A Series of Barely Related Questions

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PredatoryMollusk PredatoryMollusk's picture
A Series of Barely Related Questions

Hello Eclipse Phase community,

I'm in the process of writing a little fan project for EP, a future timeline that extends the setting by about four hundred years. I don't have any kind of scientific background, so there are some technology related things I've been pondering. I would greatly appreciate the help, and I'll probably post the timeline under Homebrew when I figure it all out. Anyway, questions.

1. Can a QE comm be used for egocasting? My guess is probably not, massive waste of resources and energy, etc. But if you can't, then how useful is a farcaster in an extrasolar situation? Wouldn't your signal take hundreds if not thousands of years to arrive back in the Sol system? These questions might be covered in Gatecrashing, I may have missed them.

2. Lighthuggers, how might they potentially work? I read a little about pion rockets on Wikipedia, and it wasn't clear to me how they were different from EP's exisisting ships powered by antimatter (they just have lots of antimatter!). Also, if a reactionless drive were somehow created to work with a Lighthugger, what other kinds of technology would come out of it? Some scary planet-busting weapons I suppose.

3. Biology question, could there possibly be an ecosystem in which heterotrophs never evolved, even at the microbial level? Could intelligent life ever rise out of such a system?

Actually that's all I've got for now, more might come up later. Again, the help and guidance is appreciated.

Arenamontanus Arenamontanus's picture
QE comms: The only reason you

QE comms: The only reason you can't do egocasting currently in EP is expense, and that likely depends on how hard it is to store qubits. In reality, making qubit pairs is very simple, but keeping them from decaying is very hard. So I don't think there is a physical limitation, just a current technological one. So in a far future QE comms might be really cheap.

Lighthuggers: EP antimatter drives look pretty good. Pion rockets is just a particular design; a future drive might be slightly better than the EP one but not enormously so.

Reactionless drives change everything, since you do not have to spend vast amounts of energy to accelerate the reaction mass you carry with you. Even if they are power hogs they are likely far, far more effective than current drives. (Unless you want to drop energy conservation out of the window they will at least require as much energy as you give to the thing you accelerate - (1/2)mv^2) This means that fast ships might be much smaller and lighter than current ones. It might also allow some weird/nasty weaponry, since they might allow you to accellerate kinetic weapons to near-lightspeed simply (remove their inertia, push, turn on their inertia again).

A total autotroph ecosystem? Maybe. Karl Schroeder has a mention of one in Permanence. It seems unstable, since parasitism is a popular trick among plants and animals alike: losing autotrophic abilities and parasiting or predating the other plants would likely occur.

Extropian

Smokeskin Smokeskin's picture
Arenamontanus wrote:

Arenamontanus wrote:

A total autotroph ecosystem? Maybe. Karl Schroeder has a mention of one in Permanence. It seems unstable, since parasitism is a popular trick among plants and animals alike: losing autotrophic abilities and parasiting or predating the other plants would likely occur.

I won't claim to have a full grasp of evolutionary biology, but couldn't autotrophy get "locked in"? If the initial organism evolve in a way that newer mutations depend on the genes for autotrophy or its function, then a viable mutation without autotrophy becomes highly unlikely for those species. And there might not be an ecological niche for an organism to "start over".

PredatoryMollusk PredatoryMollusk's picture
An assumption I've been

An assumption I've been working under is that transhumans are effectively trapped in the Sol system because we haven't figured out a practical way to travel to any nearby stars, at least in a way that wouldn't take hundreds of years. What kind of speeds could you actually reach using antimatter? Anything like 50% lightspeed? I imagine that the Factors can push 99% percent with their ships, but that they are using some kind of method that violates the known laws of physics.

As for QE comms... Let's say that transhumanity reaches a point where we stop using the Pandora Gates, this would pretty much be the only fast way to travel or communicate between systems, I would think.

And for the autotrophs, I imagined early on in the microbial stage, there were some photosynthesizers that learned to behave like viruses if they were consumed, and achieved stability that way. Millions of years later, you have nothing but plants that have developed some really unique and bizarre ways to compete with each other for limited space and resources.

Arenamontanus Arenamontanus's picture
Smokeskin wrote:I won't claim

Smokeskin wrote:
I won't claim to have a full grasp of evolutionary biology, but couldn't autotrophy get "locked in"? If the initial organism evolve in a way that newer mutations depend on the genes for autotrophy or its function, then a viable mutation without autotrophy becomes highly unlikely for those species. And there might not be an ecological niche for an organism to "start over".

Yes, that could work. So if autotrophy was tied to (say) the genetic code it might be necessary for all organisms.

Still, never underestimate the deviousness of evolution.

Extropian

Arenamontanus Arenamontanus's picture
PredatoryMollusk wrote:What

PredatoryMollusk wrote:
What kind of speeds could you actually reach using antimatter? Anything like 50% lightspeed?

You are not limited by your drive, a sufficiently big solid booster could also reach relativistic speed... except that it would have to be amazingly big. Antimatter is just close to the most efficient rocket possible.

Realistically, it seems that the main limit is how good shielding you can do. In my recent research I have struggled a bit with interstellar dust: when it hits you near lightspeed, it explodes into nasty little explosions (think mass-energy conversion - a pebble is a nuke). I found that 99% lightspeed ships that were very long and thin worked in intergalactic space over decent distances, but inside a galaxy I think (I have not run the calculations) you either need to slow down to below 80% or have really good shielding.

Extropian

NewtonPulsifer NewtonPulsifer's picture
Very small particles can be

Very small particles can be ionized by a wide angle electromagnetic beam (maser, laser, etc.) and then deflected with a strong magnetic field. This could cut down on the physical shielding.

However, the pebble is a problem. You'd need a sensor system to pick it up, then zap it to a cloud of plasma, then deflect the ionized particles with the magnetic field/shield. If the object is too large for your zapper, you're probably screwed - not likely much time/chance to steer around it. Hopefully the bigger objects are seen sooner by your sensors.....better hope those sensors don't malfunction.

Problem is, at 99.9% of the speed of light your time to react to your sensor data isn't great.

One method I read is to use a variant of the Whipple shield - basically after you hit cruise speed you launch some very thin shields ahead of the ship, spaced out by relatively huge distances. If the pebble hits the first shield, it becomes a ball of diffuse plasma from the energy released, and then just ends up spackling the second shield behind that one. I have no idea of what the ideal stand-off distance of the layers would be at 99.9% the speed of light, or even if you'd run out of shields before you reached your destination.

"I fear all we have done is to awaken a sleeping giant and fill him with a terrible resolve."- Isoroku Yamamoto

Arenamontanus Arenamontanus's picture
NewtonPulsifer wrote: I have

NewtonPulsifer wrote:
I have no idea of what the ideal stand-off distance of the layers would be at 99.9% the speed of light, or even if you'd run out of shields before you reached your destination.

Typical speeds of interstellar stuff is a few 10 km/s. So if you travel at speed v, a particle starting at a distance r meters away moving laterally inwards towards the ship (of length L meters and radius r) will hit it if (R-r)/10,000 < L/v. So you want a shield of radius r and d meters ahead so that R-r > 10,000 (L+d)/v.

For example, if your ship has L=100 m, R=10 m, v=150,000,000 m/s (50% c), d=0 (shield on front), then R must be > 10+1/150 meters, or 10.006 m. If you put the shield one km ahead, it needs to be 10+11/150 = 10.07 m. So the high speed really protects you from impactors. The further away, the larger the shield has to be but when it blows you are less affected.

The number of shields is less clear. There is also erosion from the proton beam that interstellar gas turns into at these velocities.

Extropian

PredatoryMollusk PredatoryMollusk's picture
What if your ship was built

What if your ship was built into... an asteroid?

Decimator Decimator's picture
Valkyrie antimatter starship

From one of my favorite websites.

Atomic Rocket wrote:
In addition to shielding against gamma shine and avoiding the absorption of engine heat, another major design consideration is shielding against interstellar dust grains. Flying through space at significant fractions of lightspeed is like looking through the barrel of a super particle collider. Even an isolated proton has a sting, and grains of sand begin to look like torpedoes. Judging from what is presently known about the nature of interstellar space, such torpedoes will certainly be encountered, perhaps as frequently as once a day. Add to this the fact that as energy from the matter-antimatter reaction zone (particularly gamma radiation) shines through the tungsten shields and other ship components, the heat it deposits must be ejected.

Jim Powell and I have a system that can perform both services (particle shielding and heat shedding), at least during the acceleration and coast phases of flight. We can dump intercepted engine heat into a fluid (chiefly organic material with metallic inclusions) and throw streams of hot droplets out ahead of the ship. The droplets radiate their heat load into space before the ship accelerates into and recaptures them in magnetic funnels for eventual reuse. These same heat-shedding droplets can ionize most of the atoms they encounter by stripping off their electrons. The rocket itself then shuts the resulting shower of charged particles - protons and electrons - off to either side of its magnetic field, much the same as when a boat's prow pushes aside water.

The power generated by occasional dust grains should range from the equivalent of rifle shots to (rarely) small bombs. These detonate in the shield, harmlessly, far ahead of the ship. Fortunately, almost all of the interstellar particles likely to be encountered are fewer than 20 microns across (10,000 microns = 1 centimeter), and we should expect no more than one impact per day per square meter of Valkyrie's flight path profile...

...One of the great advantages of a droplet shield is that it is constantly renewing itself. Put a dent in it, and the cavity is immediately filled by outrushing spray.

Smokeskin Smokeskin's picture
Arenamontanus wrote:Smokeskin

Arenamontanus wrote:
Smokeskin wrote:
I won't claim to have a full grasp of evolutionary biology, but couldn't autotrophy get "locked in"? If the initial organism evolve in a way that newer mutations depend on the genes for autotrophy or its function, then a viable mutation without autotrophy becomes highly unlikely for those species. And there might not be an ecological niche for an organism to "start over".

Yes, that could work. So if autotrophy was tied to (say) the genetic code it might be necessary for all organisms.

Still, never underestimate the deviousness of evolution.

Couldn't it be tied to anything vital really? Stuff like cellular membrane, the equivalent of ATP breakdown, cell division, reproduction, body layout genes, here on Earth they're the same across species, aren't they?

Arenamontanus Arenamontanus's picture
PredatoryMollusk wrote:What

PredatoryMollusk wrote:
What if your ship was built into... an asteroid?

Then you would need to accelerate the whole asteroid. But unless you are reactionless you really want to keep the mass low.

Extropian

NewAgeOfPower NewAgeOfPower's picture
Smokeskin wrote:

Smokeskin wrote:

Couldn't it be tied to anything vital really? Stuff like cellular membrane, the equivalent of ATP breakdown, cell division, reproduction, body layout genes, here on Earth they're the same across species, aren't they?

Reproduction may be sexual/asexual or something odd; see ferns.

Cellular membranes vary greatly from bacteria to bacteria, and that isn't even looking at the big difference between plant membranes and, say, giraffe cell membranes.

Even oxygen-use or a conventional biochemistry are hardly necessary; see the life forms at the bottom of the sea...

As mind to body, so soul to spirit.
As death to the mortal man, so failure to the immortal.
Such is the price of all ambition.

PredatoryMollusk PredatoryMollusk's picture
Well thank you for the

Well thank you for the feedback everyone. Basically, the point I'm at now is where transhumanity is forced to leave the Sol system because of a second Fall, and now I'm trying to figure out what happens to the survivors who escaped (in lighthuggers), those who stayed behind, and those who are scattered around the galaxy because of the Pandora gates. It's tricky because one has to think about how long it would take for each group (if they had similar technology) to reach their chosen destinations. And also, galactic geography can be a bit confusing at times, let's face it, we're all just swirling around a big vortex.