"And before you downvote, ask yourself: Senseless violence to stop outsiders who are just trying to survive: is it really any less bad when the outsiders are animals?"
I use the equivalent thing on Firefox. Partly so I can use or not use different groups of addons quickly and easily, but also so I can be logged into the same websites multiple times on different accounts.
Or you can import the two images into graphics software like gimp. Invert the colours in the top image, then knock transparency for that layer down to 50%. If the images are identical, you'll just see grey. Any differences will instantly become visible.
It would help if Linux games actually worked on Linux, instead of only on single version of Ubuntu that's usually a few years out of date, and you have to have libraries X, Y and Z installed, only it won't tell you this, so have to trawl through various support forums. And god help you if you're running something truly bizarre, like Debian.
I usually have more success running the Windows version through Wine than I do running the Linux version. I wish I was joking.
The US Army's version might be new, but the general idea isn't. The Russian Drozd is the earliest of this type of system I'm aware of, and that was fielded in the late 70s.
There probably isn't enough data to render a full image, but how many lines do we need to draw to give the impression of a person, or a tree? Surprisingly few. Couldn't the same apply to a sonar image?
It's just an idea. I'm not saying its true, just that its an interesting possibility.
We might be looking for sentences and words that just aren't there. Dolphins see with sound, so maybe all those clicks and whistles are their way of sketching images for each other.
I though slat armour worked because RPGs only had a detonator in the nose, so unless you were very unlucky and the tip of the RPG hit a slat, the RPG would just jam itself between two of the slats.