I have all my photos on my hard drive backed up onto a two drive mirrored NAS device and uploaded to a third party cloud based backup service. Many of them also have low resolution versions posted on Facebook and Flickr. But I still worry that in 70 years no trace will be left of these photos.
Printed photos sitting in a photo book with each photo in its own plastic sleeve that is stored in a dry location away from light won't last forever, but it will probably last 70 years. My digital photos have to constantly be backed up and copied over time. Cloud backup services and social media websites will go out of business. Both the drives in my NAS will eventually fail, along with the drive in my PC. For these photos to survive, someone has to perpetually do work to keep them around.
Sometimes I wonder if, despite the fact that camera phones means we take an absolutely immense amount of pictures relative to other periods of time, if in 100 years there will be more photos from 1985-1995 than 2005-2015, just because the older photos were printed and stored in photo books.
At some point I should probably print my most important photos.
Funny you should worry about 70 years when we have ink-on-paper things that have lasted hundreds of years and are still readable. According to this list of oldest surviving documents[1], preserved copies of a newspaper from 1609 exist. Oldest known book (but not sure if paper or not) is over 900 years old.
So yeah, barring direct physical damage, 70 years is nothing.
[1] http://listverse.com/2013/11/10/10-oldest-surviving-document...
This is, of course, supposing that the rather scary situation of heavily-locked-down devices and completely-restricted access to knowledge has not occurred...
All you need is one person that can access it. Do you know of any technology that we can no longer access?
They are lots of great stories about the hard work people had to do to access them (the video scans of the moon for example) but none that I know of that failed.
Technically, that's true. However, would it be economically feasible for the average person with ordinary family photos?
SD cards easily survive the kind of rough handling that would destroy a film; I can imagine the contacts corroding to the point where you'd have to replace them to read it, but the plastic casing is close to indestructible, and the stored data should be inert. Of course many will be lost or destroyed, but I would happily bet on any random SD card outlasting any random piece of film from the same era.
That article is a bit irresonsible and might lead people to think they don't need a back up or an archive store.
Re: photos, I think that long term security requires long term care, prioritisation of the important few for printed copies, and reviewing every few years. All of which take time and effort. :(