# How to bootstrap technological development from one man in the forest, to building a spaceship? [closed]

The last human alive is on the Antarctic continent and needs to find a way to leave the planet before Earth becomes unsustainable for life. (He would look for a planet orbiting a younger star. That target planet may have been discovered and selected by astronomers some time ago but nobody has actually been there. Let us suppose the travel time would take five hundred years or so)

For the sake of this question, suppose:

• That man can't die, so it's fine if it takes him ten thousand years to build the spaceship. I mean that he is fundamentally immortal and whenever there's a risk for some fatal accident or even desire to kill himself, something will happen to prevent it. He does not age and does not fall sick (or if he does, he will eventually get better). In other words, if in our universe some event would have three possible outcomes A, B, C with probabilities $p_A=99.9\%$, $p_B=0.0999\%$ and $p_C=0.0001\%$, and A results in certain death for the character, then in that world, actual probabilities become $p_A'=0$, $p_B'=99.9\%$ and $p_C'=0.1\%$.
• Runaway greenhouse effect has made the continent pleasantly warm in summer. They are covered in trees and populated by small rat-like mammals, but parts of the planet away from the poles are arid and unbearably hot.
• He could travel around the planet to find raw materials if necessary, but he'd need a way to protect himself of the heat.
• His body has been modified (artificial skeleton, etc). He has the strength and weight of today's average sixty year old man, not more. He can carry light objects, he needs to eat and drink mostly like a regular human being.
• The old research centres (and, elsewhere on the planet, ancient cities) are still there but have been abandoned for a thousand years, so there's no electrical device left in a usable form.
• He has an engineering and physics background. Based on the immortality principle, if happened to choose the academic education that would be helpful for him for this endeavour.
• The story takes place in the far future so we may assume that physics unknown today have been discovered, and new technologies have been mastered and are well understood by that guy. (No fancy space-time modifications or teleportation, or time travel. At most more efficient propulsion methods, or energy harvesting techniques.) However any actual artefact has been lost.

At this point of this story, he is growing plants, cooks his meals on wood fire and collects rainwater.

My idea is to replicate the technological development, skipping parts that are not necessary, and my main concern is how to bootstrap this development. To obtain raw materials he needs to dig into the ground (wikipedia mentions significant amounts of iron, as well as natural gas and oil), so he needs an energy source. Should he go for wind or water turbines? Is it possible to find in the ground materials for generating and maybe storing electrical energy? Once you have machines that can dig into the ground to collect any raw material, supposing he knows how electronic devices and fusion reactors work, does it become feasible to construct them given enough time and patience?

• Where does he need to get to with his spaceship? – Samuel May 1 '15 at 5:10
• I'm a bit worried that an answer may mislead you. Theoretically, with a few million years, monkeys at a typewriter could build a spacecraft. However, I think you'll find the psychological effects of the isolation and the handwavium costs of a human that do not age have such a greater magnitude of effect, that the answers may be of low importance. There's an estimated 100 billion humans that have ever graced the earth. If I pick an average lifespan of 70 years, that suggests an upper bound of 7 trillion years to accomplish the goal. Something tells me that answer is less useful than you'd like. – Cort Ammon May 1 '15 at 6:09
• Statistically speaking s/he is going to die just like certain species of jellyfish which is biologically immortal but due to the environment as well as unforeseeable tragedy thus this is how they will meet their end. Unless of course if s/he is either nigh indestructible or able to regenerate any parts of vital organs from molecules level lol. – user6760 May 1 '15 at 6:55
• This experiment shows that building a toaster is feasable, but not easy. Once you have a toaster, you only need to build a powerplant (to power the toaster) and a space ship (to escape before the powerplant shortcuts). Really: those can't be any more complex than a toaster! ;-) Seriously: you ignore two facts: one (wo)man can't comprehent all the expertise needed and second: you need more manpower to simultaniously provide the nessecary resources (power, materials, etc.). There really is a limit to what you can do by yourself. Even in the future. – agtoever May 1 '15 at 7:46
• A very famous science fiction book - The Mysterious Island, by Jules Verne, has a handful of men marooned on an island with an Engineer among them. This story is an almost-exact parallel in that your planet is their island, and your spaceship is probably their ship. Very fun to read, and frankly for many years my gold standard for a real Engineer. – Pranab May 3 '15 at 11:02

The project is far too big for him to do himself. So he needs to automate. If he doesn't start out with the knowledge needed to try the right things, he's going to be stuck; doing research takes an incredibly long time, and he'd need to recreate hundreds of years of work of millions of people.

But let's assume he knows the basics of how semiconductors work, and so on. Very soon he's going to need to build some. But for that he'll need precise machining. So he'd better start by building some machine tools. That's tough to do without regular tools, so he'd better start with metallurgy and so on.

So, he starts with tools and uses them to build machine tools (lathes, etc.) and so on. He might spend thousands of years perfecting the designs to be quick to make with the ore he can dig and burn on his own, so that he can replace parts much faster than the things wear out. (He'd also probably end up favoring more difficult-to-work-with alloys of steel that have superior corrosion resistance just because the ratio of time-to-corrode to time-being-used would be a lot higher than for a normal machine, once his time was spent on other things.)

Then he has to get some sort of really basic semiconductor fabrication facility, and some sort of electricity generation. Hydroelectric power is almost stupidly easy to use: you need some decent wire to wrap around things, and a few permanent magnets would help, and you're off to a start.

So, he's got metal and electricity and knows how to make motors. That's good, because now he can start with dumb automation of things: doors that open and so on. He might not need to bother with batteries yet; he can't walk that far anyway, so just leave power cords everywhere. Normally we'd use plastic to insulate them, but wax paper is far easier to make (or segmented clay wrappers).

Now that he has gotten to this point, if he's managed to remember any physics (I hope he wrote it all down!) he'll hopefully recall how to build a lot of common simple tools for use with electronics: voltmeters and so on. And he'll remember how to grind lenses (pretty simple, actually), and so on. Eventually he'll have a decent set of pretty basic analytical equipment, just enough to get started on semiconductors.

He really, really wants semiconductors, because, made robustly, they can last practically forever.

This would be the hardest part, though: you need to do chemistry to get the right doping agents, you need to have things clean to get good silicon crystal growth, and so on. There might be easier ways, but we haven't really found them. If he put all his effort into making simple circuits that would help him automate things he was doing by hand, he might just be able to bootstrap to the point where he could generate enough computational capacity to do something interesting: having machines designed to build machines that build those same machines and produce semiconductor facilities and so on.

Once you get to the point where you can automatically keep this process going, the man could focus his attention on each area that needs improvement. I'm not sure how many thousands or millions of years it would take one person with largely automatic factories to figure out enough materials science to make components enough tougher so he wasn't spending all his time fixing critical things that broke. Or to figure out programming languages in which he could implement enough artificial intelligence to get the machines to start e.g. selecting sites for mining, instead of him finding them and setting them up.

But eventually, maybe, he would. And then he sort of would be a god, a god of simplistic autonomous machines that would do his bidding to extract resources and eventually put them towards building a spaceship. That would, in all likelihood, not be the hard part, at least if he has time. He's got a whole planet full of resources (and robots) and as much time as he needs to set off rocket after rocket until he works it all out, and if he needs to spend a thousand years to send enough stuff into orbit to sustain him on a journey to another star, who's counting?

(I think 500 years is a serious underestimate, though; I'd expect tens of thousands.)

So, one person with just their own hands and no tools can't reasonably do it. But with machines, they quite possibly can, and one can build machines with one's own hands.

• I'd have liked to accept both this answer and J.D. Ray's because they basically each other and together provide a process I was looking for, but had to choose only one... – tendays May 3 '15 at 4:57

It may not be physically possible in a world with entropy.

http://banjobasics.julieferris.com/Wolcott69/wolcott/space.html

15.5 billion man hours was spent on the Apollo project during its first decade.

That still doesn't account for everything because the Apollo program was able to buy comodities from outside like steel. Its engineers didn't have to grind their own wheat to survive while doing it.

Let's assume he knew everything there was to know about space programs before the apocalypse and never made a wrong turn and knew exactly what to do so it would only take him 5 billion hours and he was really good at living off the wild and was able to dedicate 5 hours every day to nothing but producing things for space travel. It's still going to take him a billion days - 2.7 million years

Think of it this way: he needs X number of miles of insulated cable, he needs many tons of fuel etc but he's only one man with limited equipment. If it takes him 10,000 years to make all the wires he needs then by the time he finishes the last ones the first ones have rusted/perished/rotted. He spends years making fuel but 10,000 years later the fuel barrels are rotting through with rust and some of the chemicals have eaten through the barrels.

Some things just can't be done with one set of hands.

• My mental image of a technologically advance civilization is one of a pyramid. Each layer of technology relies on underlying layers. You might know loads about rocket science but know nothing about the microprocessors need in that rocket. Don't forget he also needs to feed, cloth, recreate, shelter, etc. while building that ship. It'd help him a lot of he could trade with unsophisticated neighbors. As he built up his tech base, he'd provide advancements to them, and they'd provide his support infrastructure. Ultimately, he'd be the crazy undying hermit wizard living over the hill. – Jim2B May 1 '15 at 16:34
• Your conclusion reminds me of the joke about attempting to produce a baby in one month by impregnating nine women... – Bobson May 1 '15 at 21:20
• +1 for the reality check. There's more to a spaceship than just good intentions! – Cort Ammon May 2 '15 at 2:48
• In theory he could compensate for the subprojects that require a large man-hour input in a short absolute period of time by building up a full self-expanding automated society, starting with wood-and-spring automatons... – Leushenko May 2 '15 at 22:31
• @JoshuaHanley He'll just make rewindo-and-repairo-automatons, duh! :P But yeah, the crux of the issue is that some things do not scale down well - even if he only needs to put his measly ~80kg in space, some parts of the spaceship still have a certain minimum mass, and even though he'd only need e.g. a bit of quality steel, he still needs the high ovens necessary to produce the required temperatures etc. Sci-fi is always so chock full of "ancient devices" that still work after millions of years, it's weird to imagine that making something last even a decade or two is quite a challenge. – Luaan Mar 14 '16 at 11:58

It would take him as long as it takes to selectively breed a sentient species, plus a few more years.

Life evolves faster than a single man could replicate all of modern technology and construct a space ship. Even if his starting critters are all rats, the best bet of our lonely earthling is to obtain some help.

He'll need to help generation after generation of his biggest, brightest, most dexterous rats successfully breed. It would probably be a good idea for him to selectively speciate his rats to get a few breeding lines going, as well. This is all assuming that none of the research bases in Antarctica are home to more advanced animals that he could evolve into helpers.

A conservative estimate for the time that this would take would be the time it took for early tree shrew-like primates to evolve into humans: about 60 million years. Of course, selective breeding programs driven by an intelligent force may move a bit quicker than that, but anywhere in the tens of millions of years is still less time than he would need to build a fully functioning spaceship on his own.

Once his rat-men have evolved, the time it will take for them to develop technologically to a point where they can build his space ship will be comparatively short, a mere tens of thousands of years at most.

• This is what I'd do. He could expose them to slightly higher levels of radiation as well to encourage mutations - most of which will be bad, but should speed things up overall. – Dan Smolinske May 1 '15 at 20:16
• While I like many of the "no way" answers, I love this answer for its spirit of "we're going to get you an affirmative answer, no matter what" Affirmatives are always more fun! – Cort Ammon May 2 '15 at 2:50
• Excellent call! This leaves but one problem - the mental health of the protagonist and the will to drive on. Minesweeper will become boring after a million years or two. – Ghanima May 3 '15 at 21:39
• This seems like only way to deal with decay problem. Since you need a developed civilization to build a spaceship, first you need to make one – Maxim May 6 '15 at 0:32
• Importantly, how would he measure rat dexterity in order to select for it? – tom redfern May 8 '19 at 12:00

The human brain does not have an infinite capacity. I have a degree in mechanical engineering and am well read at a popular level in many technical fields, but I would have no practical idea how to locate and identify necessary ores and the chemistry needed to smelt needed metals. High tech materials even less so. I took materials science classes, but never studied in detail the actual manufacturing processes for say heat treating. I would simply specify the kind of steel I would need in a design. Even though I understand the differences in different kinds of steel at a relatively deep level, I have no practical experience in actually producing them. And the industrial engineer that knows these processes would have no idea how to design the needed machines.

I have only barely scratched the surface of the list of things I would not know. Just to achieve manned LEO with chemical rockets I would need many thousands of years of science and engineering. Having complete blueprints would not even make a real difference as there is so much in-depth knowledge missing from the blueprints necessary to completely understand and implement them.

I need somehow to build everything to work together at the same time. Eventually as I built more infrastructure, entropy would destroy things I have built faster than I could maintain them. I would have to create an army of automation just to put together all of the large scale systems to pull of a rocket launch.

I would need fairly large electric power plants, computers, refrigeration, cryogenics, telescopes, and many other technologies to make this practical. I would need to be a god with essentially unlimited mental capacity, not a man.

Antarctica is resource rich but not developed, as such it would have some of the richest resources on the planet assuming that they have not been depleted in the interim. So at least one point of good news. Global warming would have to be very extreme to make Antarctica livable though.

• And you've only got one test pilot. – Samuel May 1 '15 at 8:05
• Yes, you made me realise something important: He will have to do a lot of (initially unmanned) test flights with a lot of failures before he can fine tune all the things he did not know/think about. – tendays May 1 '15 at 9:54
• @tendays Which is a really big deal if you mined, refined, forged, and placed every component in a ship that just crashed or exploded in the atmosphere. Unmanned flights need electronics, fuel, rockets, etc. Literally hundreds of years of work would go into each one. – Samuel May 1 '15 at 10:23
• @Samuel - Actually, given the one-in-a-million survival odds he gets, flying manned test missions is better than unmanned test flights. He knows he'll always survive, and his presence on board might mean that everything just happens to work right and he makes it to orbit. And if not, he won't land in a completely inhospitable location. – Bobson May 1 '15 at 21:17
• For that matter, you're going to need to invest heavily into robotics. Construction involves a lot of "do two things in different places at the same time". – Mark May 1 '15 at 22:11

Like others have mentioned, it may be essentially impossible for a person to build all of the required infrastructure, even if immortal. However, your character possesses a rather unique "power" that he could use to his advantage:

In other words, if in our universe some event would have three possible outcomes A, B, C with probabilities $p_A=99.9\%$, $p_B=0.0999\%$ and $p_C=0.0001\%$, and A results in certain death for the character, then in that world, actual probabilities become $p_A'=0$, $p_B'=99.9\%$ and $p_C'=0.1\%$.

If you allow your character to recognize this ability and use it to his advantage, he simply needs to set things up so that failure at each milestone means certain death. For example:

• The chances of properly building/securing/ventilating a mine without prior experience is low. But, if your character marches in to the deepest parts of his mine, periodically bellowing a horn or pounding a drum, his "ability" will guarantee that he got the construction right -- preventing a cave-in from crushing him and noxious gases from asphyxiating him.
• Time to learn how to forge super-strong steel? Give it a shot, and test your first batch by forming a chain with the resulting steel. Set up a rig so that, when triggered, the chain will be loaded with a platform of boulders. If the chain fails, the boulders would fall on your character -- which obviously cannot happen. The only alternative (no matter how unlikely) is that he gets the process right on his first attempt.

If done correctly, this could save many thousands of years to the required time.

• I like this idea, but if it works like Nathan Brazil in the Well of Souls series, it won't actually work out that way. Rather than the chain not failing, for example, the rig collapses before it can trigger. Or lightning strikes it. Or the boulders bounce off each other in such a way that they happen to fall all around him. It doesn't retroactively make the process right. On the other hand, as I pointed out in a different comment, this makes him a really good test pilot, because his spaceship can't explode with him in it. – Bobson May 1 '15 at 21:28
• Good point. Whatever approach he ends up actually using will have to make use of such strategies. The rigs have to be very carefully designed so that survival in the event of a failure is much less likely than simply getting it right in the first place. – tendays May 2 '15 at 8:01

So far, I like the answer about breeding minions; really that's the only viable solution. However I don't feel like the question of whether or not it can be done gets at the heart of your question, so much as where would he start?

I often entertain myself by thinking about what I would do if I were like the character in A Connecticut Yankee in King Arthur's Court, who, after time traveling accidentally, and armed with only an almanac and knowledge of how modern things work, overshadowed Merlin.

If you know what you're looking for, certain ores can be found by walking around. Useful quantities of copper, iron, and other such materials can be found lying about on the ground. Softer metals, such as copper, can be smelted in a campfire. Harder metals such as iron take more heat, and therefore more sophistication, but the source of heat can be the same fuel (firewood).

So, to your unspoken assertion, it's a straightforward thing for your immortal man to skip the ~3000 years from the start of the Bronze Age until the start of the Iron Age by reading a book that says, "here, smelt these ores using the following configuration of tools and materials that you can find by walking around." Steel is simply iron with a certain level of carbon (charcoal) added to the mix. Different amounts of carbon account for different qualities of steel, each of which is useful in different manners.

So, materials that can be found by walking around can be turned into advanced materials with a little knowledge and implementation. That said, minions would be helpful. Or some sort of magical ability to spawn another temporary instance of himself to complete a task.

Naked man in a forest can hand-construct a trap that catches a deer.
A found sharp stone butchers the deer and provides a hide, which can
be stretched, dried, tanned, and turned into clothing; meat to feed
him; antlers for tool handles; etc.

Clothed-and-fed man can rub two sticks together to make a fire.  If
he's as lucky as you assert, the sharp rock he used to skin the deer
is flint, and he has another piece with which to make sparks, making
it easy to start a fire.  But rubbing sticks works too.

Clothed, fed, warm man now has charcoal as an output of the fire.
Gathering  some clay, he makes an oven in which to burn the charcoal
to make a very hot situation where he can smelt iron in a crucible
he carved from a rock using a copper chisel he smelted in that
campfire and a hammer made from some heavy stone and the deer
antler.

Some of the iron is used to create a wire draw, through which he
pulls copper until it becomes wire.  He finds a lodestone, using a
piece of iron on a stick and waits for a rock to jump up and stick
to it, makes a truss out of some wood, wraps the copper wire around
it, then mounts the lodestone in such a way that, when the truss is
spun, electricity is created in the wire.  On to a water wheel,
which he builds out of wood using his fancy new steel saw with a
wooden handle.  He mounts the lodestone-and-copper generator to the
water wheel, and he has a power plant.

More copper wire and more lodestones, and he builds an electric
motor.  This helps immensely, and the project continues.  As you can
see, he's come a long way, but has a long way to go...

• This is a really interesting contrast to the other answers. I definitely agree with the logic you have here, but I think it breaks down as technology progresses. The early gains are quick, but later ones take more and more effort to produce smaller and smaller gains.... I don't have a writeup to continue that, though. (I really like yours.) – Bobson May 1 '15 at 21:25
• The problem here is time. Hand-drawing wire is a slow process -- it'll probably take a year or two to make enough for a generator and motor. Or consider aluminum smelting: you'll need a year-long expedition to Greenland to pick up some cryolite, and once you've got that, the rate of smelting depends on how big your power plant is -- your water-wheel-and-lodestone plant might be able to turn out a gram or two a day, if you provide an external source of heat. – Mark May 1 '15 at 22:25
• Again, my point isn't whether or not it's practical, but how one might go about it. If I have the OP's intent understood correctly, it's about the chain, not about the reasonable-ness of it. – J.D. Ray May 1 '15 at 22:58
• +1 for addressing the actual question - how to bootstrap technological development. – tendays May 2 '15 at 7:31

Invulnerable, you say?

Total yield from a modern nuclear weapon is 418400 TJ.

If all of that force could be directed at the man, that would be

Ek = 1/2 mv^2.

60 kg person would be launched at 1.18*10^8 m/s.

Lets assume that the force would not be entirely transferred to the person, even if 1/100000 of it was (presumably sitting on it would transfer at least this amount, probably much more)

Total energy transfered = 4.184 *10^12 J

Velocity = 330 km/s

Escape velocity from the Solar system is 43 km/s

So you would be travelling to other solar system with 287 km/s velocity, which would get you to proxima ceturai in under a thousand years.

Sure, the vacuum might be an unpleasant way to spend a millenium, but this guy is immortal, and a possible event happening is Oxygen spontaneously quantum teleporting into his lungs (probability of this happening normally would likely involve the creation of new numbers to describe it), so I am assuming that will happen as all alternatives would lead to his death, so probability becomes 1.

The best guidance system would be a self destruct button set to trigger if he misses his target. Therefore, he would have probability 0.99999999999999999999 of missing his target and 0.00000000000000000001 of hitting, but that becomes probability 1 of hitting, as any option that leads to his death won't occur.

Building a nuclear bomb is MUCH easier than building a rocket.

• And the invulnerable randomizer selects his bomb doesn't work ... – Joshua Jul 19 '16 at 16:16
• Getting the materials to build a nuclear bomb may not be easier to getting the materials to a rocket and building it. Any other, sufficiently large, bomb might do however. – Clearer Jan 5 '18 at 8:19

So, you need to bootstrap a million+ man-year intellectual effort by yourself. There is only one real option. You have to cheat.

You come from a technological society that has mastered nano-technology including the following that are embedded within you as part of your full medical package.

Now you can command your internal AI to extrude new copies of these magically high tech versions of machines and start the bootstrapping process. The V/R option would be useful when the AI realizes that you would like to provide input re: priorities and design decisions, status updates, etc. If you are bored by the details, you can pretty much issue the commands and go about your life as a beach bum or whatever as your army of nano-machines do all the work.

With this level of tech, you could manage LEO within 6 months, or go straight to an pulsed Orion drive mega-launch (city sized) able to go the to nearby stars within a year. Exponential growth is truly powerful.

Resource shortage are not a problem at all. The earth is covered with all the rare materials you could ever want, they are just to dispersed to be economically mined given our current methods. You could just process seawater to get all the iron, gold, silver, uranium, titanium, etc. that you would ever need.

If you need the hero stuck for a longer period, just make it take longer via any complications that suit you. Of course, we don't have any of these technologies, but they is nothing in physics that preclude their existence.

My mental image of a technologically advance civilization is one of a pyramid. Each layer of technology relies on underlying layers of technology and labor. You might know loads about rocket science but know nothing about the production of the fuel that the rocket needs.

Your sole survivor also needs to feed, cloth, recreate, shelter, etc. himself while building that ship and he has to provide all the labor for that too (for most people living in primitive conditions, that's a full-time job).

I think if the OP changed the first sentence to

"The last technologically sophisticated human alive is on the Antarctic continent and needs to find a way to leave the planet before Earth becomes unsustainable for life."

It leaves open the possibility that the few remaining humans have reverted to primitive living conditions. They can provide the necessary labor, infrastructure, and support. As your sophisticate masters one area (say iron smelting), he would pass the details on to his primitive neighbors and have them develop the necessary industry and volume of production.

Ultimately, he'd be the crazy undying hermit wizard living over the hill and passing out seemingly "magical" artifacts & spells.

By the end of the story, all of the remaining humans would live in a technologically sophisticated society again.

You might enjoy the Safehold series by David Weber.

The other comments are fantastic, if you really are dedicated to keeping your person alone (note that even for a very healthy human that would take a psychological toll that might cause him to give up - but we will ignore that for the sake of this for now).

However, you said engineering and physics background. If he had been a robotics engineer, it might be reasonable to think that he could possibly construct helpers that mitigate the man hours involved (sentience is optional, and probably more trouble than it is worth).

Once he has some robots automating time consuming/dangerous tasks (initially possibly just tilling/planting/harvesting food for instance), he can make more incremental changes - improve the power supply, improve the bots to be more capable, etc, etc. This will still take an enormous amount of time, but it would allow you to build the factories and such you need (you just have to be really lucky and have few things break down until you have robots capable of diagnosing problems)

Note that this will not help (much) with leaving to the hotter regions since you do not have a reliable communication network until shortly before you are ready to head to space. Your final tests would be manned by robots and would be designed to set communication satellites and such in orbit.

To expedite the process you might have your character find a robot that is capable enough to repair itself and follow simple instructions - the self repair explains how it is still running and allows for plot turns where the robot has to rebuild itself and such (before the reader realizes the robot can repair itself). You can decide how much and how capable this robot is to bump things along better (for instance if the robot knows how to manufacture steal or put together another robot you have saved decades of work for yourself).

One other thing that could be helpful would be having a library that contains all the science you need - everyone is right on the time scale if you have to invent the science from scratch. But if you have access to a book on rocket physics or steel smelting, you have a lower learning curve. Still will take lifetimes worth of effort to accomplish, but you are not having to learn about gravity and optimal fuel requirements to get to LOE etc.

So as others have pointed out, one pair of hands can't do it, nor can one mind hold all the information needed. Clearly if he tried to do everything himself it would be impossible. So he can't do it that way, he has to try something else.

After a thousand years nothing really useful will be left, so even going looting is a fools errand. If it weren't that long then go loot tools and equipment and books and materials that will save decades to possibly even centuries or more.

He has to use machines obviously to do everything for him, including the building of the machines eventually. Having one person do it is still pretty implausible, but he would have to focus on feeding himself, and iterating on getting basically a robot that is capable of performing other tasks including getting the materials to make other robots, and making other robots. So small scale and simple as possible is key; of course, when talking about robots, well, we don't know how to make robots that meet those requirements yet, and building the components involved requires as we currently understand some pretty high tech equipment, or getting pretty big (as computers don't have to be built out of microprocessors see http://en.wikipedia.org/wiki/Analytical_Engine).

Of course, even once he had the computer of whatever form there is still the programming which is itself a huge task (~4 million lines of code in Windows 3.1 for example); and what of a compiler and monitor; your guy might not have those but be using stone punch cards in all likelihood to start out at least.

Once he is able to build self replicating robots that gather the material for their replication and produce a surplus as well as take command from him, well, then he would be in business; but he would already have to know how to build and program such things to start out with, and never forget across the centuries it would take to get to that point. From that point it would be a matter of having his self-replicating machines make enough of themselves to build his rocket ships, test them, and so forth.

There would be an extremely low likelihood of success and it would take a very long time; however, he is functionally immortal and virtually assured of success given the set up; so he starts working on his Analytical Engine and developing a small scale forge; still probably quicker than trying to breed intelligence into his rat neighbors.

My idea is to replicate the technological development, skipping parts that are not necessary, and my main concern is how to bootstrap this development.

Bad idea. I don't think you can replicate technological progress to the present by "replaying it" as a single person. In our world, everything requires maintenance and has a "service life". This can result in unresolvable bottlenecks for Immortal Man. Basically, if he gets to a configuration in which the stuff he's trying to maintain breaks down faster than he can fix it, he's stuck and can't make progress from that point.

In our history, we built things in a certain way that was "cost effective", in order to make profits. But Immortal Man isn't trying to optimize the same parameters, so his solutions should be different. So he really ought to choose the path of building things that aren't cost effective so much as they are durable. I think it would look very different from the way we do things.

The point has been made that one person cannot do this because one human mind cannot hold the information required. I think this is a valid point. Time has been eliminated from the equation, but the person is only of normal intellectual capacity and somewhat frail physical strength.

One approach would be for the person to study the most advanced records he can find about spaceships. Then begin to build one. Of course the plan will immediately run into problems- you need a piece of, say, machined titanium. The titanium ore will have to be found, then smelted, then cast, then machined. So our hero will have to start from a vague knowledge of metallurgy, geology and mining to become enough of an expert to identify titanium (perhaps it's easier to find some in an ancient piece of machinery) and then find or create all the titanium that the project will likely ever require. Once that is accomplished, the person can then forget about finding titanium and learn the next task. A task that would be accomplished by experts in a team sitting around a conference table may take years (or hundreds of years) because the person would have to learn and re-learn each specialty to respond to concerns from other roles in a development team. Since the person is assumed to be smart enough to learn each specialty in a finite length of time, and since the interactions of humans are discrete and of limited bandwidth, eventually every single task can be accomplished, in a recursive serial fashion rather than a massively parallel fashion, but it will eventually get done if it is possible and if this person has the willpower to make it happen.

Some of the answers to this question are being hammered out already in the Open Source Ecology project with the Global Village Construction Set. It won't get you all the way to building a rocket, but you will be able to bootstrap an agricultural/industrial civilization starting with very few raw materials.

Even to design a space craft that just goes out of earth atmosphere requires precise calculation. Even a slight error might put the whole launch in problem. Space craft uses many materials that are not easy to produce. Even to get the materials needed for building space craft may take years of hard work. For building a complete space craft might take a really long time . Making building such thing almost impossible.

But if the technology at that time uses biomaterials found naturally and they have some how developed different method of mathematical abstraction different from any present methods that some how simplifies the present complex problems to be easily solved in low power computing devices . This might be possible (considering that these materials can some how processed easily to withstand the conditions during space travel) but still might take long time.