Gaia is the shorthand for the feedback system whereby the living organisms on planet Earth maintain the planet’s temperature within livable ranges . The increasing insolation output from Sol ( up 25% over the last three billion years ) is pushing the adaptability envelope (Cf Lovelock).
The fibrillations in climate at the extremes of adaptation give rise to intelligence . Intelligence can thus be seen as an inevitable consequence of a main sequence star of Sol’s mass reaching a certain age . This has two interesting corollaries:
- Putative civilizations in the local stellar group will be of about the same level .
- Intelligence can be seen as another way in which the feedback mechanism operates . Humans will have to manage the planet more pro-actively to ensure their own survival . This enevitably means the survival of the ecosphere . Shading the planet , moving off-planet to habitats , terraforming Mars, Venus et al , or colonizing other solar systems are ways of doing this .
- Exclusion ! The one response guaranteed to lead to extinction is “Business as usual” . The planetary system is nearing the limits of it’s adaptive capability . The evolution of intelligence is a symptom of this . Supra-planetary intervention is needed .
- For that , the ability to use and get large masses ( ie in the millions of tons ) into orbit is necessary .
See excellent Wikkipedia summation . en.wikipedia.org/wiki/Project_Orion
Any explosive reaction propulsion system is essentially like exploding a cracker in the middle of kettle . If you leave a hole in one end of the kettle , you have a rocket or a jet engine with thrust in the direction opposite to the hole . But Newton’s laws says that no matter how fancy your tricks , the force-components at ninety-degrees to the thrust direction cannot be used for propulsion .
Propulsion and lift .
Yet nearly all our present aircrafts’ propulsion is on the horizontal (propellers or jets) . The vertical lift is by air-pressure differentials on special surfaces (wings) .
Our problem is not a gravity-well . If it was not for the atmosphere , we could simply build a long rail-gun to get any desired mass into orbit .
1 . The Original Orion :
A buffered plate with energetic series of explosions under it (nuclear if necessary ) . All lift given by propulsion . Maximum possible efficiency 50% .
2. Orion Air-Lift
The explosion is above the plate .We do not contain the sides of the explosion . The shock-wave sweeps away the air above the plate . The air-pressure differential lifts the whole contraption .
We already know that we require far less force to get aero-dynamic lift than straight-up vertical propulsion . ( Go to any airport) .
This is essentially an inverted hovercraft . The difference is that the pressure is removed from the top of the plate in a series of pulsed explosions . Since the explosions need not be contained ( like in a jet engine) , conventional , shaped or nuclear explosives can be used . Anything with a bit of vooma .
The plate can be anything durable (concrete , granite ) . The lift is like a hovercraft : the larger the surface area , the better . 10 000 to 100 000 tons seems to be good estimates to put into orbit using conventional explosives like semtex . See tweaking .
2.1 Put a hole in the center of the plate , with a cap on top . Vertical component of thrust is added .
2.2 Fresnel type effects are possible .
2.3 The contraption will have to start falling sideways at higher altitudes . Secondary shuttles can use it for orbital launch . The whole plate can go standard Orion or Railgun Orion to go into orbit .
For those who need to zap an incoming asteroid , missiles , or in extremis , an incoming comet .
This is a purely destructive hypervelocity bullet that can be fired from the surface of the planet with little preparation necessary . A desperation tool .
Essentially , we have to drill a tunnel of vacuum in the atmosphere for our bullet , while erecting an electromagnetic-railgun to accellarate it to a reasonable fraction of lightspeed .
Have a plate with a hole in the center . Have a wire-tube of ionized air paths (laser guides from orbit or from plate ) .
Explode pulsed nukes below the hole in the plate .
The blast through the hole blows ionized air and ablatives through the laser ionized air-paths , inducing huge currents . The currents act as a linear rail-gun . It also blows a vacuum ahead of the plate .
Repeat the pulse .
What makes it cheap , easy and quick at present is that the nuclear pulse can be delivered from outside the tube (ie cruise missiles)
Ten square miles of Canadian shield rock 3000 feet deep can be converted into a pulse of plasma moving at about 0.1 c using about 100 cruise missiles . Of course , in such a case , the atmosphere ahead of the projectile will have to blown away as well .
Do not try this at home unless you have no choice !
It will make a really ,really loud bang ! The planet will go boing! . The night-sky will be like day .
Planetary temperatures will fall , due to small particulates degrading into the atmosphere . But this is only a short-term solution to increased Solar temperature .
A least-intervention solution is to gradually shift the Earth’s orbit outward . This is easily within present technology ( cf studies) . A series of asteroids or comets steered close to Luna when it is farthest from the sun will tug the Earth-Luna system into a wider orbit using only gravitational forces . (Jupiter has already done this) Mining the Sun for energy will also quickly soak up the extra energy . All dependant on massive extra-Terra activity .
This is essentially a deus-ex-machina argument . Everybody (or a significant fraction ) will become like gods and fix all the problems . The teensy problem is that most humans of first-world countries are already like “gods” , in terms of previous civilizations . They fly , see distantly , hear the dead , kill at the touch of a button , etc, etc . Extrapolate this forward . The hope is that there is a phase change . But the only phase change we know of on a reliable basis is Death .
But death is not what it used to be . In SF you have personality downloads . If your collection of photos and textmemories cobbled together by a AI passes the Turing test , is the person dead ? Half dead ? 80% dead ?
Can you see the problem ?
We thought there would be neat division : an event horizon . But in real life , the dead hang around long after they should have decently buggered off . And the more they are with us , the more we need to be purged . Their dead hands hang around in photos , patents , trademarks , statues ,plays , music ,novels , until a violent convulsion is needed to get rid of the past .
Weltschmertz while looking at old photographs should be firmly stamped on .
This is why Napoleon was known as the Great Disturber .
This convulsion is usually given the name of a revolution , or singularity .
So the singularity is always with us , but only more so if you are dead .
Hah! My quote!
A suitable revenge is to remember only the good parts .