I have absolutely no idea what I’m looking at here. I’ve been trying to decipher it for too long. I think the weed took advantage of me. I don’t see any cds in here. Also the cd rom is part of the background while blu ray and dvd rom have their own. DVD rom looks like those incredibly zoomed in pictures of metal you would see. Blu ray looks like an aerial view of some sort of thing. Cd rom is just cd rom. I also have no idea what the black bar says. I thought it would be a comparison between the 3 but there wasn’t any duplicates for comparing values. I also have no clue what this community is for so just from looking at the picture that is the conclusion I have came to. Idk if it even is a conclusion
All three images are from an electron microscope that has captured a section of each type disc. I don't know if they are all zoomed in the same amount but I think it is implied that they are. The black bar tells you how much they are zoomed in by showing you a line that I 1 micrometer long.
Maybe the image of the CD is the background because they want to show us the black bar from that image specifically. Perhaps they were just a bit lazy with the cropping or thought it looked cool that way.
I'm the images I can see that a DVD is a flat surface with lines of 'trenches'. That's probably how they do either a 1 or a 0.
The CD has a much larger pattern and has hills instead of trenches. The size of the pattern is probably what decides how much data you can fit on a disc, smaller is better.
The Blue Ray uses trenches, like DVD, but with a smaller pattern.
I know nothing about the community.
Why are DVDs and BluRays "negative" and CDs "Positive"
