What's so hard to explain? Airplanes and cars? You had them then, they're just more common now. TV? Yeah, it's like radio and movies combined. Cellphones? Ok, phones are portable now. Computers? Alright, just tell them what a computer is.
They can handle it. They were human then too, not some alien species of comparative primitive idiots.
(If the argument were instead that it's unreasonable to expect someone to accurately predict the world of 100 years hence, I would agree; long-term prediction has not historically been something anyone has been all that good at. But the difficulty of predicting the future doesn't mean one couldn't handle exposure to it.)
Do you really believe that it would be so simple? I think that it's hard to appreciate how much computers have changed the shape of our lives in large and small ways. For example, imagine bringing Turing to the present day. Would he have any trouble understanding what a computer is, as a mechanical or mathematical device? Probably not. Would he be baffled by, and initially uncomprehending of, the way that computers have changed our lives? I'd say almost certainly. (I often am, just thinking back on the way things were as recently as 20 years ago, and I lived through the change.)
Computers have changed our lives in many large and small ways. Great. Tell that to the traveler from 1915. Show them. They'll understand; they've witnessed the same phenomenon with the technological developments of their own time. They won't be used to our modern world, but their mind won't violently reject exposure to the concept.
And culturally? Well, for one (U.S.-focused) example, there's that whole Civil War/end-of-slavery thing smack dab in the middle of it.
It's by no means clear to me that the changes of 1915 - 2015 somehow completely outstrip the changes of 1815 - 1915.
(I see that you agree with my general point, and with good illustration, too. I just wanted to point this out as well.)
The UK still had slums with limited indoor plumbing during the 1950s. It wasn't until the slum clearances of the 1960s that the standard became an indoor bathroom in a house with central heating.
The big change between 1915 and 2015 is that the technological GINI coefficient has shrunk so much.
Being rich gets you few technological perks. You can buy a supercar or a private jet, but that's a difference of degree, not a difference in absolute access.
Most people have cars, and almost everyone can afford to fly. And all but the very poorest have Internet and electronic media access.
Likewise for cultural differences. Sexual morality - at least as publicly presented - is completely different now.
Work culture is somewhat different. Politics and finance have probably changed least of all.
The point being that someone from 1915 may just about be able to understand the Internet and computing. But they're going to have a really tough time learning how to parse Buzzfeed or TechCrunch or Reddit. Never mind what happens when they find PornHub or Tinder.
There are three things to learn, not one. The first is what the technology does. The second is the vocabulary of new names and the new concepts used to describe. The last is the social scripting that defines appropriate and inappropriate behaviour.
Those last two will take longest and be hardest.
I'd expect similar challenges in 2115, with the difference that there's likely to be much more social and political change, and not less.
It would surprise me if the definition of "human" hadn't changed fundamentally by then, together with almost everything we think we know today about culture, politics, and economics.
Consider these technologies and innovations that had already been developed:
* Jacquard loom (http://en.wikipedia.org/wiki/Jacquard_loom)
* Player pianos (http://en.wikipedia.org/wiki/Player_piano)
* Widespread use of interchangeable parts (http://en.wikipedia.org/wiki/Interchangeable_parts#Late_19th...)
* Assembly lines (http://en.wikipedia.org/wiki/Assembly_line)
* Tabulating machine for the 1890 US Census (http://en.wikipedia.org/wiki/Tabulating_machine)
* Transoceanic telegraph networks (http://en.wikipedia.org/wiki/Electrical_telegraph)
* Use of humans for distributed computation (http://en.wikipedia.org/wiki/Human_computer)
Automated computation is an amazing concept, but--at the risk of historic bias--what we have now is merely an optimized and widely available form of what we had then.
What I imagine they'd have a really difficult time accepting is modern physics, particularly quantum theory. Then again, the vast majority of the public today (including me) struggles with it.
Also, I didn't mean to imply full agreement with chaosfactor (https://news.ycombinator.com/item?id=9279631)'s "die from culture shock", which I think overstates it. I just meant to say that there's a wide gap between being told the facts (about anything profound, not just computers) and really coming to terms with their implications, and that I think that achieving the first is easy and the second hard.
In 1915 radio is far more primitive than you are thinking and very few people had them. 'Talking pictures' had not even been invented yet. If you took a more technically minded person from New York perhaps, they may be able to wrap their head around what is occurring. If you took a farmer from the midwest they would be totally lost. WWI has not been going on long and the world is beginning a rapid set of changes from manpower to machine power. 1914 is commonly considered the end of the Steam Age.
Next, it would be far harder for them to handle socially than strictly comprehensively. Think of the common language we use when talking to each other. People would almost be speaking your language, but they wouldn't be speaking it at all dude, post that to your blog and tweet it. Even common things like food would seem totally foreign, in the most literal sense. Foods were very regional and always made at the time of eating. Now you can get food from practically anywhere, anytime, frozen solid, and you can heat it up in magic beeping boxes with some kind of magic rays inside.
Lastly, unless you were from one of the always on cities in 1915, the pace of the modern world would wear you down so quickly you'd be in a constant exhaustion. The rate of change we consider normal these days is unprecedented. The speed we travel. The copious amount we are expected to communicate with large numbers of people are not something that commonly occurred in that past. Now imagine a future where brain implants allowed to you instantly connect to devices or other peoples minds all around you. You could understand it, but the feed of information to and from you would likely be something your mind would have issues dealing with, such as privacy something we focus on quite often these days.
The social/ cultural changes are what matters, I think, and the technology is actually much less important.
On the other hand, I think if you brought an Afghani tribesmen from the 1950s into modern US, they would be more blown away and have a harder time adjusting, (EDIT: even though they would be more familiar than an ancient Greek or Roman with telephones, cars, etc).
http://www.smithsonianmag.com/history/for-40-years-this-russ...
> “What amazed him most of all,” Peskov recorded, “was a transparent cellophane package. ‘Lord, what have they thought up -- it is glass, but it crumples!’”
Everything else can be learned - after all, even dogs get used to Roombas...