# When nanite learns to fly

A brilliant scientist has developed a special kind of nanotechnology that is able to turn any piece of metal into a copy of itself... these nanites cannot assemble into a microscopic object, much less a macroscopic one. My question is how can the nanites remain airborne and eventually escape Earth entirely to consume other world?

Note: since these nanites are tiny and can be easily lifted with a gentle breeze they should be able to maintain altitude on their own rather than settling down when the wind dies off and these nanites will devour any metal upon contact.

• They will float on the wind, right? And will probably escape into orbit by hiking a ride on a rocket. – Erik Jun 17 '15 at 6:17
• @Erik hence my question is how they remains airborne without settling down as dust and assume NASA and other space agencies cease to operate after this nanite consumed all metals. – user6760 Jun 17 '15 at 6:20
• You should add that into the question, it'll make the problem clearer and the answers better :) – Erik Jun 17 '15 at 6:21
• You may be interested in this short story (although the nanites in this story can assemble into macroscopic objects). – 2012rcampion Jun 17 '15 at 17:48

You're talking about "grey goo" right? - https://en.wikipedia.org/wiki/Grey_goo

Assuming the nanite could only replicate itself and have no other function, then @Erik is right. They wouldn't be able to fly/travel on their own accord, unless they were dispersed by wind. (also assuming they are so small that the wind would carry them easily)

As for interstellar travel, they would have to be taken to other planets by human/other spaceships. But if they were true "grey goo" bots, then they would consume the spaceship before it arrived at their destination. I'm guessing (from a narrative point of view) you would have to have the nanites be either programmable or intelligent beyond basic "self replication".

As your nanites consume only metal, this would not really be a grey goo scenario. After all the metal on the surface and within the crust had been converted to nanites, they would pretty much stop replicating. The Earth would be a non-metallic, rocky, lifeless planet.

Humanity, stripped of it's iron based blood would be gone, along with most of our cities and other creations. The nanite swarms would be trapped and the rest of the planets would be safe for millions of years.

If only that planet killing asteroid hadn't come along, smashing into the Earth and sending nanite-seeded fragments off in all directions...

• It depends on the tech level of the nanite, if it can convert atoms in to other atoms it could eventually convert all H atoms in to FE. – Magic-Mouse Jun 17 '15 at 12:35