 Hey guys welcome back to my YouTube channel this is Daniel Rosa here in Jerusalem bringing you guys another video today. This one's again about my the optical media and as you know I went those who follow this channel know I recently made a series of video regarding the M-disk. The M-disk is a variant of the DVD and Blu-ray intended for long-term archival storage. I pretty much know that by heart by now. The M-disk looks like a DVD or Blu-ray same form factor etc but it's engineered a little bit differently whereas DVDs and Blu-rays store their data through ablating a dye and that optical contrast can lose it can be lost over time as the dye degrades the M-disk substitutes that technology for an inorganic rock-like layer and the data is actually written through making microscopic bumps engraving it into that layer so as opposed to burning so it's a super interesting tech and I have to be honest after getting all excited about the M-disk doing all my doing all the videos I thought anyone might ever be interested in about it and those are up on this YouTube channel I thought to myself ah maybe I should do some stress testing and if you don't know what stress testing is or torture testing I'm talking about the videos like this you'll see all over YouTube now these videos are kind of old you can see this one's from 2009 and that's because optical media really kind of has stopped being a thing that most people care about anymore but you get the idea this guy is doing various weird things to his to his DVD he's you know etc etc he's warping it intentionally and carving into it and doing all sorts of weird things he's even this is crazy he's breaking it up now I was thinking about doing something like this for the M-disk maybe not quite as extreme I was going to put it on my roof I was going to take it swimming with me in the sea I was going to do all manner of wacky experiments the reason I decided not to is because I don't think this is actually useful or maybe entertaining but it's probably not going to be useful the only useful information or stress testing one could do for technology like the M-disk would be to time travel 100 years into the future write yourself a bunch of discs four or five discs run a checksum on those discs time travel 100 years into the future and when you've arrived into the into the future point in time run the checksum again and tell us if the M-disk is working now the obvious joke here is that time travel is impossible so there's no real actual way to do a useful experiment so what we do instead or what people do and this is the really interesting paper from I'm going to just put myself smaller so you can see the document property from the naval air warfare central weapons division which is as far as I understand a part of the US Department of Defense and they put the M-disk through some insane testing that wasn't quite the same thing as a guy on YouTube cutting up his disc or warping it they it's a 75 page document so the fact that the Department of Defense puts such effort into investigating the M-disk tells me that probably government departments are actually taking this text seriously and committing some really sensitive data because the type of data you might commit for storage on an M-disk would be data that's going to be stored offline not connected to the internet and when you're dealing with really sensitive data storage that's often a requirement a physical network air gap so you can see in this document I'm just going to jump a little bit to the relevant parts here they describe their process under test conditions this is pretty interesting stuff in my opinion if you care about optical storage the stress test is a single combined temperature humidity and light cycle it's composed of a ramp up a 24-hour dwell a ramp down and an equilibration period that is conducted with illumination throughout the cycle figure one one depicts this cycle so what they actually did they took this is a naval naval air weapons research center testing at the M-disk they held it at room temperature for 0.25 hours then they did a RH and temperature ramp RH stands for relative humidity so they brought it from 15 percent humidity controlled all the way up to 85 and they also took the disks from room temperature and up to 85 sorry 80 degrees celsius so these are extreme conditions and then you can see after the ramp up and these gradients the humidity and temperature gradients were both scientifically controlled in this accelerated aging accelerated aging chamber and then they were held for 24 hours at these very tough conditions of 80 degrees celsius and 85 percent humidity the M-disk came out of this pretty much perfect so that's really impressive in my opinion 24 hours at 80 degrees celsius and 85 percent humidity if those conditions existed on earth people probably i don't think would be able to survive exposure to 80 degrees celsius um but if it was even 40 degrees it would be incredibly hot and sticky and unpleasant so it's a pretty aggressive test um and they also controlled for the light intensity so i guess what i'm trying at the point i'm trying to make is as follows the way that professionals stress test optical media is by doing stuff like this in which again every variable is controlled the temperature humidity and even the light intensity is controlled as well and you can even see they've got some pretty crazy photographs in this long document um of the actual testing process you can see the disks there in this um in this exposure chamber and it's a literally physical chamber where and that's where they're simulating um all these environmental variables so this is kind of a useful test it's designed to um you know the the premise i guess of this type of testing is to say well if they can take 80 degrees for x many cycles then they can survive under normal conditions for x much longer i don't know if that's a if that hypothesis is being scientifically established it's true in any event it's more like it's more useful testing to your average data storage person than uh you know cutting or per scratching or warping intentionally an optical storage because if you're storing your optical media archive in a sensible manner there's guidelines online about temperature humidity and you should be following those i've done a video about them previously and so yeah if it survives that that's really all you need to know the only definitive test would require time travel which is an impossibility but this type of information is much more useful than the kind of pretty uncontrolled uh pretty uh sort of rough and ready experimentation approaches you're going to be finding on youtube so if you do want to test your optical media i'd recommend trying to go for something a bit more scientific like this i'm personally not going to do that i have trust and faith in the m disk i realized that the only way to really prove it for or against would be something like time travel so as that's not possible i'm simply putting my trust in it you might not put your trust in it and use a different storage media for your personal backup and archival needs thank you for watching the video and more videos on tech the m disk and other subjects will be coming to this youtube channel very soon