^ He's got it but I thought I should add there is also nanoscopic vision which is powerful enough to see individual bots. I don't think any of my characters doesn't have a drone with that modification to keep an eye out and a weapon to EMP them for me.

However, I've heard a couple GMs hand-wave that minor aspect of Nanoscopic vision. 1) GM handwave that one. They move fast enough to be a threat. 2) From what I understand a regular nanoswarm's close to invisible. The scary bastard TITAN ones, well, they're the clouds moving really fast against the wind and eating everything in their path so they're a little easier to spot. 4) As for flight in space, unless my players splurge on some proper manoeuvring ability [i]they don't[/i]. Microlight and Hopper won't get you very far in space. Or very far. Too far. Forever into the abyss, the nanoswarm drifts, never once doubting the importance of its mission. 5) Well the lucky thing about nanobots is that they're really really small. They're cheap and can probably get away with minimal resource usage (think Material Pouch for wizards). As for capacity, once again GM hand-wave. Hives can run non-stop with enough resources to produce.

I guess I don't understand why it matters who's looking. A drone (several drones, even) with nanovision can 'keep an eye at' at… several tiny, tiny squares of area. Again, imagine using a microscope: it only works if it's focused on the right distance, the right *place*, and held still. There's a reason the nanodetector sensors work by constantly sampling (relatively huge) chunks of air, and there's a reason the main defense again a swarm is another swarm.

Space nanite propulsion: imagine a respirocyte 1 micron across. http://www.foresight.org/Nanomedicine/Respirocytes2.html#Sec3 It can hold 8x10^-17 kg of oxygen and has a empty weight of 3.56*10^-16 kg. Assuming it squirts them out with a Maxwell distribution of velocities the average velocity at 300 K is 444 m/s. Using the rocket equation I get a total delta-v of 135 m/s. Not too impressive. No doubt faster space-nanites can be constructed, but to move really fast they need to have fast moving propellant, and that is hard to do on the nanoscale: when the propellant kinetic energy per molecule becomes comparable to the bond energy of your device it will start to falling apart. Cooling is tricky when you are very small and in vacuum (small area and your surfaces will be smaller than many infra-red wavelengths), nuclear reactions really don't scale well.

Topic has been very well covered already. However...

Hailspork wrote:

4) How do they fly in space?

You're probably better off not finding out. Nanobots designed for atmospheric propulsion are useless in space and vice versa, and hybrid variants will just end up being useless in both environments. Even if you manage to get a specialized, spacefaring cloud onto a target, then any defensive nanobots carried by the target are going to be densely packed around and inside of it, whereas your own will presumably be scattered as a vast cloud. For game purposes, you might as well assume that spaced nanobot swarms whirr and flail uselessly until they are fried by direct sunlight or run out of battery power. If you really want to sic nanobots onto something in space, then you should pack a hive or two inside of an armor-piercing rocket or projectile, and fire that at the target.

Eclipse Phase uses the term nanobot to refer to lots of little things, some of which are pretty un-robotlike. The respirocyte is a spherical globe of diamond with a bunch of sensors and molecule pumps on the surface. All it does is to float along the bloodstream pumping in and out carbon dioxide and oxygen (as well as glucose for fuel). The program it runs is not far from a thermostat - release oxygen if levels around it are lower than a certain level, absorb CO2 if levels are high, and so on. At one micron, it is like a small bacterium. Many nanoparticles could have even simpler functions. They are just clusters of atoms with a surface with the right recognition molecules to make them bind to places where they should be. Some other surface molecules might react to a particular stimuli (such as the presence of a particular chemical or microwaves) and cause it to release chemicals inside, change its binding mode etc. No intelligence whatsoever, but can be made smaller than a nanometer. Robert Freitas has proposed 3.4 micron diameter microbivores to chomp up pathogens. It attaches to pathogens and then ingests them, mincing them and finally breaking them down with engineered enzymes. The device is controlled by a 10 0.01 cubic micron nanocomputers with 5 megabits of memory each: it is not that smart, but all it needs to do is recognize the target pathogens. It has acoustic sensors that receive ultrasound commands, allowing external reprogramming if needed. Devices like these are presumably a component of a medichine or nanophage systems. I would imagine Guardians to be something fairly similar, but with even tougher disassembly systems. Nanoswarm robots are likely slightly larger, equipped with local communications systems, mobility systems that allow them to function in air, and so on. I think it is a good point that a swarm can have several components: a gardener swarm needs microbots to move seeds and harvest stuff, while nanobots kill plant pathogens. A protean swarm functions more efficiently if it can divide the production process into different scales (small bots make simple components, larger take them and assemble them into bigger stuff, and so on, while other bots scavenge and break down raw materials to feed the group). A key limitation is energy: bots living inside the body can use blood glucose (it they do not take too much), but free-living bots need to acquire energy from burning carried fuel, collecting light, ultrasound or some other radiant energy, or getting fuel from the environment. This puts some limits on how much they can do. If you want ideas for what a mature nanotech can do, check out Freitas' Nanomedicine I: http://www.nanomedicine.com/NMI.htm (scroll down for links to the full text) He has been doing the math for everything from energy requirements for swimming nanomachines to check whether nanobots can measure magnetic fields due to neuron firing.

Hi, I just came here looking for an answer on swams speed. The only clue I've been able to find in the core book is this, related to smart dust: (p.316) "Each nanobot contains tiny cameras, microphones, a tiny computer, a radio, and chemical sensors, as well as short legs that allow them to walk and climb at a rate of 5 cm per second." Note that this reffers to "walking" nanobots. I think the best idea I've read here is that "moving with the air" proposition. Seems logical to me. I hope this helps.