d20 Future and Hard SF - some random thoughts

[nerfherder]

Oh boy, physics!

Vf = Vi + a * t
300,000,000 m/s = 0 + 9.8 m/s^2 * t
t = 30,612,244.90 s = 354.31 days

Vf^2 = Vi^2 + 2*a*d
300,000,000^2 m^2/s^2 = 0 + 2*9.81*d
d = 4,591,836,734,693,880 m = 2,853,235,066,395.92 miles

The equations you quote are only accurate for speeds significantly less than the speed of light. Since you are talking constant acceleration, Special Relativity applies. You can find the equations here: http://en.wikipedia.org/wiki/Special_relativity

So, in that almost year, you'd travel quite a good distance. Of course, I'm not sure what the distances are to the nearest stars are (besides the sun).

Just over four light years.

Cheers,
Liam

 

[Plane Sailing]

I've not read either of those books, so I'm not sure what your examples mean.

Is relativistic aging similar how Card did it in then Ender series? Ender was still alive long after he should have died because of his star travelling. He only aged as long as the trip last, but everyone outside of the ship aged along a normal curve. Similar to the time dilution chart given in d20F

For generational ships, are you talking about where the crew of a ship would have to reproduce so that their children could take over because the trip was so long?

Do you know how old that makes me feel?

Essentially you have it right. In the Forever War, soldiers signed up for a tour of duty, zipped off in space ships at relativistic velocities and as a result their ageing slowed. When their tour of duty ended, not only had all their friends and family died, they couldn't even recognise the society they used to be part of, so almost always just signed up for another term.

Larry Nivens 'known space' books include some pretty hard science, in that space travel starts off using RamRobots to scout out likely planetary systems, and then sending manned Bussard Ramjet craft out at near relativistic velocities with colonists on board (I can't remember whether they were frozen or not). It was only later on in the timeline that FTL travel via his version of hyperspace appeared (purchased from the 'Outsiders').

Non Stop was one of the inspirations for the original Metamorphosis Alpha book. I don't recall whether it was obvious at the start of the book, or if it starts off as a kind of wierd tribal + tech mix, and the protagonist gradually discovers that they are all on board a generational starship where things have gone wrong (years and years and years ago). The idea was based around huge ships where new generations would be born and grow up during the flight. Several 20th century sci-fi authors used the idea in one or more short stories (a couple by AE Van Vogt come to mind, for instance).

Cheers

 

[Dannyalcatraz]

I always pictured nanotech using the body's fuel reserve (ala food nutrients) when they work. As such, the person with nanobots would need to increase their caloric intake.

Right now, I couldn't cite a story or author, but I know of at least a few stories in which the nanotech machines du jour used the body's fuel reserves...leading to them being the best weight loss product on the market.

AND subsequently allowing those with them to engage in all kinds of gluttony, especially involving alcohol (which makes for a nice fuel source).

 

[Johnny Angel]

AND subsequently allowing those with them to engage in all kinds of gluttony, especially involving alcohol (which makes for a nice fuel source).

I am now dizzy with ideas for a module.

 

[DarkKestral]

I like the ones where the nanites' fuel source is the body's sugars... and are used to keep the body in perfect working order. So nano-augmented people get to be gluttonous drunks... and happen to live longer and look better than those who aren't.

 

[Morgenstern]

<In regards to nano-tech>This statement confuses me. You must have some specific idea of nanotech from a fiction source I am not aware of. Nanotech is real, and yes it uses energy and produces heat. However, I won't have to do a matter/anti-matter annialation of an entire universe to say... make a chair or programatically change the color and texture of a piece of fabric. In fact, If I do it right, the waste energy of the process will be less than the conventional means of doing so.

No, you wouldn't need anti-matter (whole other topic which I'll leave to Pbartender ) but usually when nono-tech gets presented in fiction you dump it on a pile of wood, and and up pops a chair after a (very) short while. As if the nanite were solar powered... or perhaps (very) convienently wood-powered. Nanites are damn small - that's the point, so they really can't be solar powered - no surface area. Most likely they'll have to be chemically powered, so are a lot like bacteria.

A lot like bacteria.

The idea of in-body nanotech being able to leech of chemical energy by stealing sugars from the body isn't a bad one. Other stuff parasitizes us in that fashion, so there are already chemical blue-prints for it out there to steal for our proposed nano-tech. But as that stuff is wandering around my body, I want it to show restraint on a body-wide scale. That means the nanites have to be superbly networked so they don't snatch sugars in areas that are highly sensitive - i.e. "no feeding in my brain please. Get lunch in my muscle tissue before commuting up there to work. Ok?" That mean more energy loss (in communication and navigation) and more size/complexity of the nanite (having a working understanding of location a typical body or coding guidelines/tables for decision trees based on sugar availability). That extra work makes me wonder if it really will be all that vastly more efficient than other tools available to us. There are a lot of separate disciplines at work here that have to go a long towards making something like this happen. Especially in a tumultuous chemical envronment like a working body. A person goes jogging long enough to draw down blood oxygen levels to shift their musculature into semi-anabolic mode... Does all their nanotech flip out when it can't scavenge the oxygen it needs to metabolize its stolen sugars? Non-destructive shutdown mode... and more code. Like the body itself, you'll probably see working nanotech at that level able to produce specialized sub-units working towards a single overall goal. You plant a seed - the only part of the nanotech capable of self-replication and it releases sub-types as needed. It uses many types of working nanites to do the job, but its also putting out diagnostic nanites that tell it what is going on, and it puts out feeder nanites that go colonize the stomach and steal food there are the central source and package it for use by the other nanites in a way parallel to but undisturbed by the host metbolism. This seed doesn't actually have to suffer all the limitations of nano-tech in terms of size/suficient volume to store the MASSIVE istruction set needed - it could be the size of a kernel of corn inserted under the skin and simply manage a bunch of non-replicating servant nanites for the host's benefit.

Part of the problem is scale. The chair example is perfect for that - you are expecting machinery capable of moving atoms around to produce an object in the human scale - devices with an individual range of perception in the nanometer range are going to have to produce a object with smooth lines in the meter range - 1 atom at a time. In other words, getting it right 50 Quadrillion times along the axis (conservatively). It's like humans building a 10,000 mile long road in a perfectly straight line - by eyeballing it. If you want to give them survey equipment its going to take extra size to store that coding and every ditch digger doesn't need the full package. You just need a site manager every few miles, who reports to a bigger boss in however many levels of heirarchy it takes to do the job, but not every bit of it needs to be a von Neumann device, and really, you don't want the bactieria self-replicating because they are going to mutatate. Things at the nanoscale break when stray particles hit them. So you'd need redundancy, which means more code/size, which means more value in restricting the replication abilities to larger, hardier nanites, or things that aren't nano-sized at all.

Nano-tech IS real, and in its infancy. Electricity is alos real, and we tried to attribute ressurection to its many promises early on. We did the same thing with radiation, and we did it again with genetics. Nano-tech is the new magic du jour of fiction, and its real world incarnation will get better and better as it matures, but a lot of early thinking on it is just hooey, same as every other revolutionary advance. Its not going to work as fast as people now think, be as clean as people think, be as cheap as people think, and it's going to be a lot harder to use inside bodies than most people think. And by people I mean many of the sci-fi writers who are giving us our perceptions of where this technological concept will be when it does mature. That's mostly where I am going with this .

(small plug - I'm working on the RPG Farthest Star. It includes some of what I think of as plausible mature nano-tech in a firm-Sci-fi environment. So it has been on my mind a few years. Nano in FS does neat stuff, but it has its limits too.)

 

[Pbartender]

No, you wouldn't need anti-matter (whole other topic which I'll leave to Pbartender )

Simply put, anti-matter is thoroughly impractical as a power source or weapons-grade explosive. It's far too expensive and troublesome to make and to store. that sort of technology, at this point, doesn't even fall into the Hard Sci-fi category.

but usually when nono-tech gets presented in fiction you dump it on a pile of wood, and and up pops a chair after a (very) short while. As if the nanite were solar powered... or perhaps (very) convienently wood-powered. Nanites are damn small - that's the point, so they really can't be solar powered - no surface area. Most likely they'll have to be chemically powered, so are a lot like bacteria.

A lot like bacteria.

Exactly. Bio-engineered viruses and bacteria are nano-bots. And we already use them in that capacity. For example...

Converting alcohols into sugars.
Producing medicines, such as penicillin or insulin.
Cleaning up environmental wastes.
Synthesizing vitamins.

And other more recent and exotic things, such as...

Running a microscopic motor.
or
Salvaging precious metals from electronic components.

But as that stuff is wandering around my body, I want it to show restraint on a body-wide scale. That means the nanites have to be superbly networked so they don't snatch sugars in areas that are highly sensitive - i.e. "no feeding in my brain please. Get lunch in my muscle tissue before commuting up there to work. Ok?" That mean more energy loss (in communication and navigation) and more size/complexity of the nanite (having a working understanding of location a typical body or coding guidelines/tables for decision trees based on sugar availability). That extra work makes me wonder if it really will be all that vastly more efficient than other tools available to us.

It's not as tough as you think, Morg...

The trick is to build your nanotech (GEed bacteria or virus) to do a specific job in a specific part of the body. Bacteria already do that sort of thing... A bacteria geared for giving you food poisoning has a very hard time living anywhere outside your stomach and intestines. And you can't get tetanus by eating a rusty nail. You engineer a trait into the bacteria so that it simply dies off after a certain amount of time... Or have certain biochemical triggers that activate the bacteria or render it "dormant". The presence or absence of a certain concentration of adrenaline, for example, would be a good trigger for fast-healing nanites.

Part of the problem is scale. The chair example is perfect for that - you are expecting machinery capable of moving atoms around to produce an object in the human scale - devices with an individual range of perception in the nanometer range are going to have to produce a object with smooth lines in the meter range - 1 atom at a time. In other words, getting it right 50 Quadrillion times along the axis (conservatively). It's like humans building a 10,000 mile long road in a perfectly straight line - by eyeballing it. If you want to give them survey equipment its going to take extra size to store that coding and every ditch digger doesn't need the full package.

Again, it's not quite as difficult as it seems.

We've already got engineered bacteria that can build a perfect crystaline lattice or polymer chains. And that's the key. Crystals get built in naturally straight lines. Nanites (in bacteria form) would be great at building perfectly regular shapes. All the nanite needs to know is "Find this kind of molecule and stack this molecule on top of that molecule in this way. Do it again." Soon, you've got a spool of thread, or a rod, or a flat plate, or a disc, or a sphere or whatever.

Also, nanotech would be great for replacing one type of material with another. That's an easy one.

Nano-tech IS real, and in its infancy. Electricity is alos real, and we tried to attribute ressurection to its many promises early on. We did the same thing with radiation, and we did it again with genetics. Nano-tech is the new magic du jour of fiction, and its real world incarnation will get better and better as it matures, but a lot of early thinking on it is just hooey, same as every other revolutionary advance. Its not going to work as fast as people now think, be as clean as people think, be as cheap as people think, and it's going to be a lot harder to use inside bodies than most people think. And by people I mean many of the sci-fi writers who are giving us our perceptions of where this technological concept will be when it does mature. That's mostly where I am going with this .

All that's true, but I don't think certain nano-tech jobs will be quite as difficult as you think. Industrial and medical fields will be their strengths, since those are within the provices of a bacteria's natural environment, purpose and operating parameters.

Where people get screwed up is thinking that nano-tech will be actual "tiny robots", or that it will have any sort of computing/intelligence or communication powers. That's rediculous. Real world bacteria nanites will be specifically programmed to do a specific job under specific circumstances, and nothing else.

 

[reanjr]

Where people get screwed up is thinking that nano-tech will be actual "tiny robots", or that it will have any sort of computing/intelligence or communication powers. That's rediculous.

Maybe not intelligence, but emergent behavior is certainly possible and discernibly no different from intelligence.

 

[SpiralBound]

"FTL Travel will never be a reality!" Maybe... However, I'm willing to bet that some scientist or engineer a couple hundred years ago once authoratively stated that the currently known scientific principles of their day PROVED that man would never travel to the moon. In the pre-Model-T era it was a "known fact" that any speeds beyond 40 or 50 miles per hour would kill the occupant of the vehicle.

History is filled with instances where by the standards of the day, "x" was impossible. Those who stated that it was impossible were right... so long as you only looked at the existing technologies. Then along would come new technology that rewrote the rules and pushed the horizon of "what can't be done"(TM) off into the distance again for another little while.

Will this happen with FTL travel? I don't know, my crystal ball is as dim as anyone else's. All I know is that it's never been safe in the past to categorically state that "x" is impossible. All you do is piss off some inventors who then go and create the "impossible" thing just to spite you!

 

[Nadaka]

"FTL Travel will never be a reality!" Maybe... However, I'm willing to bet that some scientist or engineer a couple hundred years ago once authoratively stated that the currently known scientific principles of their day PROVED that man would never travel to the moon. In the pre-Model-T era it was a "known fact" that any speeds beyond 40 or 50 miles per hour would kill the occupant of the vehicle.

History is filled with instances where by the standards of the day, "x" was impossible. Those who stated that it was impossible were right... so long as you only looked at the existing technologies. Then along would come new technology that rewrote the rules and pushed the horizon of "what can't be done"(TM) off into the distance again for another little while.

Will this happen with FTL travel? I don't know, my crystal ball is as dim as anyone else's. All I know is that it's never been safe in the past to categorically state that "x" is impossible. All you do is piss off some inventors who then go and create the "impossible" thing just to spite you!

Thats the thing. We are talking about hard sci-fi. The line that seperates hard sci-fi from soft sci-fi is just that. Hard sci-fi limits itself to what we know "can" be. Soft sci-fi takes liberties with that.

No one can invent the impossible, there has to be some theoretical groundwork laid that allows the invention of application prior to its creation. However there are some things that really are impossible, like 1+1 = 3. The math is unquestionable, you can not accelerate past the speed of light if you do not have infinate energy. Your only other options are to bypass the distance or to find some way to increase speed without acceleration. Wormholes might let you do the first. But how do you create a wormhole or manipulate an existing one to sufficient length to cross a worthwhile distance? or of sufficient size to let anything bigger than subatomic particles through? or of sufficient duration to actually get something through? We don't have the framework to answer any of those questions. Neither for the option of increasing speed without acceleration. That is why such things are limited to soft sci-fi.