How could somebody prove to you that they're from the future?

show me some tech….

I’d ask to see his cash and coins.

I think we did this one last week.

@dalepetrie do you really think that in 100 years we will still pay with cash and coins?
probably he will speak a different language and will have totally different clothes and this will convince me

He would have to tell me about something specific (and not foreseeable or manipulatable I know that’s not a word) that hasn’t happened yet. Say, five days to two weeks from now. If it happens, I’d likely believe him then.

He would have to tell me about the outcome of specific major sporting events before they happen.. so when i bet on said events and make a killing i’ll be more inclined to believe him :)

@Christian95 – in a capitalist society such as ours, yes, I believe there will always be legal tender. Because I personally would transition completely to electronic payment methods right now, but I can’t do it 100%, not because of me, but because other methods of payment come at a cost to the merchant, and some small merchants will never be able to survive unless they are cash only, even 100 years from now. And I also think those electronic numbers have to be tied to something, if there’s no cash in circulation to back up the electronic money, the whole system would collapse. Personally, speaking a different language and wearing different clothes wouldn’t be all that persuasive to me, I live in a big city, I see people wearing different clothes and speaking different languages every single day.

I meant totally different

I think I could tell, how they react on certain things. If they are bored with things that supposed to be advanced to us, or will they be amused with everyday objects that for them were already obsolete. I can also tell with how they react on certain laughable matters and yet they are more intrigued why it is laughable in the first place.

First of all, I’d ask him to recount the history of the past 100 years (ie between now and his time). I’d first of all try and see if any of it sounds plausible, but more importantly, I’d be looking out for signs that he’s a complete nutter either making it up or imagining things.

I once met a guy who claimed that he had foreseen a WWII attack somewhere by looking at some stones, and then he told the HQ and the Germans caught wind of that and they never attacked the particular area because our side was prepared due to his warning. Even though the particular story could be true, the way he was describing it convinced me that the guy was simply crazy. I bet they just ingored him back then, and the Germans never made that attack for the simple reason that they’d never planned it in the first place.

I think you can generally figure it out if you keep an open mind but at the same time a sceptic attitude. Of course the guy might say something crazy, like Michael J. Fox in “Back to the Future” when he was asked to tell the guy who the US President will be in the ‘80s. When Fox said “Reagan”, the other guy laughed and said “right, and I bet Jerry Lewis is the vice-president!”. Sometimes the future is not what we’d expect it to be. I know if someone had told me in 1988 (a year before the Berlin Wall fell) that 10 years later I’d be living in Dresden (the heart of Communist DDR), I’d laugh so hard my teeth would fall off.

I don’t think I could be convinced. Unless he could build something that is not of this “age”. There will be uneducated people in every timeline, whos to say he wasn’t a test subject for time travel and knew nothing about the history of his time. They might appear to be crazy by their attitude, and what they talk about.

@Dr_C you’ve been watching back the the future 2 too much.

@Christian95: I think you’re overestimating the amount of change that will occur in one hundred years. Or maybe not, but I still don’t think the English language will change so terribly that it would be a convincing point. Clothing? Eh. Weird shit existed in the past, weird shit exists now, and weird shit will exist in the future. Crazy garments aren’t going to convince me either.

I’ll ask to see the Google barcode on the back of their neck.

I would ask for specific events. Lottery numbers, governmental election outcomes, etc…
If they tell me that the MSU Spartans win the National Championship in football, I would know they are lying. On the other hand, if they tell me that mullets and pegged pants make a come back, I would know for a fact that they have come from the future.

If he can’t take me to the future then there’s no way to be sure the person isn’t having delusions.

Ask for some photo’s (he surely has a kick-ass, futuristic cellphone/mediaplayer?) of means of future transportation, architecture, weaponry (in a hundred years i guess we still have the occasional war).
“And did that Web 4.0 got off to a good start?”

100 years is a bit much. but . . considering the case : that a person, having come from the future, can reach back into their memory ( either individual or socially acknowledged ) I’d try to find out when certain well know figures come to the end of their charge.
I.E. When the current pope dies… when Obama’s presidency extinguishes, Some names of successors ( followed up by a personal research to calculate the odds of such people potentially appearing in the global scene )..., and so on.
I don’t think I could depend on information such as: ‘what hapens in 2012 ?’... or ‘when does ww3 start/finish ?’ not only because they could be too approximate\inaccurate\unreliable… but because if this guy is say an eschatology geek… he would know how to answer my questions convincingly having based his knowledge on the decoding of Nostradamus’ prophecies (and those of many others) .
I wouldn’t ask of anything from the scientific/technical field: 1) due to constant evolution & discoveries, even my own knowledge cannot contain all notions and news (and so could be toyed with) 2) technical explanations cannot always be proved due to lack of material… 3) (i forget what I wanted to write..) etc…etc…
Another thing needs to be considered… What kind of person is he/she..? if a medic…a soldier.. a researcher. a civilian. all answers depend on his/her preparation and field of expertise.

I am from the future. But every time I try to tell people. My thoughts go blank.
Something was put into my mind to prevent me from talking.

It is very frustrating.

@Christian95 – I was mostly joking about the clothes and language comment, I knew what you meant.

To those mentioning that you’d like to hear about big events (Like the pope’s death), how exactly would you fact check?
If I tell you that in 2 years the Seattle Seahawks will win the superbowl, how will that make you believe me (until those 2 years pass)? If I say that on December 21st, 2012 (or whatever that date is), all of the Europeans die, how are you going to fact check that?
But even then. Do you remember who won the Super Bowl in, say, 1971 without looking it up? Why would somebody from 2109 remember who won the superbowl a century ago?

As to the “Lottery numbers” answer, perhaps I’m just weird, but I’ve never kept track of winning lotto numbers. I don’t expect anybody else on earth to do so either.

@rebbel On your phone (or camera) do you keep photos of modern versions of those things?

@Jeruba I know recently there was a “how could you prove to the ancient Romans that you’re from the future,” but this is a reversal. I don’t remember seeing this question posed recently

@Sarcasm As a matter of fact, i do.
Just a tram though, no modern building at the moment.

I could only possibly be convinced if the person told me, in detail, about the time I hit my head on the toilet, immediately before having a vision of the Flux Capacitor…which is what makes time travel possible.

So, let’s say I went back to 1909. I’m not even 100% sure when the Great War started, but I think it was 1914. I’d tell them that the moving pictures would become a big industry, and that they would have synchronised sound and even colour after a few decades. That the cars would become faster and faster, and that the sky would be filled by ever bigger planes. I’d try to explain aerodynamics, which might make my story more realistic (either that or they’d think I’m a complete nutter). I’d tell them about the Olympic games (which most people had not really heard of by 1909) and how big they’d be, and that soon more and more countries would take part in them, and even black people would be allowed to participate. And how women in my time are allowed to vote, and wear jeans, and even have jobs. I wouldn’t tell them they’re allowed to smoke and drive cars though, that would freak them out. I’d describe how in my time everybody has electricity, and that it’s used for all sorts of things: not just lights, but also television (which is a mini-cinema you can fit on a table), refrigerators (which can keep things cold without the ice ever melting), ovens that work without fire, electric heaters and air-condition units (or at least electric fans). And how we have telephones, even small ones that we can carry around and which work with batteries. The battery had already been invented, but it was too big. And maybe I’d try and explain computers to them, though I doubt they’d grasp the idea (even my dad had problems understanding what they were for until recently). And also how you can print anything you want in a few seconds, at home, with very cheap and small printers. And you don’t even have to pick the letters individually!
I have no idea who won any sports events back then. I don’t even know what teams existed, let alone who won the horserace. But maybe I could buy shares in Ford, and sell them before 1929, and buy booze when it was legal and sell it when it wasn’t, or warn people of a short Austrian madman with a moustache that was going to try and conquer the world in 1939. But then they’d just think I’m a prophet and burn me or something.

I think that is a truly great answer, Jack.
Enjoyable.

He would have to produce a valid license for operating a time machine.

It’s a leading theory that you can only go back as far as the time the time machine was invented. Therefore it isn’t possible that someone from 100 years in the future could visit us. Sorry to spoil it.

You’re assuming the time machine hasn’t already been invented.

@Parrappa Doesn’t a “theory” have to be tested and proven at least in certain situations? Until we encounter time machines, I don’t think that can really be considered more than a hypothesis.

Either way, doesn’t really make sense to me. Sure in computers, with things like System Restore, you can’t go back in “time” before the save states. But last I heard time isn’t data on a harddrive.

Then again, I’m not exactly a master of time travelology.

@Parrappa – my understanding is that the only known way that it would be theoretically possible would be if you could create a black hole without a singularity which had two ends. On one side would be where you want to be, and if you were to spin the black hole around at the speed of light, time would stop, so if you did that for say 1,000 years, you could then enter the other end, and come back out on the spinning end 1,000 years earlier. But in terms of a time machine, a lot of astrophysicists tend to believe in multiple universe theories these days, so in other words, anything possible has happened in some dimension. Using that logic, one would simply need to enter a dimension where everything was the same as our universe, only earlier in time. Bottom line is, if time travel is possible, we don’t yet know how it is practically possible and until we know that, we can’t say that one would have to invent time travel before we could be visited by future beings.

The only way to travel back into time would be to fly away from the planet at a great deal of speed.
Let’s say you fly away for an hour at 30 light year an hour. If you could go faster then the speed of light.
Then you turn around, break out your super power telescope and look back at the earth.
Now you can observe what was going on 30 years ago.

Ask him what happened before the 10^-43 second of our universe’s existence, then send the answer to the world’s top physicists.