie” starship.

Brian’s Post

Valkyrie Starship at Pellegrino’s website

Valkyrie at the BBC

Archive of excellent antimatter propulsion papers at Penn State U

Winchell Chung’s Valkyrie discussion

…’nuff said. I’ve been trawlling my archives and just discovered some old papers to read, so ‘night all.

Odds & Sods News, Australia Day 2010

Callisto & Ganymede, twin moons of Jupiter, yet so unalike. Why? Dr Amy Barr and Dr Robin Canup of the Southwest Research Institute (SwRI) believe the two moons diverged in their evolutionary paths about 3.8 million years ago, during the Late Heavy Bombardment. Here’s a scan of the news-pages…

Comets left their mark on Jovian moons …a good summary from Aunty.

SwRI researchers offer explanation for the differences between Ganymede and Callisto …from EurekaAlert, with original graphics from SwRI. Quick, condensed summary of this…

SwRI News release …with the pretty graphics on another page. Of course the real meat is in the paper…

Letter abstract

Nature Geoscience
Published online: 24 January 2010 | doi:10.1038/ngeo746

Origin of the Ganymede–Callisto dichotomy by impacts during the late heavy bombardment

Amy C. Barr1 & Robin M. Canup1

Top of page

Jupiter’s large moons Ganymede1, 2 and Callisto2, 3 are similar in size and composition. However, Ganymede has a tectonically evolved surface1 and a large rock/metal core2, whereas Callisto’s surface shows no sign of resurfacing3 and the separation of ice and rock in its interior seems incomplete2. These differences have been difficult to explain4, 5, 6, 7, 8, 9, 10, 11. Here we present geophysical models of impact-induced core formation to show that the Ganymede–Callisto dichotomy can be explained through differences in the energy received during a brief period of frequent planetary impacts about 700?million years after planet formation, termed the late heavy bombardment12, 13, 14, 15. We propose that during the late heavy bombardment, impacts would have been sufficiently energetic on Ganymede to lead to a complete separation of rock and ice, but not on Callisto. In our model, a dichotomy between Ganymede and Callisto that is consistent with observations is created if the planetesimal disk that supplied the cometary impactors during the late heavy bombardment is about 5–30 times the mass of the Earth. Our findings are consistent with estimates of a disk about 20 times the mass of the Earth as used in dynamical models that recreate the present-day architecture of the outer solar system and the lunar late heavy bombardment15, 16.
Top of page

1. Department of Space Studies; Center for Lunar Origin and Evolution, Southwest Research Institute, 1050 Walnut St, Suite 300, Boulder, Colorado 80302, USA

Correspondence to: Amy C. Barr1 e-mail: amy@boulder.swri.edu

…all behind Nature’s Pay-per-View isn’t it? Ah well, the news summaries aren’t bad.

Amy & Robin’s homepages are…

Dr. Amy Barr

Dr. Robin Canup

…basically the model is that the higher energy and more frequent LHB impacts that Ganymede would’ve taken is why Ganymede is more differentiated than Callisto. Did that cause Ganymede to totally differentiate and produce the intrinsic magnetic field it has today? A future research question, I’d hazard.

Palaeo Cuteness News. Researchers have made a flying model of Microraptor to better understand its flight potential.
Microraptor model
…reported at Physorg News. The researchers are based in China and Kansas U, led by chief BANDit Larry Martin, and given a voice on NOVA…

KSU Link and Summary of NOVA episode

…BANDit? you say. The Birds-Are-Not-Dinosaurs (+its) are a small, but loud bunch of palaeo-ornithologists who think the bird-like dinosaurs are really birds. A long, long academic debate has swirled around a few key personalities, like Alan Feduccia and Larry Martin, about the dino-ness of birds and the birdy-ness of dinos. For an opposing view there’s the Dinosaur Mailing List bunch of Dino Docs who think the BANDits are splitting hairs.

Project Icarus

“Project Daedalus” now has a sequel, “Project Icarus”, which promises a smarter, better design…

http://www.icarusinterstellar.org/

…look for the Terms of Reference and see what’s planned to be discussed and thrashed out over the next 5 years.

Some very cool “Project Daedalus” artwork can be found on the “Icarus” website – plus some superb animations by Adrian Mann, whose own website is a treasure-trove of retro-space & ultra-modern designs…

This Is Rocket Science

Another inspiration piece is by Nathan Fowkes…

Project Daedalus Design Project 1994

…he presages “Icarus” by imagining the second “Daedalus” stage braking into orbit around Barnard’s Star to release its secondary probes and explore.

Joe Bergeron produced this gorgeous depiction back in 1999…

Bergeron Daedalus

…plus some kin of “Daedalus”…

Bussard Ramjet

Orion Nuclear Pulse Rocket

On A Diamond Sea

Next Big Future reports on Diamond Oceans. Apparently the Lawrence Livermore National Lab has been doing ultra-pressure experiments on diamond, getting up to 4 TPa (40 Mbar) then dropping the pressure and temperature to examine what phase changes occur. Seems the stuff becomes a liquid in a pressure/temperature range of relevance to the cores of Uranus and Neptune. Interestingly diamond stays crystalline over the range of P-T normally seen in Uranus/Neptune models. However if there’s a strong, stable thermally stratified region, then heat loss from the core might be lower and the core temperature much, much higher, heading towards liquid diamond conditions.

Abstract of the work that inspired the news, at Nature…

Nature Physics 6, 40 – 43 (2009)
Published online: 8 November 2009 | doi:10.1038/nphys1438

Melting temperature of diamond at ultrahigh pressure

J. H. Eggert1, D. G. Hicks1, P. M. Celliers1, D. K. Bradley1, R. S. McWilliams1,2, R. Jeanloz2, J. E. Miller3, T. R. Boehly3 & G. W. Collins1

Which makes me wonder: has the carbon formed a natural “diamond sphere” around a hot core? Could we terraform the ocean above the diamond layer? And what happened to the excess hydrogen after methane decomposition?

Deuterium Fusion Starships IV

Friedwardt Winterberg’s fusion pulse driven space vehicles initiate fusion by injecting a rapid jolt of energy into the fusion target causing an implosion to high density fast enough that the fuel fuses before being blown apart and loses energy to brehmstrahlung. Vital to successful ignition is to rapidly compress the fuel to extremely high densities as well as injecting sufficient energy for the fuel ions to penetrate their mutual Coulombic repulsion barriers – normally the alike electric charges of protons repel.

But what if there’s a different way?

Leif Holmlid and colleagues have identified an ultra-dense form of deuterium about a million times denser than frozen deuterium. This Winterberg arxiv preprint discusses the implications of using such ultra-dense deuterium as a fusion target, concluding that the ultra-dense state is physically feasible and as a result it reduces the required 10 MJ impulse of energy to a mere 100 J.

Thus the new quantum-capacitor design theoretically has more than enough power (~1019 W/kg estimated) and enough energy storage (1 MJ/kg) to allow a very low-mass ignitor for pulsed fusion…

Digital Quantum Batteries, News at Technology Review and here…
Digital Quantum Batteries

…potentially allowing the construction of very compact space-craft if the ultra-dense state can be produced in large quantities. An earlier paper by Holmlid, Miley et.al. found small, ultradense clusters of deuterium in a metallic matrix. They speculated that larger amounts should actually be more stable, by making pressures on the enclosing matrix more even.

SO we may be justified in some speculation.

WARNING: RAMPANT SPECULATION WITHIN

First – flat discs of ultradense deuterium fired as fusion targets for a “fusion runway” starship launch system. Ignited by a proton beam at a convenient standoff distance and the resulting plasma directed by a Mag-Orion style field.

Second – fuel tankage maybe reduced to a tiny percentage. Very large mass-ratios may become feasible – assuming easy deuterium access. Imagine a cluster of simple pulse units which fall-away as exhausted. The BIS Moon-rocket of 1939 used such a cellular design for a mass-ratio of ~1000. Assuming 0.063 c exhaust velocity that’s a dv of ~0.43 c. Not bad for a fusion rocket. Alan Bond’s fusion rocket paper of 1972 (in the JBIS of course) assumed a 22,000 mass-ratio (i.e. x10 Vex) thus a dv of ~0.63 c.

Third – antimatter spiking of the fusion target starts making sense. Ultradense deuterium has a decent chance of reacting with the antimatter and usefully thermalising the gamma-rays from the neutral pions produced. If (a very big if) ultra-dense anti-deuterium can be made, then reacting the two together may allow something approaching the dream-goal of 0.78c exhaust velocity for an antimatter rocket.

Fourth – what would ultradense matter do to incident gamma-rays??? Could it reflect them? If we can collimate gamma-rays then black-hole and antimatter rockets become reasonable… feasible even, when we can power-up the machines to make them. Ultradense deuterium might also allow force-feeding the attometre scale black-holes of a Crane-Westmoreland blackhole rocket.

Fifth – could multilayer implosions of ultradense deuterium allow higher-level fusion, even black-hole creation? Hopefully the LHC will tell us if black-holes are easier to make thanks to higher-dimensions.

Ideas, ideas… more later.

Deuterium fusion Starships III

Friedwardt Winterberg’s fusion pulse driven space vehicles initiate fusion by injecting a rapid jolt of energy into the fusion target causing an implosion to high density fast enough that the fuel fuses before being blown apart. A mere 10 MJ is enough for the D-T triggered D-D pulse units to implode, but it has to be pumped into the target in a nanosecond – a power of 10 quadrillion watts (10 petawatts, 1016 W.) In his original papers Winterberg outlines two multi-use triggering systems – a super-Marx Generator, which is a huge linear bank of Marx generators, and a gigavolt charge build up on a space-ship in the high vacuum of space.

But what if there’s a different way? A new capacitor design theoretically has more than enough power (~1019 W/kg estimated) and enough energy storage (1 MJ/kg) to allow a very light weight triggering system for fusion…

Digital Quantum Batteries, summary at Next Big Future.

News at Technology Review …more details reported as only TechReview can, with the usual counterpoint view from researchers in the field.

Digital Quantum Batteries …a research paper describing the concept and preliminary designs. The system uses billions of nano-scale vacuum tubes (for want of an analogy) which can be used as information storage (thus ‘Digital’) and as power storage, via a tricky quantum effect that enhances the electric field strength far more than expected from classical electronic theory.

If this research pays off, then this is potentially a game-changer for pulsed fusion.

What Knocked Uranus over?

The early Solar System was seemingly a violent place. Most versions of its formation involve massive collisions between near-planet sized objects – Mercury’s mantle was stripped by a collision, Venus’s rotation was stilled by a collision, Mars had a hemisphere almost ripped away, Earth made a Moon out of debris from a collision, and last of all Uranus was knocked over onto its side by a massive collision…

Or maybe not. New research by Jacques Laskar and colleagues, discussed at the arXiv blog, reveals another possibility – Uranus was tipped over by a lever. Not a big, long stick but a gravity lever thanks to a ‘moon’ that massed about 1% of Uranus. In Earths that’s 0.15 – a bigger version of Mars – and thus intensely interesting for another reason. There’s good reason to think that a large ‘planet’ is lurking just beyond the Kuiper Belt and its gravitational influence provides a neat explanation for the apparent “Kuiper Cliff” – the sudden end – of the classical Kuiper Belt.

So just how did a tiny thing like a “Macho-Mars” knock over a planet almost 15 times as big as Earth? Chaos. That and the migration of Uranus and Neptune from where they formed – between about 10 and 15 AU – to where they are now, at +19 and +30 AU respectively. How did they migrate? After they formed a large, heavy disk of unaccreted material still surrounded them. Close, hyperbolic flybys of this material gradually tugged the planets away from the Sun, with some nudging from Jupiter and Saturn, themselves caught in an unstable gravitational resonance a few hundred million years after formation… well maybe. There are various issues involved with timing that are yet to be resolved. Just how quick after formation was the migration is a major unresolved issue.

But the principle remains. With a big enough lever, even an Ice Giant can end up flat on his… side