Marty has proof of time travel.

[Nowhere Man]

So in BTF 3 Marty and Doc take a picture beside the clock tower. He loses the picture, but Doc gives him another one. This is presumably the only proof that Doc invented a time machine. Could Marty later on, after Doc dies, proove that Doc invented a time machine? With photo analysis he could proove that it is real. Furthermore, do you think maybe Doc gave Marty the picture for that very reason, should there be a need for it? I mean Marty wouldn't be able to tell anyone how Doc made the time machine, so it wouldn't hurt anything. So Marty could ensure Doc get credit and possibly a Nobel prize and would be recognized as one of the greatest scientists ever.

 

[backstept]

well . . . analysis of the photo would reveal that it was taken very recently, albeit on vintage equipment, so I don't think it would prove anything

 

[Admiral James Kirk]

The Vulcan Science Directorate has determined that time travel is impossible.

 

[JonnyQuest037]

well . . . analysis of the photo would reveal that it was taken very recently, albeit on vintage equipment, so I don't think it would prove anything

Marty should travel back in time again, interfere with Doc Brown's parents ever meeting and then show everyone how Doc is slowly disappearing from the picture! That'll show 'em!!

 

[Gaith]

The Vulcan Science Directorate has determined that time travel is impossible.

 

[Psion]

The Vulcan Science Directorate has determined that time travel is impossible.

 

[hyzmarca]

I think the flying time-traveling steam locomotive will be better evidence.

 

[Mr. Laser Beam]

So in BTF 3 Marty and Doc take a picture beside the clock tower. He loses the picture, but Doc gives him another one. This is presumably the only proof that Doc invented a time machine. Could Marty later on, after Doc dies, proove that Doc invented a time machine? With photo analysis he could proove that it is real. Furthermore, do you think maybe Doc gave Marty the picture for that very reason, should there be a need for it? I mean Marty wouldn't be able to tell anyone how Doc made the time machine, so it wouldn't hurt anything. So Marty could ensure Doc get credit and possibly a Nobel prize and would be recognized as one of the greatest scientists ever.

Why would Marty want to do that though? Doc doesn't need the credit. Indeed, it could be very dangerous if word got out about the time machine.

 

[Argus Skyhawk]

Indeed, it could be very dangerous if word got out about the time machine.

Yep. Those movies showed that Doc Brown's time machine made it outrageously easy to mess up your own past, create huge unexpected changes in the timeline, and erase yourself and others from existence. Imagine the havoc that would occur if hundreds of careless people managed to build their own time machines based on Doc's design and started using them.

 

[Silvercrest]

And patenting would be a nightmare. How could you prove that you were the first one to invent it?

 

[doubleohfive]

Fortunately in real life (so far, anyway), time travel is only (theoretically) possible in one direction - the future.

 

[Silvercrest]

Personally I'm fond of the theory that the time machine will never be invented. If it is invented, people will travel to the past and keep messing with the timeline. Eventually they'll change the timeline in such a way that the time machine never gets invented. Sooner or later, it always comes back to that.

I don't know how plausible this is, but I find it really amusing.

 

[Mr. Laser Beam]

^ That is also how I view the Terminator franchise.

 

[intrinsical]

And patenting would be a nightmare. How could you prove that you were the first one to invent it?

Simple, travel back in time and be the first person in the whole wide world to file a patent - for your time machine. Having said that, the fact that the very first patent in the world isn't for a time machine kind of proves no one will ever invent one.

 

[Silvercrest]

But then someone else will travel back in time a little further, get in line ahead of you, and end up being the one filing the very first patent. What do you do then?

 

[YellowSubmarine]

The Vulcan Science Directorate has determined that time travel is impossible.

More or less this. Time travel is so improbable that all other explanations suddenly become more probable than they are. It's more likely that they had an amazing photo forgery machine that could forge anything up to the photo dating, or that another person sharing the exact same DNA as Marty lived in the given period.

Reminds me of the last time I argued with a fanatical moon hoax denier. The reason the moon hoax thing is silly is because the moon landing was possible and far easier than faking it. Not because faking it was impossible. But if landing on the Moon was not possible with the technology at the time, the same evidence would tell a different story.

If someone came to me and told me he was a time traveller, I would need an extraordinary amount of evidence to believe it. Seeing real technology from the future won't be enough. Travelling to a place in the future or past chosen by the time traveller won't be enough either. And even if he takes me to many time and places by my choosing, I'd still have my doubts. A photograph doesn't even begin to prove anything.

 

[Nowhere Man]

^ So if someone took you to the past or the future, you still woulnt believe it? What would it take then? I mean if someone took me instantaneously to to say 65 million years ago and suddenly there are Dinosours and no humans and no sign of civilization, I think I would believe it.

 

[YellowSubmarine]

It depends on the circumstances. If someone took me to a place with dinosaurs, no humans, strange flora and fauna, and told me that we've travelled to 65 million years ago, I'd assume it's a trick, and I'm seeing fake flora and fauna. That's why I'd like to choose the time and place – the time traveller wouldn't be prepared, and he'd have to take me to the real place, not to some artificially created park. And even then, I'd have my doubts, you know, the possibility for a simulation of reality, but yeah, I would be pretty much convinced.

But if you want to truly prove that time travel is happening, not simply convince me, you'd need more – including leaving something in the past, locating in the future, confirming that you've not moved to a virtual reality environment, etc. Oh, and an explanation about how it is happening would be nice too.

 

[Scout101]

That doesn't make much sense, and your suggestions seem about as easy to fake as anything else, once you've accepted the possibility of some virtual reality environment...

 

[YellowSubmarine]

Like anything, a virtual reality environment should have its limits – a virtual reality environment without limits is probably far more improbable than time travel, in fact it might imply time travel (e.g. if you simply record the history of the virtual reality, you can always travel through time inside it). Also a more convincing simulation would be always more difficult to create, and therefore more unlikely, not to mention that the difficulty decreases the incentive to make it in the first place.

Creating a park that looks like 65 million years ago to trick people into believing that they've travelled through time is one thing, but recreating a large portion of reality for the same purpose would be an overkill, especially when you can always find more gullible people around. So if you're shown more with less ability for preparation, the chance that you're experiencing real time travel goes up, and there's a point where time travel becomes more probable.

I don't know where the point is, but I'd personally ask to be taken to a specific time and place, and if I go there, I'd assume the time machine works. The reason? I believe that faking a single environment is easier than time travel, let alone artefacts like photos.