# How likely is it that a Von Neumann machine destroys the Earth? **URL:** \ **Category:** Factual Questions\ **Created:** [November 27, 2012, 8:27pm UTC](https://boards.straightdope.com/t/how-likely-is-it-that-a-von-neumann-machine-destroys-the-earth/642299 "2012-11-27T20:27:07Z")\ **Posts on this page:** 15\ **Page:** 3
**Author:** ![FordPrefect](https://avatars.discourse-cdn.com/v4/letter/f/e99b99/32.png) [@FordPrefect](https://boards.straightdope.com/u/FordPrefect)\ **Post date:** [November 28, 2012, 5:19pm UTC](https://boards.straightdope.com/t/how-likely-is-it-that-a-von-neumann-machine-destroys-the-earth/642299/41 "2012-11-28T17:19:58Z")
> [@Der\_Trihs](#): > > Well duh, we’d placate it with liquor and nanohookerbots. That won’t work, it’s better to use nanofloozybots. ---
**Author:** ![dracoi](https://avatars.discourse-cdn.com/v4/letter/d/90db22/32.png) [@dracoi](https://boards.straightdope.com/u/dracoi)\ **Post date:** [November 28, 2012, 5:41pm UTC](https://boards.straightdope.com/t/how-likely-is-it-that-a-von-neumann-machine-destroys-the-earth/642299/42 "2012-11-28T17:41:40Z")
> [@wheresmymind](#): > > Nanobots that can survive in virtually any environment on Earth, can utilize an incredible variety of energy sources, and can self-replicate already exist. They’re called bacteria and archaea, and they effectively _have_ taken over the world already. Actually, it was never really ours to begin with. Prokaryotes make up about half or more of the biomass on the planet. The 100 trillion or so bacteria living on and inside you outnumber your own cells by about 10 or 20 to 1. > > Considering that bacteria and archaea are: A) rabidly evolving; B) Incredibly diverse metabolically; C) capable of extremely rapid self-replication in the right conditions and D) have been around for about 3 billion years and still haven’t reduced the Earth to “goo,” I’d say we’re probably pretty safe from a man-made “gray-goo” scenario. Actually, you could argue that we’re already living in the gray-goo scenario, we just label it differently. Our oxygen-rich atmosphere is a waste product of photosynthesis. Many layers of rocks are the direct result of living things - some carbonates, iron ores and fossil fuels, for example. And just try to find dirt that isn’t laden with organic waste products - to find inorganic dirt, you either have to dig for it or go somewhere like the desert that hasn’t been so heavily colonized by life. So… our goo just happens to be mostly brown and we’ve decided to call that “normal.” 🙂 ---
**Author:** ![Sparky812](https://avatars.discourse-cdn.com/v4/letter/s/eb9ed0/32.png) [@Sparky812](https://boards.straightdope.com/u/Sparky812)\ **Post date:** [November 28, 2012, 5:57pm UTC](https://boards.straightdope.com/t/how-likely-is-it-that-a-von-neumann-machine-destroys-the-earth/642299/43 "2012-11-28T17:57:51Z")
> [@YogSosoth](#): > > . Even back in [the 80’s](http://www.alcor.org/Library/html/moleculartechnologycellrepairmachines.html), when Disco was danced to unironically for pleasure within living memory, Err… the paper you linked to was presented in May 1985, it is a well-known fact that disco died on July 12, 1979, thankfully, before it was able to destoy th Earth. ---
**Author:** ![Sparky812](https://avatars.discourse-cdn.com/v4/letter/s/eb9ed0/32.png) [@Sparky812](https://boards.straightdope.com/u/Sparky812)\ **Post date:** [November 28, 2012, 6:01pm UTC](https://boards.straightdope.com/t/how-likely-is-it-that-a-von-neumann-machine-destroys-the-earth/642299/44 "2012-11-28T18:01:37Z")
> [@FordPrefect](#): > > That won’t work, it’s better to use nanofloozybots. Hey, there’s a poster name/thread title hijack (or hitchhike) if I’ve ever seen it! Soooo… how likely is it that a Vogon demolition ship destroys the Earth? ---
**Author:** ![Mijin](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mijin/32/9369_2.png) [@Mijin](https://boards.straightdope.com/u/Mijin)\ **Post date:** [November 28, 2012, 7:05pm UTC](https://boards.straightdope.com/t/how-likely-is-it-that-a-von-neumann-machine-destroys-the-earth/642299/45 "2012-11-28T19:05:00Z")
> [@TriPolar](#): > > Well I meant infection by bots. They should be very effective at killing a human and moving on to the next poor sucker. Why in particular do you suppose that? Are you thinking because of the novelty of them, are you imagining them being “smarter”? > [@](#): > > Biological diseases tend to evolve towards a symbiotic state Well, infectious agents that persist the longest tend to be those that don’t kill their hosts quickly and/or have a low mortality rate. But they do not necessarily evolve towards a symbiotic state. And nature does cough up extremely virulent diseases from time to time; they just don’t tend to last very long and they don’t usually wipe out species that were not already against the ropes. ---
**Author:** ![James52637](https://avatars.discourse-cdn.com/v4/letter/j/439d5e/32.png) [@James52637](https://boards.straightdope.com/u/James52637)\ **Post date:** [November 28, 2012, 7:12pm UTC](https://boards.straightdope.com/t/how-likely-is-it-that-a-von-neumann-machine-destroys-the-earth/642299/46 "2012-11-28T19:12:30Z")
> [@wheresmymind](#): > > Nanobots that can survive in virtually any environment on Earth, can utilize an incredible variety of energy sources, and can self-replicate already exist. They’re called bacteria and archaea, and they effectively _have_ taken over the world already. Actually, it was never really ours to begin with. Prokaryotes make up about half or more of the biomass on the planet. The 100 trillion or so bacteria living on and inside you outnumber your own cells by about 10 or 20 to 1. > > Considering that bacteria and archaea are: A) rabidly evolving; B) Incredibly diverse metabolically; C) capable of extremely rapid self-replication in the right conditions and D) have been around for about 3 billion years and still haven’t reduced the Earth to “goo,” I’d say we’re probably pretty safe from a man-made “gray-goo” scenario. Could you give some cites on that? I’m pretty sure quite a bit of it wasn’t quite accurate. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [November 28, 2012, 7:23pm UTC](https://boards.straightdope.com/t/how-likely-is-it-that-a-von-neumann-machine-destroys-the-earth/642299/47 "2012-11-28T19:23:07Z")
> [@Mijin](#): > > Why in particular do you suppose that? Are you thinking because of the novelty of them, are you imagining them being “smarter”? They could be designed to work quickly and effectively. Get in the brain, cut holes in blood vessels, get out and find another host. No need to reproduce quickly or wait around before moving on. > [@](#): > > Well, infectious agents that persist the longest tend to be those that don’t kill their hosts quickly and/or have a low mortality rate. But they do not necessarily evolve towards a symbiotic state. Symbiotic is probably not the right word, but you’ve described what I was getting at. > [@](#): > > And nature does cough up extremely virulent diseases from time to time; they just don’t tend to last very long and they don’t usually wipe out species that were not already against the ropes. Diseases have to walk a tightrope where they’ll be able to reproduce within a host, spread, and then kill the host. The bots would be more single purposed. They don’t have to reproduce in the host, they could all be created in external factories. Build enough of them and they don’t even have to spread. Just spray the planet with nanobots. It might take a bunch of them to join up in a host to do the dirty work, but as long as the factory keep producing, enough of them could get out to eventually hit everyone. I just think this is a better approach than macro bots killing everyone with lasers. We’d be able to see the large bots and have a chance of striking back. And the large bots would need many more resources to create and maintain. Most of them will have to be busy producing the rest of them. ---
**Author:** ![YogSothoth](https://avatars.discourse-cdn.com/v4/letter/y/8edcca/32.png) [@YogSothoth](https://boards.straightdope.com/u/YogSothoth)\ **Post date:** [November 28, 2012, 7:34pm UTC](https://boards.straightdope.com/t/how-likely-is-it-that-a-von-neumann-machine-destroys-the-earth/642299/48 "2012-11-28T19:34:41Z")
> [@Senegoid](#): > > Maybe [this is the site](http://www.livescience.com/17875-destroy-earth-doomsday.html) you are thinking of? Top 10 Ways to Destroy the Earth, by LiveScience. Von Neumann machines is #2 (that is, 2nd-last) on the list. (Requires JavaScript to view.) Nope, wasn’t that one. It was a stand-alone website not connected to anything else. It was dull-looking and gray, and had the apocalypses divided into categories like Any Day Now, Near Future, Distant Future, and Religious. > [@Lemur866](#): > > The danger of lemurs destroying the Earth has been vastly overinflated. Says the Lemur himself. How do I know you’re not just trying to lull me into a false sense of security? For all I know, everyone I interact with are just 5 lemurs in a human skin suit! > [@James52637](#): > > [http://online.wsj.com/article/SB10001424052748703559004575256470152341984.html](http://online.wsj.com/article/SB10001424052748703559004575256470152341984.html) > > _cough cough_ We’re doomed :eek: > [@Sparky812](#): > > Err… the paper you linked to was presented in May 1985, it is a well-known fact that disco died on July 12, 1979, thankfully, before it was able to destoy th Earth. I think it survives to this day, waiting out its enemies in pockets of Discodome, ready to rise up should the opportunity ever present itself again ---
**Author:** ![ed\_anger](https://avatars.discourse-cdn.com/v4/letter/e/bbce88/32.png) [@ed\_anger](https://boards.straightdope.com/u/ed_anger)\ **Post date:** [November 28, 2012, 8:04pm UTC](https://boards.straightdope.com/t/how-likely-is-it-that-a-von-neumann-machine-destroys-the-earth/642299/49 "2012-11-28T20:04:35Z")
> [@wheresmymind](#): > > Nanobots that can survive in virtually any environment on Earth, can utilize an incredible variety of energy sources, and can self-replicate already exist. They’re called bacteria and archaea, and they effectively _have_ taken over the world already. Actually, it was never really ours to begin with. Prokaryotes make up about half or more of the biomass on the planet. The 100 trillion or so bacteria living on and inside you outnumber your own cells by about 10 or 20 to 1. > > Considering that bacteria and archaea are: A) rabidly evolving; B) Incredibly diverse metabolically; C) capable of extremely rapid self-replication in the right conditions and D) have been around for about 3 billion years and still haven’t reduced the Earth to “goo,” I’d say we’re probably pretty safe from a man-made “gray-goo” scenario. > [@dracoi](#): > > Actually, you could argue that we’re already living in the gray-goo scenario, we just label it differently. Our oxygen-rich atmosphere is a waste product of photosynthesis. Many layers of rocks are the direct result of living things - some carbonates, iron ores and fossil fuels, for example. And just try to find dirt that isn’t laden with organic waste products - to find inorganic dirt, you either have to dig for it or go somewhere like the desert that hasn’t been so heavily colonized by life. > > So… our goo just happens to be mostly brown and we’ve decided to call that “normal.” 🙂 never thought of it that way, thanks both of you 😉 ---
**Author:** ![dstarfire](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dstarfire/32/5762_2.png) [@dstarfire](https://boards.straightdope.com/u/dstarfire)\ **Post date:** [November 29, 2012, 12:45am UTC](https://boards.straightdope.com/t/how-likely-is-it-that-a-von-neumann-machine-destroys-the-earth/642299/50 "2012-11-29T00:45:16Z")
Some Solutions for nanotech problems: 1. **too many complex situations** : complex systems are generally composed of large numbers of simpler objects/systems. the concept of nanobots is vast numbers working on individually simple tasks to produce a complex result (the same way an assembly line combines multiple simple tasks to produce a complex device). 2. **Power** : The one solution I saw for powering nanobots was the molecular equivalent of a ratcheted gear; it rotated easily in one direction, but not so easily in the other. Combine that with the random motion of all particles above absolute zero, and you’ve got a molecule-sized motor. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [November 29, 2012, 1:22am UTC](https://boards.straightdope.com/t/how-likely-is-it-that-a-von-neumann-machine-destroys-the-earth/642299/51 "2012-11-29T01:22:54Z")
> [@](#): > > Quoth **YogSosoth** : > > I think it survives to this day, waiting out its enemies in pockets of Discodome, ready to rise up should the opportunity ever present itself again That is not dead which can eternal jive. > [@](#): > > Quoth **dstarfire** : > > 1. Power: The one solution I saw for powering nanobots was the molecular equivalent of a ratcheted gear; it rotated easily in one direction, but not so easily in the other. Combine that with the random motion of all particles above absolute zero, and you’ve got a molecule-sized motor. Won’t work, as that would break the Second Law. And in this house, we obey the laws of thermodynamics. ---
**Author:** ![Mijin](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mijin/32/9369_2.png) [@Mijin](https://boards.straightdope.com/u/Mijin)\ **Post date:** [November 29, 2012, 1:33am UTC](https://boards.straightdope.com/t/how-likely-is-it-that-a-von-neumann-machine-destroys-the-earth/642299/52 "2012-11-29T01:33:37Z")
> [@TriPolar](#): > > I just think this is a better approach than macro bots killing everyone with lasers. We’d be able to see the large bots and have a chance of striking back. And the large bots would need many more resources to create and maintain. Most of them will have to be busy producing the rest of them. I would agree with _that_; macro bots trying to gun us down individually would be a pretty poor way to go about things, but that’s a very specific scenario. What you simply said before was that killing humans by infection would be the simplest route. Natural infections don’t wipe out flourishing species alone, and your synthetic pathogen doesn’t sound so simple to me; manufacturing enough to kill all 7 billion people directly (i.e. not relying on the nanobots to reproduce), spraying the entire planet, assuming 0% resistance etc. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [November 29, 2012, 2:07am UTC](https://boards.straightdope.com/t/how-likely-is-it-that-a-von-neumann-machine-destroys-the-earth/642299/53 "2012-11-29T02:07:53Z")
> [@Mijin](#): > > I would agree with _that_; macro bots trying to gun us down individually would be a pretty poor way to go about things, but that’s a very specific scenario. What you simply said before was that killing humans by infection would be the simplest route. > > Natural infections don’t wipe out flourishing species alone, and your synthetic pathogen doesn’t sound so simple to me; manufacturing enough to kill all 7 billion people directly (i.e. not relying on the nanobots to reproduce), spraying the entire planet, assuming 0% resistance etc. Well even my concept is a little complicated if it’s a true nanobot takeover. I’m imagining the smallest nanobots that can link up with others and perform more complex tasks. So unless the nanobots are manufactured elsewhere you need enough of them initially to build a factory that can make new bots in volume. I doubt we’ll have any effective natural resistance to a mechanical device that can cut nerves or puncture blood vessels within seconds of entering the body. If you can make them small enough to be windborn you don’t need much to get enough of them into the air to kill 90% of everybody quickly. It would take some effort to get them into every isolated area, but once 90% of the population is gone there won’t be much resistance to having bot pilots fly some existing aircraft to do the job. But two problems remain. First, the bot factory needs a lot of resources. So you have start with enough nanobots to assemble themselves into a high volume factory, probably in stages where each stage increases the output. This requires resources, and acquiring them is likely to get noticed. Mankind has a chance if we kill the factory before it begins producing killer bots. You know, always kill the hive before the eggs hatch. Secondly, even the killer bots need to be powered somehow. They might be able to remain dormant most of the time before detecting that they’ve been ingested, but doing enough physical damage to kill people takes a good bit of energy. If the devices could extract some energy from the environment they could store it up in a flywheel device that becomes the instrument of destruction. ---
**Author:** ![wheresmymind](https://avatars.discourse-cdn.com/v4/letter/w/91b2a8/32.png) [@wheresmymind](https://boards.straightdope.com/u/wheresmymind)\ **Post date:** [November 29, 2012, 4:11am UTC](https://boards.straightdope.com/t/how-likely-is-it-that-a-von-neumann-machine-destroys-the-earth/642299/54 "2012-11-29T04:11:57Z")
> [@James52637](#): > > Could you give some cites on that? I’m pretty sure quite a bit of it wasn’t quite accurate. Which bits exactly? I’m feeling lazy, so I hope you’re happy with a bunch of Wikipedia links, but I can dig up more reliable cites if you really want. You’d probably find most of this info in the introduction to a microbiology textbook. **Prokaryotes (bacteria and archaea) can survive in virtually any environment on Earth…**[List of different types of extremophiles.](http://en.wikipedia.org/wiki/Extremophile) I’m sure you could think of someplace on Earth they can’t survive if you really try, but you’ll have to search long and hard for such a place. \*\*…can utilize an incredible variety of energy sources. \*\*[Wikipedia article on lithotrophy](http://en.wikipedia.org/wiki/Lithotroph). [Wikipedia article on microbial metabolism.](http://en.wikipedia.org/wiki/Microbial_metabolism) **…can self-replicate.** [Wikipedia article on cell division.](http://en.wikipedia.org/wiki/Cell_division) \*\*…make up about half the biomass on the planet. \*\*[Wikipedia article on biomass](http://en.wikipedia.org/wiki/Biomass_(ecology)).[Paper from PNAS.](http://www.pnas.org/content/95/12/6578.full.pdf) You’ll get different values for this depending on who you talk to, ranging from ~30-70%, but most of the informed estimations are around 40-60%, so right about half sounds about right to me. **…Prokaryotes [outnumber](http://www.scientificamerican.com/article.cfm?id=strange-but-true-humans-carry-more-bacterial-cells-than-human-ones) [human](http://commonfund.nih.gov/hmp/overview.aspx) [cells](http://www.nytimes.com/2012/06/14/health/human-microbiome-project-decodes-our-100-trillion-good-bacteria.html?pagewanted=all) [in your body](http://en.wikipedia.org/wiki/Human_microbiome) by about 10 to 1.** I may have overstated my case with the 20 to 1 claim, but suffice it to say there are on the order of 100 trillion prokaryotes and about 10 trillion human cells in your body. \*\*…prokaryotes are rapidly evolving. \*\*[Wiki on lateral gene transfer](http://en.wikipedia.org/wiki/Horizontal_gene_transfer). [Article discussing famous study that is somewhat of a poster child for bacteria evolving in the lab.](http://www.newscientist.com/article/dn14094-bacteria-make-major-evolutionary-shift-in-the-lab.html) Citation for original paper at the end of the article. **…prokaryotes are incredibly diverse.** The links describing the diversity of microbial metabolism should have convinced you of this. The number of bacterial taxa is a subject of vigorous debate in microbiology, with estimates ranging from the tens of millions to the tens of billions. Part of the problem is that while eukaryotes tend to fit into well-defined species, prokaryotes exist on a sort of continuum. I can dig up a cite if you want, but suffice it to say that the number of taxa (the concept of “species” doesn’t really work for prokaryotes) of prokaryotes in your backyard is probably greater than the number of species of eukaryotes in the entire world. **…capable of extremely rapid self-replication in the right conditions.** See the above article on cellular division. Bacteria can grow verrrry slowly in very cold or sub-optimal conditions, but in general they’re pretty good at reproducing. \*\*…have been around for about 3 billion years. \*\*[Wiki timeline of life on Earth.](http://en.wikipedia.org/wiki/Timeline_of_evolutionary_history_of_life) Looks like I may have been wrong on this one. It appears it may have been more like 3.6 billion years. Feel free to let me know if anything still sounds unbelievable. 🙂 Again, sorry about the Wiki cites but most of the articles have decent citations behind them. ---
**Author:** ![Grestarian](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/grestarian/32/3227_2.png) [@Grestarian](https://boards.straightdope.com/u/Grestarian)\ **Post date:** [November 30, 2012, 12:22am UTC](https://boards.straightdope.com/t/how-likely-is-it-that-a-von-neumann-machine-destroys-the-earth/642299/55 "2012-11-30T00:22:31Z")
> [@YogSosoth](#): > > > [@Sparky812](#): > > > > …it is a well-known fact that disco died on July 12, 1979, thankfully, before it was able to destroy the Earth. > > I think it survives to this day, waiting out its enemies in pockets of Discodome, ready to rise up should the opportunity ever present itself again No, unfortunately, it evolved. Rock became metal and punk; Funk became Rap, and Disco became Dance and Techno.:eek: Oh, but that’s a discussion for Cafe Society, so I’ll stop there. —G! Rock is dead, they say. Long Live Rock! …–Roger Daltrey (The Who) …_Long Live Rock_ …Odds and Sods [Previous page](https://boards.straightdope.com/t/how-likely-is-it-that-a-von-neumann-machine-destroys-the-earth/642299.md?page=2)