A question blatantly inspired by my old question here: What would be the impact of a modern programmer and laptop being dropped into World War II, possibly breaking Enigma? I had so much fun with the idea that I went back and reread it today and noticed that I focused a lot of my question on Enigma, but others suggested uses based entirely off of its raw number crunching ability alone.

Thus let's try an altered version of the same scenario that focuses only on that second part. Again, our time traveler somehow falls through time, unexpectedly, while headed to his last final for college. Unlike the previous question he didn't have his computer with him. However, he does have his graphing calculator and a cheap smartphone, along with a newly purchased 12 pack of batteries and his smart phone charger (I'm waiting to see how safe it will be to charge the smartphone though)

He's fallen in time to right about the time when WW2 was starting in Europe, but he is in his home in the United States. He somehow manages to get in contact with someone high enough in the government or military to be able to put him into contact with those who would be interested in him and convince this person of what his calculator can do.

He is relatively intelligent and was about to receive his bachelor's degree in software engineering, and has a decent 'dabbler level' understanding of physics, science, history of computers/software development, etc. However, his hardware knowledge is limited to what he had to learn for his degree, not enough to tell them how to build a computer. In addition while he is familiar with many aspects of his graphing calculator he has never done any real programing for either the calculator or phone, and has no way to look up the API for either now; heavily limiting his ability to program anything complex, but allowing him to manage at least basic scripts on his graphing calculator.

To keep the focus on computation power, and keep him from being too game breaking, assume that the time traveler has very little interest in most history, and particular was not interested in war history. He has a below average knowledge of WW2, and while he may have vague knowledge of a few key battles existing: D-Day, Pearl Harbor, Midway, etc. he remembers little specifics and in particular has no idea about the time-frame for these events. Between his limited historical knowledge, his uncertainty of what he does know, and the timeline changing as he interacts with it he has little to offer in way of direct intelligence about the war or what to avoid.

His long term goals are the increase of quality of life and general benefit of humanity (regardless of their home country) and to accelerate the development and adoption of technology. His short term goal, more relevant to this question, is the ending of WW2 as quickly as possible with minimal lost of life, which he considers best done by aiding the Allies war effort to speed up the Axis defeat and thus minimize the lives lost during a drawn out war.

What can the the traveler do with his two powerful computational devices to affect WW2? Where are his resources best allocated to maximize their benefit?

Any suggestions for how he can also drive his longer term goals, enhancing tech and quality of life, at the same time he is working towards ending the war are welcome! I'm interested in any answer for helping the war effort, but if some option meet those long term goals at the same time all the better.

  • $\begingroup$ In the Timecop tv series it was a laptop. But tgat was 20 years ago so probably similar to a modern calculator in power. I recall a line, "it's what's in the magic box that's important. " $\endgroup$
    – JDługosz
    Commented Dec 3, 2015 at 20:24
  • $\begingroup$ @JDługosz yep :) only thre is a big limit to a calculator; I/O. It's much harder to enter data in or remove it out compared to keyboard and monitor. Still, the concept is the same ;). Though..from my last look graphing calculators haven't grown much in the last decade, their as strong as really needed and TI quasi-monopoly stagnant them some. $\endgroup$
    – dsollen
    Commented Dec 3, 2015 at 20:33
  • $\begingroup$ I think the only reason they exist is to fit the limitations of what's allowed on the test: no qwerty keyboard. I use a HP48 emulator on my phone, or a spreadsheet in real life. $\endgroup$
    – JDługosz
    Commented Dec 4, 2015 at 1:49
  • $\begingroup$ @JDługosz oh graphing calculators have use. When your doing lots of calculations you can input them faster into a calculator. Compared to my old graphinc calculator trying to use something on my computer is far more tedious (though, perhaps that's because I haven't bothered to learn how to use a better system since I don't need the same degree of playing-with-numbers I use to). I miss my calculator sometimes, not enough to pay an over priced 100+ dollars for something weaker then the 8 dollar smart phone I just bought though lol. $\endgroup$
    – dsollen
    Commented Dec 4, 2015 at 15:18
  • $\begingroup$ why would it be faster than a program that does the same thing? You could even have toolbars for all the function buttons, and that's actually better when you have more functions than buttons and need multiple kinds of shifts or menus to find them; start entering variable names and complex logic and the "real" keyboard blows it away. $\endgroup$
    – JDługosz
    Commented Dec 5, 2015 at 5:29

3 Answers 3


If he can get himself assigned to the Manhattan Project, to help with the building of the bomb. With his calculator he might be able to speed up the project by months or even years. We might even be able to make enough fast enough to use one on Berlin.

However, with the way government works, most likely they would confiscate the calculator, jail the man for even knowing about the Manhattan Project and just give the calculator to a research team they think has the most important need.

  • $\begingroup$ the original story concept which inspired my first question actually put a bit of focus on that second paragraph, I even posted a follow up question about how o prevent the goverment from taking the laptop away. Admittedly in this question where they only have a calculator, not a laptop. preventing the goverment from taking it is much harder; a layman can use a graphing calculator. Still, if he was working with the goverment surely they would keep him around, if only to teach them how to use the more advanced features and write scripts. He loses a bit of the ability to pick where... $\endgroup$
    – dsollen
    Commented Dec 3, 2015 at 20:30
  • $\begingroup$ Well considering that the calculator is significantly more powerful than any of the handful of computers working at the time, it could do a LOT, and the government would have a hard time trusting you with such a piece of equipment and you don't even have a Master's degree! $\endgroup$
    – bowlturner
    Commented Dec 3, 2015 at 20:39
  • 2
    $\begingroup$ ....you umm...don't want to know what I've been trusted with without a masters degree :P In fact general advice is to never bother with a masters in computer science since the years of work experience are valued more. Still, I see your point :) $\endgroup$
    – dsollen
    Commented Dec 3, 2015 at 20:42
  • $\begingroup$ @dsollen I know, the point is we are dealing with the US government during a time of war... $\endgroup$
    – bowlturner
    Commented Dec 3, 2015 at 20:45
  • 4
    $\begingroup$ @dsollen I assume you mean "in software development". Masters and PhDs (or rather, the educational and research fruits of Masters and PhDs) are quite important for actual computer science. $\endgroup$
    – JAB
    Commented Nov 4, 2016 at 21:49

In the end the Allies broke all the Axis codes. Maybe the graphing calculator could do it quicker if the time traveler partnered up with a cryptologist. It wouldn’t end the war significantly sooner. The tool itself is not understandable enough to give a leap in technology until much later. I estimate the 1970s. His best bet is to make a program that can make him money either by predicting stocks, or perhaps selling computational time to big scientific endeavors. Then he could use this money in combination with his knowledge of future events to know what to invest and promote to propel advancement forward faster and share it with the developing world.

In the end it comes down more to his knowledge then to the machine itself. The machine is limited to manual input and only displayed output. This is not a Star Trek tricorder after all.

  • 5
    $\begingroup$ If you could program a reliable stock market predictor on a graphing calculator that functioned without automated input feeds fresh out of college then please contact my HR department, I guarantee we will have a job offer for you :D :P $\endgroup$
    – dsollen
    Commented Dec 3, 2015 at 20:46
  • $\begingroup$ Hopefully it's a better model than the ti-84. Otherwise it might be slower than the Colossus :P $\endgroup$
    – womp
    Commented Dec 4, 2015 at 9:49

Using the calculator to break the codes would only be a temporary solution, once the AXIS forces knew the codes were broken they would change them.

This is what, according to some historians actually happened, look up the bombing of Coventry, the enigma code had been broken (and not with any help from Jon Bon Jovi) but by ordering the evacuation of the city or setting up more air defence around the city than would normally be present would make it obvious that the Allies knew about attack and had cracked the enigma coded messages.

However it's the mundane things that the time traveller could potential effect that could make the largest changes.
Imagine just going back 70 years and telling them that not only what was possible but had been done, man on the moon, nuclear power, flat screen tv's.

Even a basic understanding of some of the technologies that exist in the future could allow the WWII scientist to know where to look, what to research.
How much faster would it be for the scientist trying to researching the best material to make a transistor out of and our time traveller says "not sure how they work but they're made out of silicon". Possible months of time saved by not have to test all the other possible materials.

This is of course assuming the time traveller doesn't end up in a state hospital with an ice pick up his nose...

@The transistor example is just that, an example. It was used in an attempt to show that even a little bit of future knowledge of how a particular technology works when given to an expert could alter the timeline on the development of that particular technology.

@Churchill vs Coventry Air raids- I did say according to some historians and again it's an example. IF it happened or didn't doesn't change the basic point that blatantly displaying the fact you've broken you enemy's ultra secret encryption will only make them change the encryption.
Unless the information gained from the broken code can be attributed to other sources, recon, resistance movements within occupied territory etc. You would only be able to use information directly from a broken code once or twice before the fact that it had been broken would be know to the enemy.

@Sarriesfan It's an parable, an example, a story told to get across a specific point. I think your focusing to much on the story I told and not the point I was trying to make, for which I apologize. Can we know draw a line under it?

  • $\begingroup$ Transistors were a known, if perhaps not widely used and by modern standards still in its infancy, technology by the time of WWII. en.wikipedia.org/wiki/Transistor#History has some of the important events. The FET was patented in Canada in 1925, and in Europe by a German inventor in 1934. Point-contact transistors were invented in 1947 and BJTs were patented in 1948, not long after WWII. I find it unlikely that someone who is not a specialist in semiconductor technology and manufacturing would have enough knowledge to significantly alter this timeline by being dropped into, say, 1940. $\endgroup$
    – user
    Commented Nov 3, 2017 at 10:49
  • 4
    $\begingroup$ The idea that Churchill sacrificed Coventry in order not to give away the code breaking of Bletchley Park is a myth. At the time of the attack November 1940 we did not have adaquate air defenses to protect even the cities we knew were likely to be attacked such as London, there were not large numbers of AA guns or nightfighters. Alan Turing had only arrived in Septmber 1940 and the Bombes that were used to crack the Engima code were not yet fully operational. $\endgroup$
    – Sarriesfan
    Commented Nov 3, 2017 at 13:35
  • 1
    $\begingroup$ You did say according to some, however the vast majority of historians point out the reasons it did not occur that way. Understanding that it is a myth is important so others do not repeat it. For example it made its way in 90s popular culture in the series Babylon 5. $\endgroup$
    – Sarriesfan
    Commented Nov 6, 2017 at 1:23

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .