I discovered the idea for this search a few days ago and found it intriguing. It is both broad as it is not restricted to a particular area of research and specific (for unexpected results) at the same time and seems to be directly probing the edge of our knowledge (At least I would call it that when researchers are being surprised by something in their fields).

There is also the scientific article search of the Internet Archive if you are looking for another one to search through:

https://scholar.archive.org/