Crowlspace

The Search for ExtraTerrestrial Intelligence and Messaging ExtraTerrestrial Intelligence are about 50 years old as a proper scientific endeavour - the first published paper was in 1958 and the first SETI was in 1960. But the Search has come up empty handed. However before we conclude ETIs are rare to non-existent we should ask ourselves if we’re conducting the Search in a reasonable manner? Have we considered the best strategy? Or has SETI been driven by wishful thinking divorced from economics?

Twin brothers James & Gregory Benford, plus Dominic Benford, have argued that Searching and Messaging driven by cost considerations (in a very general sense) won’t look anything like the hoped for (and unseen) Great Blindingly Obvious beacons, and will look a lot like the brief flashes of radio-energy seen so far…

Cost Optimized Interstellar Beacons: SETI
Cost Optimized Interstellar Beacons: METI

…following the current work on the Galactic Habitable Zone, and the Extra-Galactic Cosmic-Ray Periodic Death Scenario, the authors argue that searching and messaging should focus on the Galactic Core and stick to the Galactic Plane. This also reduces the total energy needed and increases the odds of a message finding a receiver.

All quiet here in “Crowlspace” but elsewhere in the Blogoverse is the latest Carnival of Space. And the BlogHost IS normally in Swedish, in case you’re bleary eyed and feeling a touch out-of-it.

As the World licks its collective wounds after the Financial Meltdown and we all watch the storm clouds gather, consider the Egyptians suffering under the Plagues of Moses way back in c.1500 BC (1300 BC?) Usually written off as fiction, the perfervid imaginings of a pious scribe or two, a recent analysis by Colin J. Humphreys lends the account some credibility when the details are matched against the internal calendar of the account…

All these events occurred at the correct time of year and follow logically one after the other. Thus it’s a coherent whole account, not a pastiche of scribal bits and pieces as several venerable compositional theories hold. Either the scribes who wrote it were keen observers of Egyptian natural disasters, and they pieced them together correctly, or the account is describing an actual historical catastrophe. But was it caused by the God of Moses? Or did Moses somehow see it coming and skilfully used the opportunity to march his people into the land of Midian to found a new nation? Is there a difference?

For more on Colin Humphreys’ ideas check out his book The Miracles of Exodus. He’s a physicist by training who became keen on the historicity of the Exodus tale after a trip to the Levant. Not initially a believer in the accuracy of the account his research eventually produced a convincingly coherent reconstruction of Moses’ tale. Annoyingly, direct evidence for Moses remains elusive.

Carnival of Space #73 is up at Alice’s Astro Info and it has some real fascinating ones.

First up - The Martian Chronicles ponders a crashed moonlet.

Second - Starts With A Bang ponders whether galaxies have more stars than bodies have cells. Has the interesting fact that human somatic cells only number about 4 trillion, with another trillion white blood cells, a trillion platelets, 30 trillion red blood cells, and a whopping 40 trillion bacterial cells living in our guts. Are you your human DNA alone???

Third - Twisted Physics discusses the Pioneer anomaly, and its possible origins in MOND.

Fourth - AstroENGINE seeks evidence of varying radioactive decay in Cassini’s RTGs. Apparently the researchers pondering varying decay think Cassini’s Pu-238 might be the wrong isotopes for the job. Not big on beta-decay, which is a neutrino susceptible weak-force mediated decay that the researchers are studying. Nice to know alpha-decay can be relied on…

Space Exploration Technologies, SpaceX, has numerous rockets on offer. I thought I’d do a handy summary here.

Falcon 1/1e
Falcon 9
Falcon 9 heavy
Dragon

* - figures for Dragon are currently not very detailed on the SpaceX page.
** - Falcon 1/1e need a ‘kick motor’ to launch a payload to the Moon. Only the 1e can realistically launch enough mass for a small lander.
*** - no TLI mass is quoted for the Falcon 9 heavy, but if the proportion remains the same as for the Falcon 9 between GTO and TLI, then this is the estimate.

The TLI mass for the Falcon 9 heavy might indicate a luna capability for Dragon with the right heat-shield. A two-launch Luna mission might allow a lander. The old Apollo LM massed just ~ 15 tons, thus combined with a TLI stage, this might allow landing on the Moon. Assuming ~ $210 million for the two launches, and ~ $1.5 billion for the LM (aerospace vehicle development costs ~ $100 million per ton the old way), and you’d have a lander mission for under $2 billion. Cheap!

The next Chinese space-craft, Shenzou VIII and Shenzou IX, will be unmanned - to start with - but the next manned mission, Shenzou X, will dock with one (or more) and form an orbital laboratory complex. In otherwords a Space Station. Attach a couple of propulsion modules and the Lab could be launched Moonwards, forming a Moon-Lab, just like the proposed “Wet-Lab” Skylab II that was discussed in the late 1960s as a cheaper Moon-Lab option.

Chinese News Coverage on the Plan

SpaceX’s Falcon 1 finally makes it to ORBIT!

Falcon-1 flight 4 at SpaceX

Low-Cost Rocket Makes it to ORBIT

NASA Spaceflight report

…but will it mean orbital access for 1/10 the cost??? Only time will tell…

There’s a lot of old style SF ideas in religious legends. The classic “first SF” tale is Enoch’s encounter with various angels in various layers of the heavens in the old “Book of Enoch” (c.200BC-100AD… has various ‘editions’ that are hard to date.) But creative interpretations of Bible stories didn’t stop with “Enoch”. Later Jewish legends are even more interesting from an SF point of view. Apparently, in Ginzberg’s “Legends of the Jews”, there was a belief in 7 worlds inhabited by Biblical ‘races’…

The Seven Earths

• First: Erez ~ a place of darkness, yet flames with the rotating sword that guards Eden
• Second: Adamah ~ lit by reflected light from its sky. Heavens seen are only images. Inhabited by “phantoms” which can become evil-spirits in our world.
• Third: Arka ~ Cainites, both giants and dwarfs, but two-headed. They plant trees, but there’s no grass-derived crops.
• Fourth: Ge ~ home of the Babelites, who possess great wealth and science.
• Fifth: Neshiah ~ place of “forgetting”. Inhabited by dwarfs without noses, breath through holes.
• Sixth: Ziah ~ very wealthy, but very dry (name means ‘drought’.) The inhabitants sometimes pass into our world through “water-springs”.
• Seventh: Tebel ~ our world.

• …from Ginzberg, available here. There’s a lot of resonances here with UFO-lore and classic SF. Imagine wormholes linking a number of worlds, and you’d have a story ready made.

  Another surprise for me was the Kabbalah’s take on the Tower of Babel, that it was a flying machine, originally built for good, but then used to subjugate the world. Alternatively it stretched over several billion kilometres, to the limits of the solar system (a garbled account of its range perhaps?) Very odd imaginings by the Ancients. And you thought our current SF was a new idea?

The Carnival of Space Week 72 is up and running. Informative stuff.

Also informative is this little gem… Space Elevator: Physical Principles …which covers the derivations and consequences of the main physical aspects of a basic space elevator. Written by Ranko Artukovi? of Zadar, Croatia, and definitely worthwhile for all hard-core applied maths freaks and space-nuts.

From impeccable mathematical applied-physics to dubious applied physics we have Brian Wang’s latest on the EM-Drive… Superconducting Radio-Frequency Cavities for High Q …the table he gives makes me rather dubious about the EM-Drive’s utility.

Effect of increased Q for the Emdrive

• Q=50,000 (1st gen.) Static thrust=315 mN/kW Specific thrust at 3km/s=200mN/kW
• Q=6,800,000 (supercond) Static thrust=42.8 N/kW Specific thrust at ??km/s=??N/kW
• Q=5×10^9 (supercond) Static thrust=31.5 kN/kW Specific thrust at 0.1km/s=8.8N/kW
• Q=10^11 (supercond) Static thrust=630 kN/kW Specific thrust at 0.1km/s=??N/kW

• “Q” appears to be the number of reflections within the microwave cavity before the wave is absorbed. So while the static thrust of a high Q cavity is very high it very rapidly loses thrust as speed increases, so much so that to levitate with such a drive seems rather unstable. It would be an incredible thing, if true, but the EM-Drive is yet to be demonstrated in free-fall. That will prove whether it really does convert EM energy directly into kinetic energy. By my rough figuring the first quoted figure above indicates that the EM-Drive is turning EM energy into KE at 60% efficiency at 3 km/s. Not bad.

Near Earth Objects (NEOs) might be dormant comets - well 5-10% of them, anyway…

Comets Disguised As Asteroids

…which makes them a very handy resource for propellant, shielding and whatever else you want to do with comet stuff. Check out Anthony Zuppero’s Neofuel for the details.