穴が開くのも説明間違ってない?

http://www.tdk-media.jp/dvdkihon/html/dvd30400.html
https://www.gizmodo.jp/2011/01/it-took-a-team-of-physicists-all-this-time-to-figure-out-how-dvds-work.html
変化、と書いてる