Black Goo What is It?

Remember how the black goo was originally scarabs?  They changed it to black goo for whatever reason.  So I don't think it's a stretch to look at the black goo as a group of microorganisms.  Whether that be microscopic scarabs, or as you say, nanobots.  They could be one in the same.  Whether it is a form of nanotechnology, or strictly organic, I don't know.  Nanotechnology would not surprise me though.  Although I firmly believe the goo from the beginning of the movie is different from what we see in the vases later on.  How that plays into your theory is another conversation in itself!  

But in short, no I don't think your theory is far fetched at all.  I will have to rewatch the David scene you're talking about to see if I also see metallic flakes/reflections. 

You both do raise valid points...

Indeed the Original Draft behind the Alien Prequel... which was Spaights Alien Engineers we had Nano-Scarabs, which could function maybe similar to those documents that Rick had placed here

Watching the Scene in the OT (Big Things have Small Beginnings) what i see in HD is tiny micro organisms or particles moving around in that Goo.

One Prometheus Mystery or Conflict was the Holloway Eye Worm....

Which lead me a while ago to wander was the stuff on Davids finger some kind of Nano-Worm/Tadpole Organism....  We thought Shaw was Impregnated by Holloways infected Sperm... but what if he was just the Vessel to pass a Nano-Worm Alien Sperm onto her.

What if the Substance on his finger is a Nano Organism like a Sperm is.... and these then grow, which is what the Eye Worm was?

So maybe all we was seeing was Nano-Scarabs being replaced by Nano-Worm like Organisms... they look like Goo because of how many there are... remember a close up of a Sperm Cell looks like a Tadpole.... but Seamen contains Millions of these that to the naked eye just appears as a Gooey Substance.

I think these unused props support the above theory

BD,

Lets take this a little step farther down the nano-tech rabbit hole and throw some bio into.  Scientists in S. Korea back in 2013 created a nanobot by reprogramming a bacteria cell to fight cancer.  

To me a nanobot can be either mechanical machine or bio machine.  So both could hold true.  I don't know of any biological organism that would as virulent as what the engineers have it dusted an engineer in a matter of minutes.  But then we have so many designer bio weapons out there now who knows what is possible by beings that are probably hundreds of thousands if not millions of years more advanced than we are.

From the original script, the unused props, and the appearance/nature of the goo itself, I think it's safe to assume the black goo is "alive" in one way or another.  What form it takes at a microscopic level, I don't know.  Pretty much any cluster of microorganisms will appear as goo to us.  But a sperm shape would not surprise me at all.  It would be an effective way for the black goo to disperse in the body.  

The Holloway eye worm does raise some questions though.  Is the goo really a small version of that worm that grows bigger once inside a host?  Or did David somehow pick up an already-infected worm and it got into Holloway?

My take on the Holloway worm is:  We know the black goo breaks down/changes DNA.  We also know the human body has a ton of weird stuff in it, like microorganisms, bacteria, sperm, etc.  When Holloway was infected with the goo, it interacted with one of these things in his body, most likely sperm, but not necessarily.  Either way the result is the same.  These mutated organisms are going rogue in Holloway's body.  Thus, we see one trying to escape from his eye.  

Good insight as always BigDave!  I had not seen those unused props before.