Inspired by this story, I started thinking.

Let's say we have a person, from the modern day, who miraculously gets a superpower: He can rewind time, but retain his own memories. He can rewind all the way back to his birth, and can even rewind if he is dead.

Otherwise, however, he is unexceptional for a human. Mostly, he won't live longer than a human could (though he won't have any chance of dying early, since he can rewind).

Being tired of living out the same major events over and over, and being unable to really die (after he does, it's basically blank nothingness except for an annoying popup window that just says "Would you like to rewind?" that reopens when he closes it), he decides he wants a change of scenery.

Ultimately, he decides that exploring space would be cool. But after thinking about it (or maybe trying it a few times), realizes that even if he advances human knowledge to get to cool Sci-Fi stuff, he'll still be stuck by what he can accomplish in his lifetime. So, he instead turns his efforts to curing aging, so he ("and everyone else too, I guess"), doesn't have to work his butt off to get Sci-Fi stuff to a worthwhile level.

But, after learning about the topic, he realizes that the cure for aging isn’t easily obtainable. While some techniques in the modern age could extend his life to around 150 years at max, a full-blown cure for aging would take a tech level that he (as an expert in this (as well as everything, eventually)) estimates is 300 years in the future.

Or at least it would be, if normal people were working on it.

So, he wants to accelerate development on this topic in order to reach the goal before his death. Preferably sooner, as medicine that reverses aging seems to be around 500 years away, and he’d rather not spend 200 years as a 135 year old man (though if that’s the only way, he won’t knock it).

Since he can only bring back knowledge, not infrastructure, or experimental results, or scientific consensus, he’s in a somewhat similar position to someone who just came up with a brilliant idea. Perhaps the most brilliant idea.

So, the question is: Could someone who just happens to come up with a brilliant idea advance science by decades, or even centuries? Or is that just not how it works?

Support for one’s answer could include examples of ideas discovered by chance that, had they not been, would have prevented us from making progress for a significant amount of time. Or, on the other side, showing that discoveries tend to require previous discoveries to work (e.g. If you have Theory A, it wouldn’t make sense if you brought it back to before Theory B, which it was based on, which itself couldn’t be brought back before Theory C, etc. And you couldn’t just introduce them days after each other for whatever reason.)

Solid reasoning could also constitute evidence. For example I think answering a question like “How much of science is thinking vs. doing?” would, while not answering the question per se, get well on the way to a good answer.

  • $\begingroup$ I apologize that I must vote to close and hope you can edit your question to make it on-topic. Our help center states, " avoid asking subjective questions where … you are asking an open-ended, hypothetical question: 'What if ______ happened?'" As written, your question is subjective, broad, and opinion-based. Indeed, there's no way to judge which of many answers is correct. From that same page, "avoid asking subjective questions where … every answer is equally valid: 'What’s your favorite ______?'" Could such a person affect human history? Sure. How much? That's impossible to answer. $\endgroup$
    – JBH
    Mar 8, 2019 at 17:40
  • $\begingroup$ If I edited it to make the focus closer to one of the questions as stated in the last two paragraphs ("How useful a “eurika moment” is in modern science?" or “How much of science is thinking vs doing?” respectively), would that resolve the issue? $\endgroup$
    – awenonian
    Mar 8, 2019 at 17:47
  • $\begingroup$ I'm not voting to close, yet as the OP is keen to adapt it to fit. (Plus personal bias, I like the possibilities that the question throws up.) $\endgroup$ Mar 8, 2019 at 18:00
  • $\begingroup$ IMHO this question is good (can be more focused, though). It's just the scenario that opens up too many possibilities. We can evaluate those scenarios and argue about them on objective basis - that's what we do, right? $\endgroup$
    – Alexander
    Mar 8, 2019 at 18:04
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    $\begingroup$ @Spencer That doesn't sound right. After all, even in our world with only boring forward time travel, we talk about expected development (e.g. project deadlines). It doesn't seem out of reality to make a statement like "This project has an expected delivery date of Q1 2027, but if we figure out X sooner than expected, we could potentially bump that date up to Q3 2025." Do scientists not have deadlines, or have deadlines of a vastly different nature? That could be good evidence for an answer. $\endgroup$
    – awenonian
    Mar 11, 2019 at 12:48

6 Answers 6


Your time traveler has the advantage of being able to footprint the future by mapping out who he needs to meet, what he needs to invest in, etc. This is actually way more powerful than just coming back once with a good understanding of the tech. By the time he's in his mid-20s, he could already be a billionaire by ripping off ideas that major tech companies have not come up with yet like Amazon or Facebook and grow them much faster than they did in our world because he creates them with full knowledge of how to monetize them, and who he needs to hire to manage them so that he does not to to put much time into it. So, then he'd have a good 60+ years to rapidly build well financed Research and Development teams of people he's already spent lifetimes vetting. Then he spends his days dropping in on these teams introducing the exact ideas they need when they need them.

This way, it's not just one idea to flourish, but he's eventually developing dozens of simultaneous super technologies. Each time he rebuilds his company, he comes back with new ideas that they were able to develop more quickly with his last iteration of leadership allowing him to preempt even more technologies with even more development teams for every generation moving forward.

As for infrastructure and engineering he could take shortcuts here to. He might begin work on a factory for making things that seem relatively useless in 2010 that he can then slightly tweak in 2020 just as it's almost done being built so that he can make a critical component in warp drives as soon as the right nano-materials are finished being developed. Basically, skipping the wait time on getting from idea to production

It might take him centuries, or even millina of starting over, but eventually, he could probably hit space flight within a few decades even if it would take us centuries to get there as is.

  • 2
    $\begingroup$ they can also effectively neuter any commercial competition and essentially dominate world markets by virtue of selling patents and information to existing corps whilst simultaneously building their own competing firms to market patents/processes from a further 30yrs down the timeline whilst any competition has invested significantly in 'modernizing' and their stock crashes. Nobody believing him is not really a concern as nobody turns down effectively unlimited funding. They'd also be so far ahead of the curve that there wouldn't even be laws covering his research most of the time. $\endgroup$
    – Giu Piete
    Mar 9, 2019 at 2:34
  • $\begingroup$ (to the question) by being able to direct the research, your protagonist doesn't even need to know details once they have the funding, a huge proportion of what amounts to the rate of technological advance is in wait-times, duplication for certainty, the search for funding and taking multiple avenues of approach 'cuz we don't know which is right until we know which is right' those and more can be cut out with little effort by a 'time travelling' trillionaire. $\endgroup$
    – Giu Piete
    Mar 9, 2019 at 2:38
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    $\begingroup$ good point, even if the capacity of human as a carrier of information is somewhat limited, and high-level ideas need the grounds to grow in, but definitely there will be opportunities to have an upper hand, and it indeed may be main component of the situation $\endgroup$
    – MolbOrg
    Mar 9, 2019 at 4:59
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    $\begingroup$ I like this answer the most so far, because, while the others say basically "It wouldn't help that much" this one says "If he plays his cards just right, then he could do it." I imagine that all this optimizing is a lot of work, and can create some good conflict (e.g. What happens when the lead engineer learns that the boss has basically been stealing her accomplishments from the future?). Essentially, it makes a good story. $\endgroup$
    – awenonian
    Mar 9, 2019 at 16:32
  • $\begingroup$ @MolbOrg compression...by the time he's 80 even in the first go-round he can build or have built a simple & memorable cipher(s) that when applied to a memorizable bibliography renders a bunch of proofs. He's got the publications of humanity up to(...whenever he can dictate to his mom) to work with to form a body of work that, whilst it won't advance society-wide technology for years, means that by the time he's in high school the works are the subject of undergrad studies. He's also not restricted to predicting the future, but also has the capacity to exploit historical facts...blackmail etc. $\endgroup$
    – Giu Piete
    Mar 13, 2019 at 21:57

There is a reason that we talk about research and development as separate things. Research is about extending the theoretical bounds of science; without the Maxwell equations for instance, no-one would EVER have been able to build a functioning radio system, whether they wanted to or not. Development on the other hand is more like engineering. It's about the operationalisation and application of what we already know.

Science is full of great ideas that have been found by accident. Dunlop (for example had been working on ways to make rubber tougher for years before accidentally spilling sulphur into some boiling rubber and inventing vulcanisation. Superconductors were allegedly discovered when a kid misread a science experiment instructions in a uni and put in 10.000 times too much catalyst.

Most engineering problems can be solved with time and effort; theory on the other hand requires inspiration. So the answer is that good ideas can extend science in different ways to be sure, but you actually want good ideas AND good engineers who know what to do with them to extend your scientific knowledge.

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    $\begingroup$ There are times when inspiration is the missing piece for development. For example, all the pieces of the modern float-glass process were present in the early 1900s, but nobody thought to put them together until the 1950s. $\endgroup$
    – Mark
    Mar 8, 2019 at 22:05

Alan Turing

This generally doesn't happen, but sometimes someone with the right idea and the right technology at the right time can have a huge impact. One example of this is Alan Turing. To be fair, other people were also working on computer-like things at the time, and he could draw from existing work on logic circuits. However, without all that, it's reasonable to think that one person in the mid-20th century would have thought to create complex and re-programmable electric logic circuits (computers). So, while Turing didn't work alone, in theory someone like him could maybe have, as the building blocks were all there.

Now, one could argue that the Computer is an advance in engineering, not science, but it has allowed for MASSIVE improvements in science in almost all fields. It's hard to imagine how many decades behind we would be today without the computer (or decades ahead, since no Facebook/Worldbuilding Stack Exchange to distract us...).

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    $\begingroup$ Konrad Zuse and John von Neumann would like a word. The reality is that the idea of flexible, programmable digital computing machinery was floating in the air, so to say: three independent people in the three different countries built programmable computers roughly at the same time. $\endgroup$
    – AlexP
    Mar 9, 2019 at 1:30
  • $\begingroup$ @AlexP I agree. I'm just saying that, in another world, Turing or someone like it could have done it solo. $\endgroup$ Mar 9, 2019 at 2:01
  • $\begingroup$ Konrad Zuse did do it alone. $\endgroup$
    – AlexP
    Mar 9, 2019 at 2:43

The vast majority of scientific advancements, whether theoretical or practical, tend to be inevitable. Generally the conditions are right, and the "genius" that invents or discovers something usually just happens to be the first one to put the pieces together.

If Newton hadn't developed Newtonian Mechanics, someone else soon would have. The detailed observations of planetary motion, and the ability to measure time and mass, were advancing rapidly. It was simply a matter of putting the pieces together, discovering the patterns, and making sense of them.

Similarly if Newton hadn't invented calculus in order to perform the required mathematics, someone else soon would have (and there's reason to believe others actually did).

Special Relativity required Einstein's genius, but had he not proposed it, it wouldn't have been long before someone else put together the same information and unanswered questions and derived the same solution.

Genetic inheritance, the periodic table, aircraft, spacecraft, etc. are all incredible achievements, but I can't imagine any of them being delayed by more than a few years if they hadn't been discovered or developed when they were.

People like Edison were well aware of this, and so he ran a factory full of inventors trying to stay at the head of the wave, discovering things before anyone else did.

In your situation, it won't be so easy. Almost any invention, theory, discovery, etc. that you introduce won't end up in a receptive environment. People simply won't accept it as anything other than the rambling of a mad man.

No one would have listened to Einstein's nonsense a hundred years earlier.

Introduce the germ theory of disease five hundred years ago, then suggest that people practice common hygiene and wash their hands, and you'll be accused of Judaizing.

Occasionally there actually are new discoveries that make people say "Why didn't anyone think of that decades ago?". And for a few of those discoveries, it really was possible for them to have happened decades ago. These instances are very few and very far between.

But that is the type of advancement that you are going to have to find.


I would say generally it is not how it works, even if there are examples of such history-changing technologies - bronze, iron, steam, metric system(standardization concept in general), transistors, lasers, personal computers. There are technologies which deeply affected consequent events. So as there are plenty of examples of stuff which was discovered randomly, so it possible to speed up certain things as part of the main goal accelerate technologies or getting the upper hand in competition to obtain resources and be able to focus them on some goal, in a similar way mentioned in Nosajimiki answer.

Generally, technology and the ability to do a thing is interconnected, it is a result of being able to do many different things, so as ideas have to come in the right time at the right tech level. An example handwriting input Apple Newton good idea but software and hardware was not up to the task. Same as today deep learning is a significant topic, but it would not do that much in the 90's as hardware was not up to the task, and advances on hardware tied to many other advances and specifics of technologies. And even if one would know and be able to remember all those aspects(and it really connected not only with the process themselves, but with other processes which produce production equipment you need for your process, and those other processes also may require advances in other production equipment ....

Is there or isn't there a way to achieve the goal of the character depends on the place where he is in the timeline. Is there a chance for him in the stone age to progress to the first PC in 100 years - I would say rather no, one of the big reasons he can't do everything required all by himself, so even if he has perfect knowledge he needs to teach others to do certain stuff he needs to do, and it creates a lot of problems.

Can we imagine some knowledge body carried by one human which allows him to jump from stone age to space exploration immortality - I would say yes, we could imagine such knowledge - but the problem of the guy is how far he is initially from it but it is not the only problem in the case. It can be imagined like a road, with some boulders/rocks on it (which may represent some key achievements, a bit more complex than that - achievements and the plan to reach it and next rock in a certain time frame from certain starting position(which is a constant in our case, which makes it harder)) and a condition that you need to jump from one rock to another to move to the goal - some gaps may be too big for one jump(it is the time frame of the guys existance). So, in general, it is the question, is there a path on the road(or better to say a field of rocks) - such so that one can jump from one rock to another and after a certain finite number of jumps reach the goal place.

It some sort of traveling not a fully interconnected graph, which structure is defined by starting conditions and by some virtual technology tree(sort of The Library of Babel of technologies). And even if we can imagine a technology which may be implemented with a small workforce(number of people), it may be like an island in the possible routes, an island to which there is no path, even if we can see it we not necessarily can reach it in given conditions.

Stone age is easy to demonstrate the complexity of jump, but at the same time if we look at it from our current time, biological components/technologies may be a way to reach the goal - microbiology may produce a lot of chemicals, and mutations are a potential tool so as a selection of strains of bacterias/cells/whatever may give you materials which one typically associate with our current time like plastic strains of bacteria that are able to produce plastic:

  • Scientists at Genomatica Inc. recently announced that they have developed strains of bacteria that are able to produce plastic without the use of oil or natural gas. The sustainable process utilizes little more than sugar and water to produce butanediol (BDO), which can be manufactured into everything from plastics and fibers to pharmaceuticals.

Or another one, maybe it harder to track any connection with the topic here, but it is interesting in terms of it can be another chemistry tool, April 2017 scientists discovered that octopuses, along with some squid and cuttlefish species, routinely edit their RNA (ribonucleic acid) sequences to adapt to their environment.:

For a guy living events over and over and being able to experiment with the environment and those events, it isn't that impossible to come to an idea of small creatures living unobserved, and observing them took efforts of certain individuals which technologically were simple enough. Genetics is quite a jump, so as chemistry and the whole idea that those microorganisms can be used for some useful goals. But it is a powerful tool once one realizes it, with interesting potential, and which can produce a useful combination even if you do not know about its existence before. it just to show that stone age guy, in theory, has a chance too, but it very unlikely and to meaningfully propel to idea of plastic it needs to know the past of our time which is out of reach of the guy.

As for 2000's it is a good time for your goal to be. Distances between individual rocks are smaller(in some sense), but it more of those and they have to come in the right sequence and it really a lot of them (deep recurrence, much deeper than it was for old days) and there a lot of information to carry in memory to make next iterations possible. But it is helpful that there plenty of people and there is a well-established system which helps to focus efforts in a certain direction, so as relatively developed information processing, which may be helpful to carry information back as an example. As an example - there probably is some algorithm of pseudo-random number generator(idk couped with some markov chain type stuff), which is short enough and which has relatively short seed to remember and which produces a replica of encyclopedia of Britannica(in random order, or maybe even consequent(but it less probable)), or a description of how to build a warp drive, or something more useful at current interation of the character.

2000's are good as it was a time of many opportunities created by a rapid development of technologies in a short time and at a good pace and I would say to the guy - well done well done

What kind of technologies it could be as of today

  • as story plot it is your choice of course, but I would say that most of the job is done by the time

In terms of achieving goals today is a good day for that, it possible to argue that we have everything we need for our next big jump in time and technologies.

SpaceX started as a mariachi band in 2002, now for quite some time, it delivers payloads in space and ready to deliver humans in space. And it has, theoretically, the capacity to deliver payloads on the moon.

With the moon situation, we have an interesting direction of Affordable, Rapid Bootstrapping of the Space Industry and Solar System Civilization which can be coupled with Realistic cost and feasibility of sun-shading? as mean to face global warming which may lead to implementing solutions like that ServerSky (and not necessarily just stop at 2%, go K1) Whis wich generative algorithm and software and general digitizing of researching for materials and solution may lead to burst in our knowledge of technological and biological nature using those space resources and computations.

Which if it does not solve the problem by itself, in the required time frame, which I doubt, may lead to sophisticated technologies like smart matter there some bits on that regard mostly as potential scale of the possibility provided by smart matter or it can be any gray goo of a flavor you like.

And gray goo type thing is probably suitable to be produced by means of tools we have today, but we are just lack of knowhows in that regard. And that allows you to go to K2 with from the same position as it was K1 here in the same period of time or shorter and it's a maximum power in terms of applying generative algorithms to the problems which the character is worried about and are maximum probabilities in solving them in the given time frame. (and I would say it easily can be done if the character covers only 2000-2100, so as I would argue that he could do that in 2000-2060)

Quantum computing seems another technology which we sort of close and able to do but lack knowledge of how exactly. Considering all those metamaterial discoveries which potentially can be used in theory for those etc - so it may be some right combination of specific knowledge. And QC it can be quite powerful to produce new knowledge (generative designs and all that again)


I think Nosajimiki mostly has the right idea but the wrong idea of scale. It's going to take longer and involve more technologies and be far more complicated.

At the "start", this person's activities amount to leading down pathways that seem like they will be productive, and jumping back to correct things over and over again. Start is in quotes, because they'll be doing complete do-overs multiple times, because there are only certain things that people will accept from 3 year-olds, and getting that right start will be tricky.

Also, as they progress in this effort, they will identify individuals who will be important for them to recruit or direct earlier. Because they are only one person, recruiting the right other people will be fundamentally important.

Some of these people will be important because of their own potential, which this character will want to maximize, minimize, or redirect. They will be a big asset, because each time the character goes back over previously established efforts, they will need to be careful about remembering what they did right - but a correct person placement doesn't require remembering all of the things that person needs to do.

Others will be important because in real life, people don't look too fondly on the one guy who gets everything right. While the amount they can bring back each trip is limited, most of what they will be bringing back are new concepts of how to proceed, and there will be far too many of them for one person to run down. The right people to take these ideas and run with them are a bit tricky to locate.

They're very clever people, but they're not necessarily imaginative. They can make engineering refinements very well, even though they lack the ability to come up with a major good thing on their own (or maybe the hero just wants to give them the idea they'd get later earlier).

However, they cannot attribute all of the ideas he gives them to him, or else he sticks out too much. He'll probably be able to find a few trusted confidants who are willing to keep his super-duper-genius secret that he can work more directly with. But he'll probably have difficulty finding enough of them, so will need to find people he can strategically "steal" some of his ideas and make them work.

Note that his earliest efforts would need to be getting his family to be more fiscally affluent and seeding ideas to people receptive enough to the idea of genius babies to take his ideas and running with them. If his starting point is post-Internet, he may be able to avoid the baby stigma, but until he has family resources to use, giving people ideas will be his most effective method of invoking change.

There's also an aspect of fostering competition. This is probably something that he'd mostly be willing to do with the people he surreptitiously gave technology to - give it to more people. That might seem like it's less efficient, but it's laying the groundwork for more advances. And he'll need to do a lot of that, because technology has a difficult time taking root unless there is at least a critical mass of interest in it.

He's also going to need to enact major school reform, and that will only be something that will be well received once it's clear that he's broken Moore's law the other way, and the world is having singularity-level technology explosions. I think school reform is actually going to be one of the most major things he needs to achieve.

Someone who graduated from college in 1990 and then woke up the next day in 2010 would have a difficult time coping, but assuming nobody had an issue with their missing 20 years, I think it's conceivable that they could cope. They'd need to be a major self-starter in order to catch up, but it could be doable. But that kind of a paradigm shift would be the experience of every college graduate, if someone were advancing technology like this guy would be doing.

Grant reform is, of course, another major task. But after taking over the stock market in grade school, that would kind of be his thing to do.


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