Beyond

Chris Impey, 2015, W. W. Norton, Bvtn Lib 629.4011 IMP

Prof at U. Arizona

• p55 $1 billion per launch, $80,000/kg, massive subsidies
• p95 "Musk ... built the Paypal brand and three years later sold it to eBay for $1.5B"
  • contradicted by Eric M. Jackson's "The Paypal Wars"
• p100 SpaceX 3000 employees with an average age of 30 - $3.1B NASA contract
• p101 SpaceX reusable rockets - Grasshopper tests, 8 test flights. "Designed to fly to 90 km"
  • first attempt at recovered Falcon - spin and crash
  • when SpaceX covers its costs with satellite launches and supply runs to the Space Station, he will turn his attention to Mars.
• p204 Australia - no human speciation after 30,000 years of isolation
• p204 Our Cyborg Future - implants and body parts
• p215 Antonin Gonzales "Earth Similarity Index" - Venus is 0.78
• p221 Fusion 1e11 kg of fuel to get to Alpha Centauri in less than 1000 years
• p223 Bob Forward: 10 M GW laser onto a 1000 km sail
• p223 James Benford: Microwave sail, 2000 degrees and highly reflective
• p225 "We'd send nanobots in waves, so they could pass information back down the route of travel, like a bucket brigade at a fire."
• p225 "The difficult trick is aiming the laser at such a small target when it's far away"

Dyson Shell equivalent - circular accelerator ring and thinsats - up to 0.7C? Slower is probably better. Can a travelling thinsat slingshot around a black hole and return and slow down? The nearest observed black hole is 1600 light years away, Sagitarrius V4641. Power - a shell 100 AU in diameter, and 1 micrometer wavelength, can focus on a "spot" 200 m across 2000 light years away. Not for the impatient ...

• p238 Biologist Ernst Mayr called SETI "hopeless" and "waste of time".
• p239 Radio SETI replaced by (hypothetical) lasers ... "we may use quite different strategies and technologies 100 years from now.

Billion year civilizations will be a million times more "visible" than thousand year civilizations, and twenty million times more observable than 50 year "radio" civilizations.

• p254 Researchers at Fermilab ... sifted 250,000 stars down to seventeen candidates, of which four were declared "amusing but still questionable". Ref: results quoted online at http://home.fnal.gov/~carrigan/infrared_astronomy/Fermilab_search.htm